Circadian transcription factor Dbp promotes rat calvarial osteoprogenitors osteogenic differentiation through Kiss1/GnRH/E2 signaling pathway loop.

To determine the mechanism by which D-site-binding protein (Dbp) regulates rat calvarial osteoprogenitors (OPCs) osteogenic differentiation. α-Smooth muscle actin (α-SMA) + rat calvarial OPCs were extracted and purified using immunomagnetic beads. Cells were transduced with Dbp-lentivirus and divided into Dbp knockdown, Dbp overexpression and vehicle groups. After osteogenic induction for 21 days, Alizarin red staining and alkaline phosphatase (ALP) activity were examined. Expression levels of Runx2, Ocn, Osterix, Bmp4, Kiss1, and GnRH were determined using a quantitative real-time polymerase chain reaction. The observed changes in Kisspeptin, GnRH, ERα, and Runx2 were further validated via Western blot analysis. Furthermore, E2 and GnRH secretion levels were detected via an enzyme-linked immunosorbent assay (ELISA). Chromatin immunoprecipitation (ChIP) and luciferase assay were used to assess the effects of Dbp on the Kiss1 gene promoter. The coexpression of Dbp and Kisspeptin or GnRH was also evaluated via immunofluorescence. Following osteogenic induction, Dbp overexpression significantly increased calcium nodule formation and ALP activity, as well as Runx2, Ocn, Osterix, Bmp4, Kiss1, and GnRH messenger RNA expression, while Dbp knockdown presented the opposite results. Western blot analysis and ELISA results showed that Dbp significantly promotes Runx2, E2/ERα, Kisspeptin, and GnRH expression. These findings were confirmed by the ChIP assay, which indicated that the estrogen receptor promotes Kisspeptin expression after binding to the Kiss1 gene promoter, which is regulated by Dbp. Immunofluorescence assay showed that Dbp coexpression with Kisspeptin or GnRH varied depending on Dbp expression levels. Collectively, the circadian transcription factor Dbp promotes α-SMA + rat calvarial OPCs osteoblastic differentiation through Kiss1/GnRH/E2 signaling pathway loop.

Mutant hFGF23(A12D) stimulates osteoblast differentiation through FGFR3.

Fibroblast growth factor (FGF) 23 is a member of the FGF family involved in bone development by interacting with FGFRs. In a previous study, we discovered a mutant human FGF (hFGF) 23 (A12D) in the mandibular prognathism (MP) pedigree. However, the exact role of hFGF23(A12D) during bone formation remains unclear. The aim of this study was to identify the function of hFGF23(A12D) in bone formation. We infected isolated rat calvaria (RC) cells with the recombinant lentivirus containing mutant hFGF23(A12D) and WT hFGF23 respectively. Real-time PCR, western blot and enzyme-linked immunosorbent assay confirmed that hFGF23(A12D) failed to be secreted. We measured cell growth via the CCK-8 assay based on Zsgreen expression, detected cell differentiation ability via alkaline phosphatase staining, performed RT-PCR and found that hFGF23(A12D) inhibited proliferation of RC cells and stimulated the differentiation of RC cells to osteoblasts. Through RNA sequencing, RT-PCR and western blot, we found increased expression of FGFR3. Through co-immunoprecipitation assays and immunofluorescence staining, we revealed that hFGF23(A12D) activated the mitogen-activated protein kinase signalling pathway through interactions with the intracellular domain of FGFR3. In summary, we determined the mechanisms of hFGF23(A12D) involved in osteoblast generation and formation which is specifically due to its interaction with FGFR3.

Novel mutations of AXIN2 identified in a Chinese Congenital Heart Disease Cohort.

Congenital heart defects (CHDs), the most common congenital human birth anomalies, involves complex genetic factors. Wnt/ß-catenin pathway is critical for cardiogenesis and proved to be associated with numerous congenital heart abnormities. AXIN2 has a unique role in Wnt/ß-catenin pathway, as it is not only an important inhibitor but also a direct target of Wnt/ß-catenin pathway. However, whether AXIN2 is associated with human CHDs has not been reported. In our present study, we found a differential expression of Axin2 mRNA during the development of mouse heart, indicating its importance in mouse cardiac development. Then using targeted next-generation sequencing, we found two novel case-specific rare mutations [c.28 C > T (p.L10F), c.395 A > G (p.K132R)] in the sequencing region of AXIN2. In vitro functional analysis suggested that L10F might be a loss-of-function mutation and K132R is a gain-of-function mutation. Both mutations disrupted Wnt/ß-catenin pathway and failed to rescue CHD phenotype caused by Axin2 knockdown in zebrafish model. Collectively, our study indicates that rare mutations in AXIN2 might contribute to the risk of human CHDs and a balanced canonical Wnt pathway is critical for cardiac development process. To our knowledge, it is the first study of AXIN2 mutations associated with human CHDs, providing new insights into CHD etiology.

Knockdown of tumor protein D52-like 2 induces cell growth inhibition and apoptosis in oral squamous cell carcinoma.

Tumor protein D52-like 2 (TPD52L2) and its family members form homo- and hetero-meric complexes essential for cell proliferation in multiple human cancers. TPD52L2 is involved in cell migration and attachment in oral squamous cell carcinoma (OSCC). To confirm the role of TPD52L2 in OSCC, we employed the lentivirus-delivered small interfering RNA (siRNA) technique to knock down TPD52L2 expression in two OSCC cell lines, CAL27, and KB. Knockdown of TPD52L2 by RNA interference markedly suppressed cell proliferation and colony formation. Cell cycle analysis showed that depletion of TPD52L2 led to CAL27 cells arrest in the S phase. We found an excessive accumulation of cells in the sub-G1 phase, which can represent apoptotic cells. TPD52L2 silencing also induced the cleavage of PARP. These results suggest that TPD52L2 is involved in OSCC cell growth and serves as a potential therapeutic target in human OSCC.

The effect of gold nanoparticles on the proliferation and differentiation of murine osteoblast: a study of MC3T3-E1 cells in vitro.

The current study involves in identification and molecular levels characterization of optimal size and concentration of gold nanoparticles (AuNPs). Stable, gold nanoparticles were synthesized and characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The concentration and size dependent effects of the gold nanoparticles on proliferation of pre-osteoblast cells MC3T3-E1 was evaluated employing MTT cell proliferation assay. The results revealed that 30 nm diameter gold nanoparticles at a concentration of 10(-11) ppm were the most effective in promoting cell proliferation. Assay for alkaline phosphatase (ALP) activity and ALP staining were also used to confirm the effect of gold nanoparticles on osteoblast proliferation and differentiation. Moreover, reverse transcriptase polymerase chain reaction (RT-PCR) was used to measure the expression of the osteogenic genes Runx2, ALP, OCN and OPN as response gold nanoparticles. The data demonstrated that 30 nm gold nanoparticles at a concentration of 10(-11) ppm was the best combination of size and concentration to promote the proliferation and differentiation of osteoblasts, as indicated by an increase in the ALP activity and expression of the osteogenic genes Runx2, ALP, OCN and OPN. Collectively the results of this study suggest that gold nanoparticles can promote the proliferation and differentiation of osteoblasts and could be used effectively in treatments promoting bone regeneration.

Targeted sequencing of NOTCH signaling pathway genes and association analysis of variants correlated with mandibular prognathism.

INTRODUCTION: The purpose of this study was to systematically identify variants in NOTCH signaling pathway genes that correlate with mandibular prognathism (MP) in the general Chinese population. METHODS: Targeted sequencing of NOTCH signaling pathway genes was conducted in 199 MP individuals and 197 class I malocclusion control individuals. The associations of common and rare variants with MP, cephalometric parameters, and continuous cephalometric phenotypes were analyzed by principal component (PC) analysis. The associations between rare variants and MP were tested for each gene. RESULTS: Six SNPs, including rs415929, rs520688, and rs423023 in an exonic region of NOTCH4; rs1044006 in an exonic region of NOTCH3; rs1051415 in an exonic region of JAG1; and rs75236173 in the 3'-untranslated region (3'-UTR) of NUMB were associated with MP (P < 0.05). One common variant, rs1051415, in an exonic region of JAG1 was significantly related to PC1 (P  = 3.608 × 10- 4), which explained 24.3% of the overall phenotypic variation observed and corresponded to the sagittal mandibular position towards the maxilla, ranging from a posterior positioned mandible to an anterior positioned mandible. Additionally, 41 other variants were associated with PC1-5 (P  <  0.05). With respect to rare variant analysis, variants within the EP300, NCOR2, and PSEN2 gene showed an association with MP (t   < 0 .05). CONCLUSIONS: An association between NOTCH signaling pathway genes and MP has been identified.

Oral Health Status of Chinese Children With Autism Spectrum Disorders.

OBJECTIVES: To assess and compare the oral health status of children with and without autism spectrum disorders (ASD) in China. METHODS: This study recruited 144 children with ASD and 228 unrelated children with typical development (TD) aged 3-16 years from China. Data were collected using parent-reported questionnaires. Oral problems (oral symptoms and habits), oral health measures (oral hygiene practice and dental care experience), and the impact on the child's quality of life (based on a modified version of the Parental-Caregiver Perception Questionnaire) were assessed and compared between the two groups. RESULTS: Children with ASD had worse oral health status than children with TD. Oral symptoms were more prevalent in the ASD group, especially halitosis (p < 0.001), food impaction (p < 0.001), and oral lesions (p < 0.001), than the TD group. The rate of damaging oral habits, including mouth breathing (p < 0.001) and object biting (p < 0.05), was also high in the ASD group. Compared with the TD group, more children with ASD did not brush their teeth independently and frequently (p < 0.001), had difficulty accessing dental care (p < 0.01), and reported unpleasant dental experiences (p < 0.001). The presence of ASD was associated with decreased oral health-related quality of life (p < 0.001) in these children and their families. CONCLUSION: Oral problems such as halitosis and bad oral habits are more prevalent among children with ASD. These children also lack oral hygiene practice and dental visits. This situation negatively impacts their quality of life, and must be brought to the attention of their treating dentists.

A comparative study of the osteogenic performance between the hierarchical micro/submicro-textured 3D-printed Ti6Al4V surface and the SLA surface.

Three-dimensional (3D) printed titanium and its alloys have broad application prospect in the field of biomedical implant materials, although the biological performance of the original surface should be improved. Learning from the development experience of conventional titanium implants, to construct a hierarchical hybrid topological surface is the future direction of efforts. Since the original 3D-printed (3D hereafter) Ti6Al4V surface inherently has micron-scale features, in the present study, we introduced submicron-scale pits on the original surface by acid etching to obtain a hierarchical micro/submicro-textured surface. The characteristic and biological performance of the 3D-printed and acid-etched (3DA hereafter) surface were evaluated in vitro and in vivo, compared with the conventional sandblasted, large-grit, acid-etched (SLA hereafter) surface. Our results suggested the adhesion, proliferation and osteogenic differentiation of bone marrow derived mesenchymal stromal cells (BMSCs), as well as the in vivo osseointegration on 3DA surfaces were significantly improved. However, the overall osteogenic performance of the 3DA surface was not as good as the conventional SLA surface.

Dental arch widths and mandibular-maxillary base widths in Class III malocclusions from ages 10 to 14.

INTRODUCTION: Evaluations of the dental arch widths and mandibular-maxillary base are needed for a comprehensive dentofacial analysis in subjects with Class III malocclusion. The aim of this study was to analyze the development of the dental arches and the skeletal mandibular-maxillary bases in untreated subjects with Class III malocclusions. METHODS: Two groups of subjects, 1 with Class III malocclusion and the other with Class I malocclusion, were examined. Maxillary skeletal base width, biantegonial widths, and maxillary and mandibular intermolar widths were determined on posteroanterior cephalograms at annual intervals between the ages of 10 and 14 years. RESULTS: Maxillary skeletal base widths and intermolar widths in the Class III subjects were significantly smaller than those in the Class I subjects (P <.05). No statistically significant differences were found among the groups for skeletal mandibular width or intermolar width for the total observation period. The deviations in molar differences increased from ages 10 to 14 in the Class III group. CONCLUSIONS: The main transverse deficiencies in the Class III group were maxillary deficiencies in both skeletal and dental widths. The deviations in molar differences appear to become larger from age 10 to age 14.

The effects of elevated fibroblast growth factor 23 on mandibular growth in rats.

OBJECTIVE: The aim of this study is to elucidate the local effects of fibroblast growth factor 23 (FGF23) in on mandibular condylar growth in growing rats. DESIGN: Growing Sprague-Dawley rats received intra-temporomandibular joint injections of phosphate buffer solution (PBS), adenovirus-mediated green fluorescent protein (Ad-GFP) or adenovirus-mediated fibroblast growth factor 23 (Ad-FGF23), which were marked as groups A, B, and C, respectively. In vitro, we treated rat mandibular cartilage chondrocytes with PBS, Ad-GFP, and Ad-FGF23. RESULTS: The mandibular condyles in group C grew smaller sizes than those in the other control groups due to significant differences among the experimental and control groups with the value of C-D, Q-R (P ≤ 0.05), accompanied by diminished bone mass of sub-cartilage condyles via micro CT analysis. Histologically, the length of the hypertrophic zone was diminished and was associated with decreasing chondrocyte proliferation in group C. Quantitative real-time PCR indicated significant decreases in the expression of chondrogenesis marker genes, including Type X collagen (Col X) and SRY-type box 9 (Sox 9). Moreover, elevated Ad-FGF23 suppressed chondrocyte proliferation and the expression of the chondrogenic differentiation markers Col X and Sox 9 of in vitro. CONCLUSIONS: Local injection of FGF23 suppressed the development and decreased the bone mass of condyles through the decreasing the formation of condylar cartilage, specifically by regulating condylar cartilage cell viability and chondrogenesis expression.

BMAL1 suppresses ROS-induced endothelial-to-mesenchymal transition and atherosclerosis plaque progression via BMP signaling.

Circadian rhythm disruption is intimately linked to atherosclerosis, and endothelial-to-mesenchymal transition (EndMT) is a major feature of atherosclerosis progression and unstable plaques. However, the mechanisms underlying the roles of Brain and Muscle ARNT-Like Protein-1 (BMAL1), an essential clock transcription activator, in EndMT and plaque instability have not been characterized. In the present study, we found a positive relationship among BMAL1 expression loss, EndMT, and plaque vulnerability in human carotid plaques. Furthermore, loss- and gain-of-function studies in human aortic endothelial cells (HAECs) revealed that BMAL1 inhibited oxidized low-density lipoprotein (oxLDL)-induced intracellular reactive oxygen species (ROS) accumulation and subsequent EndMT. Mechanistically, BMAL1 deficiency aggravated EndMT through BMP-mediated signaling. Collectively, our study demonstrates the underlying mechanism for the central role of BMAL1 loss in atherosclerosis progression and plaque stability transition promoted by oxidative stress, which can be targeted therapeutically to prevent the occurrence and progression of atherosclerosis.

Alterations of oral microbiota distinguish children with autism spectrum disorders from healthy controls.

Altered gut microbiota is associated with autism spectrum disorders (ASD), a group of complex, fast growing but difficult-to-diagnose neurodevelopmental disorders worldwide. However, the role of the oral microbiota in ASD remains unexplored. Via high-throughput sequencing of 111 oral samples in 32 children with ASD and 27 healthy controls, we demonstrated that the salivary and dental microbiota of ASD patients were highly distinct from those of healthy individuals. Lower bacterial diversity was observed in ASD children compared to controls, especially in dental samples. Also, principal coordinate analysis revealed divergences between ASD patients and controls. Moreover, pathogens such as Haemophilus in saliva and Streptococcus in plaques showed significantly higher abundance in ASD patients, whereas commensals such as Prevotella, Selenomonas, Actinomyces, Porphyromonas, and Fusobacterium were reduced. Specifically, an overt depletion of Prevotellaceae co-occurrence network in ASD patients was obtained in dental plaques. The distinguishable bacteria were also correlated with clinical indices, reflecting disease severity and the oral health status (i.e. dental caries). Finally, diagnostic models based on key microbes were constructed, with 96.3% accuracy in saliva. Taken together, this study characterized the habitat-specific profile of the oral microbiota in ASD patients, which might help develop novel strategies for the diagnosis of ASD.

Effects of bimaxillary surgery and mandibular setback surgery on pharyngeal airway measurements in patients with Class III skeletal deformities.

INTRODUCTION: The purpose of this study was to compare the short-term and long-term effects of bimaxillary surgery with those of mandibular setback surgery concerning pharyngeal airway measurements at 3 levels: nasopharynx, oropharynx, and hypopharynx. METHODS: The sample included 66 Japanese women in 2 groups who had been diagnosed with Class III skeletal deformities and had undergone surgical-orthodontic treatment. Those in group A (35 patients) underwent bilateral sagittal split ramus osteotomies; those in group B (31 patients) underwent LeFort I procedures with bilateral sagittal split ramus osteotomies. Lateral cephalograms were assessed within 6 months before surgery and at short-term (3-6 months after surgery) and long-term (at least 2 years after surgery) follow-ups. RESULTS: In group A, the pharyngeal airway was constricted significantly at the oropharyngeal and hypopharyngeal levels at both the short-term and the long-term follow-ups. In group B, significant changes were shown at the 3 pharyngeal levels at the short-term follow-up, whereas no significant changes were shown at the long-term follow-up. CONCLUSIONS: These results indicate that, when possible, bimaxillary surgery rather than only mandibular setback surgery is preferable to correct a Class III deformity to prevent narrowing of the pharyngeal airway space, a possible predisposing factor in the development of obstructive sleep apnea.

Dental arch widths and mandibular-maxillary base width in Class III malocclusions with low, average and high MP-SN angles.

OBJECTIVE: To analyze the development of the dental arches and skeletal mandibular-maxillary bases in untreated Class III malocclusions with low averages and high mandibular plane angles in subjects aged 10 to 14. MATERIALS AND METHODS: The records of 50 untreated Japanese girls with Class III malocclusions at age 10 were selected from the files of patients pending orthodontic surgery. The patients included those with low (< or =27 degrees), average (27 degrees through 37 degrees) and high (>37 degrees) mandibular plane angles. The maxillary skeletal base width, biantegonial width, and maxillary and mandibular intermolar width were determined on posteroanterior cephalograms obtained at annual intervals when subjects were between 10 and 14 years of age. The difference between the maxillary and mandibular intermolar width was also calculated and reported. RESULTS: All skeletal and dental transverse widths in the high-angle group were significantly smaller than those in the low-angle group (P < .05) from ages 10 to 14. On the other hand, the maxillary to mandibular molar difference was the same for the three groups (P > .05) at each age. The deviations in molar differences did increase from age 10 to age 14 in all three groups. CONCLUSION: Mandibular plane angles might play a stronger role in the transverse skeletal growth of the maxilla and the mandible than the transverse dental growth of the maxilla and the mandible.

Longitudinal intermaxillary relationships in class III malocclusions with low and high mandibular plane angles.

OBJECTIVE: To analyze the sagittal, vertical, and transverse relationships of the maxilla and mandible in Japanese girls with Class III malocclusions with different inclination of mandibular plane. MATERIALS AND METHODS: This longitudinal study utilized serial posteroanterior and lateral cephalograms of 56 untreated subjects from the age of 8 years until the age of 14 years (low mandibular plane angle group: n = 20; average mandibular plane angle group: n = 15; high mandibular plane angle group: n = 21). Sagittal and vertical growth was analyzed on the basis of lateral cephalograms, and transverse growth was analyzed on the basis of posteroanterior cephalograms. RESULTS: There was no significant difference in intermaxillary sagittal relationships among the three groups from age 8 until 14. On the other hand, there were significant changes in the vertical and transverse intermaxillary relationships during this period. When comparing the three groups at the same age, there were significant differences in vertical and transverse intermaxillary relationships in some ages, whereas no significant difference was found in sagittal relationships in any ages. CONCLUSIONS: The inclination of mandibular plane might play a role in anticipating changes in vertical and transverse intermaxillary relationships from 8 until 14 years of age.

Targeted sequencing in FGF/FGFR genes and association analysis of variants for mandibular prognathism.

To identify variants of the genes in fibroblast growth factors/fibroblast growth factor receptors (FGF/FGFR) signal pathway that predispose to mandibular prognathism (MP) in the general Chinese population systematically.Targeted sequencing of the FGF/FGFR genes was conducted in 176 MP individuals and 155 class I malocclusion controls. The associations of common and rare variants with MP as a categorical phenotype and also continuous malocclusion phenotypes generated by principal component (PC) analysis were analyzed.One common variant, rs372127537, located in the 3'-untranslated region of FGF7 gene, was significantly related to PC1 (P  =  4.22 × 10), which explained 23.23% of the overall phenotypic variation observed and corresponded to vertical discrepancies ranging from short anterior face height to long anterior face height, after Bonferroni correction. Also, 15 other variants were associated with PC1-4, although not significant after multiple corrections (P < .05). We also identified 3 variants: rs13317 in FGFR1, rs149242678 in FGF20, and rs79176051 FGF12 associated with MP (P < .05). With respect to rare variant analysis, variants within the FGF12 gene showed significant association with MP (P  =  .001).Association between FGF/FGFR signaling pathway and MP has been identified. We found a previously unreported SNP in FGF7 significantly related to increased facial height. Also, rare variants within the FGF12 were associated with MP. Our results provide new clues for genetic mechanisms of MP and shed light on strategies for evaluating rare variants that underlie complex traits. Future studies with larger sample sizes and more comprehensive genome coverage, and also in other population are required to replicate these findings.

Anchorage effect of osseointegrated vs nonosseointegrated palatal implants.

Palatal implants can be used with a transpalatal arch (TPA) connected with the second premolar to provide anchorage. The purpose of this study was to compare the anchorage effects of an osseointegrated palatal implant (OPI) with a nonosseointegrated palatal implant (NOPI), using finite element analysis. One model, which was composed of two maxillary premolars, periodontal ligament (PDL), alveolar bone, a palatal implant, palatal bone, a bracket, band, and TPA, was created on the basis of the clinical situation. The palatal implant was treated as either NOPI or OPI. The force on the premolars was investigated under three conditions: a distomesial horizontal force, a buccolingual horizontal force, and a vertical intrusive force. The PDL stress was calculated and compared with a model without an implant. The result showed that OPI could reduce PDL stress significantly. (The average stress was reduced by 14.44% for the distomesial horizontal force, 60.28% for the buccolingual horizontal force, and 17.31% for the vertical intrusive force.) The NOPI showed almost the same anchorage effect as OPI. The stress on the NOPI surface was higher than that on the OPI surface, but the stress was not high enough to result in failure of the implant. These results suggested that waiting for osseointegration might be unnecessary for an orthodontic implant.

Longitudinal evaluation of the intermaxillary relationship in Class III malocclusions.

OBJECTIVE: To analyze the sagittal, vertical, and transverse relationship of the maxilla and mandible in Japanese girls with Class III malocclusions. MATERIALS AND METHODS: This longitudinal study utilized biannual posteroanterior and lateral cephalograms of 44 untreated subjects from age 8 to 14 years (Class I, 23 girls; Class III, 21 girls). Sagittal and vertical growths were analyzed on the basis of lateral cephalograms, and transverse growth was analyzed on the basis of posteroanterior cephalograms. RESULTS: There was no significant difference in sagittal intermaxillary relationships in Class III malocclusion from age 8 to 14 years, whereas significant difference in vertical and transverse intermaxillary relationships appeared with ages during this period. When comparing Class III to Class I malocclusions at the same age point, there were significant differences in sagittal and transverse intermaxillary relationships, whereas significant difference in vertical intermaxillary relationship appeared after 12 years of age. CONCLUSION: The results suggest that the sagittal intermaxillary relationships in Class III malocclusions were established before 8 years of age and remained through puberty and that the vertical and transverse intermaxillary relationships in Class III malocclusions changed with ages from 8 to 14 years.

Classification and characterization of class III malocclusion in Chinese individuals.

BACKGROUND: Class III malocclusion is a maxillofacial disorder that is characterised by a concave profile and can be attributed to both genetic inheritance and environmental factors. It is a clinical challenge due to our limited understanding of its aetiology. Revealing its prototypical diversity will contribute to our sequential exploration of the underlying aetiological information. The objective of this study was to characterize phenotypic variations of Class III malocclusion via a lateral cephalometric analysis in a community of Chinese individuals. METHOD: One-hundred-and-forty-four individuals (58 males ≥18 and 86 females ≥16) with Class III malocclusion ranging from mild to severe were enrolled in this study. Principal component analysis and cluster analysis were performed using 61 lateral cephalometric measurements. RESULTS: Six principal components were discovered in the examined population and were responsible for 73.7 % of the variability. Four subtypes were revealed by cluster analysis. Subtype 1 included subjects with mild mandibular prognathism with a steep mandibular plane. Subjects in subtype 2 showed a combination of prognathic mandibular and retrusive maxillary with a flat or normal mandibular plane. Subtype 3 included individuals with purely severe mandibular prognathism and a normal mandibular plane. Individuals in subtype 4 had a mild maxillary deficiency and severe mandibular prognathism with the lowest mandibular plane angle. CONCLUSION: The six principal components extracted among the 61 variables improve our knowledge of lateral cephalometric analysis for diagnoses. We successfully identified four Class III malocclusion subtypes, indicating that cluster analysis could supplement the classification of Class III malocclusion among a Chinese population and may assist in our on-going genetic study.

A special method of predicting mandibular growth potential for Class III malocclusion.

The purpose of this study was to establish an equation to predict the mandible growth potential (GP) for Class III malocclusion on the basis of the analysis of the cervical vertebrae in a single cephalometric radiograph and to compare its predictive accuracy with other methods. Data comprised two groups each with 22 Japanese girls. Group A was examined to construct the prediction equation. Group B served to compare the predictive accuracy with the GP method and the method of Mito et al (MM). The following results were obtained: (1) an equation was determined to obtain mandible GP on the basis of measurements in the third and fourth cervical vertebral bodies and (2) the average errors between the predicted increment and the actual increment for each method were 1.45 mm for the equation, 2.91 mm for the GP method, and 2.48 mm for the MM. These results suggest that using cervical vertebral measurements might allow predicting the mandible GP length for Class III malocclusion.