Objective:To study the craniofacial characters of non-surgical treatment of the female patients with bimaxillary protrusion in northeastern region of China.Methods:80 patients with bimaxillary protrusion in northeastern region of China received orthodontic treatment were divided into two groups,the ANB angles of the first group were no more than 4.7?,the second one exceeds 4.7?.Cephalograms were analyzed in all the subjects.Compared with the normals in Beijing.Results: Most of the female patients with bimaxillary protrusion had shorter anterior cranial bases,longer posterior cranial bases,longer and more prognathic maxillas,longer mandible lengths,higher anterior and anterior upper facial heights,obvious procumbency,thicker mental thickness,procumbent soft tissue profile with a low lip line.Different groups had the features as follows:the main abnormal factors were the maxilla in sagittal aspect of the first group.They had the suitable facial planes.The second group's abnormal factors were the mandible,they had the divergent facial plane.Conclusion:The non-surgical treatment′s patients of bimaxillary protrusion have unique character.The results suggest it is of critical importance to adjust the position of jaws to benefit the improvement of facial features.

Objective To measure the lateral atlanto-dental interval (LADI)of normal atlanto-axial joint in children by MSCT and its MPR techniques,to explore its clinical significance.Methods We performed MPR coronal reconstruction for 207 original images of paranasal sinus scanned in neutral position,measure and compare the bilateral LADI and the variance of bilateral lateral atlanto-dental interval (VBLADI).Results There were 1 25 males and 82 females,the LADI of the former was larger than that of the latter,and there was significant difference between them (P＜0.05),the VBLADI of the former was larger than that of the latter,and there was no significant difference between them (P＞0.05).There were 126 cases younger than 7 years-old,while 81 cases older than or equal to 7 years-old,the bilateral LADI of the former was larger than that of the latter (P＞0.05),while the VBLADI of the former was larger than that of the latter (P＜0.05).Conclusion The asymmetry of bilateral LADI is common in normal children.Subluxation is generally considered suspicious if the VBLADI is larger than or equal to 3 mm,when this occurs,the clinician need to combine the clinical feature and do further examination to make a clarify diagnosis.