A localized arrested tooth development which appears to involve most commonly the anterior teeth, usually on one side of the midline, most often the maxillary central and lateral incisors. Roentgenographically, the teeth have a ghostlike appearance. Calcification and bits of prismatic enamel may be found in the pulp and the enamel is thin and absent in part. (Jablonski, Illustrated Dictionary of Dentistry, 1982)

A normal developing tooth which has not yet perforated the oral mucosa or one that fails to erupt in the normal sequence or time interval expected for the type of tooth in a given gender, age, or population group.

One of a pair of irregularly shaped bones that form the upper jaw. A maxillary bone provides tooth sockets for the superior teeth, forms part of the ORBIT, and contains the MAXILLARY SINUS.