Analysis Of The Occlusion And Determination Of Masticatory Efficience Pre And Post RPD Treatment Among Subjects With Dentition Defects Of Kennedy â…  Or â…¡

Objective:Through the analysis of occlusion and determination of masticatory efficiency before and after the RPD restoration among subjects with dentition defects of Kennedy Ⅰ or Ⅱ, quantitative analysis of the differences and changes of occlusion condition and masticatory efficiency before and after the RPD treatment, Providing an objective reference and basis to evaluate the efficacy of the RPD restoration.Methods:12 patients with distal extention edentulous were selected, according to the type of deletion divided patients into two groups, which 5 cases of unilateral distal extension edentulous as experimental group one,7 cases of bilateral distal extension edentulous as the second set of experiments. T-Scan Ⅲ system was used to test the patient’s occlusal condition before restoration, one month and three months after restoration, including the number of occlusal contact points, occlusal contact area, the position of the center of force, left and right sides of the bite force accounted for the percentage of total bite force, analyze the distribution and balance of bite force before and after the restoration. With visible spectrophotometer to analysis of masticatory efficiency of patients before and after treatment. The data was analyzed with SPSS 17.0 software package for paired t test and two independent sample t test.Results:1. After RPD, occlusal contact area and the number of the occlusal contact points among two groups of patients were significantly increased, the results had significant difference (P< 0.01);in the group 1, compared with one months after restoration the occlusal contact area and the number of contact points of three months after restoration were increased, the difference had statistical significance (P < 0.05). In the experiment group Ⅱ, compared with one months after restoration, the number of occlusal contact points of three months after restoration increased, and the difference was statistically significant (P<0.05).2. In experimental group 1, Compare to before restoration, the displacement of COF in anterior to posterior direction had significant differences one month and three months after restoration (P< 0.05), the horizontal displacement had no statistically significant differences after restoration (P>0.05). In experimental group Ⅱ, COF moved to the defected side, Compare to before restoration, the horizontal displacement had significant differences one month and three months after restoration (P< 0.05), the displacement of COF in anterior to posterior direction had no statistically significant differences after restoration (P>0.05).3. In experimental group 1, after RPD repair, the difference between left and right sides of the bite force accounted for the percentage of total bite force was not significant, and the results were not statistically significant (P>0.05). In experimental group II, the occlusal force was distributed in the non side to the side of the defect sides. Compare to before restoration, the statistical results of three months after restoration were significantly different (P<0.01).4. In experimental group 1, Compare to before restoration, the OT and DT were increased when one month and three months after restoration, the results had higher significant difference (P< 0.01). In experimental group II, compare to before restoration, the OT and DT of one month after restoration were increased, the results had significant difference (P< 0.05), compare to before restoration, the OT was decreased when three months after restoration, but the results had no significant difference (P>0.05),DT was decreased when three months after restoration, the results had significant difference (P< 0.05).5. After RPD restoration, the masticatory efficiency among two groups of patients were improved significantly, the differences had higher statistical significance (P<0.01).Conclusion(s):1. After RPD repair, the occlusal contact area and the number of occlusal contact points increased significantly.2. After RPD repair, the occlusal balance of patients was increased. COF was more close to the center of the ellipse, the difference between the percentage of the left and right side bite force was smaller, the whole occlusal contact became more balanced and stable.3. After RPD restoration, patient’s chewing efficiency is significantly improved. For patients with distal extension edentulous, the loss of the main functional teethes resulted in serious damage to the chewing efficiency, and the early repair treatment should be advocated for the patients who suffered from dentition defects of Kennedy Ⅰ or Ⅱ.4. After RPD restoration, the occlusion time and disclusion time of bilateral distal extension edentulous patients increased three months after restoration; occlusion time and disclusion time of unilateral distal extension edentulous patients somewhat shorter three months after restoration.5. T-Scan Ⅲ occlusal analysis system can provide objective, true and accurate analysis of the differences and changes of occlusion condition before and after RPD treatment, as well as provide an objective reference and basis to evaluate the efficacy of the RPD restoration.