Abstract
The frequency of TMJ disorders in patients with jaw deformities was surveyed by questionnaires and dental casts. TMJ disorders in 174 patients (84 males and 90 females, mean age of 22.0 years) were evaluated by questionnaire. Dental casts were evaluated and classified into occlusomorphologic types such as mandibular prognathism, asymmetry, open bite, maxillary prognathism, and composite of these according to previously described criteria. All variables such as gender, age, potential etiologic factors and histories, and occlusomorphology, were analyzed for association with symptoms by Fisher's exact probability test.
The frequency of reported present or past TMJ disorders was 77.6%. No difference due to gender was observed. When the frequency of TMJ disorders in different age groups was examined, the youngest being 15 years old followed by the others at increasing age intervals of 5 years, there was no significant difference between age groups. Among 135 symptomatic patients, 49 patients (36.3%) reported only one symptom of TMJ disorders, while 86 patients (63.7%) reported two or more symptoms. As for potential etiologic factors and historical events, poor posture and experience of trauma were more frequently observed among symptomatic patients than asymptomatic patients (p<0.05). There was no significant difference in the frequency of TMJ disorders between different occlusomorphologic types.
