The Effect Of Tongue On Sagittal Maxillofacial Form Based On Cone-beam Computed Tomography Data

Objective:To study the effect of tongue on sagittal maxillofacial form in order to provide clinical theoretical basis for preventing the occurrence of malocclusion,decreasing the severity and reducing the risk of relapse after orthodontic treatment by tongue functional training.Methods:We enrolled 430 patients who were scheduled to undergo CBCT.The tongue of each patient’s was coated with a contrast agent.According to the inclusion criteria,52 patients were selected(age:21.13±4.95 years),cases were divided into three groups according to the skeletal pattern(ANB):skeletal Class-I,skeletal Class-II,and skeletal Class-III malocclusion groups.The maxillofacial form and tongue were evaluated with Invivo 5 and Mimics16.0.The statistical analysis was performed with SPSS 21.0.Results:1 Relationship between tongue volume and maxillofacial formThe tongue volumes of the three groups were 23.61±3.36cm~3(Class-Ⅱ),29.37±5.49cm~3(Class-Ⅲ)and 29.05±6.62 cm~3(Class-Ⅰ)respectively.The tongue volume was significantly smaller in Class-Ⅱpatients than in Class-Ⅰ,Class-Ⅲpatients(p<0.05).The tongue volume showed a negative correlation with ANB(r=-0.433,p<0.01).And there was a statistically significant correlation between Pogy,the length of the mandible and tongue volume(r=-0.373,p<0.01;r=+0.425,p<0.01)2 Relationship between tongue position(TTx,TTy,TTz)and maxillofacial formTTy showed a positive correlation with Pogy,COLy,CORy,Ay(r=+0.755,p<0.01;r=+0.460,p<0.01;r=+0.479,p<0.01;r=+0.813,p<0.01)and a negative correlation with the mandible length(r=-0.531,p<0.01).3 Relationship between hyoid position(Hx,Hy,Hz)and maxillofacial formHy showed a positive correlation with ANB,Ay,Pogy,COLy,CORy(r=+0.324,p<0.05;r=+0.370,p<0.01;r=+0.663,p<0.01;r=+0.379,p<0.01;r=+0.310,p<0.05)and a negative correlation with the mandible length(r=-0.479,p<0.01).Hz showed a positive correlation with Pogy(r=+0.300,p<0.05)and a negative correlation with the mandible length(r=+0.336,p<0.05).Conclusion:As the volume of the tongue increases,the position of the hyoid bone and tongue move forward,the length of the mandible will increase,which is easy to cause skeletalⅢmalocclusion.