Tooth loss and craniofacial factors associated with changes in mandibular condylar morphology

BMP2 rs1005464 is associated with mandibular condyle size variation

This study aimed to evaluate the association between single nucleotide polymorphisms (SNPs) in endochondral development-related genes and mandibular condyle shape, size, volume, and symmetry traits. Cone-beam Computed Tomographies and genomic DNA from 118 individuals were evaluated (age range: 15-66 years). Data from twelve 3D landmarks on mandibular condyles were submitted to morphometric analyses including Procrustes fit, principal component analysis, and estimation of centroid sizes and fluctuating asymmetry scores. Condylar volumes were additionally measured. Seven SNPs across BMP2, BMP4, RUNX2 and SMAD6 were genotyped. Linear models were fit to evaluate the effect of the SNPs on the mandibular condyles' quantitative traits. Only the association between BMP2 rs1005464 and centroid size remained significant after adjusting to account for the false discovery rate due to multiple testing. Individuals carrying at least one A allele for this SNP showed larger condylar size than common homozygotes GG (β = 0.043; 95% CI: 0.014-0.071; P value = 0.028). The model including BMP2 rs1005464, age and sex of the participants explained 17% of the variation in condylar size. Shape, volume, and symmetry were not associated with the evaluated SNPs. These results suggest that BMP2 rs1005464 might be associated with variation in the mandibular condyles size.

Relationship between the condyle morphology and clinical findings in terms of gender, age, and remaining teeth on cone beam computed tomography images

Aim: This study aimed to evaluate the relationship between clinical findings and some factors such as age, gender, and remaining teeth on the anatomy of the temporomandibular joint in order to diagnose normal variations from abnormal cases. Methods: In this cross-sectional study, cone-beam computed tomography (CBCT) images of 144 patients referring to Tabriz Dental School for various reasons were selected and evaluated. The different aspects of the clinical parameters and the morphology of the condyle were evaluated on coronal, axial, and sagittal views. The CBCT prepared using the axial cross-sections had been 0.5 mm in thickness. The sagittal cross-sections had been evaluated perpendicular to the lengthy axis of the condyle at a thickness of 1 mm and the coronal cross-sections had been evaluated parallel to the lengthy axis of the condyle at a thickness of 1 mm. Data were analyzed with descriptive statistical methods and t-test, chi-squared test, using SPSS 20. The significance level of the study was p < 0.05. Results: There was a significant relationship between the condyle morphology, number of the teeth, and mastication side (p = 0.040). There were significant relationships between the condyle morphology, age between 20-40, and occlusion class I on the all the three views (coronal, axial, sagittal) (p = 0.04), (p = 0.006), (p = 0.006). Also, significant relationships were found in the condyle morphology and location of pain according to age, the number of remaining teeth, and gender. (p = 0.046) (p = 0.027) (p = 0.035). Conclusion: There are significant relationships between the clinical symptoms and condyle morphology based on age, gender, and the number of remaining teeth. The clinical finding that has the most significant relationship between the condyle morphology, remaining teeth (9-16 teeth), all of the age range (20-80 year), and gender was mastication side.

Understanding the mandibular condyle morphology on panoramic images: A conebeam computed tomography comparison study

Objective: To compare variations in condylar morphology (CM) in panoramic images with those demonstrated in cone beam computed tomography (CBCT) and to investigate factors related to the variations.Methods: Three thousand panoramic images were analyzed for CM classification and relationship between CM and patient factors. Then, CM of 178 cases of panoramic and CBCT images were compared.Results: CM was classified into five types: round (70.63%), pointed (15.12%), angled (8.43%), flat (4.53%), and irregular (1.28%). CM was significantly related to all patient factors (p < 0.001). Round CM in panoramic images presented as round in CBCT images. Pointed and flat CM were observed mainly in the lateral aspect of the condyle, and no angle-shaped CM was found, according to CBCT images.Conclusion: Round, flat, and pointed CM seen on panoramic images possibly reflected the actual shape of the condyle, as confirmed by CBCT, whereas angled CM appeared not to exist.