Ray S, et al. - In this prospective cross-sectional study involving 150 healthy newborns, researchers measured the variations in length, thickness, and attachments of the maxillary labial frenulum in healthy newborns and identified which anatomic measurements could be used in further research examining the maxillary labial frenulum. Study participants included healthy newborns admitted to the newborn nursery at a tertiary care children’s hospital in Maryland between September 1, 2017, and April 1, 2018. Investigators found that maxillary labial frenulum had numerous morphologic components with varying distributions. Several components with widely distributed means and SDs were helpful in distinguishing degrees of lip tethering, including alveolar edge to frenulum gingival attachment; frenulum length of stretch; frenulum gingival attachment thickness; frenulum labial attachment thickness; and the percentage of free lip to total lip length. A new understanding of the maxillary labial frenulum anatomy may be useful in future studies examining the complexity of maxillary labial frenulum and neonatal breastfeeding.