Clinical Study On The Occlusal State Affecting The Occurrence Of Human Tooth Crack

Objective1.To observe and analyze the clinical characteristics of patients with cracked tooth,and to explore the related factors of cracked tooth.2.Combine the occlusal characteristics with the data of T-Scan occlusal analyzer,and to further study the mechanism of occlusal characteristics in the development of cracked tooth.3.To explore the comprehensive treatment effect of cracked tooth,and to screen the key factors affecting the treatment effect of cracked tooth,so as to provide evidence for the selection of appropriate clinical treatment programs.Methods1.Retrospectively analyze the clinical data of 93 patients with 139 diagnosed as "cracked tooth" in the special department of Henan Stomatology Hospital from 2011 to 2019,and make analysis on the clinical characteristics,occlusal characteristics and dental characteristics of cracked tooth.2.Retrospective analysis of the medical records of 42 patients(67 cracked teeth)who follow up treatment on time,the factors that may affect treatment effect of the cracked teeth were recorded and analyzed by logistic regression analysis.3.12 patients with cracked tooth were selected as the experimental group,and 12 matched normal persons with healthy teeth were randomly selected as the control group.The occlusal characteristics of the two groups were recorded by T-Scan? occlusal analyzer.The quantitative data were tested by paired t test,the qualitative data were tested and analyzed by Fisher exact probability method.The relationship between occlusion characteristics and disclusion(occlusion)time is measured by Spearman rank correlation.Test level Alpha = 0.05.Results1.One hundred and thirty-nine cracked teeh of 93 patients were included,the ratio of male to female was 1:1.16,most of them were 36-65 years old.The prevalence of maxillary first molar was high(30.2%),and the crack was multiple(29.0%)and symmetrical(17.2%).Sixty-three teeth showed responses to the bite test(45.3%).Fifty-seven teeth(41.0%)had a deep pocket(over 3 ?)and fifty-two teeth had alveolar bone angular absorption(37.4%).High steeper cusp(44.6%)and overbite(58.3%)was common in cracked teeth.2.Asymmetry index of occlusal force,occlusion time and disclusion time in experimental group were higher than those in control group,the difference was statistically significant(P<0.05).The position of Center of force,premature contact,interference of occlusion,high steeper cusp and overbite in experimental group were higher than normal occlusion,Fisher's Exact Test showed that there was a significant difference between them(P<0.05).The overbite,high steeper cusp,premature contact or occlusal interference were positive correlation with DT and OT(P<0.05).The overlap was a positive correlation between to DT(P<0.05).3.The success rate of comprehensive treatment in 42 patients(67 cracked teeth)was 82.1%.The results of multivariate analysis showed that the crown restorative methods and the deep pocket were closely related to the treatment effect of cracked tooth(P<0.05).Conclusion1.Overbite,high steeper cusp,premature contact and occlusal interference are related to the cracked tooth.2.The disclusion(occlusion)time in patients with cracked tooth is longer than the matched normal persons with healthy teeth,the occlusal contact time is longer,the occlusal stability is poor.3.The depth of periodontal pocket and crown repair methods are independent factors influencing the success rate of cracked tooth therapy.