Evaluation of morphology and position of glenoid fossa in Class I and Class II malocclusions- A cephalometric study

Aim: To analyse glenoid fossa position in Class I, II (div 1 and 2) malocclusions and to analyse variation in the shape of the glenoid fossa in different mandibular configurations. Materials and Methods: The cephalometric study was carried on lateral films of 45 subjects aged 12 18 years. They were divided into three groups based on the ANB angle (and anterior occlusal relation) and also based on the mandibular plane angle. Analysis comprised of linear and angular measurements for the assessment of the position of the glenoid fossa and the inclination of articulating surface of the glenoid fossa, which was also correlated with the mandibular configuration. Results: A study group with Class I and II malocclusion div 1 and 2 showed statistically insignificant difference in vertical sella fossa distance whereas, Class II (div 1 and 2) malocclusions showed increased horizontal sella fossa distance than the Class I study group. Low angle subjects showed increased vertical sella fossa distance and ramus height than high angle subjects. Subjects with steep articular eminence inclination have acute gonial angles and subjects tending towards flat articular eminence have obtuse gonial angles. Conclusion: With proper mechanics, Class II cases can be corrected by anterior displacement of the glenoid fossa, high angle cases by an inferior displacement and the reverse for low angle cases.