Sucking characteristics of successfully breastfeeding infants with ankyloglossia: a case series

Partial ankyloglossia is a congenital oral anomaly characterized by restricted movement of the tongue resulting from a lingual frenulum that is either short, inelastic, or is attached distally, too near or onto the gingival ridge (1). The prevalence of ankyloglossia is not well documented because of the lack of a standard definition or a reliable clinical method of classification (2). Studies of neonates, infants and adolescents quote the incidence of ankyloglossia to be between 0.1% and 10.7% (2,3). Recently, a resurgence of breastfeeding difficulties in infants with ankyloglossia has been reported, with a frequency ranging from 25% to 44% (3,4). Feeding difficulties associated with ankyloglossia include painful nipples (4–6), poor latch (6), reduced milk supply, neonatal dehydration (7) and decreased duration of breastfeeding (4). Controversy exists regarding the management and treatment of ankyloglossia (8), although studies show that in infants with feeding problems, frenotomy improves maternal nipple pain (5,6,9,10), latch scores (6,10), tongue action, milk transfer and milk supply (10). Fortunately, the majority of infants with ankyloglossia are able to breastfeed successfully. The controversy surrounding ankyloglossia most likely stems from the lack of knowledge of the effect the condition has on feeding, and in particular breastfeeding. Five fully breastfed infants with ankyloglossia presented for a research study designed to assess the sucking characteristics of normal breastfed infants. The study was approved by the Human Ethics Committee of The University of Western Australia. Sub-mental ultrasound scans of the infant oral cavity were made during a breastfeed to image tongue motion (Fig. 1A,B). Intra-oral vacuums were measured simultaneously via a supply line filled with sterile water connected to a pressure transducer (11). The test-weigh method was used to measure milk intakes for the monitored feed and three mothers measured every feed for a 24-h period (12). All infants recorded normal growth and the three mothers who measured every feed for a 24-h period recorded normal levels (range 478 to 1356 g per 24 h) (12). The data are shown in Table 1 (Infants 3–5). Infants 1, 2 and 3 displayed no compression of the nipple; however, weak vacuums were recorded for Infant 1 (Fig. 2A,B; Table 1). Infants 2 and 4 recorded strong maximum vacuums. Infant 4 had strong minimum vacuum and displayed compression of the base of the nipple on ultrasound (Fig. 2C,D). Infant 5 had very weak maximum vacuum and compression of the tip of the nipple (Fig. 2E,F). Mean maximum vacuums quoted in the literature range from )145 (11) to )197 mmHg (13) for breastfeeding infants. Mean minimum vacuum has been measured at )64 mmHg in one study of breastfeeding infants (11). The importance of the level of vacuum has become apparent with a recent study demonstrating an association between strong infant sucking vacuums and nipple pain (14). Conversely, similar to pumping vacuums (15), low sucking vacuums have been associated with reduced efficiency and effectiveness of feeding(16). Although these infants with ankyloglossia had intra-oral vacuums outside the normal range, they were able to obtain enough milk to grow satisfactorily and none of the mothers experienced nipple pain during feeding. It is possible that the vacuum exerted by the infant is influenced by both the restriction of tongue movement or nipple ⁄breast shape. Further research is required to investigate this. Ultrasound imaging during breastfeeding showed that two of the infants compressed the nipple. One infant compressed the base of the nipple and the other compressed the tip of the nipple. Previous ultrasound imaging of infants Acta Paediatrica ISSN 0803–5253