Vertical height differences in subjects with severe dental wear.

The present study aims to determine differences in vertical facial dimensions as a result of severe dental wear. The sample consisted of 35 subjects (mean age 48.4 years) who had advanced dental wear recognized by loss of more than one-third of the estimated original incisor crown length. The control group comprised 40 subjects (mean age 26.1 years) with acceptable occlusions and no signs of severe generalized tooth wear. Lateral skull radiographs were taken for both the study sample and the control group with the mandible in the maximum retruded position, from which measurements were made using a digitizer. The results showed no significant differences for total face height (n-gn) between the groups (P > 0.05) although for the study sample, upper face height was greater (P < 0.05) and lower face height was smaller (P < 0.05). Smaller values for tooth length were found in the wear sample, with the mean differences in tooth length being 5.0 mm for upper incisors and 3.3 mm for lower incisors. The overbite was smaller in the wear sample and the lower incisor position differed from controls in this group. It is concluded that the differences in face height together with differences in lower incisor position through dento-alveolar development contribute to maintenance of total facial height, so compensating for loss of vertical height through severe dental wear.