Three Dimensional Analysis Of Upper Airway And Temporomandibular Joint In Patients With Class ? Patterns

Skeletal class ? is a common clinical malocclusion,which seriously affects patients,stomatognathic function and facial appearances.Abnormal craniofacial growth will cause changes in the structure of the upper airway and the temporomandibular joint,and even affect their capacities.The aim of this study was to study three dimensional morphological characteristics of upper airway and temporomandibular joint in patients with class ? patterns.Section 1 Three dimensional analysis of upper airway in children and adolescents with class ? patternsObjectiveUsing cone-beam CT(CBCT)and Invivo 5 software to measure the three dimensional oropharyngeal airway volume and morphology in Class II malocclusion patients and study the correlation between upper airway morphology and craniofacial structure in order to provide guidance for reasonable and effective treatment.MethodsCone beam CT data of skeletal class ? and skeletal class ? malocclusion patients(13-18 years)before orthodontic treatment were collected and divided into three groups according to age(3-6 years?7-12 years?13-18 years).Invivo5 software was used to rebuild 3D image data and then oropharyngeal airway volume,height,minimum section area and ratio of the sagittal dimension to transverse dimension of each patient were measured with Invivo 5 software.Independent-samples T test was used to compare the differences of airway morphology and size between class?and class ?malocclusion in SPSS 22.0 software package.Results3-6 years:The oropharyngeal airway volume,velopharyngeal volume,pharynx volume,and minimum section of class ? were smaller than class ?(P<0.01)7-12 years:The oropharyngeal airway volume and pharynx volume of class ? were smaller than class?(P<0.01)13-18 years:The nasopharynx volume of class ? was smaller than class ?(P<0.05).Conclusion1.The shape of upper airway is significantly affected by ages.2.The morphologies of upper airway are varied in children and adolescents with class III patterns,which may be related to the development of the craniofacial skeleton.3.We can effectively study the three dimensional structures of upper airway by using CBCT and invivo 5.Section 2 Three dimensional analysis of temporomandibular joint in children and adolescents with class ? patternsObjectiveThe aim of this study was to study the morphological characteristics of the temporomandibular joint of adolescents and adults with class ? skeletal pattern by using CBCT and invivo 5.MethodsCone beam CT datas of skeletal class ?and skeletal class ? malocclusion patients before orthodontic treatment were collected and divided into two groups according to age:Adolescent Group(12-18years)and Adult Group(18-30 years).Invivo5 software was used to rebuild 3D image data for measuring the three dimensional morphology and condyle,glenoid fossa and temporomandibular joint spaces.ResultsThe condylar anteroposterior diameter of adult is larger than adolescent.The condylar anteroposterior diameter of class ? pattern is not different from class ? pattern.The condylar medialateral diameter of class ? pattern is smaller than class ? pattern.The height of condyle of adults with class ? pattern is the largest among the four groups.The depth of glenoid fossa in adults with class ? pattern is the largest among the four groups,and there are no differences among adults with class ? pattern,adolescents with class ? pattern and adolescents with class ? pattern.The width of glenoid fossa in adults with class ? pattern is larger than adults with class ? pattern.The anterior joint space of class ? pattern is larger than class ? pattern,but the posterior joint space is smaller.ConclusionThe morphology of condyle in adults with class III pattern is longer.The condyle will still grow even after the peak period of growth,which maybe the reason of vertical growth of class III patients.The morphology of joint fossa in patients with class III pattern is broad and shallow,and the condyle is a little forward than usual.The mandibular joint morphology in adults with class III pattern is different from adults with class I pattern in osseous structures.However,the mandibular joint morphology in adolescents with class III pattern is different from adolescents with class I patterns in the position of the condyle.