The anatomical characteristic of the lower jaw of human fetuses in the second trimester

Objective: to reveal the features of anatomical structure of the lower jaw of fetuses of second trimester. Material and methods. The lower jaw of 45 human male and female fetuses of the second trimester has been researched using the method of ultrasound scanning and using the morphological techniques: morphometry and macromicroscopic preparation. Results. The average length of the alveolar arch was 64.1 ±3.6 mm, the average angular width was 30.2±4.0 mm, the average projection length was 24.8±3.5 mm, the average height of branch was 21.1±3.1 mm, the average smallest width of branch was 12.2±1.3 mm. The angle of the lower jaw was equal to an average of 127.2±9.8° with a range of values: from 115 to 156°. According to the long-latitudinal index (LLI) the fetuses had two forms: mesomandibular (39%) and leptomandibular (61%). The shape of the branch of all lower jaws according to the latitude-altitudinal index (LAI) was platyramimandibular. The significant gender differences for the mandibular angle, projection length, angular width (p=0.026; 0.046; 0.039, respectively) were found. The female fetuses were dominated by the angle and projection length, while the male fetuses were dominated by the angular width. Conclusion. Features of the anatomical structure of the lower jaw in the fruits of the second trimester were revealed normally. The data about anatomical structure of the lower jaw of fetuses of second trimester are normally interested for supplement fundamental knowledge about its development in a given age period and has an applied importance forthe detection of congenital malformations, including the use of intravital imaging methods.