Occlusal characteristics in subjects with facial pain compared to a pain-free control group.

Facial pain has been considered a common symptom of temporomandibular disorders (TMD) with a multifactorial etiology. There is controversy regarding the role of occlusion in the background of facial pain and TMD. The aim of the study was to compare the occlusal relationships with two definite measurements in subjects with and without facial pain, in a population-based sample of young adults. The study is part of the Northern Finland 1966 Birth Cohort Project. A subsample of the cohort was formed based on a questionnaire and consisted of 104 subjects, including 52 subjects with facial pain and 52 non-pain controls. Analyses of the dental occlusion of the subjects were performed in gypsum casts by following two methods: 1. the Peer assessment rating (PAR), according to Richmond, et al. (Method 1), and 2. the bilateral canine relationship and the dental midline measurement by the method presented by Pirttiniemi, et al. (Method 2). Method 2 showed higher sensitivity in detecting sagittal occlusal discrepancies than Method 1. Assessment of the intermaxillary relationships in terms of the canine relation showed the lower canine to be more mesially located in the facial pain group, compared to the controls, measured by Method 2. It can be concluded that differences in occlusal sagittal relationships, especially mesial canine relation, seem to correlate with facial pain symptoms at population level.