Diagnosis, classification and management of ankyloglossia including its influence on breastfeeding

A short lingual frenulum (ankyloglossia, tongue-tie) is defined as a congenital malformation that limits lingual mobility, thus leading to impaired tongue function [1,2]. Its prevalence in newborns is estimated in the literature at between 4.2% and 10.7% [3, 4, 5], with the male to female ratio of 3:1 [5, 6]. The discrepancies in tongue-tie frequency assessment are most probably caused by the lack of unambiguous and objective diagnostic criteria, as well as significant differences in study groups [2].

The aim of this study was to review the literature regarding current recommendations for the diagnosis of ankyloglossia in newborns, its potential impact on breastfeeding, indications for surgical treatment and its efficacy.

Areview of the literature from peer-reviewed journals was conducted by searching the PubMed database using the keywords: ’’ankyloglossia”, ’’tongue-tie” and ’’frenulotomy”. The 34 best-matching references were selected with emphasis on the most recent studies. Most of them were published between July 2012 and April 2018. Former publications cover topics that have not been raised in more recent studies.

During the developmental period, the tongue plays an important role in the proper growth of the oral cavity and the whole stomatoghnathic system. Many studies claim there is an influence of a short lingual frenulum on the development of malocclusions (especially class III disorders, maxillary hypoplasia, open bite, mandibular diastema and mouth-breathing) [7, 8, 9], as well as altered posture [8]. Moreover, a disfunction of the tongue that coexists with ankyloglossia may lead to speech defects as a result of incorrect articulation [10]. Lalakea and Messner state, however, that it is not a potential cause of delayed speech development or stuttering [1]. Nevertheless, preventive frenulotomy that aims to avoid the previously mentioned disorders is still a controversial issue. Undisturbed tongue function in the neonatal period is also essential in developing proper suction during breastfeeding. The literature widely describes the influence of ankyloglossia on difficulties in breastfeeding. According to Messner et al. [3] 25% of the newborns with a short lingual frenulum experience such problems. Ferrés-Amat et al. [11], who studied a group of Spanish infants with diagnosed natural feeding difficulties estimated the prevalence of ankyloglossia at 15%. A short lingual frenulum may impede proper nipple latch and seal during breastfeeding. Altered sucking mechanics leads to low milk transfer and its low supply, prolonged feedings, poor weight gain, tiredness and irritation of the child during breastfeeding, as well as nipple pain and trauma that is caused by the pressure of the newborn’s gingiva [2, 4, 5, 6]. Such problems may provoke the mother’s discouragement, thus leading to premature weaning and switching to a bottle [2]. On the other hand, those difficulties are not observed in bottle-fed newborns with ankyloglossia [5]. WHO recommends exclusive breastfeeding up to 6 months of age as the most beneficial for mother-infant dyads [12]. During breastfeeding peristaltic muscle movements are activated, which stimulates the proper development of the structures of the stomatognathic apparatus. During bottle-feeding such stimulation is limited [11]. Therefore, it is crucial to encourage mothers to breastfeed, to focus on the early diagnosis of any obstacles and their plausible reasons, including ankyloglossia, and to apply proper treatment as soon as possible.

Examination of the newborn’s oral cavity should include the assessment of tongue appearance, shape, position and function both in relaxation and when moving, frenulum elasticity, length of the free tongue as well as the size of lingual frenulum attachments to the tongue, the floor of the mouth and the inferior alveolar ridge. The attachment of the frenulum to the tongue should normally be approximately 1 cm posterior to the tongue’s tip [2]. One of the most common characteristics of ankyloglossia is a heart-shaped tongue tip when the tongue is lifted. Besides assessing tongue appearance, it is essential to properly examine the tongue’s function in the course of movement, while the newborn cries or sucks a finger. Thorough palpation of the tongue frenulum to check its reaction to lateral and posterior pressure is especially important in diagnosing ankyloglossia posterior (posterior tongue-tie), in which a short lingual frenulum is hidden under mucosa and anchors only the middle part of the tongue leaving a free tip, which significantly impairs tongue function and peristalsis [13]. In the study by Ghaheri et al. [14] 78% of newborns experiencing problems with breastfeeding were diagnosed with ankyloglossia posterior.

The lack of a universal, unequivocal and commonly accepted definition and objective diagnostic criteria of ankyloglossia is still an issue. There are many classifications for lingual frenulum assessment in newborns proposed in the literature. Kotlow [15] introduced a simple anatomical classification based on measuring the “free tongue” length (between the frenulum attachment to the tongue and the tongue’s tip) (tab. I).

The study by Walker et al. [16] demonstrated a correlation between the tip-frenulum length and difficulties in breastfeeding which manifested mainly as mothers’ nipple pain. The average “free tongue” length in this study, in a group of 100 generally healthy newborns was found to be 9.07mm. Coryllos’ classification [17] also includes types III and IV of ankyloglossia, which meet the diagnostic criteria of ankyloglossia posterior. Due to their uncharacteristic appearance, they may easily remain unrecognized on examination (tab. II).

However, there is no confirmed correlation between the type of frenulum according to Coryllos’ classification and the degree of breastfeeding problems [18]. The Hazelbaker questionnaire [19] (The Hazelbaker Assessment Tool for Lingual Frenulum Function – HATLFF), in turn, presented in the form of a point scale, includes both anatomical (5 items) and functional (7 items) criteria. Significant ankylogossia, which requires frenulotomy, is diagnosed with the appearance score <8, and the function score <11 (tab. III).

Nevertheless, an unambiguous correlation between the Hazelbaker score and the degree of breastfeeding difficulties has not been confirmed. Moreover, it is found that problems with breastfeeding are not directly correlated with lingual frenulum appearance, and may occur in both

anterior and posterior ankyloglossia [6, 20]. According to Ricke et al. [5] 80% of the newborns with diagnosed ankyloglossia are able to effectively suck a breast without any surgical intervention, due to the tongue’s adaptability, despite the incorrect appearance of the lingual frenulum. In the study by Kumar et al. [21] half of the examined children with a short lingual frenulum were diagnosed with asymptomatic ankyloglosia that did not cause any obstacles in breastfeeding. Therefore, in order to adequately qualify for surgical intervention, it is necessary to include breastfeeding criteria. Surgical procedure itself should be performed only in those ankyloglossia cases in which breastfeeding difficulties occur [6]. FDRBI (Frenotomy Decision Rule for Breastfeeding Infants) proposed by Srinivasan et al. [22] may be a helpful tool. According to the questionnaire, only a short lingual frenulum that coexists with breastfeeding difficulties (persistent nipple pain and/or inadequate latch and/or poor weight gain <15 g per day) and improper tongue function (inability to protrude beyond the alveolar ridge, to lift the tongue to the roof of the mouth or to adequately cup the nipple-areolar complex) may be qualified for frenulotomy. Moreover, the LATCH index may also be applied for objective and quantitative assessment of breastfeeding quality, which includes 5 categories: L (latch), A (audible swallowing), T (type of nipple), C (comfort) and H (hold) and scores them from 0 to 2. Table IV [23] presents an accurate description of the index, together with proposed example questions that may be helpful during conversations with mothers that experience breastfeeding problems.

Infant Breastfeeding Assessment Tool (IBFAT) is a similar scale, that consists of 4 questions for mothers describing their experience during breastfeeding, scored from 0 to 3 (tab. V) [16].

The study by Altuntas et al. [24] confirms the reliability of both indexes (LATCH and IBFAT) in breastfeeding quality assessment.

The most frequent surgical procedure performed in newborns with symptomatic ankyloglossia is frenulotomy. The lingual frenulum is poorly innervated and vascularized, thus the procedure normally does not require local anesthesia [2]. Alternatively, a topical anesthetic may be applied. However, its effectiveness in pain control during tongue-tie release has been questioned in the literature [25]. The procedure itself involves cutting the lingual frenulum with surgical scissors after stabilizing the tongue with the fingers or spatula. The incision should begin at the free margin of the frenulum and proceed posteriorly adjacent to the tongue with care not to injure inferiorly based submandibular salivary ducts. The mild bleeding that may occur after the surgery can be controlled with gauze and light pressure, no suture is required. It is recommended to breastfeed immediately after the procedure [2], while during the next 7-10 days tongue mobilizing exercises that prevent reattachment of the frenulum are advised [26]. Nowadays diode laser is increasingly popular as an alternative in tongue-tie release [8, 14, 27]. Its application decreases the bleeding in the operating field, minimalizes swelling and post-operative pain. [27].

Many studies regarding ankyloglossia concentrate on the direct impact of frenulotomy on breastfeeding quality improvement. Ghaheri et al. [14] presented a statistically significant increase in milk transfer, improvement in the mother’s comfort, elimination of nipple pain as well as a remission of the newborn’s reflux symptoms after tongue-tie release. The procedure was equally effective in children with both anterior and posterior ankyloglossia. Pransky et al. [28] observed breastfeeding quality improvement after frenulotomy in 78% of newborns with anterior ankyloglossia and in 91% with posterior ankyloglossia. Wakhanrittee et al. [29] observed significant nipple pain reduction and increase of the LATCH index (Latch, Audible swallowing, nipple Type, Comfort, Hold) after frenulotomy. In the study by Muldoon et al. [30] as many as 91% of the mothers interviewed reported considerable decrease in nipple pain after the procedure, which led to significant improvement in breastfeeding comfort. Nipple trauma and pain during feeding is recognized as one of the main reasons behind premature weaning and switching to a bottle [30], thus it is such an essential aspect in the breastfeeding quality assessment in previously mentioned research. According to the Cochrane Database, a systematic review of randomized research published in 2017, in the short term, frenotomy reduces mothers’ nipple pain. However, authors have not found any unambiguous proof for longterm post-frenotomy improvement in breastfeeding. The review highlights methodological shortcomings of the majority of research, including small study groups, as well as lack of long-term observation and systematic follow-ups of infants from the control group who did not undergo the surgical procedure [3]. Nevertheless, one of the most recent studies presented the long-term efficacy of frenulotomy in improving breastfeeding rates and its influence on prolonged breastfeeding. Over the period of 3 months following the procedure, 80% of the mothers reported a complete resolution of nipple pain, 49% of the infants were exclusively breastfed, while 41% switched to mixed feeding (breastfeeding supplemented with some formula) [31]. Similarly, in the study by McGoldrick et al. [32] breastfeeding was continued for 3-4 months after the procedure in 76.8% of the newborns. Moreover, the literature emphasizes the importance of early surgical intervention after diagnosing breastfeeding disorders connected with ankyoglossia, because of the high risk of premature weaning. According to Donati-Bourne et al. [33] the majority of women give up breastfeeding and switch to the bottle if surgical procedure which brings some relief to the mothers is not performed in 4 weeks.

The literature increasingly emphasizes the necessity of multidisciplinary approach in the treatment of patients with ankyloglossia. Upon the diagnosis of a short lingual frenulum interfering in breastfeeding, the mother-infant dyad should first be referred to a lactation consultant. Nursing posture correction and myofunctional therapy, which stimulates proper sucking and rooting reflexes is recommended. Such stimulating exercises are also advised before and straight after any surgical intervention [34].

Oral examination of a newborn infant in the first hours after birth should include thorough assessment of the lingual frenulum appearance and function. The recognition of problems in breastfeeding should raise the suspicion of ankyloglossia, which is listed as one of the possible causes of a changed sucking mechanism in infants. In order to systematize the examination, one of the suggested classifications may be applied, with particular emphasis on tongue function assessment, taking into account the possible occurrence of the less characteristic ankyloglossia posterior. Tongue-tie release (frenulotomy) should be performed quickly after diagnosing ankyloglossia that interferes in the sucking mechanism, in order to resolve breastfeeding problems as soon as possible. On the other hand, preventive frenulotomy in newborns with asymptomatic ankyloglossia is not recommended, due to the fact that the majority of infants with a short lingual frenulum do not experience problems in suction. Frenulotomy is a simple surgical procedure with little risk of complications, after which the newborn may immediately latch to the breast. The literature delivers a great number of studies confirming the efficacy of tongue-tie release in breastfeeding quality improvement with emphasis on decreasing mothers’ discomfort, nipple pain and trauma. Nevertheless, further research with improved methodology that focuses on long-term influence of surgical intervention on breastfeeding is still necessary.