Defining the anatomy of the neonatal lingual frenulum

Abstract

The lingual frenulum is recognized as having the potential to limit tongue mobility, which may lead to difficulties with breastfeeding in some infants. There is extensive variation between individuals in the appearance of the lingual frenulum but an ambiguous relationship between frenulum appearance and functional limitation. An increasing number of infants are being diagnosed with ankyloglossia, with growing uncertainty regarding what can be considered "normal" lingual frenulum anatomy. In this study, microdissection of four fresh tissue premature infant cadavers shows that the lingual frenulum is a dynamic, layered structure formed by oral mucosa and the underlying floor of mouth fascia, which is mobilized into a midline fold with tongue elevation and/or retraction. Genioglossus is suspended from the floor of mouth fascia, and in some individuals can be drawn up into the fold of the frenulum. Branches of the lingual nerve are located superficially on the ventral surface of the tongue, immediately beneath the fascia, making them vulnerable to injury during frenotomy procedures. This research challenges the longstanding belief that the lingual frenulum is a midline structure formed by a submucosal "band" or "string" and confirms that the neonatal lingual frenulum structure replicates that recently described in the adult. This article provides an anatomical construct for understanding and describing variability in lingual frenulum morphology and lays the foundation for future research to assess the impact of specific anatomic variants of lingual frenulum morphology on tongue mobility. Clin. Anat. 32:824-835, 2019.

Understanding the Lingual Frenulum: Histological Structure, Tissue Composition, and Implications for Tongue Tie Surgery

“…Consistent with the recently described adult and neonatal lingual frenulum anatomy [ 3 , 4 ], we have confirmed that lingual nerve branches are located superficially on the ventral tongue surface, immediately beneath the fascial layer. This emphasizes the vulnerability of these nerve branches during frenotomy surgery, particularly when using any surgical tool that creates thermal energy that can be transmitted into the underlying tissues.…”

“…Consistent with the recently described adult and neonatal lingual frenulum anatomy [3,4], we have confirmed that lingual nerve branches are located superficially on the ventral tongue surface, immediately beneath the fascial layer.…”

“…Over the last decade, there has been increasing popularity in the frenulum being conceptualized as a discrete submucosal connective tissue midline band or "string" [2]. However, the understanding of lingual frenulum structure has been comprehensively revised following two studies using microdissection of fresh tissue cadavers [3,4] showing that the lingual frenulum is formed by a midsagittal fold in a layer of fascia that spans across the floor of mouth.…”

Clinical Consensus Statement: Ankyloglossia in Children

“…But some panelists do not use this term and equate “ankyloglossia” with “anterior ankyloglossia.” When the definition of posterior ankyloglossia was considered, the panel was unable to achieve consensus. 17-22 Some in the group use the term to mean a frenulum that inserts into the posterior portion of the tongue, whereas others think of it as a submucosal tethering of the tongue ( Figure 1B ). Still others feel that it does not exist as an anatomic entity and that the term “posterior ankyloglossia” should be abandoned.…”

Frenulectomy with Diode Laser Technology in Paeditric Patients: Quantitative and Qualitative Evaluations. Randomized Double- Blind Clinical Trial

“…The lingual frenulum is formed from the oral mucosa and connective tissues within 22 weeks of gestation; at the time of its formation, any alteration of embryological processes could cause changes in its anatomical structure [1]. The anatomy of the lingual frenulum is poorly described in textbooks (Sinnatamby and Last [2]; Standring [3]); however, a recent study illustrated how it develops from concurrent muscular and mucous components [4]. Currently, there are no publications providing relevant additional details on the physiological morphology.…”