Prevalence and Severity of Mandibular Asymmetry in Non-Syndromic, Non-Pathological Caucasian Adult

BACKGROUND: Mandibular Asymmetry has been analysed in diverse, non-Caucasian groups, principally children. No large-scale analysis has been carried out on non-syndromic Caucasian adults. AIMS: To evaluate the prevalence and severity of mandibular asymmetry; to identify gender differences and evaluate side predominance, where no actual patient concern was reported and no surgery was being contemplated. MATERIALS AND METHODS: Dental records of 437 patients were analysed. This large patient cohort had no reports of pathology involving the rami or condyles or the TMJ. Following strict ‘Inclusion Criteria’, 200 DPTs were analysed: 96 male, 104 female patients (age range 18-93 years, average 59.41 years, SD ±13.94). STATISTICAL ANALYSIS: Intra-observer error was determined, r = 0.99. The Student t-test determined differences between the sides for ramal height measurements. and gender. The Asymmetry Index evaluated the severity of asymmetry between condylar heights and ramus. RESULTS: 18 % of the cohort presented substantial Mandibular Ramal Asymmetry (MRA). Male prevalence was 23.9%; female prevalence was 12.5%; severity was 18.82% and 32.88% respectively. CONCLUSIONS: Incidence of asymmetry, though significant, has no detrimental effect on the patient's well-being or dental health. Facial surgery that is contemplated in response to both minimal and extreme asymmetry may well be carried out as a result of other cultural demands.