Relationship Between Occlusion, Orthodontic Treatment and Temporomandibular Disorders

Objectives: This study presents a general objective and a specific objective. The general objective was to analyze and compare the presence of temporomandibular disorder in individuals with or without normal occlusion. The specific objective was to evaluate the influence of orthodontics in individuals with and without normal occlusion.
Methods: Eighty patients of the Clínica Universitária Egas Moniz, Instituto Universitário Egas Moniz, in Almada, Portugal since March to July, 2019 were invited to participate in this study. Initially, it was requested the signature of the informed consent. Then, each participant answered two questionnaires: the first intended to investigate whether or not the participant did orthodontic treatment in the past, and the second questionnaire was the Symptom Questionnaire, a complement of the Diagnostic Criteria for Temporomandibular Disorders (DC / TMD). Finally, two clinical examinations were performed: The first to evaluate the current presence of normal values in nine reference occlusal features and the second, the DC/TMD itself, to detect the presence of temporomandibular disorders.
Results: The correlation between malocclusion and the manifestation of temporomandibular disorders was not clinically significant, with a coefficient of p < 0,463. In patients with normal or non-normal occlusion, the use of orthodontic braces in the past has also been clinically irrelevant concerning the prevalence of temporomandibular disorders (p < 0,566).
Conclusions: The results confirm the absence of relevant clinical effects of occlusion in regard to temporomandibular disorders in the sample of this study. The low correlation value between individuals who have or have not used orthodontic braces and these dysfunctions suggests that orthodontic treatment does not play a role in their development.