The prevalence study of TMD and the associated factors in Korean malocclusion patients

Kim, Myung Hee; Nahm, Dong Seok

Abstract

In order to investigate TMD prevalence in malocclusion patients and to study its relationship with occlusal factors, 205 malocclusion patients (M67, F138, 6Y1M-46Y8M) were examined. The following examinations were carried out, Questionnaire: personal history, TMD symptoms, and the associated factors Clinical examination: TMJ sound and maximum mouth opening Orthopantomogram: condyle abnormalities, length of Co'-Inc' and Co'-Go', ratio Co'-Inc'/Co'-Go', and depth of antegonial notch Transcranial view: limitation of anterior movement of condyle Model: Angle classification, overjet, overbite, midline discrepancy, missing of posterior teeth, posterior crossbite, attrition of palatal cusp of maxillary molars, crowding/spacing The results could be summarized as follows, 1. The prevalence of TMD showed that Helkimo Anamestic Index(Ai) 0 was 46.8%, Ai I was 22.0%, Ai II was 31.2% and subjective symptoms increased with aging (p<0.001) and were frequent in females (p<0.05). 2. Flattening (4.4%) was the most frequent condyle abnormality on Orthopantomgram, and 8.3% of subjects showed some abnormalities on Orthopantomogram. 3. The cases with neck and shoulder pain (p<0.001), clenching, lip biting (p<0.01), and headache (p<0.05) showed higher scores of Ai. 4. Angle class II showed high frequency of condylar abnormalities on Orthopantomogram, and subjects whose palatal cusp of maxillary molars had been attrided had the tendency to show high Ai scores (p<0.05). The other occlusal factors had nothing to do with the symtoms of TMD. 5. In the case that 1)the value of Co'-Inc', Co'-Go' or Co'-Inc'/Co'-Go' were low or 2)the difference of Co'-Go' or Co'-Inc'/Co'-Go' between the right and the left were large, condylar abnormalities were frequently obserbed on Orthopantomogram.