The Study Of Occlusal Contact Characteristics In Patients With Cracked Tooth

Objective To investigate the occlusal characteristic in patients with cracked tooth by investigating the characters of occlusal contacts in patients with cracked tooth and comparing with normal people.This study aimed to find the etiology of cracked tooth in light of occlusion,to full the objective indices of occlusal characteristic of cracked tooth,to provide a theoretical basises and objective indices of early occlusal adjustment in the treatment of cracked tooth.Method 30 patients with cracked tooth were selected as the experiment group,30 person with normal occlusion were selected as the control group.The data of occlusal contacts of experiment group and control group were recorded during intercuspal positition, protrusive movement and lateral movement.The results were analyzed by SPSS software according to statistics method.The t-test was used to analyze the offset in transversal of center of occlusal force,the offset in vertical of center of occlusal force, the bite force percentage, the occlusion time, the protrusive disclusion time, the lateral disclusion time.The chi-square test was used to analyze the the occurrence rate of premature contact,protrusive occlusal interference and lateral occlusal interference.Results(1) The range of age in this study was in those 36-58 years.The men were more than women,the occurrence of cracked tooth in turn were maxillary first molars, mandibular first molars,maxillary second molars,mandibular second molar, maxillary first molars.(2) The occurrence rate of protrusive occlusal interference and lateral occlusal interference in patients was higher than normal occlusion,there were significant differences between them.The occurrence rate of premature contact showed no significant differences between experimental and control group.(3) The offset in transversal of center of occlusal force,the bite force percentage of affected side,the occlusion time,the protrusive disclusion time,the lateral disclusion time in the experimental group were longer than those in the control group,there were significant differences between them. Offset in vertical of occlusal force showed no significant differences between experimental and control group.Conclusion (1) The characteristic of occlusal contacts in patients with cracked tooth has significant differences with individual normal occlusion. Its center of occlusal force was close to affected side and the bite force was unbalanced in intercuspal position.There were protrusive occlusal interference and lateral occlusal interference, in protrusive movement and lateral movement.The occlusion time and the disclusion time were prolonged.(2) The results of the study indicated that the occlusal interference and unbalanced the bite force were factors closely related to cracked tooth.Early occlusal adjustment in the treatment of cracked tooth should be performed in view of the full dentition.(3) The offset in transversal of center of occlusal force, occlusion time and disclusion time could be taken as the objective indices of early occlusal adjustment in the treatment of cracked tooth.