Background: Unicystic ameloblastoma (UA) is a rare variant of ameloblastoma and
represents about 6% of all ameloblastomas. Radiologically, it is very similar to odontogenic
jaw cysts due to its unilocular radiolucency. Case Report: This report discusses the clinical,
radiological, histopathological and surgical findings of mural unicystic ameloblastoma
occupying the right maxillary sinus on a background of dentigerous cyst associated with
an impacted tooth in a 22-year-old female patient. Conclusion: It is very uncommon to
see this lesion in the maxilla since it usually involves the posterior region of the mandible.
Differentiation of an UA from a dentigerous cyst is radiographically difficult when UA is
associated with an impacted tooth. Among all UA types, UA with mural proliferation has
the highest rate of recurrence. Long-term follow-up for recurrence should be considered
for patients with UA.