1992 Volume 17 Issue 2 Pages 82-91
Radiographicai characterization of the mandibular morphology was undertaken in 8 patients admitted to Iwaki National Sanatorium with Duchenne type muscular dystrophy (DMD) in a comparison with 12 adults having normal occlusion as controls. Lateral cephalograms and standardized X-ray photographs of the temporomandibular joint (TMJ) taken by an “AX aligner” were used and morphological features were measured geometrically. The quantitative data were statistically analyzed. No differences were found in the lengths of the mandibular corpus, ramus and gonial angle between the DMD patients and controls. In DMD patients, the anterior length of the nasal floor was significantly shorter than that of the controls. The position of the mandible was protrusive to the cranium. The mandibular plane angle indicated a clockwise rotation, and the lower incisors inclined labially due to hypertrophy of the tongue. The anterior inclination of the condyle (AIC) was significantly smaller with DMD patients than in the controls, but the depth of the mandibular fossa (DMF) did not differ between them. In the controls, there were significant correlations among the mandibular corpus, ramus, gonial angle and AIC, but there were no such correlations in the DMD patients. These results lead us to the following conclusions. Normal growth of the mandible maintains a balanced relationship among the corpus, ramus, gonial angle and condylar configuration. The anterior inclination of the condyle, not observed in the DMD patients, is regarded as the result of remodeling of TMJ with normal developments of the masticatory muscle function.
