Immature primary molar in the newborn.

A clinical report of an erupted immature primary molar in a newborn is presented. The occurrence of a natal or neonatal molar can be considered a rare event since the majority of cases described are incisors. Clinical appearance, location, histological and radiographical examinations were used to establish the identity oF the lesion, The literature related to natal and neonatal teeth is reviewed with emphasis on molars, and surgical management in the newborn is discussed. Teeth present in the oral cavity at or shortly after birth have been called natal or neonatal, fetal, congenital, predeciduous, and dentition praecox. The preferred terms are natal and neonatal; those teeth present at birth are termed natal and those that erupt within 30 days after birth are called neonatal.1 Natal teeth are encountered more often than neonatal teeth in an approximate ratio of three to one.~ Though the prevalence of natal and neonatal teeth reported varies,~, 4 a range of 1 in 2,000-3,50@ is most widely accepted. A sexual predilection has been suggested with females thought to be affected more often than males. 6 The majority of natal and neonatal teeth are immature microdonts that are conical and yellow-brown opaque. They contain hypoplastic enamel and dentin, and.exhibit minimal root development. 7 Hypermobility is common and causes concern because of the likelihood of swallowing or aspirating the tooth. Sharp incisal edges may cause sublingual ulceration (Riga-Fede disease) which can result in the infant’s refusing to nurse. Additionally, the erupted tooth may cause irritation of the nursing mother’s nipples. While the literature is replete with reports of erupted incisors, few reports have been published documenting the presence of erupted posterior teeth in the newborn. The purpose of this report is to present a case of an immature erupted maxillary molar in a newborn and to review the literature pertaining to natal and neonatal teeth with special emphasis on molars. Literature Review A distinction exists in the literature between natal and neonatal teeth. These terms are well-accepted and probably will continue to be used. However, it has been suggested by Spouge5 that such teeth also should be classified according to their degree of maturity. A mature natal or neonatal tooth is one that has achieved nearly complete development when compared to other primary teeth, while the term immature natal or neonatal tooth implies incomplete or substandard structure. Several theories have been proposed as to the etiology of the premature eruption of these teeth: increased rate of eruption during or after febrile states, endocrine disturbances, dietary deficiencies, and the effects of congenital syphilis. 1 However, the most universally accepted theory attributes precocious eruption to superficial position of the tooth germ.7 Heredity may be an influence in the premature eruption of teeth as Massler and Savara1 found siblings and parents with the same condition in 10 of 24 reported cases. Additional evidence of genetic contribution is seen in the association of natal or neonatal teeth with multisystem syndromes. These disorders include chondroectodermal dysplasia (Ellis-van Creveld syndrome), oculomandibulodyscephaly (Hallermann-Streiff syndrome) and pachyonychia congenita (Jackson-Lawler syndrome). In cleft lip and palate, a multifactorial genetic disease, a higher incidence of natal and neonatal teeth also has been reported.8 Histologically, abnormalities of all tooth structures have been reported. In the dentin, large interglobular spaces with abnormal cell inclusions have been found,~ as well as an irregular pattern of the orientation of the dentinal tubules.z The enamel has been described as hypoplastic or hypomineralized with an absence of Hertwig’s sheath. 4 This absence may explain why failure of root and cementum formation has been observed. 2 Other findings include absence of Well’s basal layer and the cell-rich zone in the pulp,4 and an increase in the number of dilated blood vessels in the pulpal tissue.2 The majority of natal and neonatal teeth are true 210 IMMATURE PRIMARY MOLAR IN THE NEWBORN: Brandt et al. Table 1. Data Summary of Documented Cases of Natal and Neonatal Molars Author Natal/ Site Teeth Histological Neonatal Max. Mand. Number Identity Examination Radiographs Associated Findings Bartholin* Thomas* Bouchut* Jacobi" Kaufman