A paranasal sinus mucocele is an epithelial-lined, mucus-containing sac that completely fills the sinus and forms an expandable cystic structure. It most commonly affects the frontal and ethmoidal sinuses, and rarely the maxillary and sphenoid sinuses. Orbital displacement or external disfigurement resulting from the expansion of the frontal or ethmoid sinuses is common; however, facial asymmetry caused by maxillary bone remodeling is rare. We describe a case of large maxillary sinus mucocele that destroyed the maxillary sinus bony wall, resulting in notable left cheek swelling and disfigurement, and review the relevant literature.