The Palatal Rugaes’ Variation Of Class Ⅱ~1 Malocclusions Using Extraction Method Treated By PASS Technology

Objective: To investigate whether the maxillary palatal rugaes were changed after orthodondic treatment,in the condition of extracting the bilateral premolars and using the physiologic anchorage Spee’s-wire system to enhance the anchorage.Estimate weather it can be regarded as the stable superposition mark to evaluate the orthodontic curative effect,and provide theoretical basis for dental forensic medicine.Methods:.Total of 50patients(25 males and 25 women)had extracted the first premolars,met the criterion of inclusion and exclusion,treated with the physiological anchorage Spee’s-wire system(PASS)in the Stomatology Department of the Second Affiliated Hospital and the Fifth Affiliated Hospital of Xinjiang Medical University From 2015 to 2021.For the 50 patients before and after the gesso model with a pencil to facsimile,measured on the gesso model before and after the length of the first three palatal rugae,the transverse distance of the same points of the same name palatal rugae in two sides(Tm,Tl),the sagittal distance of the same points between adjacent palatal rugae(AP),and judge the shape and direction of each palatal rugae,finally,the change of the above indicators before and after orthodontic treatment for a comparative study.Results: APm R-0 / 1,APm L-0 / 1,APl L-2 / 3indexes were changed significantly in male group before and after extraction(P <0.05);1R,Tl 2,APm R-0 / 1,APm L-0 / 1,APl R-0 / 1,APl R-1 / 2,APl R-2 / 3,and APl L-2 / 3indexes were changed significantly in famale group before and after extraction(P <0.05).Male group: the variation of the shape of the palatal rugaes have no significant changes before and after treatment(P> 0.05);female group: he shape of L2 was statistically different before and after treatment(P <0.05).Male group: the variation of the direction of L2,R2,R3 were statistically different before and after treatment(P<0.05);famale group: the variation of the direction of R1,R2,R3,L3 were changed significantly before and after treatment(P<0.05).Conclusion: When tooth extraction and correction is combined with physiological anchorage Spee’s-wire system1,the palatal rugae will change before and after tooth extraction treatment,and the change in the lateral endpoints of the palatal rugae is the most obvious,but its morphology is stable.It is not recommended to use the medial 2/3 of the third rugae and the regional palatal vault dorsal to assess orthodontic curative effect.When conducting the personal identification of the population of orthodontic treatment,it is recommended to analyze the morphological indicators of the palate rugae,supplemented by the analysis results of quantitative data.