Associated factors and persistence of palatal groove in preterm infants: a cohort study.

Background: There is a lack of evidence on the relationship between prematurity and palatal abnormalities. The aim of this study was to evaluate the incidence of palatal groove, the associated factors and the persistence time in preterm infants from birth to 24 months of age.
Methods: The children's data, medical history and eating habits were collected using a questionnaire answered by the legal guardian and updated every dental visit. Natal and neonatal data were obtained from the medical records. During the orofacial examination, the presence or absence of a palatal groove was observed. In order to evaluate for associations between independent variables and the palatal groove, descriptive analyses and bivariate analyses were conducted using the Mann-Whitney, Pearson's chi-squared and Fisher's exact tests, when appropriate. The Poisson regression analysis was used to determine risk and protective factors for the occurrence of palatal groove. The significance level was 0.05. For the persistence of palatal groove, a survival analysis was used (Kaplan Meier method).
Results: Seventy-four preterm infants were monitored. Palatal groove occurred in n = 19 (25.7 %) and persisted for an average time of 12 months. Bivariate analysis showed a significantly higher occurrence of palatal groove in girls (68.4 % vs 40 % with non-occurrence of palatal groove) as well as in infants that stayed longer in the neonatal intensive care unit (NICU) (median 37 days vs 20 days), that did not have exclusive breastfeeding (94.7 % vs 69.1 %), were intubated (median five days vs one day) or used an orogastric tube (median 33 days vs 15 days). The quantitative data for 'NICU', 'intubation' and 'orogastric tube' were correlated and estimated as risk factors for palatal groove formation in the unadjusted Poisson regression analysis.
Conclusions: Palatal groove occur transiently in approximately one quarter of preterm infants, especially in infants that stay longer in the NICU, are intubated or use an orogastric tube.