Buccal-sided mandibular angle exostosis - A rare case report.

Buccal exostoses are benign, broad-based surface masses of the outer or facial aspect of the maxilla and less commonly, the mandible. They begin to develop in early adulthood and may very slowly enlarge over the years. They are painless and self-limiting, but occasionally may become several centimeters across and then contribute to periodontal disease of the adjacent teeth by forcing food during chewing in toward the teeth instead of away from them, as is normally the case. The following paper presents a very rare case of buccal-sided mandibular angle exoxtosis and its management with surgical exploration.

Introduction

Oral tori have been defined as slow growing, osseous outgrowths at the midline of the hard palate and at the lingual surfaces of the mandible.[12] In the mandible the tori can be bilateral or unilateral, usually in the premolar regions but infrequently also at the genial tubercles.[3] The torus is considered a developmental anomaly and has been termed Exostosis, a benign hyperplastic overgrowth of the bony surface to differentiate it from a true neoplasm.[3] It presents either as a smooth bulging of the bone surface continuous with the adjacent area or as discrete, multilocular spherical projections with a broad base that forms a nodular cluster.[13]

An exostosis is a nonpathologic outgrowth of the bone. It is believed that this is one way bone responds to stresses applied to it. The suggested aetiologic factors are masticatory hyperfunction,[4-6] genetic factors,[6] environmental factors,[47] and continuous growth.[8] Recently, the etiology of tori has been postulated to be an interplay of multifactorial genetic and environmental factors.[9-11]

Exostoses are more common in the maxilla than in the mandible in the ratio of 5.1 : 1 respectively.[12] The case report presented below illustrates a unique and rare presentation of exostosis on the buccal side of the mandibular angle and its successful management by the authors.

Case Report

A female patient aged 35 years, reported to our department with the chief complaint of vague facial pain extending from the angle of mandible to retromolar trigone since 3 months. The patient illicited a history of swelling on the angle of the mandible on the right side of the face, which gradually went onto increase in size.

On clinical examination intraorally, the patient's overall oral hygiene was fair to poor. Generalized moderate gingivitis was present with only minimal bone loss and severe attrition on all teeth surfaces. Gingival tissues were erythematous and edematous. The patient had a large, exostosis [Figure 1]. It extended from the area adjacent to the second molar to a point beyond the junction angle of mandible. The exostosis was oblong in shape, measuring 1.5cm × 1cm. It was covered with thin mucosal tissue and did not interfere with speech, chewing, or other oral functions.

Figure 1

Clinical examination

Radiographic investigation were carried out by an orthopantogram (OPG). On observation, the OPG revealed a radio-opaque mass oblong in shape near the angle of mandible on the right side [Figure 2].

Figure 2

Radiographic examination

The treatment was planned to explore the swelling under local anesthesia. Mandibular nerve block was given with lots of infiltration using 1 : 200000 lignocaine with adrenaline. Incision was made similar to the standard Ward's incision used in the third molar surgery. The operator included a few modifications to expose the exostosis adequately. The lesion was exposed, a molt periosteal elevator was placed below the exostosis in the lower border of mandible, and the growth was cut from superior end with #702 SS white bur [Figure 3]. At the lower border, a fine chisel was used and with two to three soft blows with mallet (8 pounds). The exostosis was completely dislodged. The dislodged exostosis was collected on the periosteal elevator and taken out. The rough bone was smoothened with an acrylic trimming bur. Bleeding was negligible and was controlled. Wash of povidine–iodine 5% was given and suturing was undertaken with 3-0 silk.

Figure 3

Surgical exposure

This excised mass was sent for histopathological investigation. Biopsy report stated it as a benign osteiod mass [Figure 4].

Figure 4

Excised exostosis

Postoperatively patient was appropriately prescribed medication and chlorhexidine mouth wash was advised. No obvious postoperative complications were noted. Slight swelling and decrease in mouth opening was observed following surgery and it subsequently subsided in 5 days. The patient returned 2 weeks after surgery to check healing, and sutures were still present. There was no inflammation, and the patient indicated that she had minimal discomfort after surgery and that the area felt normal 3 days after surgery. A follow-up appointment was scheduled after the next 2 weeks after surgery to check the site. Sutures were absent, and the tissue appeared healed. Patient was totally a symptomatic after 10 days.

Discussion

Torus mandibularis is recognized as a bony ridge or series of bony nodules or lumps appearing on the lingual surface of the alveolar margin of the mandible, generally in the premolar region (Hauser and DeStefano, 1989). These tori may be completely absent or present in varying degrees, and may present a variety of forms. Mandibular tori are not associated with any pathological condition and can be easily distinguished from instances where the osteological activity is the result of a pathological condition causing abnormal growth, such as trauma or tumor. Torus mandibularis is generally manifested bilaterally, though it may be present just on one side of the mandible. There is often a degree of asymmetry between sides, with the right side most commonly presenting a more pronounced torus than the left Haugen, Seah.[13]

The torus may be bosselated or multilobulated but the exostosis is typically a single, broad-based, smooth-surfaced mass, perhaps with a central sharp, pointed projection of bone producing tenderness immediately beneath the surface mucosa.

The functional influences may contribute to the development of exostoses. There is an increasing correlation between marked exostoses and a significant attrition of teeth in some older subjects. This may be a similar phenomenon as that which occurs in subpontic hyperostosis, which postulates that stress causes the crestal alveolar bone to grow under the pontic along a vector opposing the forces of occlusion.-[9,14] Therefore, the altered function may lead to exostosis development in genetically predisposed populations.

Conclusions

In the case presented, the patient had a clear concept of the procedure prior to providing the informed consent, the procedure was uneventful, and the patient was satisfied with the result. The authors emphasized that rarity of the anatomic site of buccal exostosis on the mandibular angle involved in this case should not be ignored and carefully should be differentially diagnosed from other conditions.