Correlation of Clivus Length and Angle with Chronological Age, Gender, Sagittal Growth Pattern of the Jaws, and Skeletal Maturation Using Lateral Cephalometry

Statement of the Problem: Determination of remaining growth potential of patients is the most important factor in orthodontic treatment.Purpose: This study aimed to assess the correlation of clivus length and angle with age, gender, sagittal growth pattern of the jaws, and skeletal maturation using lateral cephalometry.Materials and Method: This cross-sectional study was conducted on 390 lateral cephalograms (Vatech, paX-i3D Green, South Korea) of patients aged 6 to 25 years. The patients were assigned to three groups of skeletal class I, II, III (n=130) with equal gender distribution. The clivus length and angle, Welcher angle, maxillary and mandibular effective length, sella turcica to Nasion (SN), and the angles between SN and point A (SNA), between SN and point B (SNB), and between NA and NB (ANB )were measured. Correlations of variables with age and gender, and cervical vertebral maturation stage (CVMS) were analyzed using the Pearson and Spearman’s correlation tests, independent t-test, and one-way ANOVA at 0.05 level of significance.Results: Clivus length had a significant correlation with SNA (r= 0.103, p= 0.042), SNB (r= 0.108, p= 0.033), maxillary (r= 0.547, p< 0.001) and mandibular (r= 0.589, p< 0.001) effective lengths, SN length (r= 0.586, p< 0.001), and CVMS (r= 0.697, p< 0.001). Clivus angle had a significant correlation with SNA (r= 0.105, p= 0.039), SNB (r= 0.155, p= 0.002), maxillary (r= 0.507, p< 0.001) and mandibular (r= 0.596, p= 0.001) effective lengths, SN length (r= 0.566, p< 0.001), and CVMS (r= 0.699, p< 0.001). The mean clivus length (p= 0.006) and angle (p= 0.002) were significantly higher in males, and had a significant correlation with age (r= 0.636 and r= 0.718, p< 0.001). The mean clivus length and angle were not significantly different in class I, II, III (p> 0.05).Conclusion: All parameters were greater in males, and increased with age (except Welcher angle). Clivus length and angle had significant correlations with position of both jaws but not with sagittal relationship.