Osteoid osteoma is a rare benign osseous neoplasm which rarely affects the jaws. It is more common in long bones which can lead to postural scoliosis. The clinical characteristic feature of this tumour is the unexplained pain that is relieved by the intake of analgesics. Histologically it is characterized by the formation of central nidus with surrounding sclerotic bone. The diagnostic dilemma in this case report is aggravated by its unusual association with the teeth. The use of CT scanning is advised to distinguish from other odontogenic tumours. Treatment for this tumour is surgical removal or excisional biopsy to avoid recurrence and progression to malignant changes.
Osteoid osteoma is a rare benign osseous neoplasm. It was first described by Jaffe in 1935. Many cases of osteoid osteoma occurring in the long bones have been reported, but its association with the teeth is rare. The clinical presentation of this lesion is nocturnal pain and tenderness over the affected area that is usually relieved by non-steroidal anti-inflammatory drugs (NSAIDs). This is more typical as it occurs in more than 80% of cases . Its occurrence in the jaw usually mimics most of the common odontogenic lesions such as cementoblastoma and osteoblastoma. Histologically it consists of a demarcated central nidus with surrounding reactive sclerotic bone. This lesion is most commonly seen in males during the second and third decades. Osteoid osteoma is most commonly reported in the long bones of the lower extremities causing scoliosis, followed by the upper extremities. According to Dorfman and Czerniak it rarely involves the craniofacial bones . Earlier reports suggest an almost equal predilection for maxilla and mandible, although there are slightly more in the mandible . The occurrences in the jaw lead to tenderness and very slow disfigurement of the face . The size of the lesion is usually not more than 2 cm . There are several reports of its occurrence in the jaw but only one case has been reported associated with the teeth . This report was based on radiographic and histological evidence from the necropsy specimen . There was no evidence of the tenderness and pain mentioned in the hospital records. The present authors aim to report a case of osteoid osteoma associated with teeth that is a rare unusual presentation.
A 20-year-old Afro-Libyan patient reported to the Faculty of Dentistry complaining of tenderness and a slow growing swelling in the left mandibular body region for 6 months ( Fig. 1 ). On palpation, the swelling was non-erythematous, firm, bony, hard and tender on palpation measuring 2–3 cm in diameter ( Fig. 2 ). Intraoral examination revealed a caries free dentition and well maintained oral hygiene. The overlying skin and mucosa were normal with no erythematous or temperature changes. The regional lymph nodes were non-palpable. There was no history of frequent pyrexial episodes. The patient is a socially active person with no deleterious habits such as smoking. During the episodes of severe pain and tenderness, the use of NSAIDs was effective. NSAIDs significantly reduced the intensity of the pain but could not prevent its recurrence. Orthopantomograms and intraoral periapical radiographs were taken. The radiographic examination revealed a mixed radiopaque radiolucent lesion in relation to the left mandibular body extending from the first premolar to the first molar. The roots of the second premolar and the first molar appeared to be involved in the radiopaque lesion. There were no other lesions, deformities or diseases associated with the jaws. Vitality tests of the premolars and molars were undertaken by applying heat and gave a positive response. A complete blood examination was carried out including serum alkaline phosphatase to reveal any blood dyscrasias or disorders.
Based on the clinical and radiographic examination, a differential diagnosis of cementoblastoma, osteoma and osteoid osteoma was made. Excisional biopsy under local anaesthesia was planned. Under aseptic conditions, the left inferior alveolar nerve was blocked with local infiltration using 2% lidocaine hydrochloride and 1:80,000 adrenaline for regional anaesthesia and local vasoconstriction. A mucoperiosteal envelope flap with two oblique release incisions was carried out to expose the lesion. Clinically the lesion appeared well demarcated from the surrounding bone; the roots of the second premolar and the first molar were involved in the lesion ( Fig. 3 ). The surrounding bone was trimmed using a round bur under copious normal saline irrigation to isolate the lesion and facilitate its removal.
During the manipulation of the tumour from the inferior border, the movement of the second premolar and the first molar was observed. Further manipulation of the lesion led to the removal of the lesion into along with the attached teeth ( Fig. 4 ). The lesion was 2.5–3 cm in diameter. The mandibular left second premolar and the first molar were attached to the tumour mass. Curettage of the bony edges was done along with debridement of the socket using normal saline. 3-0 silk was used to close the flap. The patient was recalled after 3 days for a check up. Follow up was scheduled on a regular basis to observe healing and any recurrence. The lesion was sent for histopathological examination.
Microscopically, the lesion was composed of a nidus of osteoid-rich tissue and immature bone within a richly vascular connective tissue stroma. The bony trabeculae were irregular and showed varying degrees of calcification with many basophilic reversal lines. Many plump osteoblasts were seen lining the trabeculae ( Fig. 5 ). The prominent vascularity of the connective tissue stroma is an important diagnostic measure being considered in this case diagnosis ( Fig. 6 ). Based on clinical details, the history, radiographic findings and microscopic examination of the tissue mass, a final diagnosis of osteoid osteoma was made ( Fig. 5 ). After 1 year, the patient was recalled for clinical and radiographic examination that revealed satisfactory healing with no signs of recurrence.