The CBCT Analysis Of The Degree Of Maxillary Sinus Pneumatization In Skeletal Class Ⅱ Adolescents

Objective:To compare the degree of maxillary sinus pneumatization in skeletal class Ⅱ malocclusion adolescents with different vertical skeletal patterns by cone beam CT(CBCT),and to investigate the correlation between the degree of maxillary sinus pneumatization and maxillofacial morphology as well as the size of the maxillary sinus and the vertical skeletal patterns.Methods:CBCT images of 60 skeletal Class Ⅱ malocclusion adolescent patients were collected.Depending upon the SN-Go Gn angle,The subjects were divided into three groups:low-angle,normal-angle and high-angle.CBCT images and lateral cephalograms were taken in all patients.The CBCT images were reconstructed in three dimensions using MIMICS 14.1 software to measure the length,width,height,and volume of the maxillary sinus on the right and left sides,as well as the width of the midface.Lateral cephalograms were analyzed by Win Ceph8.0 software.To compare the variability of the degree of maxillary sinus pneumatization in the low-angle,normal-angle,and high-angle groups.To investigate the correlation between the degree of maxillary sinus pneumatization and maxillofacial morphology as well as the size of the maxillary sinus and the vertical skeletal patterns.ResultsThe maxillary sinus showed no significant difference in size between left and right sides or sexes.The volume,width and height of maxillary sinus in skeletal Class Ⅱ high-angle groups were greater than those in normal-angle groups and low angle groups(P<0.05).There was no significant difference in maxillary sinus measurements between normal-angle groups and low-angle groups.The volume and height of maxillary sinus were positively correlated with S-Ba、N-Ba、Mo-PP、N-ANS、S-Ar、∠SN-Go Gn、Zy-Zy.The length of maxillary sinus was positively correlated with S-N、S-Ba、N-Ba、ANS-PNS、N-ANS、S-Ar;The width of maxillary sinus was positively correlated with Mo-PP、N-ANS、∠SN-Go Gn.Conclusion:The degree of maxillary sinus pneumatization in skeletal Class Ⅱ high-angle patients is higher than that in normal-angle patients and low-angle patients.The degree of maxillary sinus pneumatization had correlation with maxillofacial morphology.The greater the mandibular plane angle,the length of cranial base and the height of the midface,the greater the pneumatization degree of maxillary sinus.Understanding this phenomenon plays an important guiding role in the formulation,implementation and prognosis of orthodontic treatment plan.