Morphometric characteristics of cervical vertebrae in subjects with short, normal, and long faces.

Abstract

The prolonged change in the head posture alters the morphological characteristics of cervical vertebrae. The difference in the head posture among subjects with short, normal, and long anterior facial heights might have a significant influence on the morphological characteristics of cervical vertebrae. Thus, the present study was conducted to evaluate the morphometric characteristics of cervical vertebrae in subjects with short, normal, and long faces. Based on Frankfort mandibular plane angle (FMA) on lateral cephalograms, 135 subjects were equally divided into three groups, i.e. Group I [Short face], II [Normal face], and III [Long face]. The angular variables like Atlas-dens angle (ADA), Pars interarticularis-dens angle (PDA), Pars interarticularis-vertebrae angle of C3 vertebrae (PVA3), Pars interarticularis-vertebrae angle of C4 vertebrae (PVA4), Lamina-Pars interarticularis angle of C2 vertebrae (LP2), Lamina-Pars interarticularis angle of C3 vertebrae (LP3), and Lamina-Pars interarticularis angle of C4 vertebrae (LP4) in the first four cervical vertebrae were measured, analyzed, and compared. Descriptive statistics, analysis of variance, Bonferroni, and Pearson's correlation coefficient tests were used. The P value of 0.05 was considered as the level of significance. All parameters except PDA and PVA3 were comparable among the groups. The PDA was 54.350 ± 1.870, 57.890 ± 1.550, and 60.290 ± 2.830 in Group I, II, and III, respectively; these differences were statistically significant [P < 0.001]. The PVA3 was 42.700 ± 5.640 in Group I, 45.850 ± 3.820 in Group II, and 45.590 ± 5.530 in Group III subjects that were also statistically significant [P < 0.01]. A fairly strong positive correlation was observed between FMA and PDA. A significant difference was found in the PDA among subjects with short, normal, and long faces. The vertical height of the face had a strong correlation with the morphology of axis vertebra.