Effects of adding poloxamer, collagen, and citric acid on mechanical strength, injectability, shape stability, and biocompatibility of mechanochemically modified beta-tricalcium phosphate cement using ball milling.

This study focuses on enhancing the mechanical properties and biocompatibility of calcium phosphate cement (CPC), a widely used bone replacement material. CPCs are limited by low mechanical strength and susceptibility to washout in body fluids. Four approaches were employed to improve CPC performance: 1. mechanochemical modification of CPC powder by ball milling to produce modified β-tricalcium phosphate (mβ-TCP) for better strength and injectability; 2. incorporation of poloxamer, a reverse thermosensitive gel, to enhance shape stability at body temperature; 3. addition of type I collagen to promote the cell viability and alkaline phosphatase (ALP) activity of osteoblast-like cells; 4. citric acid inclusion to restore compressive strength and injectability compromised by collagen. The resulting high-performance CPC demonstrated a compressive strength of 50.1 MPa, with significant improvements in injectability, shape stability, cell viability, and ALP activity of osteoblast-like cells.


Scissor bite correction with miniscrew-anchored uprighting: A case report


Myeloma cell growth suppression by osteoblast-derived extracellular vesicles: the creation of a non-permissive niche for myeloma cells by bone-forming osteoblasts.


Evaluation of torque moment in self-ligation lingual brackets.

This study investigates the moments generated when applying third-order bends to lingual brackets with different slot shapes and wires made of different materials. Three types of lingual brackets with different slot shapes: 0.018×0.018-inch square slot self-ligation bracket (AL-bracket); 0.018×0.025-inch slot self-ligation bracket (CL-bracket:); 0.018×0.025-inch slot self-ligation bracket (ST-bracket). Wires of three different materials were measured. The torque value generated during torque application was measured using a torque gauge. The AL-bracket had a significantly larger torque moment than the CL- and ST-brackets at the same angles. The CL-bracket had the smallest torque moment of the three for the square wire; however, the CL-bracket revealed a larger torque moment than the ST-bracket for the rectangular wire. The torque moment of Ti-Ni wires was observed the smallest. In lingual orthodontic treatment, the results suggested the shape of the lingual bracket slot and the wire material should be considered when adjusting and applying third-order bends.


両側性上顎中切歯巨大歯に対し変則的抜去を行った骨格性上顎前突症例

両側性上顎中切歯巨大歯に対し変則的抜去を行った骨格性上顎前突症例

上顎両側中切歯が巨大歯を呈した患者に対して当該歯の抜去を行い,マルチブラケット治療により審美的・機能的に適正な咬合を獲得できたので報告する.患者は初診時年齢12歳6ヵ月の男子で,巨大な上顎両側中切歯による審美障害を主訴として当科を受診した.顔貌所見として正貌は左右対称,側貌はconvex typeであった.口腔内所見として,大臼歯関係は両側Angle I級,オーバージェットは+5.3mm,オーバーバイトは+2.7mmであった.上顎中切歯の歯冠幅径は左側12.4mm,右側12.6mmであった.セファロ分析所見ではANB角は7.7°,FMAは35.7°であり上下顎の前後的位置関係はskeletal Class II,垂直的にはややhigh mandibular plane angleを示した.巨大歯は歯冠だけでなく歯根の幅径も過大であったため,歯冠の削合のみで排列し適切な前歯部被蓋関係と緊密な咬合を確立することは困難と考えた．加えて,患者は巨大歯にコンプレックスを持っていたことから上顎両側中切歯の抜去を行った.下顎については両側第二小臼歯を抜去し,マルチブラケット装置による矯正歯科治療を実施するとともに,上顎両側側切歯の形態修正を行った.動的矯正治療期間は3年6ヵ月,大臼歯関係は両側Angle I級を維持し,オーバージェット,オーバーバイトともに+2.0mmとなり適正な前歯部被蓋関係と緊密な咬合が獲得できた.保定には上下顎にラップアラウンドタイプリテーナーと上下顎前歯部にリンガルボンディッドリテーナーを使用した.現在,保定約5年10ヵ月が経過したが,咬合は安定している.(著者抄録)

The Journal of Chu-Shikoku Orthodontic Society

中·四国矯正歯科学会雑誌


Severe Maxillary Protrusion Treated with Surgically Assisted Rapid Maxillary Expansion

In this case, surgically assisted rapid maxillary expansion (SARME) was successfully adopted to treat a skeletal maxillary protrusion with large overjet and severe crowding. The female patient, aged 25 years and 11 months, was diagnosed with skeletal maxillary protrusion with severe crowding and excessive overjet associated with labially inclined maxillary central incisors. After achieving sufficient space for surgical incision between bilateral maxillary central incisors, the SARME was performed. A total of 8.0 mm lateral expansion of the maxilla was completed. At 48 days after surgery, the Hyrax appliance was replaced with an Anchor-Lock system used as an external surgical stent and skeletal anchorage for maxillary group distalization, and the distal movement of the maxillary molars was initiated without waiting for bone healing of the separated midpalatal suture by SARME. Twenty-five months' treatment, including surgical preparation, achieved an acceptable and stable occlusion with adequate interincisal relationship. The occlusion was much more stable with a little relapse through more than 4 years' retention period. In conclusion, SARME followed by the Anchor-Lock system might lead to favorable occlusal outcome in the long term without any relapses.


Current status of the management of idiopathic condylar resorption / progressive condylar resorption - A scoping review

The temporomandibular joint (TMJ) is a complex synovial joint shrouded in mystery, as the etiology of many TMJ disorders are unsolved. Idiopathic/progressive condylar resorption (ICR/PCR) is one such TMJ disorder characterized by a gradually deteriorating mandibular condylar mass, resulting in severe mandibular retrognathia, which often accompanied by clockwise rotation of mandible and an anterior open bite. Since the etiology of the ICR/PCR remains unclear, no definitive prevention or management options have been established. To date, various symptomatic non-surgical, surgical, and salvage management options have been developed and reported. To understand the current status of the ICR/PCR management options, this article provides an overview of the options presently reported in the literature to reduce its TMJ symptoms and improve mandibular function and form.


Prevalence of malocclusion and orthodontic treatment need in 9-12 year-old schoolchildren in Ulaanbaatar, Mongolia

Background The prevalence of malocclusion in Mongolia is increasing every year. Estimating the need for orthodontic treatment in the population is crucial for planning orthodontic care services and monitoring oral health programs. Therefore, the present study aimed to assess the need for orthodontic treatment among schoolchildren in Ulaanbaatar, Mongolia, using the Index of Orthodontic Treatment Need (IOTN). Methods A total of 656 schoolchildren aged 9-12 years were enrolled from 8 schools located in urban and suburban areas of 6 districts of Ulaanbaatar city. All the children were assessed according to the two components of the IOTN, the Dental Health Component (DHC) and the aesthetic component (AC). Statistical analyses were carried out using IBM SPSS Statistics for Windows, Version 28 (Released 2021; IBM Corp., Armonk, New York, United States). Results The prevalence of malocclusion was 561 (84.5%), consisting of 452 (68%) Angle Class I, 178 (26.8%) Angle Class II, and 34 (5.2%) Angle Class III malocclusion. For the DHC, the moderate need for treatment was 194 (29.3%) and the definite need was 53 (8.1%). For the AC, the moderate need was 148 (22.3%) and the definite need was 45 (6.9%). The association between the DHC and the AC was found to be statistically significant (p<0.001). The most common malocclusions were an increased overjet (maxillary protrusion), a contact point displacement (crowding), and an increased overbite (deep bite). The AC, Angle's molar relationship, an increased overjet, a contact point displacement, and an increased overbite were factors associated with the need for orthodontic treatment. Conclusion Approximately one-third of schoolchildren in Ulaanbaatar, Mongolia, require orthodontic treatment. This finding helps dental practitioners to better understand oral health problems, leading to an improvement in the overall quality of life of children.


A case of anterior open bite associated with idiopathic condylar resorption treated with miniscrew-assisted orthodontics


Conditioned Medium From Stem Cells of Human Exfoliated Deciduous Teeth Alleviates Mouse Osteoarthritis by Inducing sFRP1-Expressing M2 Macrophages.

Intravenous administration of conditioned medium from stem cells of human exfoliated deciduous teeth (SHED-CM) regenerates mechanically injured osteochondral tissues in mouse temporomandibular joint osteoarthritis (TMJOA). However, the underlying therapeutic mechanisms remain unclear. Here, we showed that SHED-CM alleviated injured TMJ by inducing anti-inflammatory M2 macrophages in the synovium. Depletion of M2 by Mannosylated Clodrosome abolished the osteochondral repair activities of SHED-CM. Administration of CM from M2-induced by SHED-CM (M2-CM) effectively ameliorated mouse TMJOA by inhibiting chondrocyte inflammation and matrix degradation while enhancing chondrocyte proliferation and matrix formation. Notably, in vitro, M2-CM directly suppressed the catabolic activities while enhancing the anabolic activities of interleukin-1β-stimulated mouse primary chondrocytes. M2-CM also inhibited receptor activator of nuclear factor NF-κB ligand-induced osteoclastogenesis in RAW264.7 cells. Secretome analysis of M2-CM and M0-CM revealed that 5 proteins related to anti-inflammation and/or osteochondrogenesis were enriched in M2-CM. Of these proteins, the Wnt signal antagonist, secreted frizzled-related protein 1 (sFRP1), was the most abundant and played an essential role in the shift to anabolic chondrocytes, suggesting that M2 ameliorated TMJOA partly through sFRP1. This study suggests that secretome from SHED exerted remarkable osteochondral regeneration activities in TMJOA through the induction of sFRP1-expressing tissue-repair M2 macrophages.


A dual composite resin injection molding technique with 3D-printed flexible indices for biomimetic replacement of a missing mandibular lateral incisor.

The bilayered direct composite RBFPD using 3D printed flexible indices prepared with a full digital workflow has several advantages over other dental prosthetic solutions, including noninvasiveness, cost-effectiveness, biomimetic esthetics, repairability, and shortened treatment times. Although the initial results are promising, further longitudinal studies with larger patient cohorts are required to confirm the long-term efficacy of this approach.


Influence of Orthodontic Treatment on Changes in the Maxillary Sinus Dimensions.

Objective This study aimed to investigate the correlation of craniofacial morphology with maxillary sinus morphology and to evaluate whether orthodontic treatment facilitates maxillary sinus enlargement in adults. Materials and methods A total of 45 adult women underwent cephalography and computed tomography before and after orthodontic treatment. All participants were classified into three groups: skeletal class I, II, and III. The average dimensions and volume of the maxillary sinus were calculated in each subgroup. Furthermore, multiple regression analysis was used to analyze the correlations of maxillary sinus dimensions with 20 cephalometric variables. Results Before treatment, the maxillary sinus width, height, depth, and volume were 32.2 ± 3.9 mm, 39.5 ± 3.8 mm, 38.6 ± 1.8 mm, and 36,179.3 ± 5,454.0 mm3 in skeletal class I, 33.9 ± 6.2 mm, 37.3 ± 3.5 mm, 38.6 ± 2.4 mm, and 34,729.8 ± 6,686.6 mm3 in skeletal class II, and 32.0 ± 4.3 mm, 41.8 ± 5.0 mm, 38.0 ± 2.8 mm, and 35,592.3 ± 10,334.3 mm3 in skeletal class III, respectively. Despite no significant differences in maxillary sinus width, depth, or volume, the height was significantly lower in the skeletal class II than in the other two. Regardless of the skeletal pattern, maxillary sinus height and volume increased considerably after treatment. Moreover, the maxillary sinus width was substantially involved in pretreatment U1 to SN and overbite and posttreatment U1 to NA and overjet. Conclusion Except for the height, the maxillary sinus dimensions were almost similar, irrespective of the skeletal classification. The posttreatment sinus height and volume were significantly greater than the pretreatment values, although the sinus width and length showed no significant changes during orthodontic treatment. This implies that orthodontic treatment may facilitate the enlargement of the maxillary sinus even after physical growth.


特発性下顎頭吸収の早期診断の可能性

特発性下顎頭吸収の早期診断の可能性

Journal of the Japanese Society for the Temporomandibular Joint


Etiology and Diagnosis for Idiopathic Condylar Resorption in Growing Adolescents.

This article has been written in honor of the late professor emeritus Kazuo Tanne, who passed away on 4 March 2023 [...].


Efficacy of laser in re-osseointegration of dental implants-a systematic review.

Despite their high success rates, peri-implantitis can affect the stability and function of dental implants. Various treatment modalities have been investigated for the treatment of peri-implantitis to achieve re-osseointegration. An electronic literature search was performed supplemented by a manual search to identify studies published until January 2022. Articles that evaluated re-osseointegration in peri-implantitis sites in animal models following laser therapy or antimicrobial photodynamic therapy (aPDT) were included. Case reports, case series, systematic reviews, and letters to the editor were excluded. Risk of bias and GRADE assessment were followed to evaluate the quality of the evidence. Six studies out of 26 articles identified on electronic search were included in this review. The studies included animal studies conducted on canine models. Four out of six studies reported a higher degree of re-osseointegration following treatment of implants with laser therapy. The findings suggest that laser decontamination shows potential in enhancing re-osseointegration, particularly with the Er: YAG laser, which effectively decontaminated implant surfaces. However, conflicting outcomes and limitations in the evidence quality warrant caution in drawing definitive conclusions. Based on the limited available evidence, laser therapy may show a higher degree of re-osseointegration of implants than mechanical debridement.


術後に顎関節に疼痛を訴えた顎偏位を伴う骨格性上顎前突症例

術後に顎関節に疼痛を訴えた顎偏位を伴う骨格性上顎前突症例

The Journal of Chu-Shikoku Orthodontic Society

中·四国矯正歯科学会雑誌


上顎左側第二小臼歯先天欠如を伴う片側性唇顎口蓋裂患者に対して下顎左側第二小臼歯を移植した一症例．

中·四国矯正歯科学会雑誌


Restoration of a Microdont Using the Resin Composite Injection Technique With a Fully Digital Workflow: A Flexible 3D-printed Index With a Holding Clip.

Direct composite restorations are accepted as a treatment option for microdontia, which is a relatively prevalent condition that poses esthetic concerns. While free-hand composite placement is technique-sensitive and time-consuming, the resin composite injection technique is more straightforward and predictable. A fully digital workflow has been recently introduced, but the 3D-printed resin index is rigid and challenged by undercuts, as opposed to the silicone index. This case report presents a flexible 3D-printed resin index, which can accurately transfer the digitally simulated functional and esthetic form to the final restoration. In addition, a rigid holding clip was designed to stabilize the flexible index.


A patient with unilateral posterior crossbite treated with modified unilateral surgically-assisted rapid maxillary expansion.


Mechanisms of preferential bone formation in myeloma bone lesions by proteasome inhibitors.

Proteasome inhibitors (PIs) can preferentially restore bone in bone-defective lesions of patients with multiple myeloma (MM) who respond favorably to these drugs. Most prior in vitro studies on PIs used continuous exposure to low PI concentrations, although pharmacokinetic analysis in patients has shown that serum concentrations of PIs change in a pulsatile manner. In the present study, we explored the effects of pulsatile treatment with PIs on bone metabolism to simulate in vivo PI pharmacokinetics. Pulsatile treatment with bortezomib, carfilzomib, or ixazomib induced MM cell death but only marginally affected the viability of osteoclasts (OCs) with F-actin ring formation. Pulsatile PI treatment suppressed osteoclastogenesis in OC precursors and bone resorption by mature OCs. OCs robustly enhanced osteoblastogenesis in cocultures with OCs and MC3T3-E1 pre-osteoblastic cells, indicating OC-mediated coupling to osteoblastogenesis. Importantly, pulsatile PI treatment did not impair robust OC-mediated osteoblastogenesis. These results suggest that PIs might sufficiently reduce MM cell-derived osteoblastogenesis inhibitors to permit OC-driven bone formation coupling while suppressing OC differentiation and activity in good responders to PIs. OC-mediated coupling to osteoblastogenesis appears to be a predominant mechanism for preferential occurrence of bone regeneration at sites of osteoclastic bone destruction in good responders.


Nonsurgical orthodontic treatment for a patient with Sotos syndrome.

Sotos syndrome is a genetic disorder characterized by overgrowth in childhood, specific facial manifestations, advanced bone age, and mental retardation. The purpose of this article is to describe the nonsurgical orthodontic treatment of a 10-year-old boy with a skeletal mandibular protrusion, unilateral posterior crossbite, and Sotos syndrome. After maxillary lateral expansion, the skeletal Class III relationship with an anterior crossbite improved because of mandibular clockwise rotation, whereas the facemask had a marginal effect. After growth at 16 years, he had a skeletal Class I relationship, and thus, conventional orthodontic treatment with preadjusted edgewise appliances was initiated. After 41 months of multibracket treatment, acceptable occlusion with a functional Class I relationship was obtained. One year postretention, few changes in occlusion and facial features were observed. Our results demonstrate that considering the maxillofacial vertical growth during the peripubertal period associated with Sotos syndrome, more attention should be paid to the early orthopedic treatment with the facemask and/or chincap.

American Journal of Orthodontics and Dentofacial Orthopedics (AJO-DO)


過大なポステリアディスクレパンシーと前歯部の反対咬合を伴う骨格性Ⅰ級叢生の一治験例 -長期保定症例-

To clarify the characteristics of oral dysfunction in pediatric patients with malocclusion, we compared oral function between individuals with normal occlusion and those with malocclusion.A total of 108 participants, including 41 boys and 67 girls (mean age ± standard deviation, 9.4 ± 2.2 years), were recruited from outpatients who visited the Departments of Orthodontics and Pediatric Dentistry of Tokushima University Hospital. They were classified according to their occlusal status into normal occlusion, crowding, maxillary protrusion, mandibular protrusion, open bite, and others.This study revealed that patients with malocclusion had more functional problems (e.g. tongue thrust, low tongue posture and another oral habits) than subjects with normal occlusion and that the functional problems were associated with various types of malocclusion. Especially, patients with open bite showed the characteristic features of oral function and their maximum lip closure force was significantly weaker than that of subjects with normal occlusion (p < 0.05).We found the characteristic features of oral dysfunction in each malocclusion. It is thought that it is necessary to make an individual training program to the characteristic feature of oral function.


An adult case of unilateral posterior crossbite caused by maxillary transverse deficiency treated with miniscrew-assisted rapid palatal expansion.

This report describes the successful treatment of an adult case of unilateral posterior crossbite caused by maxillary transverse deficiency with miniscrew-assisted rapid palatal expansion (MARPE). A female patient aged 35.5 years presented with masticatory disturbance, facial asymmetry, and unilateral posterior crossbite. She was diagnosed with unilateral posterior crossbite with a skeletal Class III jaw-base relationship and high mandibular plane angle. Her maxillary right and mandibular bilateral second premolars were congenitally absent, and the maxillary left second premolar was impacted. After the improvement of the posterior crossbite with MARPE, 0.018'' slot lingual brackets were placed on the maxillary and mandibular dentition. The total active treatment period was 22 months, and acceptable occlusion with a functional Class I relationship was achieved. Pretreatment and posttreatment cone-beam computed tomography images showed the disarticulation of the midpalatal suture after MARPE, and changes in the dental and nasomaxillary structures, nasal cavity, and pharyngeal airway. The case results demonstrate that MARPE produces greater skeletal expansion with minimal buccal tipping of the molars. MARPE may be effective for the treatment of maxillary transverse deficiency in adult patients.

Journal of Stomatology, Oral and Maxillofacial Surgery


Conditioned Medium from Stem Cells of Human Exfoliated Deciduous Teeth Partially Alters the Expression of Inflammation-associated Molecules of Mouse Condylar Chondrocytes via Secreted Frizzled-related Protein 1


and that the interaction between the two genes functions in conjunction with other ligands to control the spatial patterning and development of teeth.


Orthodontic Treatment Does Not Affect Frontal Sinus Development in Female Adults: A Clinical Study

Frontal sinus growth is gradual and lasts until post-puberty. However, the influence of biomechanical stimuli, such as orthodontic treatment, on frontal sinus development after the growth period has ended remains unclear. This study was designed to elucidate the impact of orthodontic treatment on the frontal sinus morphology of adult females. Sixty women were included and divided into three groups, based on the Frankfort mandibular plane angle. All participants underwent computed tomography and lateral cephalometry before and after treatment. Although two participants exhibited frontal sinus agenesis, most exhibited a bilaterally symmetric frontal sinus without fusion. The frontal sinus width and height were almost similar, irrespective of the vertical skeletal pattern, where the frontal sinus depth was significantly larger in the average mandibular plane angle group than in the low- and high-angle groups. Furthermore, the sinus volume in the low-angle group was likely smaller than that in the average and high-angle groups. On comparing pre-treatment and post-treatment measurements, minimal or no changes to the frontal sinus dimension were detected after treatment. In conclusion, orthodontic treatment did not affect frontal sinus development after the end of growth.


The Xanthine Oxidase Inhibitor Febuxostat Suppresses Adipogenesis and Activates Nrf2.

Xanthine oxidoreductase (XOR) is a rate-limiting enzyme in purine catabolism that acts as a novel regulator of adipogenesis. In pathological states, xanthine oxidoreductase activity increases to produce excess reactive oxygen species (ROS). The nuclear factor erythroid 2-related factor 2 (Nrf2) is a critical inducer of antioxidants, which is bound and repressed by a kelch-like ECH-associated protein 1 (Keap1) in the cytoplasm. The Keap1-Nrf2 axis appears to be a major mechanism for robust inducible antioxidant defenses. Here, we demonstrate that febuxostat, a xanthine oxidase inhibitor, alleviates the increase in adipose tissue mass in obese mouse models with a high-fat diet or ovariectomy. Febuxostat disrupts in vitro adipocytic differentiation in adipogenic media. Adipocytes appeared at day 7 in absence or presence of febuxostat were 160.8 ± 21.2 vs. 52.5 ± 12.7 (p < 0.01) in 3T3L1 cells, and 126.0 ± 18.7 vs. 55.3 ± 13.4 (p < 0.01) in 10T1/2 cells, respectively. Adipocyte differentiation was further enhanced by the addition of hydrogen peroxide, which was also suppressed by febuxostat. Interestingly, febuxostat, but not allopurinol (another xanthine oxidase inhibitor), rapidly induced the nuclear translocation of Nrf2 and facilitated the degradation of Keap1, similar to the electrophilic Nrf2 activator omaveloxolone. These results suggest that febuxostat alleviates adipogenesis under oxidative conditions, at least in part by suppressing ROS production and Nrf2 activation. Regulation of adipocytic differentiation by febuxostat is expected to inhibit obesity due to menopause or overeating.


Accuracy of three-dimensional printed models derived from cone-beam computed tomography

To determine the accuracy of three-dimensional (3D) printed models fabricated from cone-beam computed tomography (CBCT) scans of human mandibular dry skulls in comparison with models derived from intraoral scanner (IOS) data. Six human mandibular dry skulls were scanned by IOS and CBCT. Digital models (DMs) constructed from the IOS and CBCT data were fabricated physically using a 3D printer. The width and thickness of individual teeth and intercanine and molar widths were measured using a digital caliper. The accuracy of the DMs was compared between IOS and CBCT. Paired t-tests were used for intergroup comparisons. All intraclass correlation coefficient values for the three measurements (mesial-distal, buccal-lingual, width) exceeded 0.9. For the mandibular teeth, there were significant discrepancies in model accuracy between the IOS (average discrepancies of 0.18 ± 0.08 mm and 0.16 ± 0.12 mm for width and thickness, respectively) and CBCT (0.28 ± 0.07 mm for width, 0.37 ± 0.2 mm for thickness; P < .01). Intercanine (P = .38) and molar widths (P = .41) showed no significant difference between groups. There was a statistically significant difference in the accuracy of DMs obtained from CBCT and IOS; however, this did not seem to result in any important clinical difference. CBCT could be routinely used as an orthodontic diagnostic tool and for appliance construction.


Relationship between oral parafunctional and postural habits and the symptoms of temporomandibular disorders: A survey-based cross-sectional cohort study using propensity score matching analysis

Temporomandibular disorders (TMDs) are a multifactorial joint disease of the masticatory system. The possible etiological factors involved in the onset and progression of TMDs include oral parafunctional habits (OPFHs) and postural habits (PHs). However, little information is available on the association between OPFHs and PHs and a predisposition to TMDs. Thus, to investigate whether the presence of OPFH and PH predisposes individuals to TMDs, a survey-based cross-sectional cohort study of self-reported TMD was performed. A total of 2292 patients with TMD were recruited for the survey. Through one-to-one propensity score matching, 166 patients with and without sleep bruxism (SB) were selected. The SB group had a significantly higher risk of masticatory muscular pain or fatigue than the non-SB group ( = 0.018). Furthermore, the SB group without other OFPHs and PHs did not show a significantly higher risk of TMD symptoms than the non-SB group. Diurnal clenching and bad posture also affect the stomatognathic system, causing pain or fatigue; however, it did not result in TMDs in patients without any OPFHs and PHs. This implies that OPFHs and PHs may increase the risk of TMD symptoms in coexistence with other habits.


Development of the Sphenoid Sinus in Japanese Children: A Retrospective Longitudinal Study Using Three-Dimensional Computed Tomography

The sphenoid sinus (SS) is located close to vital structures, such as the pituitary gland, and it has significant clinical relevance. This study aimed to clarify the growth pattern of the SS in Japanese children using three-dimensional computed tomography (CT). Seventy-eight participants with congenital, acquired, or external auditory canal cholesteatoma were recruited and underwent CT more than twice during their treatment. Using the volume-rendered images, the size and volume of the SS were measured. Furthermore, on the scout image, the morphological measurements of the cranial base were determined. The size and volume of the SS increased with age, and peaked at the mean age of 15 years. For males, the volume of the SS was smaller than that of females aged <5 years. The growth rate of the SS was significantly higher in males than in females. The maximum growth rate was detected at the age of 12 years for males and 10 years for females. For females, the increase in the length of the anterior cranial base ceased at approximately 10 years of age and remained constant thereafter. In contrast, for males, the length of the anterior cranial base increased gradually until 15 years of age. Considering the similarity of the periods between the adolescent growth spurt and the maximum growth rate of the SS, changes in the size of the SS may be used as an indicator of the physical growth spurt.


Characteristics of Oral Dysfunction in Pediatric Patients with Malocclusion

小児不正咬合患者の小児患者における口腔機能障害の特徴

To clarify the characteristics of oral dysfunction in pediatric patients with malocclusion, we compared oral function between individuals with normal occlusion and those with malocclusion.A total of 108 participants, including 41 boys and 67 girls (mean age ± standard deviation, 9.4 ± 2.2 years), were recruited from outpatients who visited the Departments of Orthodontics and Pediatric Dentistry of Tokushima University Hospital. They were classified according to their occlusal status into normal occlusion, crowding, maxillary protrusion, mandibular protrusion, open bite, and others.This study revealed that patients with malocclusion had more functional problems (e.g. tongue thrust, low tongue posture and another oral habits) than subjects with normal occlusion and that the functional problems were associated with various types of malocclusion. Especially, patients with open bite showed the characteristic features of oral function and their maximum lip closure force was significantly weaker than that of subjects with normal occlusion (p < 0.05).We found the characteristic features of oral dysfunction in each malocclusion. It is thought that it is necessary to make an individual training program to the characteristic feature of oral function.


矯正歯科治療の経過予後からみた埋伏下顎大臼歯の歯科用CB-CT画像の特徴と牽引可否との関連性

【目的】埋伏下顎大臼歯は，発生率は低いものの骨性癒着が認められた際は重大な不正咬合の原因となる．その治療予後の予測は未だ困難であり，重要な臨床課題の一つである．本研究では臨床的に牽引が不可能であった下顎大臼歯のエックス線画像を見直し，牽引可能であった例と比較することで，牽引の可否を鑑別するための特徴的な画像所見を検討した． 【方法】資料として徳島大学病院矯正歯科を受診した第三大臼歯を除く下顎大臼歯の埋伏を有する患者5 名の歯科用コーンビームCT (以下CB-CT) 画像とパノラマエックス線画像を用いた．Ducommun らの骨性癒着歯の評価項目である歯根膜腔消失・歯根吸収・組織置換に加え，置換性歯根吸収(歯根吸収により生じた歯根表面の凹凸部の骨硬化像)，歯根彎曲の有無を評価した． 【結果】パノラマエックス線画像では5 例全てで歯根膜腔の消失を認めたが，歯根吸収や組織置換像は観察されなかった．一方，CB-CT 画像では牽引が不可能であった3 例全てで歯根膜腔の消失と置換性歯根吸収像を認めた．牽引が可能であった2 例でも歯根膜腔の消失がみられ，うち1 例では歯根吸収像も認めたがその近傍に骨硬化像はなかった． 【考察】Ducommun らの評価項目のみでは，牽引可能であった1 例が偽陽性となったが，置換性歯根吸収の評価項目への追加により偽陽性はなくなった．このことから置換性歯根吸収の評価が埋伏下顎大臼歯の牽引の可否の鑑別に極めて重要であると考えられた． 【結論】埋伏下顎大臼歯の診断において，CB-CT 画像での当該歯の周囲組織の詳細な観察により，牽引が可能であるかを非常に高い精度で診断できる可能性が示唆された．

The Journal of Chu-Shikoku Orthodontic Society

中·四国矯正歯科学会雑誌


犬歯の埋伏による重度歯根吸収を呈した上顎切歯に対して下顎小臼歯の自家移植を行った歯性上顎前突の一治験例

中·四国矯正歯科学会雑誌


Establishment of a new rehabilitation program using masticatory training food for jaw deformity patients.

The rehabilitation using this training food may become a useful method for postoperative hypofunction in patients with jaw deformities.

Compared with the non-training group, the training group showed a trend toward greater recovery amount of MBF from Pre to T3, and a significantly greater recovery amount in MP (p < 0.05) from Pre to T3. When the time-series change of MP was evaluated in both groups from T0 to T3, a significant difference was observed in the interaction terms (p = 0.03). This result indicates that the effectiveness of the training may be demonstrated by following the postoperative course further.


Thread shape, cortical bone thickness, and magnitude and distribution of stress caused by the loading of orthodontic miniscrews: finite element analysis.

Cortical bone thickness is assumed to be a major factor regulating miniscrew stability. We investigated stress distribution in two miniscrews with different thread shapes (type A and B) and in cortical bone of three different thicknesses using three-dimensional (3D) finite element (FE) models. More specifically, 3D FE models of two different miniscrews were created and placed obliquely or vertically into a cylindrical bone model representing different cortical bone thicknesses. When force was applied to the miniscrew, the stress distribution on the screw surface and in the peri-implant bone was assessed using FE methodology. Miniscrew safety was evaluated using a modified Soderberg safety factor. Screw head displacement increased with a decrease in cortical bone thickness, irrespective of screw type. The smallest minimum principal stresses on the screw surfaces remained constant in type A miniscrews on changes in cortical bone thickness. Minimum principal stresses also appeared on the cortical bone surface. Lower absolute values of minimum principal stresses were seen in type A miniscrews when placed vertically and with upward traction in obliquely placed type B miniscrews. Both miniscrews had acceptable safety factor values. Taken together, orthodontists should select and use the suitable miniscrew for each patient in consideration of bone properties.


Aberrant upregulation of the endogenous PP2A inhibitor CIP2A is vital for myeloma cell growth and survival

The serine/threonine kinase TAK1 is constitutively overexpressed and auto-phosphorylated in multiple myeloma (MM) cells. Protein phosphatase 2A (PP2A) is a major serine/threonine phosphatase which dephosphorylates proteins phosphorylated by various serine/threonine kinases to regulate multiple cellular functions. We recently reported that the serine/threonine kinase TGF-β-activated kinase-1 (TAK1) is highly expressed and auto-phosphorylated to mediate critical growth and survival signaling in MM cells. We demonstrate here that regulation of PP2A activity inversely affects the phosphorylation levels of TAK1 in MM cells, and that MM cells aberrantly overexpress cancerous inhibitor of PP2A (CIP2A), an endogenous inhibitor for PP2A. CIP2A gene silencing as well as treatment with the CIP2A inhibitor TD52 potently induced MM cell death along with suppression of TAK1 expression in MM cells. These results suggest the critical role of PP2A inactivation via CIP2A upregulation in TAK1 phosphorylation and its protein expression and thereby MM cell growth and survival, posing the CIP2A-PP2A axis as an important therapeutic target.


Volumetric Assessment of the Frontal Sinus in Female Adolescents and Its Relationship with Craniofacial Morphology and Orthodontic Treatment: A Pilot Study

International Journal of Environmental Research and Public Health


Mechanical stability of orthodontic miniscrew depends on a thread shape.

The miniscrew with a novel thread shape showed a higher initial stability compared to those with a regular thread shape. Thus, in order to obtain a sufficient initial stability, it is important to select the type of screw thread that is appropriate for the thickness of the cortical bone.

The MIT, RT, TR and K of type C miniscrew were significantly greater than those of type A and B miniscrews when the miniscrews were placed in the thinner artificial bone. Furthermore, the TR value of type C miniscrew was more than 1, indicating the MRT value was larger than the MIT value in the novel miniscrew. The values of K∗ and tan


HIF-1α controls palatal wound healing by regulating macrophage motility via S1P/S1P1 signaling axis.

signaling. These results suggest that HIF-1α signaling may contribute to the regulation of palatal wound healing.


Effect of immersion in NaCl solution on the electrical conductivity and the reduction of the shear bond strength of resin-modifi ed glass-ionomer-cements after current application


Alveolar corticotomy for extrusion of an ankylosed lower first molar.


Treatment decision of camouflage or surgical orthodontic treatment for skeletal Class III patients based on analysis of masticatory function.

The study subjects were 45 patients with skeletal Class III malocclusion (15 cases with camouflage orthodontics and 30 cases with orthognatic surgery) and 12 individuals with normal occlusion. We analyzed the pre-treatment records of electromyographic activities of masseter and temporalis muscles and jaw movements.

Camouflage orthodontic treatment is inappropriate for patients with relatively severe dentoskeletal discrepancies. Wits appraisal of -6.0 mm is a potentially useful parameter for treatment decision.


Conditioned Medium From the Stem Cells of Human Exfoliated Deciduous Teeth Ameliorates Neuropathic Pain in a Partial Sciatic Nerve Ligation Model.

In neuropathic pain (NP), injury or diseases of the somatosensory system often result in highly debilitating chronic pain. Currently, there is no effective drug for the complete and definitive treatment of NP. We investigated the therapeutic potential of conditioned medium (CM) derived from stem cells from human exfoliated deciduous teeth (SHED-CM) against NP using a mouse partial sciatic nerve ligation (PSL) model. Abnormal pain sensation, such as tactile allodynia and hyperalgesia, can be caused by PSL. In the behavioral test, intravenous administration of SHED-CM greatly improved the PSL-induced hypersensitivity. We found that treatment with SHED-CM resulted in the recruitment of M2 macrophages in the injured sciatic nerve and ipsilateral L4/L5 dorsal root ganglion and suppressed microglial activation in the spinal cord. Notably, specific depletion of the anti-inflammatory M2 macrophages by mannosylated-Clodrosome markedly reduced the antinociceptive effect of SHED-CM. Intravenous administration of CM from M2 induced by SHED-CM (M2-CM) ameliorated the PSL-induced hypersensitivity. We found that M2-CM directly suppressed the expression of nociceptive receptors as well as proinflammatory mediators in Schwann cells. Taken together, our data suggest that SHED-CM ameliorates NP through the induction of the analgesic anti-inflammatory M2 macrophages. Thus, SHED-CM may be a novel therapeutic candidate for NP.


Signs, Symptoms, and Morphological Features of Idiopathic Condylar Resorption in Orthodontic Patients: A Survey-Based Study

Idiopathic condylar resorption (ICR) is an aggressive degenerative disease of the temporomandibular joint that is most frequently observed in teenage girls. However, no specific cause of ICR has been identified. To explore the specific causes of the onset and progression of ICR, we performed a survey-based study on ICR in orthodontic patients and described its subjective symptoms, clinical signs, and condylar morphological features. A total of 1735 participants were recruited from 2193 orthodontic patients. For each participant, subjective symptoms and clinical signs of temporomandibular disorders (TMDs) were evaluated through clinical examination and a questionnaire. Furthermore, three-dimensional computed tomography (CT) was performed to diagnose ICR. Among the 1735 patients evaluated, ICR was present in two male and ten female patients. All 12 patients had maxillary protrusion and an anterior open bite. Four patients with ICR underwent orthodontic treatment. Based on CT findings, patients with ICR had significantly different condylar sizes and shapes from patients with TMDs alone. The coexistence of intrinsic and extrinsic factors, such as sex-hormone imbalance and a history of orthodontic treatment, might lead to the onset of ICR. We suggest that growing patients suspected of having ICR should undergo CT evaluation because CT findings may precede clinical symptoms and signs.


Volume Magnetic Susceptibility Estimation of α- and β-Phases in Titanium Alloys for Biomedical Applications.

Metallic medical devices in the human body cause serious artifacts in magnetic resonance imaging owing to the volume magnetic susceptibility (χν) mismatch between the device and tissue around the device. To reduce artifacts, medical devices produced from alloys with χν values of approximately -9 × 10-6 are required. Controlling the phase constitution is a basic technique used to control the χν value of an alloy, and the χν value of each phase is a fundamental property. In this study, an α+β-type Ti alloy and two β-type Ti alloys were investigated. The estimated χν values of the α-phase of the alloys were similar to or smaller than that of pure Ti. In contrast, the estimated χν values of the β-phase of the alloys were larger than that of pure Ti. Since the χν value of pure Ti is much larger than -9 × 10-6, the χν values of the β-phases suggested that increasing the volume fraction of the β-phase was not appropriate for producing a Ti alloy with a lower χν value.


A Multidisciplinary Approach to Malocclusion Caused by Facial Multiple Fracture.

In the case of multiple facial fractures, a simple open reduction occasionally causes various disorders during healing process after the surgery. Moreover, esthetic disturbance of a facial deformity might be induced. Therefore, the acquisition of facial symmetry and the recovery of occlusal and masticatory functions become increasingly important. This case report presents a successful treatment of facial multiple fracture induced by a car accident. A 20-year-old male was diagnosed with suffered multiple midface and mandibular fractures induced by a car accident. Midface fractures included the LeFort I and II type fractures, as well as sagittal fracture at midline and fractures from right maxillary sinus anterior wall to orbital wall. In the mandible, midline and left body fractures were detected. The patient underwent open reduction and rigid fixation of the fractured left zygoma, comminuted LeFort I and II fractures, and midline and left body of the mandible with intermaxillary fixation by multibracket appliance; maxillary osteotomy with iliac bone grafting; orthognathic two-jaw surgery with coronoid process grafts onto the depressed zygoma; and onlay graft of hydroxyapatite block on mandible. As the result, the multidisciplinary treatments successfully recover functions and esthetics to the satisfactory level of the patient with multiple facial fractures. As treatments for multiple facial fractures are required complexity due to the extent of trauma, multidisciplinary approach under the close cooperation between hospital departments is thought to be important.


Mechanical unloading aggravates bone destruction and tumor expansion in myeloma.


TGF-β-activated kinase-1 inhibitor LL-Z1640-2 reduces joint inflammation and bone destruction in mouse models of rheumatoid arthritis by inhibiting NLRP3 inflammasome, TACE, TNF-α and RANKL expression.

TAK1 inhibition with LLZ may become a novel treatment strategy to effectively alleviate inflammasome-mediated inflammation and RANKL-induced osteoclastic bone destruction in joints alongside its potent suppression of TNF-α and IL-6 production and proteinase-mediated pathological processes in RA.


トルクを付加した際の歯および歯根膜における応力分布の有限要素解析

トルクを付加した際の歯および歯根膜における応力分布の有限要素解析


矯正歯科臨床における下顎頭吸収への対応

矯正歯科臨床における下顎頭吸収への対応

The Journal of Hokkaido Orthodontic Society


Longitudinal Morphological Changes in the Adenoids and Tonsils in Japanese School Children.

The adenoid (Ad) and tonsil (Ts), located in the upper airway, play an important role in immunological protection. These lymphoid tissues grow rapidly, reach a peak of growth at the age of 6-8 years, and decrease in their size thereafter. However, little information is available on the longitudinal growth patterns of Ad and Ts in the general population. This study aimed to evaluate the individual growth of Ad and Ts during childhood using lateral cephalograms taken longitudinally from the same individuals at the ages of 8-12 years. Our results showed that the cross-sectional areas of the Ad, nasopharynx (Np), and oropharynx (Op) significantly increased with age while small changes in the size of Ts were present throughout the study period. In addition, the values of Ad/Np and Ts/Op decreased significantly with age in the elementary school. Furthermore, there was a strong and significant correlation between the Ad/Np ratio and upper airway resistance, indicating the narrowest distance in the upper airway. In conclusion, the airway occupation in Np and Op increased with age due to the increase in the sizes of Np and Op but not the decrease in the sizes of Ad and Ts.


Long-term Management of a Patient with Apert Syndrome.

The two-stage operation combining early distraction osteogenesis and postgrowth orthognathic surgery proves to be an effective therapy for correcting midfacial hypoplasia and skeletal mandibular protrusion caused by Apert syndrome.

The Journal of Contemporary Dental Practice


Influence of insertion depth on stress distribution in orthodontic miniscrew and the surrounding bone by finite element analysis.

We aimed to elucidate stress distribution in miniscrews and the surrounding bone when miniscrews inserted at different depths were implanted vertically or obliquely. The distributions of the equivalent stress on the screw surface and the minimum principal stress in the surrounding bone were calculated using finite element models. When the miniscrews were inserted vertically and obliquely, screw head displacement, greatest equivalent stress on the miniscrew surface, and absolute value of minimum principal stresses in the surrounding bone decreased with increasing insertion depth. Stresses in the obliquely inserted miniscrew with upward traction were smaller than in other insertion conditions, irrespective of insertion depth. With the application of orthodontic force, stress distribution around the miniscrew and surrounding bone is closely related to the insertion depth and insertion angle, which mutually affect each other. In particular, the obliquely inserted miniscrew with upward traction might be the most secure against screw failure and fracture.


Pathogenesis and treatment of multiple myeloma bone disease.

Multiple myeloma (Plasma cell myeloma), a malignancy of the plasma cells, exhibits tumor expansion preferentially in the bone marrow and the development of bone-destructive lesions. Multiple myeloma is still an incurable disease with changes in the bone marrow microenvironment in favor of the survival and proliferation of multiple myeloma cells and bone destruction. In this review, we described the recent findings on the regulators involved in the development of myeloma bone diseases, and succinctly summarize currently available therapeutic options and the development of novel bone modifying agents for myeloma treatment.


Low-intensity pulsed ultrasound ameliorates neuropathic pain induced by partial sciatic nerve ligation via regulating macrophage polarization


Treatment of hemifacial microsomia using conventional orthodontic techniques: Report of a case with long-term follow-up.

Early orthodontic management only can have some limitations but could be one of the treatment options for hemifacial microsomia.

The Journal of the American Dental Association


Macrophage Motility in Wound Healing Is Regulated by HIF-1α via S1P Signaling.

Accumulating evidence indicates that the molecular pathways mediating wound healing induce cell migration and localization of cytokines to sites of injury. Macrophages are immune cells that sense and actively respond to disturbances in tissue homeostasis by initiating, and subsequently resolving, inflammation. Hypoxic conditions generated at a wound site also strongly recruit macrophages and affect their function. Hypoxia inducible factor (HIF)-1α is a transcription factor that contributes to both glycolysis and the induction of inflammatory genes, while also being critical for macrophage activation. For the latter, HIF-1α regulates sphingosine 1-phosphate (S1P) to affect the migration, activation, differentiation, and polarization of macrophages. Recently, S1P and HIF-1α have received much attention, and various studies have been performed to investigate their roles in initiating and resolving inflammation via macrophages. It is hypothesized that the HIF-1α/S1P/S1P receptor axis is an important determinant of macrophage function under inflammatory conditions and during disease pathogenesis. Therefore, in this review, biological regulation of monocytes/macrophages in response to circulating HIF-1α is summarized, including signaling by S1P/S1P receptors, which have essential roles in wound healing.

International Journal of Molecular Sciences


Temporary Anchorage Devices (TADs)を用い非抜歯遠心移動治療を行った長期安定2症例

今回，我々はTemporary Anchorage Devices(TADs)を用いて上下顎歯列全体の遠心移動による非抜歯治療を遂行し，保定後5年以上の経過時においても安定した咬合関係が維持された2症例を経験したので報告する．症例1は，初診時年齢29歳の女性で，開咬を主訴として来院した．口腔内所見は，overjet -1.0mm，overbite -1.0mmで，上下顎歯列正中の不一致を認めた．アーチレングスディスクレパンシーは上顎-0.5mm，下顎-2.0mmであり，臼歯関係は右側Angle I級，左側Angle III級であった．側面頭部エックス線規格写真分析の結果，∠ANB3.9°よりskeletal Class I，FMA33.6°よりhigh mandibular plane angleであり，口唇突出感のある前歯部開咬を伴う歯性上下顎前突と診断された．上顎両側臼歯部頬側歯槽部に歯科矯正用アンカースクリューを，下顎両側大臼歯部にアンカープレートを植立し，マルチブラケット装置を装着した後，歯列全体の遠心移動により咬合を確立した．症例2は，初診時年齢60歳の女性で，下顎前歯部の叢生を主訴として来院した．口腔内所見は，overjet +6.0mm，overbite +1.5mmで，アーチレングスディスクレパンシーは上顎-2.5mm，下顎-6.0mmであり，両側第一小臼歯は鋏状咬合を呈し，臼歯関係は両側Angle I級であった．側面頭部エックス線規格写真分析の結果，∠ANB4.4°よりskeletal Class I，FMA26.1°よりlow mandibular plane angleであり，口唇突出感のある叢生を伴う歯性上顎前突と診断された．上下顎両側臼歯部頬側歯槽部に歯科矯正用アンカースクリューを植立後，上下顎とも臼歯部の遠心移動を先行させ，前歯部の排列スペースを確保した後，上下顎歯列全体の遠心移動を行うことで咬合を確立した．TADsを固定源にマルチブラケット装置を用い，上下顎歯列全体の遠心移動による咬合確立を行った2症例であるが，それぞれ保定7年10ヵ月，5年7ヵ月経過後も安定した咬合が維持されていた．従来であれば抜歯治療の適用となる症例であったが，TADsを用いた歯列全体の遠心移動により非抜歯にて適切な咬合が獲得でき，長期的安定性も得られることが示唆された．(著者抄録)

The Journal of Chu-Shikoku Orthodontic Society

中·四国矯正歯科学会雑誌


歯科矯正用アンカースクリューの導入に伴う治療方針の変化(第一報) 抜歯・非抜歯および抜歯部位の判定に関する検討

【目的】近年，歯科矯正用アンカースクリュー(以降アンカーと明記する)の普及により，臼歯の固定や移動が容易に行えるようになり，抜歯，非抜歯，抜歯部位の選択についても変化が起きている．今回，アンカーの導入前後での治療方針の変化について，とくに臼歯抜歯の適応に関する調査を行ったので報告する．【方法】徳島大学病院矯正歯科を受診した初診時年齢12歳以上の患者を対象とし，2002年以前にマルチブラケット治療の診断を受けた100名(Pre群)と2008年以降に診断を受けた100名(Post群)を無作為に抽出した．先天性疾患および歯牙欠損症例，顎変形症は除外した．診断内容における臼歯抜歯(第三大臼歯は除く)の有無，抜歯部位等に関する比較検討を行った．【結果および考察】Pre群とPost群の間で抜歯症例数および抜歯部位に違いは認められなかった．一方，skeletal Class IIの症例はPre群では上顎片顎小臼歯抜歯によるカムフラージュ治療が多かったのに対し，Post群ではその割合は減少していた．また，skeletal Class IIIの症例ではアンカーを用いた非抜歯治療の割合が増加していた．High mandibular plane angle caseにおいてはアンカーの使用により，上顎第一大臼歯の挺出防止ならびに圧下が可能となり上下顎第一小臼歯を抜去する割合が増えた．【結論】アンカー導入で，臼歯の移動や挺出の防止および圧下が可能となり抜歯部位の選択基準に変化が生じたと考えられた．(著者抄録)

中·四国矯正歯科学会雑誌


Case report update: A case of unilateral mandibular condylar osteochondroma treated with ipsilateral condylectomy and contralateral ramus osteotomy.


Biomechanical and tribological properties of the temporomandibular joint

Frontiers of Oral and Maxillofacial Medicine


A Long-term Follow-up of Mandibular Deviation Caused by Congenital Cervical Lymphangioma Treated with an Orthodontic Approach.

The hybrid technique combining functional appliance and intermaxillary elastics proves to be an effective therapy for correcting occlusal cant and mandibular deviation caused by cervical lymphangioma.

The Journal of Contemporary Dental Practice


The immunoregulatory role of p21 in the development of the temporomandibular joint-osteoarthritis.

Our findings indicate that p21 in chondrocytes contributes to regulate matrix synthesis via the control ofm aggrecan and MMP-13 expression under mechanical stress. Thus, p21 might regulate the pathogenesis of osteoarthritis in the TMJ.

mice aged 8 weeks were divided into the untreated and treated groups. In the treated groups, mechanical stress was applied to the temporomandibular joint (TMJ) through forced mouth opening for 3 hr/day for 7 days. The dissected TMJs were assessed using micro-CT, histology, and immunohistochemistry.

Clinical and Experimental Dental Research


Comprehensive treatment for severe periodontitis with pathologic tooth migration-related bimaxillary protrusion: A case report with 3-year follow-up.

Favorable esthetics, stable occlusion, and highly cleansable periodontal tissues were achieved with well-planned interdisciplinary and comprehensive treatment, although the patient had severe periodontitis and PTM-related bimaxillary protrusion.

The Journal of the American Dental Association


Effect of region-dependent viscoelastic properties on the TMJ articular disc relaxation under prolonged clenching.

The disc of the temporomandibular joint (TMJ) is located between the mandibular condyle and temporal bone, and has an important load-bearing and stress absorbing function. The TMJ disc presents viscoelastic characteristics that are largely dependent on its collagen fibre and proteoglycan composition and organization. The purpose of this study is to investigate the possible effects of region-specific dynamic viscoelastic properties on stress relaxation during prolonged clenching. Two finite element models were used to compare the stress distribution within the TMJ disc, namely, one with uniform disc material property and another one with region-specific disc material properties. Similar results were observed in both models with slight differences in the location of maximum stress. Larger stresses were observed in all cases for the model with uniform disc material property. Moreover, the higher values for the model with uniform disc material property appeared in the lateral region, while in the model with region-specific disc properties, these values moved to the lateral and central region. This investigation confirms that both models are sufficiently accurate to investigate stress distribution in the TMJ disc, and, particularly, the model with the region-specific disc material properties ensure better simulations of the TMJ disc behaviour.

Journal of the Mechanical Behavior of Biomedical Materials


Evaluation of torque moment in esthetic brackets from bendable alloy wires.

The current study identified the material characteristics of CR, ZR, and PC brackets during torque tooth movements. The present results demonstrate a characteristic combined effect between different esthetic brackets and bendable alloy wires.


Surgical orthodontic treatment of skeletal mandibular protrusion with multiple impacted ankylosed teeth treated with alveolar corticotomy

To present a case of skeletal mandibular protrusion with multiple impacted ankylosed teeth, which were treated with conventional orthognathic surgery and alveolar corticotomy, respectively. Tooth ankylosis is characterized by the fusion of a root surface with the surrounding alveolar bone. Various treatment modalities for tooth ankylosis have been developed and are used commonly in the clinic. Corticotomy is defined as the application of intentional surgical injury to the cortical bone to mobilize a tooth with the adjacent bone and soft tissues. The corticotomy technique has been improved in recent years to avoid possible risks such as periodontal damage, tooth devitalization, and osseous necrosis due to an inadequate blood supply. A female patient aged 16 years and 3 months was diagnosed with anterior crossbite and the impaction and ankylosis of multiple canines. After the confirmation of ankylosis, alveolar corticotomy was performed on the maxillary left and mandibular right canines. After 6 months of traction (patient age, 19 years and 7 months), both canines had extruded successfully. After the completion of preoperative treatment, bilateral intraoral vertical ramus osteotomy was performed to correct the anterior crossbite involving a skeletal mandibular protrusion. The amounts of mandibular setback on the right and left sides were approximately 7 and 5 mm, respectively. The total treatment period was 55 months. Acceptable occlusion with a balanced profile was maintained over a 5-year retention period, indicating the long-term stability and success of the treatment. Our results indicate that alveolar corticotomy should be considered to facilitate the treatment of multiple impacted ankylosed teeth. This report proposes an efficacy of alveolar corticotomy for extrusion of impacted ankylosed teeth.


矯正歯科治療中に生じた下顎中切歯の歯肉退縮に対して結合組織移植術を行った歯性上顎前突症例 長期保定症例

歯肉退縮は，矯正治療中や治療後にしばしば生じるリスクのひとつであり，歯根面の露出により審美障害ならびに知覚過敏や根面う蝕などの問題を誘発する． 歯肉退縮の予防を目的とした，矯正治療前の歯周外科処置も報告されているが，現時点では一般的ではなく，実際に歯肉退縮が発生した後，結合組織移植術(CTG)などの歯周形成外科手術によって対応しているのが現状である． 今回我々は，歯性上顎前突患者の矯正治療中に下顎左側中切歯に生じた歯肉退縮に対して，1年10か月間の矯正治療終了後にCTGを施行し，術後6年経過した現在も歯肉退縮の再発を認めず，良好な状態が維持された症例を経験したため報告する．


Orthodontic treatment of open bite involved in diffuse hypercementosis: A case report.

Open bite is considered one of the most complicated malocclusions in orthodontic treatment. In this study, the authors successfully treated total open bite involved in hypercementosis using orthodontic miniscrews. A woman aged 25 years 8 months had total open bite. Her occlusal contact at the maximum intercuspation was present at the right second molars. A panoramic radiograph showed diffuse hypercementosis. The titanium miniscrews were interradicullay implanted between the first and second molars, and intrusion force was applied for 14 months. After active treatment, the patient's maxillary first molars showed about 1.6-millimeters of intrusion, resulting in counterclockwise mandibular rotation. Her acceptable occlusion was maintained after 1.0-year retention. Miniscrews might be useful tool to improve malocclusion involved in diffuse hypercementosis though they are considered to be difficult to move and brought on ankylosis.


Effects of water immersion on shear bond strength reduction after current application of resin-modified glass-ionomer-cements containing and not containing an ionic liquid.

The enhancement in the bonding strength of advanced dental cements has enabled long-lasting dental restorations. However, the high bonding strength can cause difficulty in removing these restorations. Therefore, "smart" dental cements with simultaneous strong bonding and easy on-demand debonding ability are required. A resin-modified glass-ionomer-cement (RMGIC) with an ionic liquid (IL) has demonstrated significant reduction in the bonding strength with current application (CA). This research investigates the effect of immersion in distilled water on the electric conductivity and bonding strength of RMGIC with and without an IL and CA. The RMGIC without the IL exhibited significant electric conductivity after immersion, and a significant decrease in bonding strength with CA. In comparison, the electric conductivity after immersion and the decrease in bonding strength with CA were greater for RMGIC with the IL. Thus, the feasibility of smart dental cements capable of electrically debonding-on-demand is indicated.


Immediate Effect of Masticatory Muscle Activity with Transcutaneous Electrical Nerve Stimulation in Muscle Pain of Temporomandibular Disorders Patients

Transcutaneous electrical nerve stimulation (TENS) is a non-invasive treatment modality for acute and chronic pain. However, little information for muscle activity is available on the immediate effects of TENS in masticatory muscle pain related to temporomandibular disorders (TMDs). The present study aimed to evaluate the immediate effects of TENS treatment on TMD-related muscle pain. Thirty-six patients with TMD-related muscle pain and 39 healthy subjects served as TMD and control groups, respectively. For objective evaluations, maximum mouth opening, and maximum bite force were measured before and after TENS. The pain intensity was assessed according to a 100-mm visual analog scale (VAS). TENS was applied to painful muscles for 20 min with frequencies of 100-200 Hz. The treatment outcome was evaluated using Global Rating of Change (GRC) scales. In the TMD group, VAS values significantly decreased after TENS. Although there was significant increase in the maximum mouth opening after TENS for only TMD group, the maximum bite force of both groups was significantly greater after TENS. According to GRC scales, one patient with TMD-related muscle pain expressed negative feelings after TENS. Conclusively, TENS treatment might quickly relieve pain in masticatory muscles and improve masticatory functions in patients with TMD-related muscle pain.


Fgf10-CRISPR mosaic mutants demonstrate the gene dose-related loss of the accessory lobe and decrease in the number of alveolar type 2 epithelial cells in mouse lung.

CRISPR/Cas9-mediated gene editing often generates founder generation (F0) mice that exhibit somatic mosaicism in the targeted gene(s). It has been known that Fibroblast growth factor 10 (Fgf10)-null mice exhibit limbless and lungless phenotypes, while intermediate limb phenotypes (variable defective limbs) are observed in the Fgf10-CRISPR F0 mice. However, how the lung phenotype in the Fgf10-mosaic mutants is related to the limb phenotype and genotype has not been investigated. In this study, we examined variable lung phenotypes in the Fgf10-targeted F0 mice to determine if the lung phenotype was correlated with percentage of functional Fgf10 genotypes. Firstly, according to a previous report, Fgf10-CRISPR F0 embryos on embryonic day 16.5 (E16.5) were classified into three types: type I, no limb; type II, limb defect; and type III, normal limbs. Cartilage and bone staining showed that limb truncations were observed in the girdle, (type I), stylopodial, or zeugopodial region (type II). Deep sequencing of the Fgf10-mutant genomes revealed that the mean proportion of codons that encode putative functional FGF10 was 8.3 ± 6.2% in type I, 25.3 ± 2.7% in type II, and 54.3 ± 9.5% in type III (mean ± standard error of the mean) mutants at E16.5. Histological studies showed that almost all lung lobes were absent in type I embryos. The accessory lung lobe was often absent in type II embryos with other lobes dysplastic. All lung lobes formed in type III embryos. The number of terminal tubules was significantly lower in type I and II embryos, but unchanged in type III embryos. To identify alveolar type 2 epithelial (AECII) cells, known to be reduced in the Fgf10-heterozygous mutant, immunostaining using anti-surfactant protein C (SPC) antibody was performed: In the E18.5 lungs, the number of AECII was correlated to the percentage of functional Fgf10 genotypes. These data suggest the Fgf10 gene dose-related loss of the accessory lobe and decrease in the number of alveolar type 2 epithelial cells in mouse lung. Since dysfunction of AECII cells has been implicated in the pathogenesis of parenchymal lung diseases, the Fgf10-CRISPR F0 mouse would present an ideal experimental system to explore it.


Hemifacial Microsomia Caused by First and Second Brachial Arch Syndrome Treated with Orthodontic Approach: A Case Report.

This report proposes an efficacy of conventional orthodontic treatment for growing patients with hemifacial microsomia involved in the FSBAS.

The Journal of Contemporary Dental Practice


本邦における外科的矯正治療の実態調査-2017年度日本顎変形症学会実態調査の結果 より-


Effects of loading direction in prolonged clenching on stress distribution in the temporomandibular joint.

Parafunctional habits, such as bruxism and prolonged clenching, have been associated with dysfunctional hyperactivity of the masticatory muscles, including the lateral pterygoid muscle. The resultant loading to the temporomandibular joint (TMJ) is subject to the degradation of bone, cartilage and disc in the TMJ. In this study, we examined the effect of clenching direction on the stress distribution in the TMJ. In this line, we hypothesised that asymmetrical clenching involved in parafunction might result in increased stresses on the TMJ disc as well as on the condylar and temporal articular surfaces. The distribution of stress for various directional loadings was analysed using a three-dimensional finite element model of the TMJ, with viscoelastic properties for the disc. The numerical results revealed that load direction influenced the amount and distribution of stresses on the disc surfaces. In particular, the lateral region of the disc suffered higher stress values. Moreover, the results showed a significant stress relaxation in the disc that revealed its capacity for stress energy dissipation. From the present study, it can be established that during prolonged clenching, the higher stresses are concentrated in the lateral region, which could imply that TMJ disorders related to damage or wear in the disc and the condylar cartilage, overall, occur when lateral dysfunctional displacements are present.

Journal of the Mechanical Behavior of Biomedical Materials


徳島大学病院矯正歯科における保険診療に関する実態調査-先天性疾患における裂奇形の併発について

矯正歯科治療に健康保険が導入されて約40年が経過し，唇顎口蓋裂と顎変形症の他に2018年現在53項目が保険治療の対象になっている．今回，我々は当科における矯正歯科治療の保険適用患者の実態を調査し，特に唇顎口蓋裂と他の先天性疾患との関連性について臨床統計学的検討を行ったので報告する．徳島大学病院病院情報システム・データウェアハウスを用い，2008年1月から2018年12月までの11年間に当院矯正歯科を受診した患者から保険治療を受けている患者を抽出し，顎変形症単独症例を除く先天性疾患患者について，電子カルテ全文検索システムを用いて臨床統計学的検討を行った．研究対象期間に当科にて保険治療を受けた矯正患者は345人で，そのうち，本研究対象患者は，顎変形症単独症例を除く207人であった．患者の内訳は，裂奇形を主徴候とする症例が全体の5割を占め最も多く，次いで，6歯以上の先天性部分性無歯症，ゴールデンハー症候群(鰓弓異常症を含む)，ダウン症候群の順であった．また，症候性疾患の中で裂奇形の併発は，ピエール・ロバン症候群，ダウン症候群，ゴールデンハー症候群の順に多く，その裂型は，口蓋裂(軟口蓋裂を含む)，唇顎口蓋裂，唇裂の順に多かった．以上のことから，当病院は裂奇形を併発した先天性疾患への専門的な対応が不可欠であり，希少疾患にも柔軟に対応できるよう複数の診療科，職種による診療科の枠組みを超えたチーム医療体制の構築が必要であることが示唆された．

The Journal of Chu-Shikoku Orthodontic Society

中·四国矯正歯科学会雑誌


The C-terminal region including the MH6 domain of Msx1 regulates skeletal development.

MSX1 is a causative gene for oligodontia in humans. Although conventional Msx1-deficient mice die neonatally, a mutant mouse lacking the C-terminus MH6 domain of MSX1 (Msx1) showed two different phenotypes; newborn homozygotes with cleft palates died neonatally, whereas those with thin palates remained alive and had craniofacial dysplasia and growth retardation compared with wild-type mice, with most mice dying by the age of 4-5 weeks. In a previously reported case of human oligodontia caused by a heterozygous defect of the Msx1 MH6 domain, a small foramen was observed on the occipital bone. The aim of this study was to test the hypothesis that the Msx1 MH6 domain is involved in bone formation in vivo. In Msx1 mice, cranial suture fusion was delayed at embryonic day 18.5, and the anteroposterior cranial diameter was smaller and long bone length was decreased at 3 weeks of age. The femoral epiphysis showed no change in the trabecular number, but decreased bone mass, bone density, and trabecular width in Msx1 mice. In addition, cancellous bone mass was reduced and the cartilage layer in the growth plate was thinner in Msx1 mice. The mRNA expression levels of major osteoblast and chondrocyte differentiation marker genes were decreased in Msx1 mice compared with wild-type mice. These findings suggest that the C-terminal region including the MH6 domain of MSX1 plays important roles not only in tooth development and palatal fusion, but also in postnatal bone formation.

Biochemical and Biophysical Research Communications


The Roles of ROS Generation in RANKL-Induced Osteoclastogenesis: Suppressive Effects of Febuxostat.

Receptor activator of NF-κB ligand (RANKL), a critical mediator of osteoclastogenesis, is upregulated in multiple myeloma (MM). The xanthine oxidase inhibitor febuxostat, clinically used for prevention of tumor lysis syndrome, has been demonstrated to effectively inhibit not only the generation of uric acid but also the formation of reactive oxygen species (ROS). ROS has been demonstrated to mediate RANKL-mediated osteoclastogenesis. In the present study, we therefore explored the role of cancer-treatment-induced ROS in RANKL-mediated osteoclastogenesis and the suppressive effects of febuxostat on ROS generation and osteoclastogenesis. RANKL dose-dependently induced ROS production in RAW264.7 preosteoclastic cells; however, febuxostat inhibited the RANKL-induced ROS production and osteoclast (OC) formation. Interestingly, doxorubicin (Dox) further enhanced RANKL-induced osteoclastogenesis through upregulation of ROS production, which was mostly abolished by addition of febuxostat. Febuxostat also inhibited osteoclastogenesis enhanced in cocultures of bone marrow cells with MM cells. Importantly, febuxostat rather suppressed MM cell viability and did not compromise Dox's anti-MM activity. In addition, febuxostat was able to alleviate pathological osteoclastic activity and bone loss in ovariectomized mice. Collectively, these results suggest that excessive ROS production by aberrant RANKL overexpression and/or anticancer treatment disadvantageously impacts bone, and that febuxostat can prevent the ROS-mediated osteoclastic bone damage.


Effects of functional training after orthognathic surgery on masticatory function in patients with mandibular prognathism.

Our findings suggested that functional training using the gum chewing and patient-education exercise improved masticatory function in patients with mandibular prognathism.

In the training group, the AI value during MVC increased significantly and the EI value during gam chewing decreased significantly after surgical orthodontic treatment (AI: p < 0.01; EI: p < 0.01), indicating the improvement of activity balance of masseter and temporalis muscles and conversion of the jaw movement from abnormal to normal pattern (p < 0.01).


Factors Secreted from Dental Pulp Stem Cells Show Multifaceted Benefits for Treating Experimental Temporomandibular Joint Osteoarthritis

Temporomandibular joint osteoarthritis (TMJOA) is a degenerative disease characterized by progressive cartilage degeneration, abnormal bone remodeling, and chronic pain. In this study, we aimed to investigate effective therapies to reverse or suppress TMJOA progression. To this end, we performed intravenous administration of serum free conditioned media from human exfoliated deciduous teeth stem cells (SHED-CM) into a mechanical-stress induced murine TMJOA model. SHED-CM administration markedly suppressed temporal muscle inflammation, and improved bone integrity and surface smoothness of the destroyed condylar cartilage. Moreover, SHED-CM treatment decreased the number of IL-1β, iNOS, and MMP-13 expressing chondrocytes, whereas it specifically increased PCNA-positive cells in the multipotent polymorphic cell layer. Notably, the numbers of TUNEL-positive apoptotic chondrocytes in the SHED-CM treated condyles were significantly lower than in those treated with DMEM, whereas the proteoglycan positive area was restored to a level similar to that of the sham treated group, demonstrating that SHED-CM treatment regenerated the mechanical-stress injured condylar cartilage and subchondral bone. Secretome analysis revealed that SHED-CM contained multiple therapeutic factors that act in osteochondral regeneration. Our data demonstrated that SHED-CM treatment promoted the regeneration and repair of mechanical-stress induced mouse TMJOA. Our observations suggest that SHED-CM has potential to be a potent tissue-regenerating therapeutic agent for patients with severe TMJOA.


Low-intensity pulsed ultrasound enhances the rate of lateral tooth movement and compensatory bone formation in rats.

The present study provides evidence of the beneficial effects of LIPUS on the lateral tooth movement.

American Journal of Orthodontics and Dentofacial Orthopedics (AJO-DO)


Interdisciplinary therapy for severe periodontitis with Angle Class II Division 1 malocclusion: A case report with 7-year follow-up

Previous studies have suggested that occlusal discrepancy is a risk factor contributing to periodontal disease. Occlusal discrepancy could increase the risk of developing infrabony defects. The authors present a case of a patient with severe periodontitis who exhibited many infrabony defects in the molar region due to malocclusion-induced trauma. They report the 7-year treatment outcomes of the patient after periodontal regenerative and comprehensive orthodontic therapies for functional recovery with implant prosthodontics. A 56-year-old woman sought treatment with the chief symptom of masticatory disturbance. In the molar region, excessive tooth mobility, deep periodontal pockets, and infrabony defects were observed. She had excessive overjet, resulting in collapse of anterior guidance. Malocclusion was considered to be an exacerbating factor of the infrabony defects. After initial periodontal therapy, the authors performed periodontal regenerative therapy in the mandibular molar regions. The authors carefully placed implants in a position in the maxillary molar region that would ensure an appropriate anterior dental relationship after orthodontic treatment. Comprehensive orthodontic treatment was subsequently performed, using implants as anchoring units. Definitive surgery was then performed on the mandibular molars before placing the final prosthesis. Favorable periodontal condition and stable occlusion have been maintained for the 7-year posttreatment period. Comprehensive and interdisciplinary treatment enables stable occlusion and establishment of periodontal and peri-implant tissues with high cleansability, even in patients with severe periodontitis and malocclusion. In this case, a favorable long-term treatment outcome can be expected.

The Journal of the American Dental Association


正中二分割Le Fort I型骨切り術併用による上下顎同時移動術を施行した骨格性下顎前突症の一例

The Journal of Chu-Shikoku Orthodontic Society

中·四国矯正歯科学会雑誌


Viscoelastic properties of the central region of porcine temporomandibular joint disc in shear stress-relaxation.

In this study, shear relaxation properties of the porcine temporomandibular joint (TMJ) disc are investigated. Previous studies have shown that, in fatigue failure and damage of cartilage and fibrocartilage, shear loads could be one of the biggest contributors to the failure. The aim of the present study is to develop an evaluation method to study shear properties of the disc and to do a mathematical characterization of it. For the experiments, twelve porcine discs were used. Each disc was dissected from the TMJ and, then, static strain control tests were carried out to obtain the shear relaxation modulus for the central region of the discs. From the results, it was found that the disc presents a viscoelastic behavior under shear loads. Relaxation modulus decreased with time. Shear relaxation was 10% of the instantaneous stress, which implies that the viscous properties of the disc cannot be neglected. The present results lead to a better understanding of the discs mechanical behavior under realistic TMJ working conditions.


Optimal discrete-time Prony series fitting method for viscoelastic materials.


A Clinico-statistical Investigation on Cleft Lip and/or Palate Patients during the Past 10 Years in the Department of Orthodontics and Dentofacial Orthopedics, Tokushima University Hospital

徳島大学病院矯正歯科における過去10年間の口唇裂・口蓋裂患者に関する実態調査．

A clinical-statistical investigation was carried out with cleft lip and/or palate patients in the Department of Orthodontics and Dentofacial Orthopedics, Tokushima University Hospital, during the 10 years from April 2006 to March 2016.
1 The number of cleft lip and/or palate patients was 96, accounting for 6.2% of orthodontic patients during the 10 years. The patients consisted of 55 males and 41 females with a male to female ratio of 1:0.75.
2 The distribution of cleft type was as follows: cleft lip and palate 36.5%, cleft lip and alveolus 33.3%, cleft palate 19.8%, and cleft lip 10.4%. The unilateral cleft lip was more frequently seen on the left side than on the right side, and in males than in females.
3 The peak age of the first visit was 0 years (58.3%). As Hellman's dental developmental stage, the percentage of stage A was 44.8%.
4 As for the resident distribution, 87.5% patients came from Tokushima prefecture.
5 90.6% of patients were referred from the Department of Plastic and Reconstructive Surgery in Tokushima University Hospital.
6 By classification of crossbite, cases of type 4 (anterior crossbite) were most frequent, at 52.9%.

徳島大学病院矯正歯科に来院した口唇裂・口蓋裂患者の実態を把握する目的で，2006年4月から2016年3月までの10年間に当科を受診した口唇裂・口蓋裂患者を対象として臨床統計を行い，以下の結果を得た．
1．過去10年間の口唇裂・口蓋裂患者は96名であり，矯正歯科総患者数の6.16%を占めていた．男女比は1:0.75であった．
2．裂型分類では唇顎口蓋裂(36.5%)，口唇顎裂(33.3%)，口蓋裂(19.8%)，口唇裂(10.4%)であった．披裂部の側性は唇顎口蓋裂，口唇顎裂においては左側に，口唇裂では右側に高い割合でみられた．裂型別性差に関しては口唇裂，口唇顎裂，唇顎口蓋裂においては男子に，口蓋裂においては女子に高い割合で認められた．
3．初診時年齢は0歳(58.3%)が最も多く，次いで1歳(11.5%)，2歳(7.3%)と続いた．初診時におけるHellmanの咬合発育段階で分類すると，乳歯咬合完成前のⅠA期(44.8%)が最も多く，次にⅠC期(32.3)，ⅡA期(7.3%)と続いた．
4．患者の居住地の地域分布は徳島県が87.5%で最も多く認められた．
5．紹介元の医療施設においては，当院形成外科からの紹介が90.6%を占めていた．
6．交叉咬合の分類において，前歯のみが交叉咬合を呈するType 4が52.9%と最も高かった．

Journal fo Japanese Cleft Palate Association


Crosstalk between Fas and S1P1 signaling via NF-kB in osteoclasts controls bone destruction in the TMJ due to rheumatoid arthritis


Excessive gingival display treated with 2-piece segmental Le Fort I osteotomy: A case report.

It is hoped that 2-piece segmental Le Fort I osteotomy becomes a common treatment option for patients with protrusive profiles and excessive gingival displays.


矯正患者における永久歯の先天性欠如に関する臨床統計調査

矯正患者における永久歯の先天性欠如に関する臨床統計調査

中·四国矯正歯科学会雑誌


徳島大学病院矯正歯科における口唇裂・口蓋裂患者の永久歯の歯数異常に関する調査

徳島大学病院矯正歯科における口唇裂・口蓋裂患者の永久歯の歯数異常に関する調査

中·四国矯正歯科学会雑誌


Time-course observation of patients with arthrosis of the temporomandibular joint on MRI

Patients with arthrosis of the temporomandibular joint are examined by MRI, but fewer cases are followed over time by performing MRI several times. The objective of this study was to investigate the presence or absence and types of changes in the structure of the mandibular condyle and articular disc on MR images over time in patients examined by MRI for the diagnosis of arthritis of the temporomandibular joint in order to clarify the usefulness of performing MRI several times.
 MR images for patients who underwent MRI several times based on the clinical diagnosis of arthrosis of the temporomandibular joint were analyzed.
 Twenty-three patients were examined by MRI twice or more. The shortest and longest intervals between the first and final examinations were 75 and 2,588 days, respectively, and the mean was 735 days. Changes in the bone structure of the mandibular condyle were noted on the first MRI in approximately 63 % and new changes were noted on the final examination in approximately 24 %. In addition, the articular disc position in the closed or open mouth had changed on the later examinationin approximately 15 %.
 Performing MRI several times along the clinical course was found to be useful to diagnose the disease stage, judge the treatment effects, and help predict the outcome in patients with arthrosis of the temporomandibular joint.


In vitro evaluation of frictional force of a novel elastic bendable orthodontic wire.

These findings demonstrate that the Ti-Nb alloy wire has almost the same frictional resistance as the Ti-Ni alloy wire, although it has a higher elastic modulus.


Potential role of rebamipide in osteoclast differentiation and mandibular condylar cartilage homeostasis

Temporomandibular joint osteoarthritis (TMJ-OA) is a degenerative disease that involves changes in subchondral bone and progressive degradation of cartilage. Currently, rebamipide, a gastroprotective drug, is administered to protect gastric mucosa and accelerate ulcer healing. Recent studies have shown that rebamipide also attenuates cartilage degeneration by suppressing oxidative damage and inducing homeostasis of the extracellular matrix of articular chondrocytes. Regarding the latter, reduced expression of cathepsin K, NFATc1, c-Src, and integrin 3, and increased expression of nuclear factor-kappa B, have been found to be mediated by the transcription factor, receptor activator of nuclear factor kappa-B ligand (RANKL). Treatment with rebamipide was also found to activate, mitogen-activated protein kinases such as p38, ERK, and JNK to reduce osteoclast differentiation. Taken together, these results strongly indicate that rebamipide mediates inhibitory effects on cartilage degradation and osteoclastogenesis in TMJ-OA. Here, we highlight recent evidence regarding the potential for rebamipide to affect osteoclast differentiation and TMJ-OA pathogenesis. We also discuss the potential for rebamipide to serve as a new strategy for the treatment of TMJ-OA.


Effect of pulsed ultrasound toothbrush on Streptococcus mutans biofilm removal.

The sonic vibration with pulsed ultrasound showed more reduction of the biofilm compared to the control and the sonic vibration with and without continuous ultrasound. Thus, pulsed ultrasound action may be beneficial for biofilm removal of interproximal regions.


Reactive oxygen species up-regulate expression of muscle atrophy-associated ubiquitin ligase Cbl-b in rat L6 skeletal muscle cells.

Unloading-mediated muscle atrophy is associated with increased reactive oxygen species (ROS) production. We previously demonstrated that elevated ubiquitin ligase casitas B-lineage lymphoma-b (Cbl-b) resulted in the loss of muscle volume [Nakao R. et al. Mol Cell Biol, 29: 4798-4811, 2009]. However, the pathological role of ROS production associated with unloading-mediated muscle atrophy still remains unknown. Here, we showed the ROS-mediated signal transduction caused by microgravity or its simulation contributes to Cbl-b expression. In L6 myotubes, the assessment of redox status revealed that oxidized glutathione was increased under microgravity conditions, and simulated microgravity caused a burst of ROS, implicating ROS as a critical upstream mediator linking to downstream atrophic signaling. ROS generation activated the ERK1/2-early growth response protein (Egr) 1/2-Cbl-b signaling pathway, an established contributing pathway to muscle volume loss. Interestingly, antioxidant treatment, such as N-acetylcysteine and TEMPOL, but not catalase, blocked the clinorotation-mediated activation of ERK1/2. The increased ROS induced transcriptional activity of Egr 1 and/or Egr 2 to stimulate Cbl-b expression through the ERK 1/2 pathway in L6 myoblasts, since treatment with Egr 1/2 siRNA and an ERK 1/2 inhibitor significantly suppressed clinorotation-induced Cbl-b and Egr expression, respectively. Promoter and gel mobility shift assays revealed that Cbl-b was upregulated via an Egr consensus oxidative responsive element at -110 to -60 bp of the Cbl-b promoter. Together this indicates that under microgravity conditions, elevated ROS may be a crucial mechanotransducer in skeletal muscle cells, regulating muscle mass, through Cbl-b expression activated by the ERK-Egr signaling pathway.

American Journal of Physiology, Cell Physiology


Effects of gum chewing exercise on maximum bite force according to facial morphology.

Development of the masticatory system is influenced by functional needs. Furthermore, masticatory exercise can improve masticatory function. The aim of this study was to evaluate the potential effect of the gum chewing exercise on the maximum bite force (MBF) in adult subjects with different facial morphologies. MBF was measured by a portable occlusal force gauge and lateral cephalogram was used for evaluation of craniofacial morphology in 19 individuals (7 males and 12 females) with a mean age of 25.4 years (SD ± 4.3). The volunteers underwent gum chewing exercise for 5 min twice a day for 4 weeks. MBF was measured before (T1) and after the 4-week exercise (T2). The facial morphology of the subjects was classified into the brachy (n = 7), mesio (n = 7), and dolicho (n = 5) facial types. In all three groups, exercise was associated with a significant increase in MBF, though the percent increase was highest in the dolicho facial type. We conclude that gum chewing exercise can improve masticatory performance, especially in individuals with dolicho facial morphology.

Clinical and Experimental Dental Research


Effectiveness of presurgical nasoalveolar molding therapy on unilateral cleft lip nasal deformity.

To evaluate the effectiveness of pre-surgical nasoalveolar molding (PNAM) in patients with unilateral cleft lip nasal deformities. Methods: This was a retrospective study involving 29 patients with unilateral cleft lip and palate defects, of whom 13 were treated with palatal devices with nasal stents (PNAM group) and 16 were treated with palatal devices without nasal stents or surgical tapes (control group). Submental oblique photographs and orthodontic models were longitudinally obtained at the initial visit (T1) and immediately before (T2) and after cheiloplasty (T3). Asymmetry of the external nose, degree of columellar shifting, nasal tip/ala nose ratio, nasal base angle, interalveolar gap, and the sagittal difference in the alveolar gap were measured. The study was conducted in the Orthodontic Clinic at Tokushima University Hospital, Tokushima, Japan between 1997 and 2012. Results: At T1, there were no significant intergroup differences in the first 4 asymmetry parameters. At T2, the PNAM group showed a significant improvement in all values compared to the control group. At T3, the PNAM group showed significant improvement in nasal asymmetry and columellar shifting. Model analysis showed significantly greater changes in the inter-alveolar gap and the sagittal difference of the alveolar cleft gap from T1 to T2 in the PNAM group. Conclusion: The use of PNAM is indispensable for pre-surgical orthodontic treatment at the early postnatal age.


Stress Distribution in Obliquely Inserted Orthodontic Miniscrews Evaluated by Three-Dimensional Finite-Element Analysis.

An obliquely inserted miniscrew and its surrounding tissues generally provide sufficient anchorage for 2 N of orthodontic loading, but care must be taken to avoid screw failure during placement and removal of obliquely placed miniscrews.

The International Journal of Oral & Maxillofacial Implants


Skeletal anchorage for intrusion of bimaxillary molars in a patient with skeletal open bite and temporomandibular disorders.

The treatment of severe skeletal anterior open bite is extremely difficult in adults, and orthognathic surgery is generally selected for its treatment. We report the case of an 18-year-old adult patient with skeletal anterior open bite and temporomandibular disorders who was successfully treated using temporary anchorage devices. She had an open bite of -2.0 mm and an increased facial height. Miniplates were implanted in both the maxilla and mandible, and molar intrusion resulted in counterclockwise rotation of the mandible over a period of 12 months. After active treatment, her upper and lower first molars were intruded by approximately 2 mm and her overbite became +2.5 mm. Her retrognathic profile improved with counterclockwise rotation of the mandible. Orthodontic treatment aided with skeletal anchorage is beneficial for intrusion of bimaxillary molars in patients with anterior open bite.


TAK1 inhibition subverts the osteoclastogenic action of TRAIL while potentiating its antimyeloma effects.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) agonists induce tumor-specific apoptosis indicating that they may be an attractive therapeutic strategy against cancers, including multiple myeloma (MM). Osteoclastogenesis is highly induced in MM, which in turn enhances MM growth, thereby forming a vicious cycle between MM tumor expansion and bone destruction. However, the effects of TRAIL on MM-enhanced osteoclastogenesis remain largely unknown. Here, we show that TRAIL induced apoptosis in MM cells, but not in osteoclasts (OCs), and that it rather facilitated receptor activator of NF-B ligand-induced osteoclastogenesis along with upregulation of cellular FLICE inhibitory protein (c-FLIP). TRAIL did not induce death-inducing signaling complex formation in OCs, but formed secondary complex (complex II) with the phosphorylation of transforming growth factor -activated kinase-1 (TAK1), and thus activated NF-B signaling. c-FLIP knockdown abolished complex II formation, thus permitting TRAIL induction of OC cell death. The TAK1 inhibitor LLZ1640-2 abrogated the TRAIL-induced c-FLIP upregulation and NF-B activation, and triggered TRAIL-induced caspase-8 activation and cell death in OCs. Interestingly, the TRAIL-induced caspase-8 activation caused enzymatic degradation of the transcription factor Sp1 to noticeably reduce c-FLIP expression, which further sensitized OCs to TRAIL-induced apoptosis. Furthermore, the TAK1 inhibition induced antiosteoclastogenic activity by TRAIL even in cocultures with MM cells while potentiating TRAIL's anti-MM effects. These results demonstrated that osteoclastic lineage cells use TRAIL for their differentiation and activation through tilting caspase-8-dependent apoptosis toward NF-B activation, and that TAK1 inhibition subverts TRAIL-mediated NF-B activation to resume TRAIL-induced apoptosis in OCs while further enhancing MM cell death in combination with TRAIL.


Fas/S1P1 crosstalk via NF-B activation in osteoclasts controls subchondral bone remodeling in murine TMJ arthritis

Enhanced turnover of subchondral trabecular bone is a hallmark of rheumatoid arthritis (RA) and it results from an imbalance between bone resorption and bone formation activities. To investigate the formation and activation of osteoclasts which mediate bone resorption, a Fas-deficient MRL/lpr mouse model which spontaneously develops autoimmune arthritis and exhibits decreased bone mass was studied. Various assays were performed on subchondral trabecular bone of the temporomandibular joint (TMJ) from MRL/lpr mice and MRL+/+ mice. Initially, greater osteoclast production was observed in vitro from bone marrow macrophages obtained from MRL/lpr mice due to enhanced phosphorylation of NF-B, as well as Akt and MAPK, to receptor activator of nuclear factor-B ligand (RANKL). Expression of sphingosine 1-phosphate receptor 1 (S1P1) was also significantly upregulated in the condylar cartilage. S1P1 was found to be required for S1P-induced migration of osteoclast precursor cells and downstream signaling via Rac1. When SN50, a synthetic NF-B-inhibitory peptide, was applied to the MRL/lpr mice, subchondral trabecular bone loss was reduced and both production of osteoclastogenesis markers and sphingosine kinase (Sphk) 1/S1P1 signaling were reduced. Thus, the present results suggest that Fas/S1P1 signaling via activation of NF-B in osteoclast precursor cells is a key factor in the pathogenesis of RA in the TMJ.

Biochemical and Biophysical Research Communications


歯科矯正用アンカースクリューを用いて上下歯列遠心移動を行った三年保定症例

歯科矯正用アンカースクリューを用いて上下歯列遠心移動を行った三年保定症例

The Journal of Chu-Shikoku Orthodontic Society

中·四国矯正歯科学会雑誌


Effects of co-transfection with myostatin-targeting siRNA and ActRIIB-Fc fusion proein on skeletal muscle growth.


Role of Smad3 and S1P Signaling in Mandibular Condylar Cartilage Homeostasis


Effect of freezing storage time on the elastic and viscous properties of the porcine TMJ disc.

The correct characterisation of the articular disc of the temporomandibular joint (TMJ) is key to study the masticatory biomechanics. For the interval from extraction until testing, freezing is the most used preservation technique for biological tissues, but its influence on their behaviour is still unclear. An important error can be committed in the characterisation of such tissues if freezing has any effect on their mechanical properties. Thus, the aim of this study was to determine whether the freezing storage time causes any change in the mechanical properties of the TMJ discs. To check that, the specimens were stored in a -20°C freezer during different time intervals: 1 day, 1 week, 1 month and 3 months. Fresh specimens, tested right after extraction, were used as the control group. Compressive stress relaxation tests were carried out on the specimens and a quasi-linear viscoelastic (QLV) model was used to fit the experimental curves. A statistical analysis detected significant differences among the groups. Post-hoc tests determined that freezing the specimens more than 30 days may lead to changes in the viscoelastic properties of the tissue.

Journal of the Mechanical Behavior of Biomedical Materials


Relationship between somatic mosaicism of Pax6 mutation and variable developmental eye abnormalities-an analysis of CRISPR genome-edited mouse embryos.

The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) system is a rapid gene-targeting technology that does not require embryonic stem cells. To demonstrate dosage effects of the Pax6 gene on eye formation, we generated Pax6-deficient mice with the CRISPR/Cas system. Eyes of founder embryos at embryonic day (E) 16.5 were examined and categorized according to macroscopic phenotype as class 1 (small eye with distinct pigmentation), class 2 (pigmentation without eye globes), or class 3 (no pigmentation and no eyes). Histologically, class 1 eyes were abnormally small in size with lens still attached to the cornea at E16.5. Class 2 eyes had no lens and distorted convoluted retinas. Class 3 eyes had only rudimentary optic vesicle-like tissues or histological anophthalmia. Genotyping of neck tissue cells from the founder embryos revealed somatic mosaicism and allelic complexity for Pax6. Relationships between eye phenotype and genotype were developed. The present results demonstrated that development of the lens from the surface ectoderm requires a higher gene dose of Pax6 than development of the retina from the optic vesicle. We further anticipate that mice with somatic mosaicism in a targeted gene generated by CRISPR/Cas-mediated genome editing will give some insights for understanding the complexity in human congenital diseases that occur in mosaic form.


Roles of hypoxia inducible factor-1α in the temporomandibular joint.

Temporomandibular joint osteoarthritis (TMJ-OA) is a degenerative disease characterized by permanent cartilage loss. Articular cartilage is maintained in a low-oxygen environment. The chondrocyte response to hypoxic conditions involves expression of hypoxia inducible factor 1α (HIF-1α), which induces chondrocytes to increase expression of vascular endothelial growth factor (VEGF). Here, we investigated the role of HIF-1α in mechanical load effects on condylar cartilage and subchondral bone in heterozygous HIF-1α-deficient mice (HIF-1α(+/-)). Mechanical stress was applied to the TMJ of C57BL/6NCr wild-type (WT) and HIF-1α(+/-) mice with a sliding plate for 10 days. Histological analysis was performed by HE staining, Safranin-O/Fast green staining, and immunostaining specific for articular cartilage homeostasis. HIF-1α(+/-) mice had thinner cartilage and smaller areas of proteoglycan than WT controls, without and with mechanical stress. Mechanical stress resulted in prominent degenerative changes with increased expression of HIF-1α, VEGF, and the apoptosis factor cleaved Caspase-3 in condylar cartilage. Our results indicate that HIF-1α may be important for articular cartilage homeostasis and protective against articular cartilage degradation in the TMJ under mechanical stress condition, therefore HIF-1α could be an important new therapeutic target in TMJ-OA.


Co-Administration of Myostatin-Targeting siRNA and ActRIIB-Fc Fusion Protein Increases Masseter Muscle Mass and Fiber Size.

Myostatin, a member of the TGF- superfamily, is a negative regulator of skeletal muscle cell growth and differentiation, and binds with high affinity to the activin type IIB receptor (ActRIIB). The soluble ligand-binding domain of ActRIIB fused to the Fc domain of IgG (ActRIIB-Fc) potently binds and inhibits TGF- family members in muscle, leading to rapid and marked muscle growth. The present study was designed to assess the effectiveness of the co-delivery of myostatin-targeting siRNA (Mstn-siRNA) and ActRIIB-Fc into skeletal muscle as a potential treatment of atrophic myopathies. Eleven-week-old, male C57BL/6 mice were injected with atelocollagen (ATCOL)-mediated Mstn-siRNA with/without ActRIIB-Fc locally into the masseter muscle twice a week. Inhibition of myostatin function by the combination of Mstn-siRNA and ActRIIB-Fc increased muscle weight and myofibril size in murine masseter muscle. Real-time RT-PCR analysis revealed significant downregulation of myostatin mRNA expression in both the Mstn-siRNA-treated and the combination treatment group. Furthermore, myogenin mRNA expression was upregulated in the combination treatment group, while MuRF-1 and Atrogin-1 mRNA expression was downregulated compared to administration of each compound alone. These findings suggest that double inhibition of myostatin is a potentially useful treatment strategy to increase muscle mass and fiber size and could be a useful treatment of patients with various muscle atrophies, including muscular dystrophy.

Journal of Nutritional Science and Vitaminology


The nuclear receptor AhR controls bone homeostasis by regulating osteoclast differentiation via the RANK/c-Fos signaling axis.

The aryl hydrocarbon receptor (AhR) pathway plays a key role in receptor activator of NF-κB ligand (RANKL)-mediated osteoclastogenesis. However, the mechanism underlying the regulation of AhR expression in osteoclasts and the signaling pathway through which AhR controls osteoclastogenesis remain unclear. We found that the expression of AhR in bone marrow-derived osteoclasts was upregulated by RANKL at an earlier stage than was the expression of signature osteoclast genes such as those encoding cathepsin K and NFAT, cytoplasmic, calcineurin-dependent 1. In response to RANKL, bone marrow macrophages isolated from AhR(-/-) mice exhibited impaired phosphorylation of Akt and MAPK as well as NF-κB, whereas their response to M-CSF remained unchanged. Osteoclast differentiation mediated by the AhR signaling pathway was also regulated in an RANKL/c-Fos-dependent manner. Furthermore, ligand activation of AhR by the smoke toxin benzo[a]pyrene accelerated osteoclast differentiation in a receptor-dependent manner, and AhR-dependent regulation of mitochondrial biogenesis in osteoclasts was observed. Moreover, AhR(-/-) mice exhibited impaired bone healing with delayed endochondral ossification. Taken together, the present results suggest that the RANKL/AhR/c-Fos signaling axis plays a critical role in osteoclastogenesis, thereby identifying the potential of AhR in treating pathological, inflammatory, or metabolic disorders of the bone.


Novel human mutation and CRISPR/Cas genome-edited mice reveal the importance of C-terminal domain of MSX1 in tooth and palate development.

Several mutations, located mainly in the MSX1 homeodomain, have been identified in non-syndromic tooth agenesis predominantly affecting premolars and third molars. We identified a novel frameshift mutation of the highly conserved C-terminal domain of MSX1, known as Msx homology domain 6 (MH6), in a Japanese family with non-syndromic tooth agenesis. To investigate the importance of MH6 in tooth development, Msx1 was targeted in mice with CRISPR/Cas system. Although heterozygous MH6 disruption did not alter craniofacial development, homozygous mice exhibited agenesis of lower incisors with or without cleft palate at E16.5. In addition, agenesis of the upper third molars and the lower second and third molars were observed in 4-week-old mutant mice. Although the upper second molars were present, they were abnormally small. These results suggest that the C-terminal domain of MSX1 is important for tooth and palate development, and demonstrate that that CRISPR/Cas system can be used as a tool to assess causality of human disorders in vivo and to study the importance of conserved domains in genes.