[Odontogenic tumors and neoplastic-like changes of the jaw bone. Clinical study and evaluation of treatment results].

The purpose of the study was clinical analysis of 164 odontogenic tumours and tumour-like lesions of the jaws treated at the Department of Maxillofacial and Oral Surgery, Jagiellonian University College of Medicine between 1956 and 1996, and to evaluate early late and therapeutic results. Odontogenic tumours have a specific histological structure reflecting various stages of odontogenesis and are located mainly in the jaws, exceptionally in other parts of the skeletal system. Due to their specific structure and location they have been identified and classified by pathologists into a separate group of neoplasms differing from other tumours developing in the oral cavity and facial bones first of all in histogenesis, but also in biology, clinical manifestations and radiological sings. The currently recommended histological classification of odontogenic tumours established by the WHO in 1992 comprises a variety of odontogenic tumours and tumour-like lesions of bones of ectodermal, ecto-mesodermal and mesodermal origin as well as lesions histogenetically not associated with the dental organ, but constituting this group. They include histologically benign tumours, locally malignant and malignant tumours, the latter making up the least numerous group. Due to marked polymorphism histological diagnosis of odontogenic tumours is difficult, therefore co-operation between a clinicist, radiologist and pathologist is especially important. Treatment of choice in patients with odontogenic tumours is surgical operation: in case of benign tumours extirpation and curretage, whereas in case of malignant and locally malignant tumours--segmental resection of the jaws. Removal of extensive tumours is associated with the need of surgical tissue repair and prosthetic rehabilitation, and in young patients surgical treatment must be followed by orthodontic treatment. Clinical analysis included case histories of 164 patients admitted to the Department of Maxillofacial and Oral Surgery (Head: Professor MD S. B. Bartkowski) between 1956 and 1996. Additional control examinations were performed to analyze late results of therapy. The 40-year clinical material comprised 164 odontogenic tumours including 91 (55.5%) in women, and 73 (44.5%) in men. The mean age of the patients was 32.5 years, but about 30% of the patients were below 18. The tumour was most frequently located in the mandible i.e. in 118 (72.0%) patients, and in the maxilla in 44 (26.8%), and in both jaws in 2 (1.2%) patients. Due to tumour recurrence 19 (11.6%) patients were referred to our clinic from other centres, the remaining ones received their first treatment. The most frequent reason for patient referral was deformity of the jaws, maleruption or lack of teeth or their dislocation, and in case of extensive lesions face deformation and bulging of the tumour into the oral cavity. Radiological examination showed noncharacteristic transparencies, round or oval in shape, single- or multiventricular or foci of noncircumscribed bone densities usually in the vicinity of the teeth, frequently dislocated or unerupted. Rarely osteolysis of the roots of teeth or their amputation was found. Histological examination of the 164 tumours revealed (in order of frequency): ameloblastoma--60 (36.6%), central reparative giant cell granuloma--52 (31.7%), cementoma--15 (9.2%), odontoma--13 (7.9%), odontogenic myxoma--12 (7.3%), ameloblastic fibroma--4 (2.4%), calcifying epithelial odontogenic tumour--3 (1.8%), odontogenic fibroma--2 (1.2%), adenomatoid odontogenic tumour--2 (1.2%) and odontoameloblastoma--1 (0.6%). Of the 60 ameloblastomas three tumours were histologically malignant. Of the 164 patients 152 were selected for surgical treatment. Surgical treatment of histologically and clinically benign tumours included tumour extirpation, curettage, excision and/or electrocoagulation, whereas malignant and locally malignant tumours such as ameloblastomas, myxomas, Pindborg's tumours, invasive reparative giant c