The decision was made to perform an excisional biopsy of the mass under intraveneous general anesthesia. A sulcular incision was used to elevate a full thickness mucoperiosteal flap. The thin cortical buccal bone covering the lesion was removed while carefully preserving the surrounding teeth and the inferior alveolar neurovascular bundle. The lesion consisted of many small tooth-like structures with a surrounding sac. The entire lesion was removed without violating the integrity of the mandible. The patient tolerated the procedure well and has had an uneventful postoperative course.

Excisional Biopsy

Histologic examination reveals multiple pieces of decalcified hard and soft tissue embedded in two separate blocks labeled A1 and A2. All specimens are composed of miniature tooth-like structures (Figures 2 & 3) made up of dentin, enamel matrix (Figure 4), and dental pulp (Figures 2 & 3). The tooth-like structures are focally lined by a dental follicle (Figure 2) which is made up of a lining epithelium supported by a fibrous connective tissue wall.

Figure 2 Low power (x40) H & E histology shows multiple tooth-like structures made up of dentin, enamel matrix, pulp and dental follicle focally surrounded by dental follicle lined by epithelium.

Figure 3 Higher power (x200) H & E histology shows two tooth-like structures with dentin and dental pulp. The dental pulp is superiorly lined by one layer of viable odontoblasts.

Figure 4 High power (x400) H & E histology shows the enamel matrix at high magnification with the fish-scale appearance.