Tongue tie, the clinical evidence

A real clinical entity: diagnosis requires palpation and clinical experience

Posterior (submucosal) tongue tie is a recognised condition requiring palpation for diagnosis; visual inspection alone is insufficient. Hong et al. (2010) established ankyloglossia as a spectrum from anterior to posterior restriction, and demonstrated significantly higher revision rates for posterior ties (approximately 21%) compared to anterior ties (approximately 4%). The AAP's 2024 clinical report supports palpation as a diagnostic standard.

What most classification systems capture is the anterior-posterior location of frenulum attachment. What they do not adequately capture is the height of the attachment on the underside of the tongue, or the elasticity of the frenular tissue itself. These two factors are frequently more important determinants of functional impact than location alone. A frenulum attached at the mid-tongue but with very limited elasticity may be significantly more restricting than one attached anteriorly with good tissue compliance. This is why palpation by an experienced clinician is not a supplementary step but the central diagnostic act: it allows assessment of tissue quality, insertion height, and how restriction changes with tongue movement, none of which are visible on inspection alone.

Consensus documents and population-level guidance necessarily simplify to criteria that can be reliably communicated and applied across varied clinical settings. This is appropriate for their purpose, but it means they cannot fully capture the three-dimensional clinical picture that determines functional significance in individual patients. That gap is where clinical experience carries the most weight.

Combined surgery and myofunctional therapy: evidence supports the pathway

The evidence base for structured rehabilitation before and after frenotomy is real and strengthening. Zaghi et al. (2019) reported outcomes in 348 patients undergoing frenuloplasty combined with myofunctional therapy, demonstrating improved functional outcomes and low recurrence rates. Smart et al. (2025, International Journal of Paediatric Dentistry) specifically addresses pre- and post-operative care in children with ankyloglossia. A 2022 systematic review (PMC) examined the effectiveness of myofunctional therapy and reported improvements across breastfeeding, speech, sleep, tongue structure and function, and posture following combined treatment.

A 2025 prospective observational study found that post-operative stretching exercises were associated with reduced breastfeeding difficulty and lower rates of recurrent frenulum formation. The overall evidence supports combined treatment as superior to surgery alone. RCT-level evidence for specific exercise protocols is not yet available, but the direction of the literature is consistent.

Laser as a treatment modality: broadly equivalent functionally to scissors

Multiple systematic reviews and a 2025 randomised controlled trial (diode laser versus scalpel in infants, PMC12781438) support laser frenotomy as a safe and effective treatment modality. Functional outcomes are broadly equivalent between laser and conventional surgery. Laser advantages include significantly reduced bleeding, reduced post-operative pain, no sutures required, a clear operative field, and faster wound healing. Procedure time is shorter and the need for general anaesthesia is reduced in older patients.

One systematic review identified higher rates of oral aversion with laser compared to scissors (adjusted OR 4.05). This is a clinically relevant finding that practitioners should be aware of and discuss with families. The overall evidence supports laser as a legitimate, well-studied modality for frenotomy across age groups.

Upper lip tie: evidence does not support routine treatment of isolated lip tie, but the deeper problem is what we do not know

Upper lip tie (maxillary labial frenulum restriction) is a genuinely contested area. The Academy of Breastfeeding Medicine has stated explicitly that there is no evidence to support surgical treatment of isolated upper lip tie. Published grading systems for lip tie demonstrate poor interrater and intrarater reliability, and more than 80% of newborns are scored as having the highest grade by some assessors, which raises significant questions about diagnostic accuracy. These grading systems classify lip tie by insertion point alone, without accounting for tissue elasticity or functional impact, the same limitation that affects tongue tie classification discussed elsewhere on this page. No randomised controlled trials exist for lip tie release.

The absence of RCTs is part of the problem, but it is not the whole problem. The more fundamental gap is the absence of any natural history cohort data on what happens to these structures over childhood. We do not know what proportion of lip ties cause functional difficulty and what proportion never do. We do not know how many resolve spontaneously, or how the frenulum changes in appearance and function as a child grows. Young children fall frequently, and frenulum trauma from a fall is common, yet we have no longitudinal data on what happens to these structures after trauma, whether the appearance or function changes, and whether that changes the clinical picture. Without this foundational data, clinical decisions about lip tie are made on the basis of fragments: small case series, individual clinical observations, and the appearance of a structure whose natural course we have not formally studied. Better validated assessment tools are needed, both to improve the consistency and quality of individual clinical assessment, and to enable the kind of research that could properly delineate where lip tie represents a genuine functional problem and where it is a normal anatomical variant. Progress on the research question and progress on the clinical question are, in this sense, the same problem.

This does not mean clinical judgement is uninformed or that every decision is a guess. It means we are working with pieces of a picture whose complete form is not yet established. Where a significant tongue tie is present alongside a lip tie, there is a clinical rationale for considering both structures. We do not routinely recommend release of a lip tie, and we explain our reasoning, including what is not known, at every assessment where it arises, but would recommend intervention where we feel it is impacting function.

The RCPI/HSE 2025 consensus statement goes further than we do on this question: it states there is no evidence that lip and buccal ties are a genuine pathological entity, and that procedures to divide them should be discouraged. We agree with the evidentiary starting point. There is no population-level evidence to support routine division of isolated lip tie, and we do not recommend it routinely. Where we differ is in treating an absence of evidence for routine, population-level benefit as equivalent to "never clinically significant in an individual." In a minority of cases, where a lip tie is contributing to a clear functional problem, such as a persistent, significant diastema or a documented restriction in lip mobility with a plausible link to real symptoms, we think there is a clinical rationale for intervention, and we say so honestly to families rather than either over-treating routinely or withholding treatment where a genuine, individually assessed problem exists.

Posterior tongue tie classification: location alone misses what matters most clinically

The classification problem with posterior tongue tie runs deeper than the absence of a validated system. Existing classification approaches, including the commonly used Coryllos and Kotlow frameworks, classify frenulum restriction primarily by anterior-posterior location of attachment. This captures one dimension of the anatomy but not the two factors that most determine functional significance: the height of the frenular insertion on the underside of the tongue, and the elasticity of the frenular tissue.

A frenulum that inserts at the mid-tongue but has severely limited elasticity may be more functionally restricting than one that inserts anteriorly with compliant, elastic tissue. A high insertion on the tongue body that limits elevation cannot be fully appreciated visually and requires palpation to identify. Consensus documents and population-level guidance must default to criteria that can be reliably described and applied across diverse clinical settings; this is appropriate and necessary for their purpose. But that simplification creates a gap between what the literature classifies and what the experienced clinician actually assesses. The three-dimensional picture of how the tongue moves, how the frenulum behaves under tension, and how restriction changes with functional loading is not captured by any current classification framework.

At NTTC, assessment describes functional impact rather than anatomical grade. We are transparent with families when the clinical picture involves nuance that a classification system cannot convey, and we explain our reasoning fully. We expect the research literature to develop better tools for this in coming years.

The RCPI/HSE 2025 consensus statement states explicitly that "posterior ankyloglossia" is an anatomically incorrect term and must not be used as a reason to perform a surgical procedure. We think this correctly identifies a real problem with how the term is sometimes used, and incorrectly concludes from it that posterior restriction should not inform treatment decisions. The term does not describe a tie "at the back of the tongue"; it describes the posterior component of a frenulum that, in every case, runs along the underside of the tongue. Retiring the term would not change the underlying clinical question, which is whether a given frenulum, wherever it attaches, is restricting tongue movement enough to matter functionally. Our concern is that treating the terminology itself as the problem risks directing attention away from restrictions that are genuinely harder to see, rather than resolving the diagnostic gap that makes them harder to see in the first place. This is a genuine, named disagreement between our clinical position and the consensus statement, not a semantic one.