Not an average toothache

A 24-year-old male presented to the emergency dental service complaining of a two-week history of mild swelling in the right mandible and a pulse-like sensation in the LR6 region. The patient had not seen a regular dentist for several years.

On examination, a discrete smooth hard swelling was palpable in the right angle of the mandible region. Intra-orally, the LR6 restored with a large amalgam restoration was slightly tender to percussion. An intra-oral peri-apical radiograph (Figure 1) showed an impacted LR7 with a radiolucent region distally.

A right-sided orthopantomogram (Figure 2) was then taken which showed a large, well-defined unilocular radiolucent lesion in the right angle of the mandible. The lesion appeared to be associated with the unerupted LR8 and LR7 with loss of outline of the lower border of the mandible. An urgent referral was made to the maxillofacial team due to risk of pathological mandibular fracture. The patient underwent further imaging and incisional biopsy and was diagnosed with an orthokeratinized odontogenic cyst (OOC) of the right angle of the mandible.