Turner’s hypoplasia is an teeth abnormality that affect appearance of the teeth. Hypoplasia is quantitative defect of enamel and it is histomorphologically explained as an external defect involving the surface of the enamel and associated with reduced thickness of enamel. Appearance of the Turner`s teeth are variable, though commonly is manifested as a portion of missing or diminished enamel on permanent dentition. Unlike other abnormalities which affect a number of teeth, Turner’s hypoplasia usually affects only one tooth in the jaw and, it is named as a Turner’s tooth. Both primary and permanent dentition could be affected by enamel hypoplasia, however, it is more common in permanent dentition. Hypoplasia is the consequence of disruption in the process of enamel matrix formation, which will result in causing defect in quality and thickness of enamel. The macro and microscopical appearances of turner’s tooth suggest that only some specific ameloblasts (cells that produce enamel) have ceased to form enamel, whereas others are partly or completely able to fulfill their task and produce healthy enamel.
When Turner’s hypoplasia is found on a canine or a premolar, it is most likely caused by an infection that was present when the primary tooth was still in the mouth. Most possibly, the primary tooth was heavily decayed and an area of inflamed tissues around the root apex affected the development of the permanent tooth. Lower bicuspids suffer from Turner’s hypoplasia more often, because constant molars above them are very vulnerable to the infection. The abnormality in appearance of the affected tooth will depend on the severity and longevity of the infection. If Turner’s hypoplasia is found in the anterior area of the mouth, it is most likely caused by a traumatic injury to a primary tooth (picture 1). The traumatized tooth, which is most often a maxillary central incisor, is pushed into the developing tooth underneath it and consequently affects the formation of enamel. Because of the location of the permanent tooth’s developing tooth bud in relation to the primary tooth, the most likely affected area on the permanent tooth is the vestibular surface. Hypoplasia can be categorized by the appearance and tooth tissue defect in four types. In type I hypoplasia enamel discoloration is present. In type II hypolasia there is abnormal coalescence. Type III is more severe and some parts of enamel are missing, while type IV (picture 2) is a combination of all three previous types of hypoplasia.
The clinical characteristics of Turner’s hypoplasia are unfavorable esthetics, higher dentin sensitivity, malocclusion and they are more prone to caries. The visual diagnostic of Turner’s hypoplasia is possible because the discoloration and pathological changes of enamel are visible. The X-ray examination may show the deformed tooth apex, thus can give the ideas about the provoking factor of the disease. The treatment of Turner’s hypoplasia needs a complex dental therapy. According to the results of X-ray, the consequences of the problem (it may be trauma or infection) must undergo correction. The adequate therapy for this type of condition is to promote a complete oral rehabilitation in both esthetics and function. The cosmetic defects can be corrected by applying veneers or crowns depending of the amount of enamel and dentin destruction, and function must be provided by adequate occlusion.