The Occlusion Analysis Of Ann Ⅱ~1 Borderline Cases After Extraction Or Not

Background:Ann Ⅱ~1 malocclusion is a common clinical wrong occlusion type,above the jaw thrust forward,mandibular retraction,front teeth deep cover,molar relationship as the main characteristics of the far.Treatments of the Ann Ⅱ~1 malocclusion divided into tooth extraction and tooth extraction treatments based on whether the tooth extraction rectification.Regarding whether tooth extraction or not,clinical orthodontists mainly consider the crowding degree of dentition,spee curve height,soft tissue profile,bone profile and tooth arch protuberance.Treatments for tooth extraction,Ann Ⅱ~1 malocclusion can take advantage of the maxillary adduction maxillary anterior teeth,tooth extraction gap correctional deep cover,improve the side looks beautiful,mandible using forward molar tooth extraction clearance,correct molar relationship.No tooth extraction rectification can enlarge bow,Ⅱ traction,pushing molar to far way to adduction front teeth,correct molar relationship.In most cases,whether in clinical doctor tooth extraction can agree,but there are still a part of malocclusion in the critical state of can tooth extraction or not,they have no obvious indications tooth extraction or no,extraction or non-extraction can achieve the goal of balanced,stable,beautiful,we will be part of this case for critical cases.One of the clinical bases for orthodontists to determine whether orthodontic patients should be treated with tooth extraction or non-extraction is lateral appearance protrusion.The commonly used judgment principle is that patients with large facial protrusion usually need tooth extraction correction,while patients with small facial protrusion usually do not need tooth extraction treatment.However,whether tooth extraction or tooth extraction should be used to treat critical cases with facial protrusion close to normal is a difficult point in the clinical design of orthodontics.Objective:Analyze the occlusion of Ann Ⅱ~1 malocclusion critical cases after the orthodontic treatment of extraction or non-extraction,in order from the aspects of occlusal contact to provide a reference for the establishment of critical cases.Methods:Selected 126 cases of Ann Ⅱ~1 malocclusion of half a year from 2016 to 2018 in the first affiliated hospital of Zhengzhou university Huiji campus clinic orthodontics division,three orthodontic doctors experienced by most certain principles and clearly not agree principle to select the final sample,41 cases of critical cases.Treatments of the cases to record the plan whether tooth extraction will be divided into 30 cases critical to extraction treatment group(14 cases)and non-extraction treatment group(16 cases),Tee-tester bite analyzer is used to measure the record three groups of patients after the treatment of the occlusal contact indicators,total contact area(TCA),total occlusion force(TOF),asymmetry index of occlusal force(AOF),centre of force(COF),record every occlusal contact data of the extraction and non-extraction treatment for patients with malocclusion.SPSS21.0 statistical software was used to sort,screen and statistically analyze the data of the three groups.Independent sample t test was used to compare the occlusal indexes of critical cases after extraction correction and non-extraction correction.Results:1.The comparison of malocclusion group,extraction treatment group,non-extraction treatment group in TCA、TOF,malocclusion group with extraction treatment group there was no significant difference(P > 0.05),the difference between extraction treatment group and non-extraction treatment group,malocclusion group and non-extraction treatment group had statistical significance(P < 0.05).2.Extraction treatments and non-extraction group,malocclusion group and non-extraction treatment group,the force per unit area value difference was not statistically significant(P > 0.05),malocclusion group and extraction group and correcting unit area there are significant differences between groups(P < 0.05).3.The asymmetry index of occlusal force(AOF)and centre of force(COF)of extraction treatment group and non-extraction treatment group,there were no statistically significant difference(P > 0.05).Malocclusion group with extraction treatment group,malocclusion group and non-extraction treatment group,between asymmetry index of occlusal force(AOF),center of force(COF),difference was statistically significant(P < 0.05).Conclusion:1.Patients without tooth extraction correction have more advantages in occlusal contact area and bite force than patients with tooth extraction correction.2.The occlusal improvement was more significant in patients treated with tooth extraction.3.Extraction or non-extraction has no effect on ICP a occlusal stability,both treatments are able to achieve a stable and balanced occlusion.