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Whether there is a relationship between impaction of the third molars and the onset of crowding remains to be determined, and extraction of third molars after orthodontic treatment is left to the judgement of the practitioner. This report describes a case where a third molar caused external root resorption (ERR) of the mandibular second molar after orthodontic treatment. As ERR of the mandibular second molar was detected after non-extraction orthodontic treatment, the affected tooth was extracted and substituted with the third molar. External root resorption of the second molar occurred despite being determined as low risk given the state of the impacted third molar as observed on a panoramic radiograph obtained at the end of active treatment. The present results indicate that in cases where the mandibular third molar is present, the corpus length is short, and non-extraction treatment has been performed, it is necessary to obtain X-ray images on a regular basis or preventively extract the third molar to avoid ERR of the second molars.

Summary Objective To observe and analyze the interaction between excessive mechanical stress (MS) and decreased sex hormones on Temporomandibular Joint Osteoarthritis (TMJ-OA), and to discover TMJ-OA disease susceptibility genes by molecular biological analysis to elucidate part of the mechanism of TMJ-OA onset. Design For experimental groups, orchiectomy (ORX) or ovariectomy (OVX) was performed on sexually mature 8-week-old mice. A metal plate was attached to the posterior surface of the maxillary incisors to apply excessive MS on mandibular condyles. Male mice were divided into control, ORX, MS, and ORX + MS groups, while female mice were divided into control, OVX, MS, and OVX + MS groups. Mandibular condyles were evaluated by histology and molecular biology. Results Histomorphometric analysis of the TMJ in ORX + MS and OVX + MS groups revealed the thinnest chondrocyte layers, highest modified Mankin scores, and significant increases in the number of osteoclasts. Gene expression analysis indicated upregulation of Angptl7 and Car1 genes in the mandibular condyles of mice subjected to the combined effects of excessive MS and reduced sex hormones. In vitro analysis suggested that cartilage-like cells overexpressing Angptl7 enhanced calcification, and osteoblast-like cells overexpression Car1 suppressed cell proliferation and calcification. Conclusions A severe TMJ-OA mouse model was successfully developed by applying excessive MS on the mandibular condyle of male and female mice with reduced sex hormones. Disease-susceptibility genes Angptl7 and Car1 were newly discovered in the experimental groups, suggesting their involvement in the onset mechanism of TMJ-OA.

The purpose of this study was to biomechanically evaluate maxillary protraction using an orthodontic anchor screw. We conducted three-dimensional finite element analysis to determine the initial di...

Aggressive periodontitis during adolescence has a poor prognosis due to rapid alveolar bone resorption. Few studies have investigated long-term follow-up after surgical orthodontic treatment performed in conjunction with that for invasive periodontitis. Here, we report a case of mandibular prognathism accompanied by generalized aggressive periodontitis and crowding. A 31-year-old woman was referred to our department for treatment of masticatory dysfunction due to reverse overjet. The patient exhibited a class III molar relationship, protrusion of the ANB of －6.0°, and severe maxillary crowding. Initial periodontal examination revealed deep periodontal pockets and extensive inflammation. Mandibular prognathism accompanied by generalized aggressive periodontitis and crowding was diagnosed. Therefore, it was necessary to adopt an interdisciplinary approach involving surgical, orthodontic, and periodontal treatment. Prior to commencement of orthodontic treatment, plaque control, scaling, and root planing of all teeth were performed by a periodontist to suppress inflammation and reduce probing depth. During pre-surgical orthodontic treatment, the maxillary first premolars were extracted to reduce crowding of the maxillary incisors. To correct the mandibular prognathism, the mandible was repositioned by sagittal split ramus osteotomy. Proper occlusion of the incisors and maximum intercuspation were achieved by post-surgical orthodontic treatment. After completion of active orthodontic treatment, acceleration of inflammation was observed together with aggravated resorption of the alveolar bone surrounding the molars. However, reduction of probing depth and inflammation were observed after scaling and root planing. The surgical-orthodontic treatment time was 1 year and 11 months, which was followed by a 2-year retention period. There was no tooth loss due to periodontitis, and an overall satisfactory outcome was achieved.

Aggressive periodontitis mostly affects young people, causing rapid destruction of periodontal tissue and loss of supporting alveolar bone. The destruction of periodontal tissue induces pathological tooth movement, resulting in various types of malocclusion such as crowding or spacing in the dentition. This report describes orthodontic treatment for malocclusion due to generalized aggressive periodontitis. The patient was a 31-year-old woman who presented with the chief complaint of displacement in the anterior teeth. An oral examination revealed pathological tooth mobility throughout the entire oral cavity due to severe loss of periodontal support. Many gaps in the displaced maxillary anterior teeth and crowding in the mandibular anterior teeth were also observed. The goal of subsequent treatment was to achieve ideal overjet and overbite by aligning the teeth and closing the spaces via non-extraction orthodontic treatment with stripping. The periodontal disease was managed by a periodontist who provided guidance on oral hygiene and periodontal disease control throughout the course of orthodontic treatment. Appropriate occlusion and a good oral environment were achieved. The condition of the periodontal tissue stabilized during and after orthodontic treatment, and favourable occlusal stability was observed at the 2-year follow-up examination.

Repositioning of the jaw in orthognathic treatment generates changes in the soft tissues of the maxillofacial region, with consequent changes in the airway. The purpose of this study was to determine how type of orthognathic surgical procedure affected the 3-dimensional morphology of the upper airway. Forty patients were divided into the following 2 groups according to the type of surgical procedure used: a horseshoe osteotomy (HS) group (20 patients, comprising 11 men and 9 women; average age 24.3±4.5 years) who underwent bimaxillary surgery; and a LeFort I osteotomy (LF) group (20 patients, comprising 8 men and 12 women; average age 22.5±4.6 years) who also underwent bimaxillary surgery. Cephalometric measurements were taken and 3-dimensional pharyngeal morphology evaluated in each group. The amounts of maxilla rotation, posterior maxilla impaction, and mandibular setback all revealed a significantly larger value in the HS group. Evaluation of pharyngeal volume revealed a significant decrease in the upper pharyngeal segment in the LF group. A significant decrease in the lower pharyngeal segment was observed in both groups. Differences were noted in postoperative pharyngeal morphology between the two groups. The results of this study suggest that HS has less effect on the upper pharyngeal segment, regardless of the amount of posterior maxilla impaction.

Temporary anchorage devices (TADs) allow molar intrusion as an additional treatment option to conventional treatment for open bite cases. We investigated the treatment option criteria for open bite treatment. A total of 33 patients with skeletal Class I to Class II open bite who had stable occlusion one year after treatment were enrolled in the study, including 15 patients who had undergone surgical orthodontic treatment, 8 patients who had undergone treatment with molar intrusion, and 10 patients who had undergone treatment with anterior teeth extrusion. Pre-treatment cephalometric analysis of these patients was used for comparison. Furthermore, receiver operating characteristic (ROC) curve analysis was employed to examine the measurement parameters that would be valid as treatment criteria. In the results, FMA showed that patients treated with molar intrusion had a moderately high angle, while those treated with surgical orthodontic treatment had a severe high angle. The area under the curve (AUC) of the ROC curve indicated that FMA is the most appropriate parameter for treatment option criteria. In addition, the cutoff value indicated that the borderline between molar intrusion and surgical orthodontic treatment was 37.5° for FMA. In this study, we suggested criteria for the treatment of open bite with molar intrusion.

Background Rheumatoid arthritis of the temporomandibular joint (TMJ-RA) has been reported to have a larger incidence range than systemic rheumatoid arthritis (RA). The presence or absence of mechanical stress (MS) is considered a factor in this. In this study, we hypothesized that TMJ-RA develops or worsens when excessive MS is applied to the temporomandibular joint of RA mouse models. We aimed to clarify the relationship between TMJ-RA and MS through morphological and histological evaluation. Methods Collagen antibody-induced arthritis (CAIA) was induced in male DBA/1JNCrlj 9–12 weeks old mice by administering Type II collagen antibody and lipopolysaccharide to produce RA model mice. MS was applied to the mandibular condyle. The group was separated into non-RA (control group (N = 5) and MS group (N = 5)), and RA group (CAIA group (N = 5)and CAIA MS group (N = 5)). To confirm the morphological changes in the mandibular condyle, micro-CT imaging was performed. Histological evaluation of the TMJ was performed by hematoxylin and eosin staining for condylar cartilage cell layer thickness, Safranin O staining for proteoglycans, and tartrate-resistant acidic phosphatase staining for osteoclast count. Immunohistochemical evaluation was performed to assess the localization of cartilage destruction enzymes using ADAMTS-5 (a disintegrin and metalloproteinase with thrombospondin motifs) antibody. Additionally, CD3 (cluster of differentiation), CD45, and γδ TCR (T cell receptor) antibodies were used to localize and identify the type of lymphocytes. Results In the CAIA MS model, a three-dimensional analysis of the temporomandibular joint by microcomputer tomography showed a crude change in the surface of the mandibular condyle. Histological examination revealed a decrease in the chondrocyte layer width and an increase in the number of osteoclasts in the mandibular condyle. T cell accumulation was observed, and γδ T cell involvement was confirmed. Conclusions In the CAIA model, the TMJ was less sensitive to the initiation of RA. However, the results suggested that it was exacerbated by MS, and that γδ T cells may be involved in TMJ-RA.

Quercetin is a flavonoid with a wide range of pharmacological activities, including anticancer, antioxidant, and anti-inflammatory effects. Since it is a nutrient that can be consumed with a regular diet, quercetin has recently garnered interest. Quercetin acts as a phytochemical ligand for the aryl hydrocarbon receptor (AhR). Cleft lip and palate are among the most frequently diagnosed congenital diseases, and exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during pregnancy induces cleft palate via AhR. In this study, we investigated the preventive effect of quercetin intake on the TCDD-induced cleft palate and its mechanism of action. The in vivo results suggest that quercetin intake by pregnant mice can prevent cleft palate in fetal mice. In vitro, the addition of TCDD induced a reduction in cell migration and the proliferation of mouse embryonic palatal mesenchymal cells, which was mitigated by the addition of quercetin. The addition of quercetin did not alter the mRNA expression levels of the AhR repressor but significantly suppressed mRNA expression of CYP1A1. In addition, the binding of AhR to a xenobiotic responsive element was inhibited by quercetin, based on a chemically activated luciferase expression assay. In conclusion, our results suggest that quercetin reduces the development of TCDD-induced cleft palate by inhibiting CYP1A1 through AhR.

The aim of this study was to investigate 3-dimensional (3D) airway volume in patients with unilateral cleft lip and palate (UCLP) using computed tomography (CT). The study population comprised 15 UCLP patients (UCLP group) scheduled to receive alveolar bone grafts and 15 with impacted teeth (control group). The clinical requirements for a CT scan were met in both groups. Measurements were recorded from 3D reconstructions of Digital Imaging and Communications in Medicine data obtained from the CT images. Airway volume, cross-sectional area, and linear and angular measurements were recorded. Airway volume and cross-sectional area showed no significant difference between the two groups. The narrowest section of the airway in the UCLP group was tighter than that in the control group, however (p=0.017). The results of this study suggest that this difference in the measurements of the narrowest section of the airway is involved in the particular maxillofacial morphology found in UCLP patients.

This case report describes the unusual choice of extraction of maxillary incisors with short roots as part of an orthodontic treatment plan. The patient was a 20-year-old woman referred to our department in whom the diagnosis was maxillary protrusion and open bite. Both of the maxillary central incisors had short roots. Two treatment options were considered. The first involved extraction of the 4 first premolars with the aim of improving dentoalveolar protrusion and crowding. If preservation of the central incisors subsequently became difficult due to root resorption, prosthetic options were to be considered. The second treatment option involved extraction of the maxillary central incisors with short roots and the mandibular first premolars. The second treatment option was selected as survival of the central incisors following orthodontic movement was uncertain and the patient also wanted to minimize the risk of future extractions and the use of prosthetics. Active treatment was performed over a span of 31 months, and circumferential type retainers were used on both arches for retention. For such treatment to be successful, careful diagnosis and orthodontic treatment planning must be taken to ensure the anterior dental esthetics are properly restored.

This report describes a patient with severe high angle class II malocclusion and mandibular retrusion in whom surgical orthodontic treatment to prevent an increase in ramus height resulted in a significant improvement in esthetics and long-term stability. The patient was a woman aged 30 years 5 months who presented with the chief complaint of maxillary protrusion. She had a convex facial type, a chin button on lip sealing, and a gummy smile. Cephalometric analysis revealed a normal maxilla anterior-posterior position, but significant mandibular retrusion with pronounced clockwise rotation. The anterior maxillary tooth axis was standard, but labially inclined in the mandible. Based on these findings, the diagnosis was skeletal class II high angle malocclusion and mandibular retrusion. The proposed treatment plan comprised 2-jaw surgery with premolar extraction. Le Fort I osteotomy, in particular, was planned in the maxilla to move the ANS upward by 3.0 mm and the PNS downward by 3.0 mm. Sagittal split ramus osteotomy (SSRO) was planned to adjust the mandible and move the mandible forward by 10.0 mm. To prevent postoperative relapse, the short lingual split method was used in performing the SSRO. The mandible was split to minimize stretching of the median pterygoid muscle. Postoperatively, the ANS, PNS, and pogonion showed movement of 2.0 mm upward, 3.0 mm downward, and 8.0 mm forward, respectively. Additionally, lip closure was now natural, and the gummy smile had markedly improved. At 6 years postoperatively, there has been no change skeletally or dentally. Follow-up is being continued to monitor further progress.

Non-coding RNAs (ncRNAs) comprise a major portion of transcripts and serve an essential role in biological processes. Although the importance of major transcriptomes in osteogenesis has been extensively studied, the function of ncRNAs in human osteogenesis remains unclear. Previously, we developed hiPSCs from patients with cleidocranial dysplasia (CCD) caused by runt-related transcription factor 2 (RUNX2) haploinsufficiency. To gain insight into ncRNAs in osteogenesis, we surveyed differential ncRNA expression profiling and promoter differences of RUNX2 using patient-specific iPSCs and cap analysis gene expression (CAGE) technology to define the promoter landscape. Revertant iPSCs (Rev1 iPSCs) edited by CRISPR/Cas9 system to harbor mutation-corrected RUNX2 exhibited increased proximal promoter expression of RUNX2, while CCD iPSCs did not. We identified 2271 ncRNA genes with altered expression levels before and after differentiation, 31 of which showed at least 20-fold higher expression in Rev1 iPSCs. Bioinformatic analysis also categorized AC007392.3, LINC00379, RP11-122D10.1, and RP11-90J7.2 as enhancer regulatory regions, and HOXA-AS2, MIR219-2, and RP11-834C11.3 as dyadic regulatory regions of these ncRNAs. In addition, two miRNAs, termed MIR199A2 and MIR152, were found to have high enrichment of osteogenic-related terms. Upon further examination of the role of MIR152 on osteoblast differentiation, we found that MIR152 knockdown induced upregulation of ALP and COL1A1 in Saos-2 cells. Thus, ncRNAs were found to regulate the osteogenic differentiation potentials of hiPSCs that are used for bone regeneration and repair owing to their differentiation potentials. These data allow understanding ncRNA profiles of hiPSCs during osteogenesis.

Here, we report retention following surgical orthodontic treatment in a patient with vertical maxillary excess associated with temporomandibular joint osteoarthritis (TMJOA) and marked mandibular retrusion. The patient was a man aged 20 years 10 months who presented with the chief complaint of maxillary protrusion. The facial profile was of the convex type due to marked mandibular retrusion. In addition, the patient had a gummy smile. Intraoral findings revealed a Class II molar relation, +11 mm overjet, and 0 mm overbite. Mandibular dentition arch length discrepancy showed crowding of -2 mm, and the maxillary dentition showed a spaced arch of +5 mm. Panoramic radiographs confirmed flattening of the condylar head and proliferation of the bone margin. Cephalometric analysis of the skeletal pattern revealed that, horizontally, the maxilla was anterior and the mandible posterior; vertically, a dolichofacial pattern was noted. The anterior maxillary tooth axis was standard, but the anterior mandibular tooth axis showed labial inclination. Based on these findings, skeletal maxillary protrusion associated with TMJOA was diagnosed. Surgical orthodontic treatment comprised bilateral mandibular first premolar extraction with two-jaw surgery and genioplasty. Orthodontic treatment was performed with a multibracket system using a 0.22-slot pre-adjusted edgewise appliance. At 2 years and 11 months after initiation of treatment, the maxilla was transposed 6 mm upwards by orthognathic surgery and the mandible 17 mm anteriorly and 5 mm upwards by counterclockwise rotation. At 3 years and 10 months, the Pogonion was moved 6 mm anteriorly by genioplasty. At 4 years, orthodontic treatment was concluded on confirming satisfactory occlusion and improvement in facial features. At 2 years after completion of treatment, occlusion and the maxillofacial morphology remain stable, with almost no relapse. In addition, no temporomandibular joint disorder symptoms have occurred. Careful comprehensive follow-up observation will be continued.

Surgical orthodontic treatment has been reported to improve oral health-related quality of life (OHRQL). Such treatment comprises three stages: pre-surgical orthodontic treatment; orthognathic surgery; and post-surgical orthodontic treatment. Most studies have focused on change in OHRQL between before and after surgery. However, it is also necessary to evaluate OHRQL at the pre-surgical orthodontic treatment stage, as it may be negatively affected by dental decompensation compared with at pre-treatment. The purpose of this prospective study was to investigate the influence of surgical orthodontic treatment on QOL by assessing change in condition-specific QOL at each stage of treatment in skeletal class III cases. Twenty skeletal class III patients requiring surgical orthodontic treatment were enrolled in the study. Each patient completed the Orthognathic Quality of Life Questionnaire (OQLQ), which was developed for patients with dentofacial deformity. Its items are grouped into 4 domains: "social aspects of dentofacial deformity"; "facial esthetics"; "oral function"; and "awareness of dentofacial esthetics". The questionnaire was completed at the pre-treatment, pre-surgical orthodontic treatment, and post-surgical orthodontic treatment stages. The results revealed a significant worsening in scores between at pre-treatment and pre-surgical orthodontic treatment in the domains of facial esthetics and oral function (p

Purpose The present study evaluated the relationship between the bone void induced in the surrounding cortical bone upon screw insertion, and insertion torque. 3D bone morphometry was analyzed using micro-computed tomography (micro-CT) with different screw diameters and cortical bone thicknesses. Materials and methods Titanium alloy miniscrews with different diameters were used. Specimens were collected from porcine pelvic bones and divided by cortical bone thickness into 48 regions per cm2. Screws were inserted into 32 regions by self-drilling, and maximum insertion torque was recorded. The remaining 16 regions were part of the control group. Specimens were partitioned into regions and micro-CT was used to measure the void volume in bone, including the microdamage surrounding the screw. The proportion of void volume in cortical bone (Vv/Cv) for each region was calculated and compared between the groups. Results Compared with the control group, characteristic microdamage distribution was observed in the group with screws inserted, and a particularly high Vv/Cv was noted on the bone marrow side. In the screw insertion groups, both insertion torque and Vv/Cv were significantly higher in areas with thicker cortical bone. There were no significant differences in the Vv/Cv for different screw diameters, but the influence of the insertion torque was apparent. Conclusion These results suggest that to reduce the bone void to the cortical bone surrounding the screw, it is important to use appropriate insertion torque in accordance with cortical bone thickness.

We performed orthodontic treatment, fitted prostheses, and provided restorative treatment in a patient with Bloch-Sulzberger syndrome and cleft lip and palate during the early mixed dentition period. We report the case after a subsequent 6-year retention phase including the period of pubertal growth. A girl aged 8 years 4 months visited our hospital with the chief complaint of crowding of the anterior teeth and anterior crossbite. She had bilateral cleft lip, alveolus, and palate; a Class II molar relationship; winging of both the maxillary bilateral central incisors; and spacing in the mandibular anterior teeth arches. Anterior crossbite comprised 0 mm overbite and -1 mm overjet. The crown diameter was at least one standard deviation smaller than normal in both the deciduous and permanent teeth, and the crowns were slightly peg-shaped. Panoramic radiograph confirmed congenital absence of 21 permanent teeth. Cephalometric analysis revealed poor growth of the maxilla, downward growth of the mandible, and lingual inclination of the maxillary central incisors. The diagnosis was skeletal anterior crossbite with cleft lip, alveolus, and palate, accompanied by hypodontia. Orthodontic treatment comprised an edgewise appliance and an expansion arch to improve crowding and anterior crossbite. The appliance was removed 2 years after treatment initiation, followed by crown restorations of the maxillary central incisors and mandibular deciduous anterior teeth. A metal retainer was then fitted to the maxillary dentition. She was subsequently placed in a 6-year retention phase including pubertal growth, during which occlusal stability and esthetics were maintained.

Here, we report a case of dental implant treatment involving computer-assisted surgery for bilateral agenesis of the maxillary lateral incisors. The patient was a 39-year-old woman with the chief complaint of functional and esthetic disturbance due to maxillary and mandibular malocclusion. The treatment plan comprised non-extraction comprehensive orthodontic treatment and prosthodontic treatment for space due to the absence of bilateral maxillary lateral incisors. A preliminary examination revealed that the mesiodistal spaces left by the absent bilateral maxillary lateral incisors were too narrow for implant placement (right, 5.49 mm; left, 5.51 mm). Additional orthodontic treatment increased these spaces to approximately 6 mm, the minimum required for implant placement if risk of damage to the adjacent teeth due to inaccuracies in directionality of drilling is to be avoided. For dental implant treatment with computer-assisted surgery, preoperative planning/simulation was performed using Simplant® ver.12 software and a toothsupported surgical template fabricated using stereolithography. Two narrow-diameter implants were placed in a two-stage procedure. It was confirmed that there was sufficient distance between the implant fixtures and the roots of the adjacent teeth, together with no exposure of alveolar bone. Following a 4-month non-loading period, second-stage surgery and provisional restoration with a temporary screw-retained implant crown were performed. Cement-retained superstructures made of customized zirconia abutment and a zirconia-bonded ceramic crown were fitted as the final restoration. At 5 years after implant surgery, there were no complications, including inflammation of the peri-implant soft tissue and resorption of peri-implant bone. Computer-assisted implant surgery is useful in avoiding complications in bilateral agenesis of the maxillary lateral incisors when only a narrow mesiodistal space is available for implant placement.

Purpose The purpose of this study is to determine variations in hard palate thickness among sexes and four ethnic groups to identify optimum area for temporary anchorage devices (TADs) placement. Materials and methods Cone-beam computed tomography (CBCT) volume data on 160 patients were selected. Patients belonged to one of four ethnic groups (Asian, African-American, Caucasian or Hispanic; 20 men and 20 women in each group, 16–45 years old). Hard palate thickness from the incisor fossa to the palatal root of the maxillary first molar was determined on each image and compared between sexes and ethnic groups. Results The data revealed that thickness was greatest at the paramedian area in the incisive canal zone (C-zone) and the median area posterior to the incisive foramen. A significant difference in thickness of palate was confirmed between sexes, and was approximately 0.5 mm and 1 mm greater in men at the median and paramedian, respectively. Among ethnic groups, a trend of decreasing thickness was as follows: Caucasian > Hispanic > African-American > Asian. Conclusion The anterior (incisive canal zone) paramedian and posterior median areas of the hard palate were thicker and suggest that these areas are appropriate for TADs placement. Some differences were also observed local to the paramedian in the C-zone among ethnicities. This indicates that sex and ethnicity should be taken into consideration in selecting sites for placement of TADs.

This study aimed to investigate the reason for high failure rates of mini-screws during orthodontic treatment. We hypothesized that decreasing the length of the mini-screw outside the bone relative to the length inside the bone (outside/inside length ratio) and equalising it to the tooth crown/root ratio would lead to increased stability of the mini-screw against lateral loading when assessed using finite element analysis.We analysed stress distribution of mini-screws in the cortical and trabecular bone and von Mises stress levels when a 2-N force was applied to the head of four mini-screws of 6, 8, 10 and 12 mm in length. The direction of the force was perpendicular to the major axis of the screws.Stress levels of screws in cortical bone increased in proportion to the length of mini-screws outside the bone. The length of mini-screws inside the bone did not affect stress levels in the cortical bone.The results of this finite element analysis indicate that to stabilize the mini-screw, controlling the screw length outside the bone is more important than controlling the outside/inside length ratio.

Purpose The purpose of this study were to: (1) establish a facial soft tissue morphometric technique employing a 3-dimensional optical device; (2) evaluate its precision; and (3) determine the presence of diurnal variation in facial soft tissue morphology. Materials and methods Ten volunteers were enrolled using a 3-dimensional optical measuring device, SURFLACER VMH-300F. Measurements were conducted in the morning, during the daytime, and in the evening. Two analyses, reproducibility of measurement through comparison between the two measurements in each group (morning vs. morning, daytime vs. daytime, and evening vs. evening), and diurnal variation through inter-group comparison (morning vs. daytime, morning vs. evening, and daytime vs. evening) were carried out. Results The mean difference between two measurements in each group was 0.24 ± 0.06 mm in the morning group, 0.25 ± 0.08 mm in the daytime group, and 0.24 ± 0.06 mm in the evening group. As to diurnal variation, the difference was 0.38 ± 0.07 mm between the morning and daytime groups, 0.39 ± 0.03 mm between the morning and evening groups, and 0.40 ± 0.04 mm between the daytime and evening groups. Conclusions When facial morphology was measured at 3 different time points within a single day, the mean error was 0.24 ± 0.06 mm. Measurement at these 3 time points revealed no significant diurnal variation in facial soft tissue morphology. This technique and its results are anticipated to contribute to quantitative evaluation of facial soft tissue morphology.

While osteomas often occur in the orofacial area, it is relatively rare for one to occur in the temporomandibular joint area. Here, we report a patient who underwent multidisciplinary treatment including high condylectomy for peripheral osteoma arising in the left mandibular condyle. The patient was a 46-year-old woman with the chief complaint of facial asymmetry. Cephalometric analysis revealed skeletal anterior crossbite due to anterior deviation of the mandible, with chin deviation of 10 mm to the right. A computed tomography scan revealed bone hyperplasia in the mesiodistal and inner areas of the left mandibular condyle, which exhibited outward anterior displacement. Bone scintigraphy showed a circular area of strong radioisotope accumulation with indistinct boundaries, consistent with the lesion in the left mandibular condyle. The above findings led to a diagnosis of skeletal mandibular prognathism with facial asymmetry due to peripheral osteoma originating in the left mandibular condyle. After orthodontic treatment and surgical resection of the tumor and mandibular condyle, preservation and prosthetic treatment were undertaken. A well-balanced facial appearance and good occlusion were achieved.

Background The present study aimed to clarify the characteristics of dentoskeletal morphology and treatment changes after 2-maxillary premolar extractions to treat Class II malocclusion, by comparing pre- and post-treatment lateral cephalograms and dental casts from cases with 4-premolar extractions. Methods Subjects comprised patients who had undergone orthodontic treatment for Class II molar relationship using either maxillary first premolar extraction (U2 group, n = 27) or maxillary and mandibular first premolar extraction (UL4 group, n = 27). Pretreatment (T1) and post-treatment (T2) lateral cephalograms and dental casts were examined. Groups were compared for differences at T1 and T2, and in T2–T1 change using unpaired t tests. Among the analysis items showing significant differences at T1, those that could discriminate between groups U2 and UL4 at T1 were extracted by stepwise logistic regression analysis. Results Dentoskeletal morphology in the U2 group exhibited a severe Class II molar relationship, little need for maxillary incisor retraction, and a morphology in which bite opening was severe. Treatment changes in the U2 group showed that extraction spaces were used for mesial movement of maxillary molars in many cases, that bite-opening resulted from mandibular clockwise rotation, and that contraction of the upper arch and expansion of the lower arch occurred in anteroposterior and lateral directions. Severity of Class II molar relationship, anteroposterior position of mandibular incisors, and lower arch depth were selected as criteria for distinguishing pretreatment between groups U2 and UL4. Conclusion Cases with 2-maxillary premolar extraction showed a characteristic dentoskeletal morphology compared to cases with 4-premolar extraction.