Morphological Study Of Teeth And Alveolar Bone In Persons With Frontal Occlusal Plane Inclined

Objective:Previous studies on the occlusal plane mostly focused on the lateral side,and there are few reports on the morphological research of the frontal occlusal plane inclined.There is no report on the morphological characteristics of the teeth and alveolar bone of such persons.In this study,the CBCT NNT viewer and Dolphin Image software were used to measure the morphological measurement indexes of teeth and alveolar bone of persons with frontal occlusal plane inclined.Features provide a reference for the diagnosis and treatment of occlusal plane inclined.Methods:The experimental group was selected from 2018-2021 to the Orthodontics Department of the Affiliated Stomatological Hospital of Kunming Medical University,20 subjects(including 9 males and 11 females)whose frontal occlusal plane inclined angle was greater than 3°.The control group was selected as 20 subjects whose frontal occlusal plane inclined angle was less than 3°,no facial asymmetry deformity,neutral occlusal relationship between the molars,the midline of the upper and lower dentition aligned with the midline of the face,and no severe malocclusion(among them)7 males and 13 females).Part Ⅰ:Convert the subject’s CBCT image data into DICOM format and import it into Dolphin Image 11.9 software to generate lateral cranial radiographs,trace and measure the OPA angle(anterior occlusal plane angle)and OPP angle(posterior occlusal)on the lateral radiograph.Plane angle),OPC angle(maxillary occlusal plane angle),statistically analyze the two sets of measurement data to study whether statistical difference existed.Part 2:The upper and lower central incisors,the first premolars,and the first permanent molars on both sides represent the anterior,middle,and posterior segments of the dentition,respectively.Use CBCT NNT viewer and Dolphin Image software to measure the tested tooth and its alveolar.For bone measurement indicators,compare and analyze whether there are differences in the measurement data on both sides of the same group of subjects through statistical methods;and compare whether there are differences in the same measurement index between the experimental group and the control group to analyze morphological characteristics of the teeth and alveolar bone of the patients with frontal occlusal plane inclined.Results:1.The inclination of the lateral occlusal plane in persons with frontal occlusal plane inclined is not statistically different from that of persons with normal occlusal planes(P>0.05).2.Bilateral comparison study of the patients with frontal occlusal plane inclined showed that:① The clinical crown height of the lower posterior segment of the low-side was significantly greater than that of the higher one(P<0.05),but there was no significant difference between the two sides and the normal control group(P>0.05);②The Tip of the upper front segment of high-side was significantly greater than that of the low-side,and the low-side was significantly less than the average of the normal control group(P<0.05).The Tip of the anterior and posterior segments of the mandibular dentition was greater on the low-side than on the high-side,and the difference was statistically significant(P<0.05).The measured value of the high-side of the anterior segment of the mandibular dentition was significantly less than the average value of the control group(P<0.05),while there was no significant difference between the two sides of the posterior segment of the mandibular dentition and the average value of the control group(P>0.05).③the Torque angle for middle maxillary teeth is low-side significantly greater than the high-side,and low-side measuring average value significantly greater than the control group,with significant difference(P<0.05);The Torque angle of middle part of mandibular dentition is high-side significantly greater than the low-side,and average measured values of low-side is less than the control group obviously,the difference was statistically significant(P<0.05).3.The experimental and control group comparative study showed that:①The clinical crown height in the middle maxillary dentition of the experimental group was higher than the average of the control group(P<0.05);② The inclination of alveolar bone in the posterior segment of mandibular dentition was greater in the experimental group than in the control group(P<0.05).③The torque Angle of the anterior segment of the mandibular dentition was less than the mean of the control group,and the difference was statistically significant(P<0.05).Conclusions:1.In persons with frontal occlusal planes inclined,the inclination of the lateral occlusal plane can be expressed as normal.Therefore,X-ray lateral cephalometric measurements cannot be used as a diagnostic basis alone.2.The difference in the morphology of the teeth and alveolar bone of persons with frontal occlusal plane inclined on both sides mainly exists in the anterior segment,middle segment of the maxillary dentition,and full mandibular dentition.The clinical dental crowns on both sides of this area should be adjusted targeted when formulating treatment plans.Height,crown axis inclination and torque angle.3.Persons with the frontal occlusal plane inclined and the normal occlusal planes’ teeth and alveolar bone morphology differences mainly exist in the middle of the maxillary dentition and the anterior and posterior segments of the mandibular dentition.More attention should be paid on the clinical crowns height,innclination of alveolar bone and crown torque angle in these area directly when making the traetment plane.4.Persons with the frontal occlusal plane inclined.Their midline of the upper dentition is deviated to the lower side of the occlusal,and the midline of the lower dentition is deviated to the higher side of the occlusal.Attention should be paid to midline of dentition when clinical examination and treatment planning.