Lingual frenulum: Prevalence of tongue tie amongst general population and mentally challenged populationIntroduction: The role of soft-tissue position and activity in the etiology of malocclusion has been well documented. One type of oral soft tissue that may often be overlooked in routine orthodontic examinations is the frenum. 1A frenulum is a small muscle, covered by a mucous membrane that attaches the lips and tongue to the adjacent bones in the mouth. The maxillary midline frenum, the mandibular midline frenum, the right and left upper and lower labial frenums, and, the lower lingual frenum. All told there are normally seven oral frenula. However, considerable variation can be observed in normal frenum, shape, and position . 2 Although the terms frenulum, Latin for small bridle, and frenum, Latin for bridle, have been used synonymously for years, the Nomina Anatomica derived at the 6 th and 7 th International Congress of Anatomists, Paris, 1955, and New York, 1960, chose to use the term Frenulum Linguae. 3 The primary function of frenum is to keep the lips and tongue in harmony with the growing bones of the mouth during fetal development. 3At birth the tongue is usually short with the frenulum extending to the tip. At times a bifid like tip may be noted. 3 In normal sequence the lingual frenum recedes during the first 6 months to 6 years of life. Persistence of this lingual frenum causes an anatomical abnormality called ankyloglossia. 4Tongue-tie (more formally known as ankyloglossia) is a congenital anomaly characterized by an abnormally short lingual frenulum, which may restrict mobility of the tongue tip. 5Ankyloglossia is uncommon, but not rare. Incidence figures reported in the literature vary widely, ranging from 0. 02% to 4. 8%. 6-10 Incidences of upto 10. 7% have been reported. 11 The prevalence seems to be higher in the neonates and it has been speculated that the milder forms of Ankyloglossia may resolve with growth, explaining this age related differences. 12 An aberrant frenum, which is a congenital anomaly, can be familial13 and is more common in boys than in girls. 9 Tongue-tie also occurs more commonly in males—with a male-to-female ratio on the order of 3: 1, and shows no racial predilection. 14To the best of our knowledge, review of literature provides no uniformity of information with regard to the incidence of tongue tie . This study is an attempt to report the incidence of tongue-tie in a local population. Since these anomalies are claimed to be associated with speech problems and the mentally challenged 3, the purview of this study was expanded to incorporate the incidence of tongue ties in the mentally challenged children. Material and methods: A total of 700 children were examined for the presence of a tongue-tie, 350 of them went to regular schools and 350 were mentally challenged in special schools. The children belonged to the 9-17 years age group. The criteria used to categorize subjects as having a tongue-tie included the following. The tip of the tongue could not be protruded outside the mouth without clefting. The tip of the tongue could not sweep the upper and lower lips easily, without straining. A diastema was seen between the mandibular central incisors which was created by the lingual frenum. When the tongue was retruded, it blanched the tissue lingual to the anterior teeth. The lingual frenum did not allow a normal swallowing pattern. The tongue-tie, if present, was graded according to the classification given by Kotlow. 15 The anatomical measurements were used to classify the tongue-tie. It was carried out at the maximum opening of the mouth and with the tip of the tongue touching the palatal papilla. According to Kotlow, the term free-tongue is defined as the length of tongue from the insertion of the lingual frenum into the base of the tongue to the tip of the tongue. Because the tongue is a muscle, which in young children is flexible and often difficult to stabilize, placing an instrument at the insertion point and approximating the tip of the tongue determine this measurement. Measurements of the free tongue were carried out with a divider and scale with results expressed in and read to the nearest millimeter and graded into Grades 1 to 5 according to Kotlow15 as under; 1. Clinically acceptable, normal range of free tongue: greater than 16mm2. Class I: Mild ankyloglossia: 12 to 16 mm3. Class II: Moderate ankyloglossia: 8 to 11 mm4. Class III: Severe ankyloglossia: 3 to 7 mm5. Class IV: Complete ankyloglossia: less than 3 mmD: my casescase photossanjay patilsanjay tongue tie1. jpg C: Documents and SettingshpDesktopNew Folder3. jpg
Fig 1a: Class I-Mild tongue-tie Fig 1b: Class II-Moderate tongue-tie
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Fig 1c: Class III-Severe tongue-tie Fig 1d: Class IV-Complete tongue-tie
Statistical analysis: Data was analyzed using SPSS (Statistical package for social sciences) software for statistical computations. The chi-square test was used in this study for the preliminary analysis of demographic variables comparing normal and mentally retarded population. Significance was considered at the p < 0. 05 level. Results: 113 (16. 4%) of 700 subjects were identified as having significant tongue-tie, of which 65 (18. 57) were from general population and 48(13. 71 %) from mentally challenged population. When the two populations were separated, the normal (18. 57%) as against the mentally challenged (13. 7%), it was noted that the incidence of tongue tie was less in the mentally challenged; the difference was not statistically significant. (Table 1; Figure 1)GroupOut of the total population sample size 700% of the total populationGeneral population6518. 57Mentally challenged4813. 71Total11316. 14Chi-square= 3. 0507, p = 0. 0810, NS (Sign. At 10% level of significance)Table 1: Incidence of tongue tie in the Karnataka populationFigure 1: Incidence of tongue tie in the population studied (N= 700)When the males and the females were compared, it was evident that the males had predominance over the females with regard to the incidence in both populations studied; however, the difference between the genders was not statistically significant (Table 2)GroupMale
General population4264. 622335. 386557. 52Mentally challenged3164. 581735. 424842. 48Total7364. 604035. 40113100. 00Chi-square= 0. 0094, p= 0. 9970, NSTable 2: Incidence of tongue tie according to gender in two populationsWhen the grades of tongue tie were evaluated from within the population showing tongue tie, it was seen that Kotlow’s Grade I, II and III were predominantly seen. However, the differences between the different grades were not statistically significant. Grades IV the more severe form of tongue tie was seen in only 8. 85% of the population( Table 4, figure 2). GradesTotal population
Grade I5447. 792538. 462960. 42Grade II3228. 322030. 771225. 00Grade III1715. 041320. 0048. 33Grade IV108. 85710. 7736. 25Total113100. 0065100. 0048100. 00Chi-square= 6. 2452, p = 0. 1000, NS (Sign. At 10% level of significance)Table 3: Grades of tongue-tie seen in the entire population and within the two populationsFigure 2: Grades of tongue-tie seen in the total populationDiscussion: Tongue tie has been a much debated topic with respect to its effects on breast feeding, speech and other social issues. Its implications in dentistry have usually been limited to the gingival stripping seen following its high attachment. However, its association in Orthodontics has been basically speculation. Owing to lack of studies particularly in the Indian scenario, it was found to be necessary to evaluate the incidence of this tissue in the local area and evaluate if a need was felt to ascertain its orthodontic implications. The recent study by Northcutt 2 propelled the need for this study, however, the methodology described by Northcutt was not utilized in this study and that of Kotlow was used to grade the tongue tie. It was envisaged that the measurable method utilized by Kotlow for the free portion of the tongue, would be more objective when compared to a rather subjective method used by Northcutt based on the ‘ N’ point. The sample size taken belonged to the 9 to 17 years age group a time long after the development of the tongue was completed. Very few studies have reported the incidence of tongue ties in this age group. Of the 700 subjects that examined, 113(16. 4%) were identified as having significant tongue-tie, of which 65 (18. 57) were from general population and 48(13. 71 %) from mentally challenged population. These results showed higher incidence in comparison with other studies conducted by Messner et al9 who showed an incidence of 4. 8%, Hogan et al11 showed 10. 7% and Ballard et al16 showed 3. 2% in patients and 12. 8% in those who attended the clinics; The high incidence noted in our study could probably be attributed to the methodology utilized in classifying malocclusions and the lack of uniformity in classification systems with regard to tongue ties. There was a difference between the two genders with males carrying higher incidence than females however, these findings were not statistically significant. These findings seem to agree with the results of Messner et al9, Ballard et al16; but differed from Ruffoli et al. 4Conclusions: The incidence of tongue tie in the age group of 9-17 years was found to be 16. 14% in the present study. In the age group of 9 to 17 years, an age where the development of the lingual frenulum has been already attained, this survey indicated that the tissue definitely needs to be further explored with regard to its consequences with regard to the development and relapse tendencies of crowding in cases having crowding in the lower anterior region. Relationship to the low lying tongue with Kotlow’s Grade III tongue tie and its association needs to be further investigated. Definitive classifying criteria needs to be determined to classify and definitely diagnose the varied grades of tongue tie particularly as the classification systems presented are confusing in themselves in literature and secondly, the tongue is a movable tissue making the lengths of the varied tissues taken variable.