By C\^orte-Real, I.; Braga, A.C.; Nogueira, R.; Felino, A.; Valente, F.; Vaz&
Revista Portuguesa de Estomatologia, Medicina Dentaria e Cirurgia Maxilofacial
Objectives: This study aimed to determine the fetal philtrum length at early stages of gestation and perceive its growth through different gestational ages in case of normal and pathological fetal development.Methods: This cross-sectional observational study was conducted based on ultrasound images obtained at an institutional centre specialised in Prenatal Diagnosis. A total of 108 fetuses between 10 and 26 weeks of gestation were included, of which 90 corresponded to normal pregnancies and 18 to pregnancies diagnosed with fetal pathology. The fetal philtrum study was performed by ultrasound during a routine evaluation for each fetus. Fetal philtrum length was measured by ultrasonography, based on a mid-sagittal plane from the posterior border of the columella to the top of the upper lip. Data analysis was conducted through predictive models.Results: The best regression model for predicting the philtrum length between the 10th and 26th gestational weeks was the linear one (without constant). This model, defined by the equation S.7 = 0 294 x (R-2 = 0 970, p = 0.001), represents a 0.294 mm increase of the philtrum length per week of gestation. No statistically significant differences were found in the mean value of the philtrum length, either in the presence or absence of fetal pathology.Conclusions: This study provides additional data about the growth pattern of the philtrum in early stages of gestation and offers a simpler way to identify alterations in the philtrum length. However, more studies with larger samples are needed to understand better the relationship between philtrum anomalies and craniofacial abnormalities in order to obtain a more accurate prenatal diagnosis. (C) 2016 Sociedade Portuguesa de Estomatologia e Medicina Dentaria.