Background: Congenital clefts of the upper lip and palate are not more often as a part of this or that syndrome, but as an independent congenital disease in the form of an isolated developmental defect of separate organs. Therefore, it is necessary to detect and systematize peculiarities of the development and structure of the maxilla and its body in the perinatal period of ontogenesis. Material and methods: The study was conducted on 53 dead 4-10-month fetuses and 11 newborns (5 isolated organ complexes in particular) of both sexes without external signs of anatomical defects or abnormalities and without vivid macroscopic deviations from the normal structure of the skull. Before the beginning of the craniometric examination every specimen was fixed in craniostat in the horizontal auricular-ocular plane, in so-called “Frankfurt horizontal line”. All the measurements on the skulls were made by means of a tape measure, caliper, slide compasses and dial calipers. results: With the age of fetuses a short and wide shape of the upper jaw changes into a high and narrow one. The absence of the zygomatic-cellular crest is a characteristic sign of the fetuses of all the age groups and newborns. During perinatal period of ontogenesis infraorbital opening is usually projected in the point of crossing of the line connecting a lateral angle of the eye with the wing of the nose and the line passing from the medium angle of the eye to the angle of the mouth. conclusions: A typical shape of the maxilla during the perinatal period is short and wide found in early fetuses (4-5 month) – in 94% of cases, in fetuses of 6-7 months of age – in 82% and in fetuses of 8-10 months of age (late fetuses) – in 68% and newborns. A typical shape of the anterior surface of the maxilla for early fetuses is irregular trapeziform, and for 6-7-month fetuses, late fetuses and newborns – an elongated triangle shape.