Characterization of physiologic occlusion.

Abstract

Objectives: To characterize and describe the occlusal relationship in Thai subjects with physiologic occlusion. Materials and methods: One hundred and twenty-four subjects (49 males and 75 females) fulfilled the criteria of physiologic occlusion by Mohl (1988) were examined for the static and dynamic occlusal relationship. Total number of tooth, horizontal and vertical overlap, Angle’s classification were examined for static occlusion. For dynamic occlusion, maximum mouth opening including lateral and protrusive excursions were examined. In addition, the subjects’ occlusal schemes were classified according to the definition from Glossary of Prosthodontic Terms (8th edition) as well as the presence of occlusal interferences during mandibular excursions. Discrepancy between retruded contact positon (RCP) and intercuspal position (ICP) was also performed. Results: The majority of the populations with physiologic occlusion had total number of existing teeth of 28 and Angle’s classification class I. The mean vertical overlap and horizontal overlap were 1.88±1.25 and 2.33±1.31 mm respectively. The average maximum mouth opening, left and right excursive / protrusive movement was 46.52±4.57, 8.77±1.3, 8.55±1.23, and 6.28±1.55 mm respectively. The most common occlusal scheme was group function. Occlusal interference was presented in 20.2% of the population. The most common occlusal interference was protrusive interference (12.1%). About 80% possessed no RCP-MIP discrepancy with the average of 0.15±.0.3 mm. Conclusions: The common occlusal characteristics of physiologic occlusion among Thais are group function occlusal scheme, Angle’s classification I, absence of occlusal interference, approximate 45 mm of maximum mouth opening and absence of RCP-ICP discrepancy.