The effects of an untreated tongue-tie restriction: What does the evidence tell us?

A tongue-tie may be identified in the first days or weeks of life, sometimes when a family is already experiencing feeding difficulties, pain or concerns about milk transfer. However, the presence of a lingual frenulum that appears short, tight or restrictive does not, by itself, tell us how a baby will function now or how that child will develop in the future.

Not every tongue-tie requires treatment. Some babies feed comfortably and effectively without intervention, while others may experience functional difficulties where restricted tongue movement is one contributing factor. The important question is therefore not simply whether a frenulum is present, but whether restriction is affecting function.

It is also important to distinguish between treating a current problem and attempting to prevent a hypothetical future one.

Frenulotomy in an infant should be considered in relation to the clinical problems and functional findings that are present at that time. It should not be undertaken simply because a child might develop speech, sleep, breathing, dental, facial or postural difficulties in the future. We do not have a crystal ball: it is not possible to know which infant with a tongue-tie will subsequently develop one of these problems, whether the frenulum will be a contributing factor, or whether the problem would occur regardless of the frenulum.

There are also ethical considerations in performing an invasive procedure on an infant for a future outcome that cannot currently be predicted and for which preventative benefit has not been established. If a child develops a functional difficulty later in childhood, that difficulty can be assessed at that time. The child's anatomy, growth, oral structures, function and wider circumstances will then be known, allowing the most appropriate management to be considered based on the problem that actually exists.

The same principle applies in the other direction. Releasing a tongue-tie in infancy does not guarantee that a child will never experience speech, breathing, sleep, dental or postural difficulties. These outcomes are influenced by many factors. For example, a child who has undergone frenulotomy may later experience speech difficulties for reasons unrelated to the frenulum. A high palate, dental development, hearing, motor planning, phonological development and other structural or functional factors may all be relevant to speech.

The purpose of this article is therefore not to suggest that every untreated tongue-tie will cause problems, nor that every tongue-tie should be released to prevent possible future difficulties. Instead, it considers what is currently known about the potential relationship between restricted tongue function and breastfeeding, bottle feeding, breathing, speech, facial and dental development, posture, sleep, and swallowing and eating.

The evidence is not equally strong across these areas. Some associations have been investigated in clinical studies and systematic reviews, while other proposed relationships remain uncertain and require better research.

Anatomy provides information. Function provides context.

Breastfeeding and chestfeeding

The strongest body of evidence concerning infant tongue-tie relates to breastfeeding, although even here the evidence has important limitations.

A restrictive lingual frenulum may affect the infant's ability to elevate, extend or move the tongue with the range and coordination required for effective feeding. Depending on the individual infant, this may contribute to difficulty maintaining an effective attachment, generating or maintaining suction, or transferring milk efficiently. Maternal nipple pain and nipple compression or damage may also occur.

However, these signs are not specific to tongue-tie. Breastfeeding is a complex interaction involving infant positioning, breast and nipple anatomy, milk flow, gestational age, infant tone, regulation, oral-motor skills, respiratory status and many other factors. A tongue-tie may be one contributing factor rather than the sole explanation.

Randomised trials and systematic reviews suggest that frenotomy can reduce maternal nipple pain in the short term for some breastfeeding dyads. However, evidence for consistent improvement in objective breastfeeding outcomes and longer-term breastfeeding duration is less certain. The Cochrane review concluded that frenotomy reduced maternal nipple pain in the short term but did not demonstrate a consistent positive effect on infant breastfeeding, with the evidence limited by small studies and methodological weaknesses (O'Shea et al., 2017).

A later systematic review and meta-analysis reported improvements in standardised breastfeeding difficulty and maternal pain following frenotomy, although the authors also noted limitations within the available evidence (Bruney et al., 2022).

The UK randomised trial by Emond et al. (2014) is particularly useful when considering whether every tongue-tie should be treated immediately. In infants with mild-to-moderate tongue-tie and breastfeeding difficulties, immediate frenotomy did not produce an objective improvement in breastfeeding at five days compared with standard breastfeeding support. Maternal breastfeeding self-efficacy did improve, and many families in the comparison group subsequently chose frenotomy when difficulties persisted.

This supports an individualised approach. A tongue-tie that is present but not causing meaningful functional difficulty does not automatically require intervention. Where significant feeding difficulties persist despite skilled support, however, assessment of whether restricted tongue movement is contributing may be appropriate.

Bottle feeding

Tongue-tie is less extensively studied in bottle-fed and combination-fed infants than in breastfed infants.

Some infants with restricted tongue movement may have difficulty maintaining an effective seal around a teat, generating suction or coordinating tongue movement with the flow of milk. Families may describe milk loss from the mouth, clicking, loss of suction, prolonged feeds, fatigue, coughing or spluttering, unsettled feeding or difficulty taking sufficient volumes.

However, these signs are not diagnostic of tongue-tie. Teat flow, feeding position, pacing, respiratory health, neurological or developmental factors, oral-motor coordination and normal individual variation can all influence bottle feeding.

The evidence for treating ankyloglossia specifically to improve bottle feeding remains limited. The American Academy of Pediatrics systematic review found insufficient evidence to assess the effects of frenotomy on non-breastfeeding outcomes, including feeding beyond breastfeeding (Chinnadurai et al., 2015).

This does not mean that bottle-feeding difficulties should be dismissed when a tongue-tie is present. It means that the feeding problem should be assessed in its own right, rather than assuming that the frenulum is responsible.

Breathing and oral posture

The relationship between tongue mobility, tongue resting posture and breathing has attracted increasing clinical and research interest.

The tongue contributes to the shape and function of the oral cavity and normally rests within the mouth with an interaction between the tongue, palate, jaw and surrounding muscles. Restricted tongue mobility may, in some individuals, influence the range of resting tongue positions that can be comfortably achieved.

Researchers have therefore investigated whether ankyloglossia may be associated with altered oral posture, mouth breathing or upper-airway function.

However, it is important to distinguish a plausible functional mechanism from evidence of causation. A restricted frenulum does not automatically result in mouth breathing or airway dysfunction, and mouth breathing has many possible causes, including nasal obstruction, allergy, enlarged adenoids or tonsils and other airway factors.

Current evidence does not justify predicting that an infant with tongue-tie will develop breathing problems later in childhood. Nor does it establish that infant frenulotomy prevents future breathing difficulties.

This is an area where further prospective research is needed, particularly research that assesses tongue function rather than relying solely on the appearance of the frenulum.

Speech

Speech is one of the areas most frequently raised when discussing possible longer-term effects of an untreated tongue-tie.

The tongue is involved in the production of many speech sounds, and adequate movement, speed, precision and coordination are important for articulation. It is therefore biologically plausible that significant restriction of tongue movement could affect speech in some individuals, particularly where the restriction limits the movement required for particular sounds.

However, biological plausibility does not establish that tongue-tie causes speech disorders.

A systematic review by Wang et al. (2022) identified 16 studies examining ankyloglossia and speech articulation. Most studies were small and the overall quality of evidence was low. The authors found no clear connection between ankyloglossia and speech disorders and concluded that better-designed research using consistent definitions and assessment methods was needed.

This is important when considering an infant. It is not possible to look at a baby's frenulum and reliably predict whether that child will have a speech difficulty years later.

Speech development is multifactorial. Hearing, phonological development, motor planning, language development, oral structure, palate shape and other developmental factors may all contribute. A high palate, for example, may influence oral structure and speech independently of whether a child has previously had a tongue-tie released.

Consequently, infant frenulotomy should not be presented as a guarantee against future speech problems. If a child develops a speech difficulty later, the appropriate response is assessment of the speech difficulty at that time, rather than assuming that the presence or previous treatment of a tongue-tie explains the problem.

Facial growth and dental development

The possible relationship between tongue restriction and facial or dental development is an area of considerable interest, but it is also an area in which claims can easily become stronger than the evidence supports.

The tongue exerts forces within the oral cavity and has an important relationship with the palate, dental arches and surrounding structures. Restricted tongue mobility may alter tongue position or function in some individuals, and researchers have investigated whether ankyloglossia is associated with differences in dental arch dimensions, malocclusion and facial morphology.

A 2024 systematic review examining ankyloglossia and facial development identified associations between ankyloglossia and reduced intercanine and intermolar widths, as well as Class III malocclusion and mandibular incisor crowding. However, the authors assessed the quality of the available studies as low and highlighted the lack of good-quality prospective research (Kotarska et al., 2024).

These findings are therefore interesting but should not be interpreted as proof that an untreated tongue-tie causes abnormal facial growth.

Facial growth is influenced by numerous genetic, skeletal, dental, muscular, respiratory and environmental factors. The palate and dental arches also develop and change throughout childhood.

Similarly, there is currently insufficient evidence to conclude that releasing a tongue-tie during infancy prevents later orthodontic problems or ensures normal facial development.

If dental or skeletal concerns become apparent as a child grows, they can be assessed by the appropriate dental or orthodontic professional at that stage. The child's actual anatomy and developmental pattern can then be considered rather than attempting to predict the future from an infant frenulum.

Posture and whole-body function

Claims about tongue-tie and posture are common, but the evidence base is considerably less developed than that relating to infant feeding.

The tongue does not function in isolation. It has anatomical and functional relationships with the mandible, hyoid region and surrounding muscles. Changes in tongue position can therefore influence the way other structures are recruited during particular movements.

This has led to hypotheses concerning relationships between tongue restriction, head and neck position, cervical muscle activity and wider postural patterns.

However, a proposed anatomical or biomechanical relationship is not the same as evidence that an untreated tongue-tie causes poor posture.

There is currently insufficient high-quality evidence to conclude that infants with untreated tongue-tie are likely to develop postural problems, or that frenulotomy in infancy prevents such problems.

Posture is influenced by growth, musculoskeletal development, vision, balance, strength, motor development, habitual movement patterns and many other factors. If a postural concern develops, it should therefore be assessed in the context of the individual child rather than automatically attributed to a lingual frenulum.

This is an important area for future research, particularly studies that use objective functional measures rather than assumptions based on anatomy alone.

Sleep and sleep-disordered breathing

Sleep is another area where the relationship with tongue-tie is increasingly being investigated.

The position and tone of the tongue are relevant to the upper airway, and researchers have therefore considered whether restricted tongue mobility might be associated with sleep-disordered breathing or obstructive sleep apnoea.

The research is interesting but not yet definitive.

A 2024 systematic review and meta-analysis reported an association between a short lingual frenulum and obstructive sleep apnoea in children. The same review also identified a strong association between a high-arched palate and obstructive sleep apnoea, highlighting the importance of considering more than the frenulum alone (Camañes-Gonzalvo et al., 2024).

More recently, a systematic review published in 2026 examined eight studies involving 1,171 children and concluded that the relationship between ankyloglossia and paediatric sleep-disordered breathing remains unclear. The authors also found insufficient evidence to determine whether frenotomy should be used as a treatment for sleep-disordered breathing in children with ankyloglossia (Venugopal et al., 2026).

This distinction is important. An association between two conditions does not mean that one causes the other, and evidence that a frenulum is associated with sleep-disordered breathing does not demonstrate that releasing an infant's frenulum will prevent sleep problems years later.

If a child develops snoring, mouth breathing, disturbed sleep or other symptoms suggestive of sleep-disordered breathing, these symptoms should be assessed at the time they occur. The child's airway, tonsils, adenoids, palate, craniofacial development, weight, nasal health and other relevant factors can then be considered.

Swallowing, eating and digestion

As children move from milk feeding to complementary foods, tongue movement becomes important for manipulating food, forming and moving a bolus and coordinating swallowing.

A restricted tongue may potentially affect some aspects of oral food management in an individual child, particularly where the range of movement is substantially limited. Some children may develop compensatory strategies that allow them to manage food effectively despite restriction.

However, the evidence connecting infant ankyloglossia with later swallowing or eating difficulties remains limited.

The available literature includes reports of improvements in some non-breastfeeding feeding functions following treatment, but systematic reviews have concluded that the evidence is insufficient to establish clear longer-term benefits of frenotomy for these outcomes (Chinnadurai et al., 2015).

It is also important to distinguish swallowing and oral processing from digestion itself.

Digestion involves the gastrointestinal tract and a complex range of physiological processes. It would therefore be inappropriate to state that an untreated tongue-tie causes digestive disorders.

Where a child has difficulty chewing, managing textures, swallowing or progressing with eating, the problem should be assessed as a feeding or swallowing concern in its own right. Other causes should be considered rather than assuming that a lingual frenulum is responsible.

What does the evidence actually tell us?

The evidence surrounding untreated tongue-tie is not a simple question of whether problems will or will not occur.

The research suggests that restricted tongue function can be relevant to feeding in some infants, particularly breastfeeding, and there is increasing interest in possible associations between ankyloglossia and later speech, craniofacial development and sleep-disordered breathing.

However, the quality of evidence varies substantially between these areas.

For speech, current systematic review evidence has not established a clear causal relationship. For facial development, associations have been reported, but the quality of the available studies is low. For sleep-disordered breathing, studies have produced evidence of an association but recent systematic review evidence still describes the relationship as unclear and finds insufficient evidence to recommend frenotomy as a treatment for paediatric sleep-disordered breathing. Evidence concerning posture is particularly limited.

This matters because an association does not establish causation.

It is also important to recognise a major limitation in the research: there are relatively few high-quality prospective studies following infants with untreated tongue-tie over many years. Without good natural-history research, it is difficult to determine which children would develop problems without treatment, which would not, and what other factors might contribute to those outcomes.

This is why it is inappropriate to tell families that an untreated tongue-tie will inevitably cause future speech, sleep, breathing, dental or postural problems.

It is equally inappropriate to suggest that releasing every infant tongue-tie will prevent those problems.

Treat the problem that exists, not the problem we imagine might happen

The distinction between current function and future possibility is central to responsible decision-making.

A frenulotomy is an intervention performed on an infant. It should therefore be considered because there is a current clinical reason to consider it, supported by assessment of the infant's function and circumstances, rather than because of a fear that the child might develop a problem years later.

We cannot know in infancy whether a particular child will later develop a speech disorder, obstructive sleep apnoea, malocclusion, altered posture or difficulty with eating. We also cannot know whether the lingual frenulum would have contributed to that problem.

Anatomy changes with growth and development. The palate develops, the dental arches change, facial structures mature and neuromuscular patterns develop throughout childhood. A problem that does not exist today cannot be assessed accurately as though it already exists.

If a clinically significant difficulty develops later, it can be investigated at that time. The child's current anatomy and function can then inform the clinical decision.

This approach also avoids the assumption that frenulotomy provides lifelong protection. A child who has undergone frenulotomy may still develop speech difficulties, sleep-disordered breathing, orthodontic problems, postural issues or feeding difficulties for reasons unrelated to the frenulum. Releasing the frenulum does not remove the many other factors that influence development.

For example, a high palate may be relevant to speech or airway function regardless of whether a tongue-tie was previously released.

The goal should therefore be appropriate care for the child in front of us, rather than attempting to predict and surgically prevent every possible future problem.

Observation is not the same as doing nothing

Choosing not to undertake frenulotomy does not have to mean ignoring a tongue-tie.

Where an infant is feeding comfortably, growing appropriately and functioning well, observation may be entirely appropriate. Families can be supported, information can be provided and the child's function can be reviewed if circumstances change.

Similarly, where feeding difficulties are present, conservative support can be an active part of management. This may include skilled feeding assessment, positioning and attachment support, consideration of milk transfer, monitoring growth and hydration, and addressing other potential contributors.

If difficulties persist, the assessment can be revisited.

This approach allows decisions to remain responsive to the infant's actual needs rather than making an irreversible decision based on what might happen years later.

When should families seek further assessment?

Families should seek appropriate assessment when there is a current functional concern.

In infancy, this may include persistent maternal nipple pain, difficulty maintaining attachment, concerns about milk transfer, prolonged or exhausting feeds, poor weight gain, concerns about hydration or significant difficulty coordinating feeding.

As a child develops, concerns may relate to speech, eating, swallowing, sleep, breathing, dental development or other aspects of function.

The appropriate professional assessment will depend on the problem. A speech and language therapist may be appropriate for speech concerns; a dentist or orthodontist for dental or facial development; an appropriately qualified clinician for sleep or airway concerns; and a feeding or swallowing specialist where eating or swallowing is problematic.

The presence of a tongue-tie can be considered as part of the assessment, but it should not automatically become the explanation for every difficulty.

Summary

A tongue-tie is an anatomical finding; its significance depends on function. Not every infant with a tongue-tie will experience difficulties, and the presence of a frenulum alone is not a reason to undertake treatment.

The evidence surrounding the longer-term effects of an untreated tongue-tie is developing and varies considerably between areas. Research has investigated possible relationships with breastfeeding, bottle feeding, breathing, speech, facial and dental development, posture, sleep and swallowing, but the quality and consistency of the evidence are not the same across these areas.

There is stronger evidence that some infants with restricted tongue function may experience breastfeeding difficulties, particularly maternal nipple pain, than there is for many of the proposed longer-term effects. Evidence concerning speech remains inconsistent; research into facial growth and dental development is suggestive but limited by study quality; evidence concerning posture is currently weak; and the relationship between ankyloglossia and sleep-disordered breathing remains uncertain.

Importantly, the possibility of a future problem should not be confused with evidence that a future problem will occur.

Frenulotomy in infancy should be considered in the context of the problems and functional findings that are present at that time. It should not be undertaken simply to try to prevent a hypothetical future speech, sleep, breathing, dental or postural problem.

We do not have a crystal ball. We cannot predict which children will develop these difficulties, whether a tongue-tie will contribute to them, or what other anatomical and functional factors may be involved as a child grows.

Anatomy also changes with growth and development. If a clinically significant problem emerges later, it can be assessed and managed at that time, based on the child's current anatomy and function.

Equally, a child who has undergone frenulotomy in infancy is not protected from developing future difficulties. Speech, sleep, breathing, dental development, posture and eating are influenced by multiple factors, and problems may arise for reasons unrelated to the lingual frenulum. A high palate, for example, may be relevant to oral function, speech or airway function independently of whether a tongue-tie was previously released.

The most appropriate approach is therefore neither to treat every tongue-tie nor to dismiss every tongue-tie. It is to assess function, identify problems that are actually present, consider the available evidence, support the infant and family, and review as the child develops.

We do not need to predict the future to provide appropriate care today.

Anatomy provides information. Function provides context.

References

Bruney, T.L., Scime, N.V., Madubueze, A. and Chaput, K.H. (2022) ‘Systematic review of the evidence for resolution of common breastfeeding problems—ankyloglossia (tongue tie)’, Acta Paediatrica, 111(5), pp. 940–947. doi:10.1111/apa.16289.

Camañes-Gonzalvo, S., Montiel-Company, J.M., Paredes-Gallardo, V. et al. (2024) ‘Relationship of ankyloglossia and obstructive sleep apnea: systematic review and meta-analysis’, Sleep and Breathing, 28, pp. 1067–1078. doi:10.1007/s11325-024-03021-4.

Chinnadurai, S., Francis, D.O., Epstein, R.A., Morad, A., Kohanim, S. and McPheeters, M. (2015) ‘Treatment of ankyloglossia for reasons other than breastfeeding: a systematic review’, Pediatrics, 135(6), pp. e1467–e1474. doi:10.1542/peds.2015-0657.

Emond, A., Ingram, J., Johnson, D., Blair, P., Whitelaw, A., Copeland, M. and MacArthur, C. (2014) ‘Randomised controlled trial of early frenotomy in breastfed infants with mild–moderate tongue-tie’, Archives of Disease in Childhood – Fetal and Neonatal Edition, 99(3), pp. F189–F195. doi:10.1136/archdischild-2013-305031.

Kotarska, M., Wądołowska, A., Sarul, M., Kawala, B. and Lis, J. (2024) ‘Does ankyloglossia surgery promote normal facial development? A systematic review’, Journal of Clinical Medicine, 14(1), 81. doi:10.3390/jcm14010081.

National Institute for Health and Care Excellence (NICE) (2005, updated 2026) ‘Division of ankyloglossia (tongue-tie) for breastfeeding’, HealthTech guidance HTG95. London: NICE.

O’Shea, J.E., Foster, J.P., O’Donnell, C.P.F., Breathnach, D., Jacobs, S.E., Todd, D.A. and Davis, P.G. (2017) ‘Frenotomy for tongue-tie in newborn infants’, Cochrane Database of Systematic Reviews, 3, CD011065. doi:10.1002/14651858.CD011065.pub2.

Venugopal, N., Neposlan, J., Bysice, A., Khoury, S., Madou, E., Lee, R., Strychowsky, J.E., St-Laurent, A., Lawlor, C.M. and Graham, M.E. (2026) ‘Is ankyloglossia correlated with pediatric sleep disordered breathing? A systematic review’, The Laryngoscope, 136(3), pp. 1088–1098. doi:10.1002/lary.70134.

Wang, J., Yang, X., Hao, S. and Wang, Y. (2022) ‘The effect of ankyloglossia and tongue-tie division on speech articulation: a systematic review’, International Journal of Paediatric Dentistry, 32(2), pp. 144–156. doi:10.1111/ipd.12802.