Evaluation of relationship between cranial base angle and maxillofacial morphology in Indian population: A cephalometric study

OBJECTIVE: To investigate the role played by the cranial base flexure in influencing the sagittal and vertical position of the jaws in Indian population. MATERIALS AND METHODS: Lateral cephalograms of 108 subjects were divided into three categories (Group A: NSAr > 125°, Group B: NSAr-120°-125°, Group C: NSAr < 120°) according to value of NSAr. Measurement of eight angular (SNA, SNB, NPg-FH, ANB, NAPg, SN-GoGn, Y-Axis, ArGo-SN) and seven linear (N-S, S-Ar, Ar-N, Ar–Pt A, Ar–Gn, Wits appraisal, N- Pt A) variables were taken. RESULTS: Pearson correlation coefficient test was used to individually correlate angular and linear variables with NSAr for the whole sample as well as in individual group. Unpaired t-test was used to analyze the difference in the means of all the variables between the three groups. Significance was determined only when the confidence level was P < 0.05. Several parameters (SNB, NAPg, ANB, Y-Axis, GoGn-SN) showed significant positive correlation while others showed negative correlation (SNA, NPg-FH, N-S) with NSAr. CONCLUSIONS: This study show cranial base angle has a determinant role in influencing the mandibular position and it also affects both the mandibular plane angle and y-axis. Flattening of the cranial base angle caused a clockwise rotation of the mandible. The jaw relation tends to change from class III to class II, with progressive flattening of the cranial base and vice-versa.