Cervical spine curvature and craniofacial morphology in an adult Caucasian group: a multiple regression analysis.

The aim of this study was to investigate the relationship between cervical curvature and skeletal facial morphology. Pre-treatment lateral cephalograms in natural head position were obtained from 98 orthodontic adult subjects (56 males and 42 females; mean age = 31.5 years, standard deviation +/-5.8 years). The amount of concavity of the cervical curvature was calculated by a second-order quadratic interpolation of the most infero-posterior points of the bodies of the seven cervical vertebrae on the radiographs. Linear regression with stepwise elimination was carried out to evaluate the sagittal and vertical craniofacial dimensions. The results revealed that the amount of curvature was related to (1) the horizontal position of the upper incisors with respect to the maxillary and mandibular skeletal bases and (2) the sagittal millimetric dimension of the maxillary base. These cephalometric variables explained 51 per cent of the total variance of cervical curvature. There was no significant correlation between cervical curvature and any other cephalometric variable. Cervical curvature was not influenced by age or gender.