Developmental defects in the primary dentition of low birth-weight infants: adverse effects of laryngoscopy and prolonged endotracheal intubation.

Trauma caused by laryngoscopy and orotracheal intubation affects mainly the maxillary anterior teeth. Examination of the primary dentition of 63 low birthweight, prematurely born children showed that developmental defects of these teeth occurred in 85.0% of 40 intubated children compared to only 21.7% of nonintubated children, a fourfold difference. Trauma caused by laryngoscopy affects mainly the left maxillaly anterior teeth; in the intubated group of Children with defects of maxillary anterior teeth, 66.1% of the affected teeth were on the left compared With 33.9% on the right, a twofold difference. Traumatic injury caused by laryngoscopy and endotracheal intubation at the critical period of amelogenesis may contribute to defects in the dentition of low birth-weight infants whose dental development already is compromised by derangements of calcium metabolism and other systemic factors. Previous studies of the primary dentition in premature infants have demonstrated a high prevalence of enamel hypoplasia.~-5 Although general systemic factors such as hypocalcemia have been implicated in the etiology, local traumatic factors also may have a significant role. Two previous reports 6,7 have suggested that endotracheal intubation and mechanical ventilation may have traumatic effects on the developing unerupted primary dentition of newborn infants. It also has been well documented that the use of the laryngoscope during endotracheal intubation may injure erupted teeth. 8-12 This study examined the prevalence and distribution o’f developmental dental defects in a group of low birthweight infants in order to determine the possible adverse effects of laryngoscopy and prolonged endotracheal intubation. Patients and Methods The patients in this study were children aged two years and older who were attending the Growth and Development Clinic of the Mater Children’s Hospital, South Brisbane. This clinic was established in 1978 to provide a multidisciplinary longitudinal followup of all surviving infants of low birth weights managed at the Mater Mothers’ Hospital. 13-16 A total of 63 children with low birth weights were available for study. They were all prematurely born, with birth weights of between 605 g and 1,500 g, and a mean birth weight of 1,154 g. There were 37 males and 26 females. Forty received endotracheal intubation and mechanical ventilation in the neonatal period, while 23 did not. At the time of dental examination, the ages of the children ranged from two years, two months to five years, five months, with a mean of three years, eight months. All these children were single births except for a set of twins and three sets of triplets (two sets of which had two surviving members each). Only two children from the third set of triplets were included in the study because the third child had a cleft lip and palate -teeth in the region of orofacial clefts often are defective. The dental examinations were performed under ideal conditions at the University of Queensland Dental School. The teeth were dried and a mirror and probe used to detect caries, opacities, and enamel hypoplasia. The diagnosis of opacity was restricted to teeth with white or yellow brown areas that did not have hypoplastic enamel, i.e., pitting, ridging, or other disturbances of surface contour. If a tooth showed both opacity and hypoplasia, a diagnosis of hypoplasia was made. All tooth surfaces were examined and the severity and extent of each dental defect recorded in a comprehensive chart. Intraoral photographs were taken in some children. Postnatal medical and dental histories were obtained from the parents. Maternal and neonatal medical histories were 28 DENTAL DEFECTS IN INTUBATED INFANTS: Seow et al. ]’able 1. Distribution of Defective Teeth in 40 Intubated and 23 Nonintubated Low BirthWeight Children Tooth