Occlusal contacts in maximum intercuspation in normal dentitions.

A cross-sectional study of the contacts in maximum intercuspation was undertaken using a method to identify occlusal contacts, which is indicated as satisfactory by modern research. The aims were to describe in subjects with normal dentitions and normally functioning masticatory systems: (a) the general distribution of contacts; (b) the numbers in the various classes and types of occlusal contacts; (c) the numbers of teeth without contact. A randomized sample of 18 women and 20 men was used. Classical theoretical proposals for the numbers, distribution and nature of occlusal contacts were not supported. Wide variability was evident and asymmetry of distribution on the right and left sides of individual subjects was common. Contacts with stabilizing tendencies involved the mandibular supporting cusps in 79% of occurrences. Overall, the difference in the number of contacts with stabilizing effects was not significantly different from the number with unstabilizing tendencies. Contacts with mechanically unstabilizing effects did not produce clinically discernible, unfavourable sequelae in the dentitions. Because of the sparse number of stabilizing contacts, interventions involving the occlusal surfaces should maintain or improve on the number of such contacts in maximum intercuspation.