Craniofacial morphology in subjects with advanced dental attrition

• Main Author: Crothers, Andrew John
• Published: University of Edinburgh 1991
• Subjects: 617.6
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.645186

The present study identifies the differences in hard and soft craniofacial morphology that may be found in the presence of advanced dental attrition and ageing when detailed linear and angular cephalometric comparisons of a study sample (N = 35, mean age 48.4 years) were made with a control group of young adult subjects (N = 40, mean age 26.1 years), using computer based recording and measurement apparatus. Existing computer programmes were modified for the purpose of the present study to enable the recording of 51 defined sequential radiographic points, producing 32 linear and 21 angular variables of craniofacial form for each subject. Method error determinations were carried out for both digitiser and cephalometric variables. X and Y co-ordinate identification accuracy, linearity of the digitiser table and cursor and point placement error by the operator were examined statistically with an analysis of variance, using skewness and kurtosis parameters to ensure the elimination of any distribution errors prior to t-test comparisons between the study sample and the control group. Comparisons were made between hard and soft tissue measurements for the study sample and the control group and the statistically significant differences tabulated. The results of the study showed marked linear and angular differences in craniofacial morphology between the categories. In the presence of ageing and attrition, total facial height was not found to differ significantly between the study sample and controls, and the smaller vertical incisor crown heights seen in the study sample were compensated for by apparent eruption of the lower incisor teeth and an apparent downwards displacement of the maxillary plane as measured n-sp and s-pm (p< 0.05). An edge to edge incisor relationship was confirmed in the study sample, related to a longer mandible as measured pgn-cd (p< 0.001), and greater values of mandibular prognathism (s-n-pg, p< 0.01) when compared to controls. The facial profile soft tissue differences between control and sample categories demonstrated a flatter and longer upper lip, and more protrusive lower lip and chin in the study sample. The study demonstrates a relationship between attrition and sagittal soft tissue morphology, and a relationship between ageing, attrition and vertical soft tissue relations.