DENTIGEROUS cysts surrounding the crown of unerupted teeth are formed
by cystic changes in the dental follicle after completion of enamel formation.
They are twice as common in men and typically appear between the ages of 20
and 50 years.
A healthy 65-year-old Caribbean man had a slowly progressive, painless
swelling of the right lower eyelid since receiving blunt trauma to the cheek
18 months earlier. Ocular motility and vision were unchanged and he had only
occasional watering of the eye. Visual acuity was 20/20 OU with no relative
afferent pupillary defect, and ocular ductions were full. A 2-cm-diameter
soft fluctuant mass was located just behind the inferonasal orbital rim (Figure 1A). The right upper canaliculus was
stenotic but irrigation with isotonic sodium chloride solution flowed through
the lower canaliculus to the nose. The clinical differential diagnosis was
either a large diverticulum of the lacrimal sac or a mucocele of the maxillary
sinus expanding into the orbit through the nasolacrimal duct.