A labially positioned mesiodens:

This case report describes a labially positioned maxillary midline mesiodens in an 8-year-old male. The clinical and radiographic appearance and therapeutic considerations are presented. The purpose of this article is to alert the clinician to the importance of radiographic localization prior to surgical intervention, because in some instances a labial surgical approach is preferred over the traditional palatal technique. In this case a labial surgical approach was utilized which allowed for greater conservation of alveolar bone and improved access during removal of the mesiodens. Supernumerary teeth, hyperdontia, are of particular interest to pediatric dentists who commonly make the initial diagnosis. The condition is frequent enough that some feel an anterior occlusal film should be mandatory as part of a child’s complete initial examination (Rotberg and Kopel 1984). The prevalence of supernumerary teeth is reported to be from 1 to 3% (Luten ~967; McKibben and Brearley 1971). An increased incidence in children with cleft palate and cleidocranial dysostosis also has been observed (Pinkham 1988). The vast majority of supernumerary teeth are associated with the permanent dentition and occur predominantly in the premaxillary midline region and are termed mesiodens (Nazif et al. 1983; Rotberg and Kopel 1984). Of these, most are reported to remain unerupted (Tay et al. 1984). Two types of supernumerary teeth exist and are classified as either supplemental (tooth-like) rudimentary. The etiology of supernumerary teeth is unclear, but the most popular theory involves hyperactivity of the dental lamina (Primosch 1981). A hereditary link and a predilection for males has been suggested (Brunning et al. 1957; Sedano and Gorlin 1969), but has yet to be determined. Most problems associated with mesiodens are related to altered growth and development in the area. Common sequelae include overretention of primary teeth, impaction or delayed eruption of permanent teeth, dilaceration or abnormal root development, and/ case report or abnormal crowding or spacing of the anterior teeth. Other less frequent problems are root resorption of adjacent teeth, dentigerous cyst formation, and nasal eruption of inverted supernumerary teeth (Smith et al. 1979; Primosch 1981; Rotberg and Kopel 1984). Therapeutic Considerations Treatment of mesiodens centers on several factors and consideration of these variables will determine whether to treat the supernumerary early or to observe the condition. The first factor is the child’s age. In the very young child the ability to tolerate a surgical procedure is of major concern. The benefit of early treatment must be weighed against the long-term effect that any unpleasant experience may have. Second is the stage of dental development of the surrounding dentition and proximity of the mesiodens to the permanent incisors. In cases of immature root development, consideration must be given to the risk of surgical trauma to the developing roots of the permanent incisors and the potential of altering future dental development. Mesiodens that are intimately positioned with the developing permanent incisors may either alter the permanent bud positionally, impede eruption, and/ or alter root development; whereas, removal of this same supernumerary tooth may cause the same sequelae through surgical trauma. In instances where the surgical approach jeopardizes the viability of sensitive developing tissue, it may be appropriate to delay treatment. Lastly, one must evaluate the relative position of the mesiodens within the premaxilla. Assessment of access to the supernumerary must be considered in relation to the amount of bone removal and potential damage to existing incisors. In children, eruption of mesiodens is possible and, although complete eruption is infrequent, some mesiodens may erupt partially so that a more favorable surgical approach may be attained with time. Pediatric Dentistry: March, 1989 Volume 11, Number 1 59 Therefore, the accurate location of supernumerary teeth is critical in determining the proper treatment approach. Clinical examination, including labial and palatal palpation, along with proper radiographs can be used with high accuracy to determine the mesiodens' location in the premaxilla. Both vertical and horizontal shift radiographic techniques, using 2 occlusal or periapical radiographs, are helpful in localizing midline mesiodens. Other useful radiographs include panoramic and lateral occlusal films. Opposing views exist as to when supernumerary teeth should be treated, if at all (Primosch 1981). Some authors recommend early removal of most supernumerary teeth, particularly those that are inverted and/ or are unlikely to erupt (Primosch 1981; Nazif et al. 1983; Rotberg and Kopel 1984). It is felt that this may prevent the need for orthodontic treatment and/or additional surgical procedures, such as surgical exposure or periodontal surgery at a later date. Advocates of early intervention feel treatment would take advantage of the spontaneous eruption of the permanent incisors and increase potential for self-correction (Tay et al. 1984). Others feel that mesiodens that appear likely to erupt into a more favorable position can be monitored and removed more easily at a later date (Stermer BeyerOlsen 1985; McDonald and Avery 1987). A cautious approach is advised for inverted supernumerary teeth as they present a difficult surgical problem due to proximity to developing permanent teeth (Stermer BeyerOlsen 1985). Some recommend postponement of surgery until root development of the neighboring permanent incisors is complete (Tay et al. 1984). This case involves an inverted conical-shaped rudimentary supernumerary tooth located in the premaxillary midline and is unusual in that a labial surgical approach was utilized. This allowed for improved access and greater visualization in removal of the tooth. The report describes the clinical and radiographic appearance, rationale for surgical intervention, and surgical approach used in treating an 8-year-old male with a mesiodens.