A study to correlate the incidence of cross arch balance and working side occlusal wear facets among different age groups: An in vivo study.

Introduction: The prevalence of group function and canine guided occlusion is common in natural dentition, but cross arch balance is not often seen. Hence, a study was carried out with following objectives: Analysis of incidence of cross arch balance in different age groups and working side occlusal wear facets in following subjects. Materials and Methods: A total of 200 patients with natural dentition were included in the study. Subjects with cross arch balance were analyzed for working side occlusal wear facets. Data were analyzed statistically by Chi-square test. Results: The incidence of cross arch balance in the study group was 0.7%. On examination, subjects with group function on the working side and cross arch balance on the non-working side had more occlusal wear facets. Conclusion: From the study, it was observed that there was no significant variation in the number and extent of wear facets between the cross arch and without cross arch subjects due the smaller sample size hence it was difficult to conclude the relationship non-working side contact as interference and its influence in wearing of dentition in this study.

Occlusal scheme in a group of Thais

PURPOSE: To study the distribution of various occlusal schemes as well as associated static occlusal relationship among Thais. MATERIALS AND METHODS: The subjects' occlusal schemes on the left and right sides were classified as canine protected occlusion, group function, or unclassified according to the definition from Glossary of Prosthodontic Terms (8th edition). In addition, the presence of occlusal interferences during mandibular excursions were recorded. The measurement of the horizontal overlap and vertical overlap was also performed. Chi-square, One-way ANAVA and Mann-Whitney U statistical tests were used with level of significance set at P=.05. RESULTS: Total of 104 subjects were included in this study. The ratio for male to female was 1.8 to 1. Average age of the population was 25.01+/-6.87 years old. The mean vertical overlap and horizontal overlap were 1.94+/-1.20 and 2.41+/-1.32 mm respectively. The majority of the populations (68.3%) possessed group function occlusal scheme. For the remaining, 17.3% possess canine protected occlusion and 12.5% possess combination of both occlusal schemes. We also found that occlusal interference was presented in 20.2% of the population. The most common was protrusive interference (57.14%), the second was balancing interference (38.1%) and the third was working interference (4.1%). CONCLUSION: Among Thais, the most common occlusal scheme was group function, however there were no significant occlusal factors related to any particular occlusal scheme.

A Clinical Study To Evaluate Tooth Contact Patterns And Correlation With Masticatory Efficiency in Dentulous Subjects.

A variety of functional tooth contact patterns exist in population of young adult patients.The purpose of the present study is to find the relationship between different lateral tooth contact patterns and dental morphology and their effect on masticatory efficiency. Forty young dentulous subjects were selected and their impression with irreversible hydrocolloid was made. Polyvinyl silicone bite registration paste was used to record lateral tooth contact patterns in functional range of mandibular movement. Overjet and overbite including mesiodistal relation of tooth recoded with cast secured in the intercuspal position and masticatory efficiency was determined by calorimetric method by using raw carrot. Among all subjects 15% having canine protection, 55% group function, and 30% balance occlusion. There is positive correlation between age and masticatory efficiency [r=+0.656, p<.01] and negative correlation between overjet and masticatory efficiency [r=-0.409, p<0.01]. In the present study Canine protection occlusion had significantly lower mean masticatory efficiency than group function and balanced occlusion group. This signifies that the masticatory efficiency is dependent on lateral tooth contact patterns.