Ankyloglossia (from the Greek words “ankylos”, meaning tied, and “glossa”, meaning tongue) is a congenital anomaly of the tongue characterized by a short lingual frenulum. This condition results in a limitation of tongue movements (partial ankyloglossia) or a fusion of the tongue to the floor of the mouth (total ankyloglossia) [1].

Ankyloglossia is more common in males compared to females, with a male-to-female ratio of 3:1. Its prevalence in the general population ranges from 4% to 10.7% ^[2][3][2,3], although these percentages are derived from studies conducted with different diagnostic criteria.

In neonates, ankyloglossia manifests with a prevalence of 5%, often as an isolated event. However, it can also be associated with malformation syndromes, such as Simpson–Golabi–Behmel syndrome, Opitz syndrome, Beckwith–Wiedemann syndrome, orofacial-digital syndrome, and cleft lip and palate [4].

Among the current diagnostic classifications for ankyloglossia, based on various anatomical and functional criteria, none has been universally accepted yet [2].

The ability of tongue elevation and protrusion is the most important quality for functions such as breastfeeding, feeding, speech, and development of dental arches ^[5][6][5,6].

Indeed, ankyloglossia is often associated with difficulties for infants in breastfeeding and bottle-feeding, limited tongue mobility, speech difficulties, malocclusion, and gingival recession. These challenges arise due to the restricted movement of the tongue caused by the short lingual frenulum ^[7][8][7,8].

Additionally, a short frenulum can greatly reduce tongue movements and create problems during swallowing. The limited mobility of the tongue can interfere with the proper movement of food or liquid during the swallowing process, leading to difficulties in ingesting and digesting food correctly. This can cause discomfort and compromise the efficiency of the feeding process ^[2][9][2,9]. During breastfeeding, a pathological frenulum can result in ineffective attachment of the baby, causing inadequate milk suction and persistent pain in the mother’s nipple. These are all factors that can negatively impact nutrition and lead to early weaning [7].

If the frenulum anomaly is severe enough to cause mechanical and functional limitations, surgical reduction of the frenulum (frenulectomy) is indicated, followed by speech therapy for immediate rehabilitation of the tongue muscle.

Ankyloglossia often leads to difficulties in pronouncing certain consonants and sounds, such as /z/, /s/, /t/, /d/, /l/, /sh/, /ch/, /th/, /dg/, and especially the letter /r/ ^[8][10][8,10].

Speech therapy, in conjunction with frenulectomy, frenulotomy, or frenuloplasty, can be a therapeutic option to improve tongue mobility and consonant pronunciation. By addressing any limitations in tongue movement and working on specific speech exercises, speech therapy can help individuals with ankyloglossia improve their articulation and overall speech abilities [11].

However, there is not always a direct relationship between hypertrophic lingual frenulum and language limitations. Many children and individuals with ankyloglossia are able to compensate for this reduced tongue mobility and do not appear to suffer from any speech-related issues. The evidence demonstrating that ankyloglossia and abnormal tongue position can influence skeletal development and be associated with malocclusions is limited [12].

Some studies, however, suggest that a high-arched palate and an elongated soft palate are associated with hypertrophic lingual frenulum [6].

Localized gingival recession on the lingual aspect of mandibular incisors, in some cases, is precisely due to an anomalous attachment of the lingual frenulum that causes the recession. As with most periodontal conditions, eliminating plaque-induced gingival inflammation can minimize gingival recession without any surgical intervention. However, when recession persists even after oral hygiene management, surgical intervention may be indicated [2].

Guilleminault [13] states that a short lingual frenulum is a frequent phenotype for pediatric sleep apnea. Many studies in the literature have shown an improvement in sleep quality in patients who underwent frenulectomy, both with laser and scalpel procedures ^{[4][14][15][16]}[4,14,15,16].

Epidemiology: Jamilian et al. ^[17][20] reported a higher incidence of ankyloglossia in males, in line with a study conducted in India by Pavithra et al. ^[18][21] on a population of 700 children, although the gender difference was not statistically significant. On the contrary, Ruffoli et al. ^[19][18] did not find differences between males and females. In general, the literature reports a higher prevalence of ankyloglossia in males, as also demonstrated by studies conducted by Jorgenson et al. ^[20][27], Messner et al. ^[21][28], and Ballard et al. ^[22][29].

Prevalence: A prevalence of 16.4% was reported in the population in India by Pavithra et al. ^[18][21], with the majority being classified as grade I (48%), followed by grade II (30%), grade III (15%), and grade IV (8.85%), according to the Kotlow classification. This incidence was found to be higher compared to other studies, including those conducted by Messner et al. (4.8%) ^[21][28], Hogan et al. (10.7%) ^[23][30], Ballard et al. (3.2%) ^[22][29], and Friend et al. (12.8%) ^[24][31].

Differences could be attributed to different classification methodologies and measurements.

Classification: Currently, there is no unanimous consensus in the literature regarding the classification of ankyloglossia, which can also explain the differences between studies and the difficulty in comparison. Numerous methods have been proposed, such as those by Kotlow et al. ^[25][32], Garcia Pola et al. ^[26][33], Horton et al. ^[27][34], and Ruffoli et al. ^[19][18].

One of the most commonly used systems for the classification of ankyloglossia is the Kotlow classification. Kotlow was the first to propose an anatomical criterion for classification, determining that a free tongue has a frenulum within the normal range if it measures equal to or greater than 1.6 cm, a value also confirmed by the Ruffoli classification. The same study by Jamilian ^[17][20] used the criteria of Ruffoli, observing a sample of 300 children, and found that only children with a lingual frenulum <1.5 cm had limited tongue mobility. However, only children with a frenulum length <0.7 cm had abnormal language patterns and inadequate tongue movement.

Surgical and rehabilitative therapy: The study by Tancredi et al. ^[28][26] highlights the operative and postoperative advantages of treating hypertrophic lingual frenulum using diode laser therapy, evaluating the extent of postoperative healing and differences in pain perception compared with traditional surgical methods.

Firstly, patients treated with laser therapy reported significantly reduced pain compared to those treated with traditional methods, both immediately after surgery and one week postoperation. Additionally, the laser resulted in better tissue healing. These advantages are complemented by other benefits, including minimal bleeding, a “clean” surgical field, no need for sutures, and no requirement for anti-inflammatory or antibiotic therapy. Laser treatment is also faster.

Unlike a scalpel blade, the laser does not cut through the structures that make up the lingual frenulum (collagen and elastic fibers) but rather causes denaturation and coagulation. Therefore, it can be concluded that laser-assisted intervention offers numerous advantages over conventional surgical techniques. This is also confirmed by other recent studies. In particular, Nammour et al. ^[29][35] focused on the significant advantage of not having to suture traumatized tissues during the procedure. However, Brignardello-Petersen ^[30][36] and Viet et al. ^[31][37] highlighted the reduction in patient discomfort, shorter operation time, and reduced amount of anesthesia required as benefits of using a diode laser compared to traditional surgery.

However, Tancredi’s study has several limitations. Firstly, it was not possible to divide the participants into the two groups in a proportionate manner, controlling variables such as ethnicity, oral hygiene level, socio-economic conditions, and other determining factors equally. Secondly, the retrospective nature of the study limited the collection of relevant data regarding postoperative improvement, such as tongue mobility, speaking ability, chewing, and swallowing. Additionally, the sample size was small, and there was an error in the pain measurement index due to the use of a numeric rating scale (NRS), which tends to report extreme values rather than a visual-analog-scale (VAS) index. The study by Komori et al. ^[32][23] also highlights the effectiveness of using a laser in the treatment of lingual frenulum. In this case, the laser used is the CO₂ laser, which has been shown to be useful in treating frenula. It is simple to use and safe, providing good postoperative results. The use of the CO₂ laser ensures reliable hemostasis and early healing, as the surface and depth of resection are reduced compared with conventional laser use. In the study by Haytac et al ^[33][38], they demonstrate how patients treated with the use of this laser had significantly lower pain values on the visual analog scale (VAS) compared with those treated with traditional methods. However, a significant issue in these studies is the limited sample sizes.

In addition to this aspect, the laser offers numerous benefits, including adequate hemostasis, reduced operating time, easier access, surgical site disinfection, precise incision, minimal tissue damage, more effective tissue healing, reduced inflammation, better control of postoperative pain, and greater acceptance and compliance, especially in pediatric patients. Reddy et al. ^[34][39] compared three techniques for the treatment of lingual frenulum: electrosurgery, cold blade, and diode laser. After follow-up periods of 7 days and 30 days, better tissue healing was observed in patients treated with the laser, while the other techniques reported higher indices of pain and swelling. Also, Derikvand et al. ^[35][40] have demonstrated positive factors of using laser technology in terms of healing and postoperative complications. Furthermore, Barot et al. ^[36][41] reported an improvement in tongue mobility and speech in patients treated with a laser. The absence of traditional surgical instruments and the hemostatic effect of the laser allow for bloodless surgeries without the need for sutures, which would be uncomfortable during the postoperative period, especially when performing myofunctional exercises.

These elements are particularly useful in young patients who may experience more anxiety towards surgery compared with adults. Children are more accepting of the laser; the sight of the beam of light during the preparatory phase of the procedure generates curiosity and can help increase patient compliance during the intraoperative phase.

Following surgery and myofunctional exercises, communication became easier, and parents and other children found it easier to understand words. There was also an increase in speech rate, improved production of previously difficult sounds, and the production of new words by children with language delays. Parents also noticed positive changes in their children’s feeding habits, as they ate more quickly, were less demanding, spit out food less frequently, and chewed more effectively. There were also improvements in sleep quality, as children were less likely to sleep in odd positions, kick, or move during the night. They slept more deeply, woke up less fatigued, and had reduced mouth breathing, teeth grinding, and snoring. Parents also noted a reduction in neck pain, headaches, open-mouth breathing, and vomiting reflex, as well as decreased hyperactivity, inattention, reflux, and constipation.

Regarding traditional surgical therapy, there are two methods: simple frenulotomy and Z-plasty frenuloplasty.

In the literature, there is no ideal surgical treatment procedure for ankyloglossia. Several studies have attempted to demonstrate the effectiveness of various surgical techniques by comparing them to each other. Ito et al. ^[37][42] studied the procedures of frenuloplasty and frenulotomy to correct articulatory disorders following surgery. Yousefi et al. ^[38][43] reported that Z-plasty shows superiority in improving articulation compared to simple release. Z-plasty is a surgical procedure that releases contractile or scar tissue based on the suturing technique used in plastic surgery. However, this surgical procedure is usually challenging to perform under local anesthesia in children and is therefore performed under general anesthesia or conscious sedation. It is important to demonstrate that the surgical outcomes of Z-plasty with four flaps are superior to simple frenulotomy, which can be performed under simple local or regional anesthesia. In the literature, postoperative complications are not commonly reported, but events such as excessive bleeding, upper airway collapse, infection, diathermy burn of the lip, ulcer under the tongue, lingual dysfunction, swallowing abnormalities, and reattachment of the surgical site have been reported. In the study by Kim et al. ^[39][25], no specific complications were observed ^[39][25].

An increasing number of healthcare practitioners are seeking evidence-based information in the literature for the treatment of ankyloglossia. However, few researchers are publishing articles on this topic. Most of the published articles consist of limited clinical cases and case series. There are available larger cohort studies on frenulectomy techniques for infants related to breastfeeding ^[40][44]. However, research on the treatment of ankyloglossia among children ^[41][22], adolescents ^[42][45], and adults is still limited.

The study by Daggumati also has its limitations, and its results must be carefully considered, as the sample size is modest, although it is still the largest study in the literature for the group of patients who did not undergo surgical treatment. Furthermore, the perception of language quality is entirely subjective and heavily relies on the responses of parents to questionnaires.