2-19. OTHER DEVELOPMENTAL ANOMALIES
a. Dens in Dente. In this condition, during the developmental state, a tooth
within the original tooth is formed. The new tooth is usually composed of enamel and
sometimes includes dentin and cementum.
b. Concrescence. In this condition, after the roots are developed, cementum is
deposited between two adjoining teeth and joins them together. Only the roots are
united. The crowns are always separate.
c. Fusion. In this condition, two developing and adjoining teeth join to form a
single large crown. Fusion may occur between two normal adjoining teeth or between a
normal tooth and a supernumerary tooth. Fusion may involve the crown and root (total
fusion) or the roots may be separate. Usually, there are two distinct pulp chambers. In
fusion of the root, the dentin of the two teeth is continuous as opposed to concrescence.
d. Gemination. In gemination, or twin formation, a double crown is attached to
a single root. The crown appears twice as wide as normal with a shallow groove
through the center.
e. Enamel Pearls (Enamel Drops). In this condition, small islands of enamel,
1 to 2 mm in diameter, are located on the root surface close to the cementoenamel
junction. If covered by cementum, they probably will not be noticed on the extracted
tooth except histologically. They are of significance only as potential problems in
development of periodontal lesions.
Section IV. ORAL MANIFESTATIONS OF SYSTEMIC DISEASES
Many systemic diseases may develop manifestations in the oral cavity,
sometimes before it is evident in any other part of the body.
This is an acute, contagious disease caused by a virus. It is transmitted by saliva
droplets via the respiratory tract. The disease usually occurs in children and the initial
episode provides immunity to further attacks of the disease. Koplik's spots appear
several days before the characteristic skin lesions of measles. The spots are bluish-
white and surrounded by an inflamed red zone. These spots are formed on the buccal
mucosa opposite the molars.