Thickness of the lower wall of tympanic cavity in premature infants

Abstract

Introduction. At this time, the problem of the pathology of the middle ear in newborns and infants is very topical due to the high frequency of their detection of otitis media. It connected with certain anatomical characteristics of the structure of the nasal cavity and the middle ear, and the presence of amniotic fluid in the middle ear. Most authors study ear pathology in children in their early years. Only a few researchers study ear diseases in premature babies. It should be noted that otitis media in premature infants is quite difficult and in the future it is necessary to conduct surgical intervention - miringoplasty or shunting of the tympanic cavity. Modern scientific achievements have considerably expanded the practical possibilities of endoscopic operations with diseases of the ear. The introduction of them contributed to the development of the priority direction - endoscopic operations, which have several advantages over traditional otomicrosurgical operations. That’s why the study of embryological aspects of the development of the middle ear, its anatomy and topographic anatomy in the fetuses, remains very important. The aim of the study. To study the peculiarities of the development of the inferior wall of the tympanic cavity in the early period of ontogenesis. Materials and methods. The study was carried out on corpses of 58 fetuses of 271,0-375,0 mm of parietal-coccygeal length (PCL) and 11 newborns by methods of ordinary and fine preparation under the control of binocular enlarging lens, macromyscope and morphometry, photomacrography of the “OLIMPUS μ 1000 Allweather 10.0 Mpix” digital camera. Result. We have found out that the inferior wall of the tympanic cavity limits the jugular fossa and begins to form on the 8th month of intrauterine development as an processus of the petrosal part of the temporal bone. The development of internal jugular vein contributes to the formation of this wall. Within process of increasing of its diameter the lower edge of the annulus tympanicus begins to depart from the promontory and the tilt angle of the upper edge increases. As a result the annulus tympanicus moves from a horizontal position in a more inclined. 66 Natural Science Readings (May 28-30, 2020, Bratislava) The thickness of the inferior wall of the tympanic cavity during this period is 0,63±0,03 mm. During the ninth month of intrauterine development that the tympanic cavity becomes more irregular in shape, numerous cells appear on its walls. The inferior wall of the tympanic cavity increases its size and the lower edge of the annulus tympanicus departs from the promontory even more, and the angle of inclination of the upper edge increases. As a result the tympanic cavity from the almost horizontal position moves in the inclined. The thickness of the inferior wall of it is 0,72±0,02 mm. During the tenth month of intrauterine development the formation of the inferior wall of the tympanic cavity continues as a result of the increase of the diameter of the internal jugular vein. Its thickness is 0,87±0,04 mm. The tympanic cavity of the newborns has the form an irregular cube with rounded edges that is filled with embryonic tissue. The inferior wall of the tympanic cavity is a bone plate under which the bulb of the jugular vein is located. Its thickness is small and is 1,06 ± 0,03 mm. Discussion. The results of this study will contribute to the rational choice of methods for surgical interventions in the middle ear of newborns and babies in the first months of life. Conclusions. 1. The thickness of the inferior wall of the tympanic cavity is 1.06 ± 0.03 mm of newborns, which should be taken into account when performing manipulations and surgical interventions on the middle ear. 2. The thickness of this wall of newborns does not differ from the thickness of it of children of 13 years. 3. The thickness of this wall of the fetuses of the 8th - 10th months is thinner than of newborns.