Research Overview - Frenectomy of Ankyloglossia (Tongue Tie)

Frenectomy for the correction of ankyloglossiaa: A review of clinical effectiveness and guidelines. Rapid Response Report, Canadian Agency for Drugs and Technologies in Health, June 15 2016.

First of all - what is a tongue tie, and why is it an issue?
 
Tongue tie, or ankyloglossia for those who love greek derivatives, is a congenital anomaly in which the child is born with an abnormally short and/or thick lingual frenulum that limits the movement of the tongue. Potential concerns are breastfeeding problems including difficulty latching, nipple pain, infection, poor milk supply, discontinuation of breastfeeding, inadequate weight gain, oral hygiene concerns, speech problems, and developmental and social consequences.  A hereditary link is noted, but these don’t explain all cases, with prevalence being reported between 4-10% and more commonly males.  


The Canadian Agency of Drugs and Technologies in Health (government funded, independent not-for-profit organisation https://www.cadth.ca) published a “Rapid Response Report” summary with critical appraisal of clinical effectiveness and guidelines of clipping of the frenulum (frenectomy) for the correction of tongue tie (ankylogossia) in June 2016. This is an extremely thorough review of the evidence, though they note they are not conducting a meta-analysis.
 
Their search turned up 150 articles, and after exclusion criteria, they were left with eight reports. This include two systematic reviews (one review published in two reports, but as they reported additional data in the second report, both were included), one randomised controlled trial (RCT), and four non-randomised studies. The ’n’ of total cases was around 6000. Data was obtained from studies in 11 countries.  Included within the systematic reviews (SR) were RCTs, non randomised studies, and case series, and data from the primary clinical studies included two retrospective chart review and one prospective controlled before and after study.  
 
The patient populations studied for one SR included children from 0-18 years, whereas the other SR focused on neonates and infants less than six months of age with ankyloglossia and breastfeeding problems. The interventions included various methods of tongue-tie division: simple release (frenotomy = simple horizontal cut), laser release, and frenulectomy/frenectomy (removal). The procedures were conducted by a range of health professionals including family, neonatal, and paediatric doctors, general, paediatric or speciality surgeons, and lactation or specialist consultants. The outcomes tracked were breastfeeding efficacy, feeding out comes, nipple pain, milk supply, weight gain, adverse events, speech outcomes, and parent satisfaction.
 
One SR rated the evidence as high to moderate quality for breastfeeding efficacy, and weak for the other outcome measures. The other SR reported mixed study quality (RCTs higher, non randomised studies and case series/reports being lower quality, with the overall strength of the evidence being low to insufficient for the majority of outcomes.
 
A multitude of confounding factors were noted with all the outcome measures, particularly with the difficulty separating the parents subjective report relative to results. Variations in diagnostic approach were noted, with differing levels of expertise and assessment tools utilised.
 
The majority of studies reported no significant harms or minimal harm. The most common harm reported was minor and/or limited bleeding, with other potential harms of re-operation, scarring, slowed healing time due to tissue slough and pain. Serious harms were observed in a single case series as a result of the procedure being conducted by untrained personnel.
 
No evidence based guidelines were identified regarding frenectomy for the correction of akyloglossia in newborns and infants. The results are likely not generalisable to the wider population due to the variation in assessment, age, correction technique, follow up time, comorbidities etc.
 
They conclude that the use of frenectomy to treat ankyloglosssia in neonates and infants with breastfeeding problems appears to be safe and may be confer benefit to the mother and baby. However, the results should be interpreted with consideration of the subjectivity of outcome measures; generalisability issues due to differences in patient populations, procedure, and outcome measure; lack of information on long term benefits and harms; unclear influence of potential co-founders; and questionable reliability of pooled and poor quality figures.  Given the minimal harms they report, and probably benefit (albeit of uncertain magnitude), they state frenectomy may be a viable treatment option for infants of mothers who wish to breastfeed and are experiencing difficulty. 

Tongue-tie, from embryology to treatment: a literature review. Dezoio, Piras, Gallottini, and Denotti. J Pediatric and Neonatal Individualised Medicine. March 2015.


This free access journal article provides an excellent overview of ankyloglossia (http://www.jpnim.com/index.php/jpnim/article/view/040101).  It is written with numerous author opinions without strong references which weakens it’s level of evidence (particularly compared to the depth of the Canadian article reviewed), however it does provide a good review of tongue tie. The Italian authors nicely describe the embryology of the tongue in a way that doesn’t have you dozing off. They add commentary as to the importance of the tongue in the ‘'functional matrix hypothesis that states the origin, growth, and maintenance of all skeletal tissues and organs are always necessarily secondary phenomena and offset by other previous events that occur in not skeletal tissues, organs or functions areas (functional matrix) that specifically bound’’.  They present a clear table describing the classification of ankyloglossia per Kotlow’s assessment (Class I-IV).
 
They consider factors related to the definition of the shape and lingual functionality, which relate to the posture of the cervical spine, the lip seal and breathing, the TMJ, and relations with the inter maxillary bone. They state ''when the frenum is short, it is impossible or really difficult to establish normal anatomical rapports, so the anatomical deficiency becomes also a functional problem; this issue generates other anatomical problems related to the short frenum’’.
 
The following three pages describe the embryology, physiology, and possible sequelae of a tongue tie in depth in an accessible format.  They then discuss diagnosis (and selected measures used), age and treatment, techniques, and effects on the tissue by laser treatment. They conclude that ‘’tongue tie is a very important problem - if not treated well it can create problems not only relate to feeding and speech, but also involving growth and posture’'. 

Reviewed and written by Matthew Doyle, Chiropractor