Topographic and anatomical relationships of the lower jaw and auricle in human prenatal ontogenesis

Abstract

Aim to describe the topographic and anatomical relationships of the fetal lower jaw and auricle in the mid-gestation period. Material and methods. The 110 mandibles of human fetuses of the second trimester were selected for the study and divided into groups by sex and age. The morphological techniques and the method of ultrasound scanning were used to determine the topographic relationships of the lower jaw and the fetal ear, the location of the central part of the auricle relative to the lower jaw (the line connecting the gnathion point and the external occipital protuberance) at different age periods. Results. During the mid-gestation period, with the growth of the fetus, the auricle normally shifts upward relative to the mandible. At the beginning of the study period, the auricle is located just below the angle of the lower jaw. Its central part (C) is below the line (AB) connecting the gnathion point and the external occipital protuberance. The perpendicular from the conditional center of the auricle to the line AB is half the diameter of the auricle 3.7 1.1 mm. In the second age group, the auricle is located at the level of the branch and angle of the lower jaw Its conditional center (C) is below the line AB and is of the diameter of the auricle 3.1 0.8 mm. By the end of the mid-gestation period, the auricle is displaced to the level of the processes of the lower jaw above the notch. Its central part is above line AB, the perpendicular from point C to line AB is 6.1 1.4 mm. Conclusion. The deviations in the formation of the topographic and anatomical relationships of the lower jaw and auricle of the fetus from 14 to 27 weeks of gestation can be additional criteria for the development of congenital fetal pathology and require the fetoabnormal alertness.

Keywords

• mandible
• auricle
• fetus
• mid gestation period
• ultrasound scanning method
• morphological methods