Central Incisor Vertical Overlap in Functional Models of Occlusion Nagryz pionowy siekaczy centralnych w modelach funkcjonalnych zgryzu

Background. Vertical overlap of incisors is regarded as an important element of the anterior teeth guidance in de− termining the presence or absence of opposing posterior teeth contacts during the protrusive and lateral excursions of the mandible. Till now, the different values of the incisal overlap have been considered as a standard in natural dentition, as well as in prosthetic rehabilitation of patients with partial missing teeth. Objectives. The aim of the present study was to explain those controversial opinions by evaluating the real valu− es of the central incisor vertical overlap in dependence on functional models of occlusion in natural dentition. Material and Methods. The studies were performed in a population of 500 students of Stomatology Faculty in Wroclaw, aged from 20–25 years. Among them, a group of 326 students was selected with a complete and natural dentition and without rotation or crowding of the anterior teeth. In the selected group of students, the functional models of occlusion were recognized, and the central incisors vertical overlap was measured in the intercuspal po− sition. For statistical estimation of results of the studies, Student’s test−t was used with p−value < 0.05. Results and Conclusions. The studies revealed that vertical overlap of the central incisors ranged from a small to very high values, 0–10 mm, in the most frequent functional models of occlusion. The statistical analysis indicated that the mean value of the central incisor vertical overlap found in bilateral cuspid protected occlusion was the highest and different significantly from that in other models of occlusions such as unilateral cuspid protected occ− lusion, group function occlusion or balanced occlusion. Moreover, vertical overlap of the central incisors in group function occlusion was very similar to that found in unilateral cuspid protected occlusion. The observed differen− ce of the mean values between the above mentioned occlusions was not statistically significant. The lowest mean value of the central incisor overlap was found in balanced occlusion. The value was different significantly from that in group function occlusion. The data obtained from the studies may be very helpful in prosthetic rehabilita− tion for creating the proper occlusal relationships according to selected concept of occlusion (Dent. Med. Probl. 2003, 40, 1, 75–79).