A determination of the standards of morphometrics variables of the stomatognathic system of a fetus

Introduction: Many factors affect the growth and development of the mandible. The most common one is micrognathia; this can pose and neonatal emergency. Early recognition of mandibular and other face anomalies could provide immediate care for these infants, and presence of neonatologist or other doctors in the delivery room. The aim: Aim of this study was to develop normal ranges of the facial markers: mandibular length, jaw index and the facial angle in the fetus using 3D ultrasound. Material and methods: The research was conducted as a cross-sectional study in the second trimester of pregnancy. Fetuses (female n=23 and male n=27) from singleton pregnancy between 29-37 week of gestation were examined by ultrasound. All images were acquired transabdominally, using Voluson E16. Ultrasound was performed by an experienced operator (SM) and measured the values of head circumference, abdominal circumference, biparietal diameter, femur length, body mass. For mandibular length, inferior facial angle, and the jaw index was calculated (Jaw Index =AP mandibular diameter / BPD * 100), the profile images were used (only images in the exact midsagittal plane were used). The characteristics of the fetal profiles were determined by the Schwartz and Ricketts profile analysis using soft tissue landmarks and analysis of the profile photographs. Results: The results show that the jaw index ranged from 25.33 and 34.06 with an average of 26.00 for all examined fetuses. Conclusion: The physiological position of the mandible is retrognathic and that the average physiological length of the mandible in the third trimester is 2.31cm. There is no difference in mandibular length between genders. Corresponding Author: Samra Salga-Nefic Rosenweg 2a, 3125 Toffen, Switzerland, e-mail: samrasalaga@gmail.com A determination of the standards of morphometrics variables of the stomatognathic system of a fetus INTRODUCTION Many factors affect the growth and development of the mandible: genes, irregular cell migration, low growth potential, feeding habits, and other habits acquired by newborns.1 The most common anomalies are microgenia (weak mandible growth) and retrogenia (small mandible growth in the sagittal plane).1 Deviation of physiological mandibular growth and development may incapacitate the essential functions of the stomatognathic system. Fetuses with mandible anomalies are at risk of airway obstruction through retro-positioning of the tongue-base into posterior pharyngeal airway.2 Micrognathia is frequently seen in Pierre Robin sequence, however it can be found in many genetic syndromes.3 Antenatal diagnosis of anomalies by ultrasound is widely used nowadays. The aim of this study was to develop normal ranges of the facial marker: mandibular length, jaw index and the facial angle in the fetus using 3D ultrasound. MATERIAL AND METHODS The research was conducted as a cross-sectional study in the second trimester of pregnancy. Fetuses (female n=23 and male n=27) from singleton pregnancy between 29-37 week of gestation were examined by ultrasound. All images were acquired transabdominally, using ultrasound Voluson E16, GE Healthcare, Austria GmbH & Co OG. Salaga-Nefic S., Mehmedbasic S., Kozadra J., Zukanovic A., Tiro, A., Dzemidzic, V., Nakas E. A determination of the standards of morphometrics variables of the stomatognathic system of a fetus. South Eur J Orthod Dentofac Res. 2019;6(1):6-11. Submitted: July 30, 2018; Revised: March 7, 2019; Published: April 30, 2019 6 South Eur J Orthod Dentofac Res Salaga-Nefic S. et al. Morphometrics variables of the fetus