Assessment of temporomandibular joint morphology and mandibular length in various skeletal malocclusions- A prospective CBCT study

Temporomandibular joint (TMJ) is a complex structure which may be loaded differently in every individual leading to chances of differential condyle and fossa patterns. The aim of this study was to assess the changes in mandibular length, condyle and glenoid fossa in individuals with various skeletal malocclusions. This study was carried out with CBCT images of 45 patients divided into three groups, comprising of 15 patients in each group within the age group of 18-25years having Class I, Class II and Class III skeletal patterns respectively. Images were analyzed for the mandibular length, condylar and glenoid fossa shape variations. The measurements showed that GroupIII had significantly larger values of condylar width, depth, height and volume than other groups(P<0.05). Superior joint space was significantly lesser in Group III (P< 0.001), whereas anterior joint space was significantly lesser in Group III and II than Group I (P <0.001 &<0.05 respectively). The posterior joint space was found to be larger in Group II than Group I and III (P < 0.001 &<0.005 respectively). Mandibular length was significantly increased in Group III (P<0.001) and reduced in Group II(P<0.05). Significant differences of mandibular length, condylar width, height, length, condylar volume and joint spaces among the three sagittal groups were noted and hence can be concluded that TMJ morphology differed according to the difference in sagittal relationship of maxilla and mandible. Still, larger sample size is needed to study along with the soft tissue considerations in future.