An investigation of cervicovertebral morphology in different sagittal skeletal growth patterns

The purpose of the present study was to examine and compare cervicovertebral morphology in subjects with different sagittal skeletal patterns. The material comprised lateral head films of 90 untreated subjects, 45 girls and 45 boys, aged 13-15 years. The radiographs were obtained in the natural head position using a fluid level method. The subjects were divided into three groups according to ANB angle: ANB angle between 1 and 5 degrees (skeletal Class I), larger than 5 degrees (skeletal Class II), and smaller than 1 degree (skeletal Class III). Each ANB group consisted of 30 subjects, 15 girls and 15 boys. Twenty-nine linear and four area measurements were used to assess cervicovertebral morphology. Differences between the ANB groups and between genders were assessed by means of analysis of variance and the least significant difference test. In addition, cephalometric measurements for all subjects were subjected to discriminant analysis. The results of the analysis of variance showed that there were statistically significant differences in the measurements of the lumen length of C1, inferior depths of C2 and C4, anterior intervertebral spaces of C2 and C3, posterior intervertebral space of C3, and anterior and posterior body heights of C4 among the ANB groups. The total length of C1, inferior depths of C2-C5, anterior intervertebral spaces of C2-C4, posterior intervertebral space of C2, anterior body heights of C4 and C5, and posterior body heights of C3-C5 demonstrated significant gender differences. The results of the discriminant analysis indicated that 54.4 per cent of the original grouped cases were correctly classified in the total sample. The final discriminant model was able to classify correctly 20 of the 30 Class I subjects (66.7 per cent), 17 of the 30 Class II subjects (56.7 per cent), and 12 of the 30 Class III subjects (40.0 per cent).