A survey of natal and neonatal teeth in newborn infants.

Since there is no comprehensive research of natal and neonatal teeth in Taiwan, careful investigation of natal or neonatal teeth is worthy of being studied. This retrospective study investigated the prevalence and clinical characteristics of natal or neonatal teeth in a hospital setting, and analyzed the possible relationships between investigated variables of the natal or neonatal teeth.All of the 12,019 infants born at an assigned hospital between January 1, 2008 and December 31, 2014 were investigated for natal or neonatal teeth. The identified individuals were reviewed for systemic diseases. Dental examinations included the location, clinical appearance, and degree of mobility. A positive family history of natal or neonatal teeth and mother's physical condition before delivery were also investigated. The collected data were analyzed using Fisher's exact test.Thirty infants were identified with a total of 43 natal or neonatal teeth (females, 19; males, 11). Most of the teeth were in the mandibular primary incisor position (97.6%). A radiographic examination confirmed that not all of the natal or neonatal teeth were supernumerary. No significant differences were observed between males and females in tooth morphology, positive family history, and treatment methods (p > 0.05) or between normal and conical shapes in positive family history, premature infant, mother's physical condition before delivery, and treatment methods (p > 0.05).Most of the natal or neonatal teeth were in the mandibular primary incisor position and not all of them were supernumerary. No gender differences were found in tooth morphology, positive family history, and treatment methods. The tooth morphology was not significantly related to a positive family history, premature delivery, or the mother's physical condition before delivery.