A Cineradiographic Study of Breast Feeding

Abstract

T HE following description of a cineradiographic study of breast feeding supplements our previous paper on bottle feeding (Ardran, Kemp and Lind, 1958). The investigations were made concurrently and with the same apparatus.Forty-one infants were examined while feeding at the breast. They were of both sexes and of ages ranging from a few days to several months. METHOD Before the examination the mother's nipple and its surrounding areola were thinly coated with a paste of barium sulphate powder in Lanoline. The baby was laid on a couch so as to obtain films of the head and neck in lateral projection. The mother leaned over the couch with her body twisted so as to allow one breast to project clear of the chest wall. A nurse adjusted the baby to the mother's nipple and when feeding was established the radiographic exposure was made. One cinefilm was taken of each subject (25 frames per second), the exposure limited to approximately four seconds, the dose-rate being about 0-3 r at the skin per 100 frames. Care was taken to make the mother comfortable by adjusting the height of the couch and by providing suitable supports for her arms. In seven individuals the inner and outer margins of the areola were also marked with pieces of tin foil embedded in plastic skin.Four women also had 16 mm colour cinefilms taken to show the infant taking the nipple into the mouth and feeding. Films were also taken of the mother's breast as feeding was interrupted by removal of the child. RESULTS

Biomechanics of milk extraction during breast-feeding

“…Tongue undulation during breast-feeding has been the topic of many studies (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Submental US imaging revealed the complex motion of the tongue, as was also demonstrated here.…”

“…Observation of cine-X-ray film (13) and US movies recorded during breast-feeding clearly revealed an anterior-posterior movement of the nipple with respect to infants' mandible oscillations. The nipple is moving posteriorly (i.e., toward the inside of the mouth) while the tongue and mandible are lowered, and anteriorly (i.e., toward the outside of the mouth) when the tongue and mandible are moving upward and compressing the nipple against the hard palate (3, 24).…”

“…According to the classic theory of breast-feeding, the infant draws the nipple into its mouth, with the areola and the underlying enlarged and branching lactiferous ducts held between the infant's upper gums. Then, a roller-like peristaltic wave of contraction throughout the surface of the tongue squeezes milk from the ampullae into the esophagus (3,13). Simultaneous recordings of orokinetogram and pressure near the nipple during breast-feeding similarly led to conclusions that oral activity was associated with nipple squeezing (18,19).…”

“…Because both the tongue and the mandible are oscillating during breast-feeding, we were interested in exploring their relative motions. We recently received a movie clip of a cinefilm of radiographic exposure during breast-feeding from the study of Ardran et al (13), which clearly demonstrated the movement of the nipple, tongue, and mandible. With permission from the Nuffield Department of Obstetrics and Gynecology (University of Oxford, Oxford) we used dynamic analysis to explore the tongue motion with respect to the mandible during breast-feeding.…”

“…The two proposed mechanisms that have been a subject of scientific controversy to this day are (i) sucking-emptying of the nipple-breast contents by development of subatmospheric pressures within the infant oral cavity (9)(10)(11)(12) and (ii) mouthingsqueezing out of the nipple-areola contents by compression between the jaws or other mouth parts (3). With the appearance of cine-X-ray and ultrasound (US) imaging modalities, a significant role was also attributed to tongue undulation which was naturally referred to as "tongue peristalsis" while chewing the nipple (13,14). However, advanced computational modeling has not yet been used along with imaging data to perform hypothesis testing on the underlying explanations of the suckling behavior during breast-feeding.…”