Three Dimensional Analysis Of Upper Airway In Adults With Class ? Skeletal Patterns

ObjectiveIn order to detect the difference of upper airway form between class ?and class ?skeletal patterns,discuss the effect of the position and dimension of the maxilla and mandibular on upper airway and explore its mechanism.In order to evaluate the shape of upper airway before treatment,provide theoretical fundation for making effective clinical treatment plan and prevent the happening of OSAHS.MethodsSelecting patients' CBCT data from 2014 to 2016,radiology department of the first affiliated hospital of zhengzhou university,Stomatological hospital of Henan province.60 adults were selected and divided into three groups according to SNA,SNB and ANB angle.Each group contains 10 males and 10 females.Collect cone-beam computed tomography images before treatment and use Dolphin 11.5 to rebuild 3D image data.After construction,upper airway can be divided into four sections,that's nasopharynx,velopharyngeal,tonguepharyngeal,laryngopharyngeal.Then to measure airway lengths,lateral and anteroposterior dimensions,cross-sectional area and volumes.The results were statistically analyzed and evaluated.ResultsAll measurements of nasopharynx,cross-sectional area and lateral dimension of velopharyngeal for maxillary retrusion of Class ?was significantly lower than mandibular protrusion of Class ?and Class?.Length,lateral dimension,crosssectional area and volume of tonguepharyngeal and length,lateral dimension,crosssectional area of laryngopharyngeal for mandibular protrusion of Class ? were significantly higher than maxillary retrusion of Class ?and Class?.There were statistical differences among the three types.Cross-sectional area and volume of nasopharynx and velopharyngeal had positive correlation with SNA and ANSPNS,Cross-sectional area of tonguepharyngeal and laryngopharyngeal and volume of tonguepharyngeal had positive correlation with SNB,Go-Gn,Ar-Gn.And all measurements had no correlation with ANB.Conclusions1.There are differences between class ? and class ? skeletal patterns in adults for the 3D features of upper airway.It was affected by the length and position rather than the relative position of maxilla and mandible.2.The shape of upper airway is an oval and the transverse diameter is significantly larger than sagittal diameter at all segments.The minimum area of oropharyngeal airway is located in velopharyngeal.3.CBCT and Dolphin are practical tools for evaluation of airway,which can provide precisely measure of the three-dimensional features of airway,and provide theoretical fundation for the reasonable treatment plans making.