Retrospective Analysis Of Ameloblastoma Recurrence Factors

Objective:Ameloblastoma is an odontogenic tumor which is derived from odontogenic epithelial, and the onset of position is main in maxillo facial. It belongs to the category of the benign tumor, though, after surgical treatment, prognosis is often poor, and easy to relapse because of the growth of local invasive.This characteristic makes it is different from general benign tumor, but we can’t see it as a malignant tumor, and it should be in the benign between malignancy which belongs to "critical tumor". In order to reduce the patients pain that is from the recurrence of the tumor with two or more operations and ensure the quality of the survival of patients, it is particularly important to study the factors of recurrence and improve the cure rate for us. In order to provided more reasonable and scientific references for treatment of ameloblastoma, we have compared different clinical manifestations, pathological classification and surgical methods of the ameloblastoma with the recurrence and explored the relationship between them through the retrospective analysis in this research.Methods:The 45 cases of ameloblastoma who have taken treatment in the department of Oral and Maxillofacial Surgery of the first affiliated hospital of Dalian Medical University are collected between May 1999 and January 2104, we retrospective analyse the clinical data and the follow-up data of the patients. Next we use SPSS 17.0 software to do chi-square test with recurrence and relevant factors. The statistical analysis level of significant difference was set at probability is less than 5%(P<0.05).Results:1.Clinical data:In the 45 cases of ameloblastoma patients, man who accounted for 53.3% with a totol of 24 cases, women with a total of 21 people, the proportion is 46,7%, the ratio is about 1.14:1, and patients age between 12-77, with an average age of 35.3 years, the median age is 29 years old, besides morbidity peak age of 20 to 39, accounted for 57.8% of all patients; 40 cases occurred in mandible, and occurred in maxillary is 5 cases, the ratio is about 8:1, among mandibular tumor,17 cases bcate in the mandibular body,17 cases locate in the mandibular angle and up branch area, and 6 cases locate in the anterior tooth and premolar, and all the 5 cases of maxillary tumors locate in maxillary molar and maxillary sinus area; The shortest duration is 15 days, the longest is 17 years; Classic intraosseous ameloblastoma which is the most general type in clinical classification is 27 cases, accounting for 60%, and unicystic ameloblastoma which is the second position in clinical classification is 12 cases, accounting for 26.7%, besides 6 cases is peripheral ameloblastoma which is the least position in clinical classification, accounting for 13.3%; Among pathological types, follicular pattern is 20 cases, accounted for 44.4%,plexiform pattern is 16 cases, accounted for 35.6%, acanthomatous type is 4 cases, accounted for 8.9%, basal cell type is 3 cases, accounted for 6.7%, and foiled to parting is 2 cases, accounted for 4.4%; Patients who had underwent conservative surgery are 34 cases, the remain(11) had underwent radical surgery.2.The factors and the recurrence relations:In the 45 patients, the postoperative recurrence is 16cases, and the recurrence rate is 35.6%; Tumors which are located in maxillary,their recurrence rate is 80% is higher than mandible which recurrence rate is 30%; The recurrence rate which more than 12 months duration is higher than the course of the disease within 12 months; The recurrence rate of the conservative surgery is 44.1%(15/34), however, the radical surgery is 9.1%(1/11), it show that the recurrence ratehad significant difference between different operative methods(P<0.05). In the 45 patients, the recurrence rate of classic intraosseous ameloblastoma is 51.9%(14/27), unicystic amebblastoma is 8.3%(1/12), and peripheral ameloblastoma is 16.7%(1/6), there are significant differences between the three (P<0.05); Pathological types have associated with recurrence, plexifcrm pattern prognosis is good(P<0.05).Conclusions:1.Ameloblastoma has more occurred in mandible, and mandible patients are much more than maxillary, its incidence has no difference between men and women, but men tend to be slightly higher. The onset age is given priority to with 20 to 39 years, and the onset age has associated with clinical classification. From the perspective of clinical classification, the incidence of classic intraosseous ameloblastoma is the highest, unicystic ameloblastoma is the second, and peripheral amefoblastoma is the least. The main pathological types are follicular pattern and plexiform pattern,2.Between different sex, different age and relapse without too much relevance, but the length of the course of the disease has associated with the recurrence, the longer course of the disease, the higher rate of the recurrence; The onset of position has associated with the recurrence, the recurrence rate which is higher in maxillary than in mandible; The recurrence rate are different because of different treatment modalities, the recurrence rate of the radical surgery is lower than the conservative surgery. The prognosis of classic intraosseous is poorer; The cure rate of follicular pattern is low, easy to relapse, but plexiform pattern which the postoperative recurrence is less, the cure rate is high, and the prognosis is good.3. To design a reasonable operation scheme, we should be comprehensive consideration of the patients age, the onset of position, clinical classification and pathotoy type and other iactors in clinical treatment, and improper operation design is also an important factor of recurrence.