Ankyloglossia, often referred to as "tongue tie," is a common congenital anomaly that is usually detected soon after birth. It is characterized by partial fusion-or in rare cases, total fusion-of the tongue to floor of the mouth due to an abnormality of the lingual frenulum.
By definition, a frenulum, which is a small frenum, is a narrow fold of mucous membrane connecting a moveable part to a fixed part. Its purpose is to stabilize and check undue movement of that part. The lingual frenulum is generally under the mid-portion of the tongue. As such, it can help to stabilize the base of the tongue but does not interfere with tongue tip movement. With ankyloglossia, however, the lingual frenulum has an anterior attachment near the tip of the tongue and may also be unusually short. This causes virtual adhesion of the tongue tip to the floor of the mouth and can result in restricted tongue tip movement to some extent.
The diagnostic characteristics of ankyloglossia are easy to detect. Usually, the patient is unable to protrude the tongue past the edge of the lower gingiva or mandibular incisors. With protrusion attempts, the tongue tip becomes notched in midline, resulting in a heart-shaped edge. In addition, the patient is unable to touch the roof of the mouth with the tongue tip when the mouth is open. A diagnostic classification system of severity has been proposed by Kotlow (1999).
The prevalence of ankyloglossia is unclear, since the reported figures vary significantly from less than 1% to as frequent as 97% in newborns (Lewis & Counihan, 1965). More recent reports place the prevalence at about 4%-5% in newborns (Messner et al., 2000; Ricke et al., 2005).
Although ankyloglossia can be significant at birth, the severity and functional effects tend to decrease with time and oral growth. During the first 4 to 5 years of life, the oral cavity changes significantly in shape and size. The alveolar ridge grows in height, the teeth begin to erupt, and the tongue grows and narrows at the tip. At the same time, the lingual frenulum recedes, stretches, and may even rupture. Therefore, as the child grows, the severity of the tongue-tie lessens and the initial restrictions of lingual movement are diminished.
For patients with ankyloglossia, the functional effects can include the following:
- Feeding problems. The literature on ankyloglossia primarily deals with potential difficulty with breast feeding (Nicholson, 1991; Jain, 1995; Fitz-Desorgher, 2003; Ricke et al., 2003). Although approximately 25% of newborns with ankyloglossia will have some trouble latching on to a nipple for sucking the majority have no early feeding problems. As the child grows older, he may have difficulty moving a bolus in the oral cavity and clearing food from the sulci and molars. This problem could result in chronic halitosis and contribute to dental decay.
- Dentition. If the lingual frenulum is attached high on the gingival ridge behind the lower mandibular incisors, it can pull the gingiva away from the teeth and even cause a mandibular diastema. However, this is usually not a problem until age 8-10.
- Cosmetics and personal interactions. There is no doubt that ankyloglossia may look abnormal and has even been described as a forked or "serpent" tongue. There can also be difficulty in social and recreational functions like "French" kissing, licking an ice cream cone, or catching snowflakes on one's tongue.
- Speech. Through the centuries, it has been a common folk belief that if the tongue tip cannot move well due to ankyloglossia, it must affect speech. In fact, this is even mentioned in the Bible. In Mark 7:35, it says "… and the bond that tied his tongue was loosed, and he talked plainly." Despite the common belief of this effect, there is no empirical evidence in the literature that ankyloglossia typically causes speech defects. On the contrary, several authors, even from decades ago, have disputed the belief that there is a strong causal relationship (Wallace, 1963; Block, 1968; Catlin & De Haan, 1971; Wright, 1995; Agarwal & Raina, 2003). In addition, there are very few other articles in the literature that even address the effects of tongue-tie on speech.
Despite these reports and the lack of evidence, many professionals still believe that ankyloglossia is a common cause of speech problems. In a recent survey, Messner and Lalakea (2000) found that 60% of ENTs, 50% of SLPs, and 23% of pediatricians believed that ankyloglossia is likely to cause speech problems. The only study found in the literature that has even tested that assumption is by the same authors (Messner & Lalakea, 2002). In their study, 9 out of 15 patients showed "improvement" in speech after frenulectomy. However, many months went by between the pre- and post-operative assessments. Also, there is no information on the types of misarticulations noted preoperatively. Finally, the authors admitted that they used a relatively small and disparate study group. In addition, they noted that they did not use a standard speech sample, and that multiple SLPs performed the assessments, which were not blinded. Therefore, the results of this study should be considered with caution.
Certainly, children with ankyloglossia are often found to have no speech problems. So how is this possible? Actually, it doesn't make common sense that lingual restriction would have a major effect on speech when one considers the type of sounds that are produced by the tongue tip. Lingual-alveolar sounds (t, d, n) are produced with the top of the tongue tip and therefore, they can be produced with very little tongue elevation or mobility. The /s/ and /z/ sounds require the tongue tip to be elevated only slightly, but can be produced with little distortion if the tip is down. The most the tongue tip needs to elevate is to the alveolar ridge for production of an /l/. However, this sound can actually be produced with the tongue tip down and the dorsum of the tongue up against the alveolar ridge. Even an /r/ sound can be produced with the tongue tip down as long as the back of the tongue is elevated on both sides. The most the tongue needs to protrude is to the back of the maxillary incisors for production of /th/. All of these sounds can usually be produced, even with significant tongue tip restriction. This can be tested by producing these sounds with the tongue tip pressed down or against the mandibular gingiva. This results in little, if any, distortion.
In evaluating the effect of ankyloglossia on speech, therefore, it is important to focus on lingual-alveolar sounds (particularly /l/) and interdental sounds (voiced and voiceless /th/). Tongue-tie could be considered a contributing factor if the child cannot produce these sounds, even with the alternate placement noted above, and all other speech sounds are produced normally. Tongue tie may also be a bigger problem if there is oral-motor dysfunction as well.
It should be recognized that both ankyloglossia and speech problems commonly occur in children. Therefore, it is not surprising that these conditions often occur together. A co-occurrence of two common problems does not mean that there is a causal relationship, however. Instead, when there are speech problems and ankyloglossia, this may be a co-incidence and other causes for the speech problems should be considered.
Treatment of Ankyloglossia
When ankyloglossia is noted at birth, one option is to leave it alone and let nature take its course, unless there are early feeding problems. If the child demonstrates any of the problems noted above, a frenulectomy (surgical release of the tongue) can be done. In past times, midwives used a sharpened fingernail to slit the frenulum immediately after birth.
In modern times, frenulectomies are usually done by either a general surgeon, an otolaryngologist, a plastic surgeon, or an oral surgeon. Although these surgeries are commonly done, there does not appear to be consistency in what are considered indications for the surgery. In a survey of oral and maxillofacial surgeons, plastic surgeons, and pediatric general surgeons in Australia who perform frenulectomies, Brinkman et al. (2004) reported that "There was no clear consensus regarding clinical indicators for surgery or functional outcomes following surgery."
Frenulectomy can be done in the office with no anesthetics. In older children, the operation requires general anesthesia to ensure adequate cooperation from the patient to gain access to the floor of the mouth to perform the procedure. The frenulum is divided with scissors or with electrocautery. The band is thin, and generally requires no sutures. The procedure takes only a few minutes to perform. Tongue mobility is generally adequate to prevent adhesions from forming that may again limit tongue mobility. In rare cases of ankyloglossia, the tongue is scarred to the floor of the mouth, severely limiting the mobility of the tongue. A series of flaps are then created on the floor of the mouth to close the defect created after releasing the tongue. This "Z-plasty" minimizes the risk of scar formation. Risks of frenulectomy are very low, but may include pain, minor bleeding, or infection.
There is virtually no evidence in the literature to establish a definite causal relationship between ankyloglossia and speech disorders. In fact, there is very little in the literature that addresses ankyloglossia and speech at all. This is probably because a causal relationship is not what is typically seen clinically. Therefore, it can be assumed that ankyloglossia is unlikely to cause speech problems in most cases.
Most experienced speech-language pathologists would conclude that frenulectomy is rarely indicated for speech reasons unless it is very severe or there are concomitant oral-motor problems. It may, however, be warranted for problems with early feeding, bolus manipulation, dentition, or aesthetics. Although frenulectomy is a minor procedure with a low risk of morbidity, the true danger is the disappointment that can result when parents are led to believe that this will correct speech problems that are actually due to other causes.