Özlem Üçok

Role of Fine Needle Aspiration Cytology in the Preoperative Presumptive Diagnosis of Ameloblastoma

OBJECTIVE To determine the role of fine needle aspiration cytology (FNAC) on the preoperative presumptive diagnosis of ameloblastoma. STUDY DESIGN Sixty-three patients, diagnosed preoperatively and postoperatively with ameloblastoma, were evaluated between 1990 and 2003. The patients were classified according to whether they were diagnosed with ameloblastoma preoperatively or postoperatively, on histologic examination. RESULTS The accuracy rate for ameloblastoma was 0.95% for all biopsy methods, while the incisional biopsy rate was 75.00%. Concerning clinical diagnosis, ameloblastoma was mistaken mostly (56.41%) for odontogenic cysts (22 of 39). CONCLUSION FNAC should be utilized more commonly on intraosseous and soft tissue lesions in the oral and maxillofacial regions, to obtain sufficient material. It is convenient, inexpensive and noninvasive as compared with other biopsy methods.

Use of the dynamic volume spline method to predict facial soft tissue changes associated with orthognathic surgery

OBJECTIVE The shape of the face can be estimated before the surgery by using 3-dimensional computer programs that provide tools to guide skill modifications. The aim of this study was to present the dynamic volume spline method to predict facial soft tissue changes after the modification of the skull associated with orthognathic surgery. STUDY DESIGN Soft tissue volume is modeled by a dynamic volume spline that includes the elastic behavior of the actual tissue. The model is a hybrid of spring-mass model and finite element model, and combines their advantageous properties. It provides fast and realistic soft tissue simulations. Postsurgical shape of the patients face is estimated by reshaping the skull and letting the soft tissue model relax over the new boundary conditions formed by the new skull shape. Postsurgical estimations were compared with the conventional methods estimations, where the soft tissue is not modeled biomechanically. Also, postsurgical estimations were compared with the actual postsurgical data for 6 orthognathic surgery patients. RESULTS The mean of the error between the estimated shapes and the actual postsurgical shapes was ∼1.8 mm when the whole face was considered. CONCLUSION When the facial soft tissue is modeled by the dynamic volume spline, the postsurgical shape is estimated better than by the conventional method and previous methods in the literature.