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

Abstract

Lingual frenotomy has become an increasingly common surgical procedure, performed for a broad range of indications from birth through adulthood. This study utilizes histology to define the structure and tissue composition of the lingual frenulum and floor of mouth (FOM) fascia. En bloc specimens of anterior tongue, lingual frenulum, and FOM tissues were harvested from ten embalmed adult cadavers. An additional three fresh tissue cadaveric specimens were frozen with the tongue supported in an elevated position, to enable harvesting and paraffin embedding of the elevated lingual frenulum as a discrete specimen. All 13 specimens were prepared as ten-micron coronal sections using stains to determine the general morphology of the lingual frenulum, its relationship to neighbouring structures (Mason’s Trichrome), presence of elastin fibers (Verhoeff-van Gieson), and collagen typing (Picrosirius Red). Our results have shown a submucosal layer of fascia spanning horizontally across the FOM was present in all specimens, with variability in fascial thickness and histologic composition. This FOM fascia suspends the sublingual glands, vessels, and genioglossus from its deep surface. The elevated lingual frenulum is formed by a central fold of this FOM fascia together with the overlying oral mucosa with variability in fascial thickness and composition. With tongue elevation, the fascia mobilizes to a variable extent into the fold forming the frenulum, providing a structural explanation for the individual variability in lingual frenulum morphology seen in clinical practice.

Reliability of Sonoelastography Measurement of Tongue Muscles and Its Application on Obstructive Sleep Apnea

“…Recently, the anatomical details of tongue muscles have been appreciated by the development of the super-resolution volume reconstruction method ( Woo et al, 2012 ), establishment of a spatial-temporal atlas during speech and swallowing ( Woo et al, 2015 ) and the segmented analysis of different muscle fibers on MRI imaging ( Stone et al, 2018 ). Furthermore, the increase of fat depositing in the tongue base of obese and aging patients ( Kim et al, 2014 ), regional differences in proportion and diameter of muscle fiber types ( Stål et al, 2003 ) as well as the size and collagen composition of the lingual frenulum ( Guilleminault et al, 2016 ; Mills et al, 2020 ) would be related to the stiffness measurement in patients with OSA. In addition, we found that the age distribution of the participants in their study ( Chang et al, 2020 ) was different from that of ours.…”

Histological Examination of the Lingual Frenulum in Patients With Ankyloglossia

“…PŮVODNÍ PRÁCE Linguální frenulum je při narození obvykle prodlouženo a dosahuje až k apexu. Poté ustupuje v důsledku růstu během prvních šesti měsíců a tento proces pokračuje až do šesti let života [11].…”

25 Years of Research in Human Lactation: From Discovery to Translation

“…More recently cases of tongue tie have appeared with increased frequency, most likely driven by the increased diagnosis of posterior tongue tie. However, the subsequent increase in frenotomy [ 106 ] have raised concerns about increased post-surgical complications [ 107 ]. Furthermore, preliminary evidence suggests that milk production can remain compromised in a number of infants after frenotomy for posterior tongue tie, indicating other potential causes of insufficient supply [ 108 ].…”

“…Finally, the frenulum contains Type III collagen fibres which are much more distensible and mobile than the stronger less distensible Type I fibres previously identified [ 109 , 160 ]. Combined, these findings call for tongue tie grading to embrace normal variability and sheds light on concerns of adverse effects of frenotomy providing the basis for more prospective studies [ 107 ].…”