Orthokeratinized odontogenic cyst in a Hong Kong community: the clinical and radiological features

The aim was to evaluate the principal clinical and conventional radiological features of a consecutive series of cases of orthokeratinized odontogenic cyst (OOC) affecting a Hong Kong Chinese community and to determine the outcome by follow-up.

All cases were accompanied by appropriate radiography and were confirmed by histopathology.

The clinical and conventional radiological presentations, differential diagnoses and outcomes of follow-up of five consecutive OOCs were reviewed. There were two males and three females. All affected the posterior sextant. The mean age at first presentation was 33.5 years. The mean of their period of prior awareness was 0.11 years. Swelling was the most frequent presenting symptom. All presented as well-defined corticated radiolucencies; three were unilocular and two were multilocular and all displayed expansion. This resulted in displacement and erosion of the lower border of the mandible in one case and the downward displacement past the lower border of a lateral cortex in two others. The inferior dental canal in each mandibular case exhibited both displacement and absence. The antrum was affected in a sole maxillary case. Four patients were followed up for a mean of 8.5 years. The fifth patient discharged himself shortly after surgery. No lesions recurred.

OOCs in this community displayed an expansile character, but did not recur after moderately long follow-up. The time between the prior awareness of their disease and their presentation for diagnosis and treatment was, so far, the shortest for any lesion affecting the jaw in this Hong Kong Chinese community.