Three Dimensional Cephalometric Analysis In Yunnan And Its Clinical Application

Objective: The objective of this study is to analyze the people of Yunnan with 3D cephalometry, to establish a set of values of craniofacial hard tissue,and in order to provide basis for diagnosis and therapy of the dentofacial deformity and temporomandibular joint disease.Materials and Methods: Part one: 727 patients were selected at the Affiliated Stomatological Hospital of Kunming Medical University. Of all the cases, there are 365 males and 362 females, the mean age was 29.5 years old (range, 11-65years).According to the age, all cases were divided into three groups. The data from CBCT scan were analyzed using SimPlant11.04 software depended on the 24 key landmarks on the three dimentional jaw. Part two: 4 cases with maxillofacial malformation, 10 cases of temporomandibular joint ankylosis and 6 cases of coronoid process hyperplasia without organic temporomandibular joint disease were recruited at the Affiliated Stomatological Hospital Affiliated to Kunming Medical University,cephalometry was analyzed on their three dimentional jaw. 4 cases with maxillofacial deformities underwent orthognathic surgery, 10 with temporomandibular joint ankylosis and 6 with coronoid process hyperplasia underwent coronoidectomy.Postoperative opening month was statistically analyzed.Results: 1. There were significant differences between CBCT-2D and CBCT-3D including the measurement project of bone tissue angle and alveolar tissue angle, line distance measurement project and facial width, mandibular width and zygomatic width (P<0.05). There were significant differences between male and female about facial width, mandibular width and zygomatic width of CBCT-3D (P<0.05). Adult face lower height (ANS-Me) has significant difference between male and female (P<0.05).2. In 4 cases with maxillofacial deformity, the orthognathic surgery was deemed successful, healing course was uneventful. Acceptable maxillomandibular relationship,satisfactory aesthetic results with good facial contour and symmetrical lower lip were achieved based on clinical examination. 10 cases of temporomandibular joint ankylosis and 6 cases of coronoid process hyperplasia were diagnosed with the length of the coronoid process. The mouth opening in all cases was obviously improved following the coronoid process resection.Conclusions: 1. There are several differences between the results of CBCT-3D and CBCT-2D, but the CBCT-3D data have more reliability. In addition, the height of the lower face in the males is higher than that in the females. Generally, the widths of the facial, mandibular and zygomatic in the males are more than that in the females.Based on CBCT, three dimensional cephalometric value can provide a reference for clinical.2. All patients' appearances and stomatognathic system were significantly improved following the orthognathic treatment. The measured values are the reference for clinical diagnosis and virtual surgery, and digital technique could effectively improve the overall treatment level of orthognathic surgery, and has an effective reliability. In addition, the values of the length of coronoid process could provide a better reference and clinical application value.