Renata Maria Moreira Moraes Furlan

Protrusive tongue strength in people with severely weak tongues

Abstract The purpose of the study was to quantify tongue protrusion force and compare its characteristics between participants with severely weak tongues and those with normal lingual strength. The sample consisted of 11 participants with severe lingual strength deficits and 11 age- and sex-matched participants with normal lingual strength. Tongue force was evaluated quantitatively using the Forling instrument, and the average force, maximum force, average force application rate, and area under the graphic curve were analysed. These parameters were compared between the groups. In the participants with severely weak tongues, the average and the maximum forces in N (Newton) were 2.03 ± 1.17 and 3.56 ± 1.77, respectively. The average force application rate in N/s (Newton per second) was 1.25 and the area under the graphic curve in Ns (Newton times second) was 18.6. The values of the participants with normal lingual strength were, respectively, 13.27 ± 6.15 N, 18.91 ± 7.95 N, 10.46 N/s, and 108.08 Ns. All parameters analysed differed significantly between the groups. The data collected could aid speech-language pathologists in diagnosing problems related to tongue force.

Evaluation of the force applied by the tongue and lip on the maxillary central incisor tooth

PURPOSE To describe the development and testing of a system that measures forces exerted by the tongue and upper lip on a tooth during rest and during swallowing. METHODS Twenty-eight subjects, aged 19-31 years (mean: 23.2 years) were submitted to measurement of forces exerted by the upper lip and tongue on the maxillary right central incisor tooth. Flexiforce resistive sensors were fixed on the labial and lingual surfaces of the tooth. They were connected to an amplifier circuit and a data acquisition board for processing and transmitting information to a computer. RESULTS At rest, the tongue force on the tooth was 0.00±0.00 N and the lip force on tooth was 0.02±0.02 N. The difference between them was significant. During swallowing, the values were 0.31±0.38 N and 0.15±0.14 N, for the tongue and lip, respectively. This difference was not significant. CONCLUSION At rest, the lip exerts a larger force than the tongue on the maxillary right central incisor tooth. During swallowing, there was no difference between lip and tongue force on the tooth.

Métodos quantitativos para avaliação da força de língua

ABSTRACT For several years, researchers have been looking for methods to quantify tongue force and a lot of devices were constructed for this purpose. The purpose of this study is to present a critical literature review about the devices to quantify tongue strength. Thirty devices were found. They were grouped into four different categories: mouthpiece containing sensors (n=9), sensors attached on teeth surface or on palatal plates (n=8), bulbs filled with some fluid and connected to a pressure sensor (n=7) and other technologies (n=8). These methods can, potentially, help speech-language pathologists in the orofacial myology evaluation, making the diagnosis of tongue force more reliable. Some of them present disadvantages such as not being sensitive enough to small changes in force, difficulties in positioning reproducibility and other specific points. The large variation in maximum and average strength/pressure values are related to the large diversity of the methods, which use different technologies.

Influência de altura, peso e índice de massa corporal na força axial da língua

PURPOSE To analyze the influence of weight, height and body mass index in the axial tongue force. METHODS Medical records with data from 44 subjects aged between 20 and 37 years, 11 (25%) males and 33 (75%) female, were analyzed. The investigated information were weight, height, result of clinical evaluation for tongue force (lingual tonus) and instrumental assessment of axial tongue force, which was accomplished by using the FORLING. Data was statistically analyzed. RESULTS No differences were observed between the force values regarding the variables body mass index classification and clinical classification of tongue force. Body mass index and weight had positive correlation with mean tongue force. There was a strong positive correlation between the variables mean force, maximum force and highest maximum force. CONCLUSION Although body mass index and weight correlated positively with the mean axial tongue force, there was no association between body mass index classification and the axial tongue forces.

Relationship between perception of tongue position and measures of tongue force on the teeth

Purpose To verify whether there are differences of tongue force on the teeth at rest and during swallowing between individuals who report appropriate tongue position and those who report tongue thrust. Methods Tongue forces on the teeth were evaluated in 28 participants aged 19 to 31 years. To this end, a Flexiforce® resistive sensor was fixed to the palatal surface of the maxillary right central incisor (tooth 8) and was connected to an amplifier circuit, a data acquisition board, and a computer. Measurements were taken at rest and during saliva swallowing. Participants were asked about their habitual tongue position and where the apex of tongue touched when they swallowed. The Mann Whitney test was used for statistical analysis at 5% significance level. Results At habitual position, tongue force on the teeth was 0.00 N both for participants that reported tongue touch and for those who did not. At directed swallowing, tongue force was 0.34 N for the group of individuals whose tongues touch the teeth and 0.08 N for the group of individuals whose tongues do not touch the teeth. This difference was significant. Conclusion No significant difference was found between the tongue forces of participants of both groups at habitual position. However, participants with tongue thrust during directed swallowing presented greater force than those whose tongues do not touch the teeth during this task.

Relationship between clinical and instrumental assessment of the tongue in healthy young adults

PURPOSE To verify the association of tongue clinical evaluation aspects with quantitative evaluation of tongue force. METHODS A cross-sectional study was conducted with 48 healthy adults, 13 men and 35 women (ages 20-44 years; mean - M=24.8 years; standard deviation - SD=5.3 years). By clinical evaluation, the following aspects were checked: tongue force, alternate movements, snap, suction and vibration of the tongue. The evaluator also checked if the floor of the mouth elevated during tasks of tongue elevation and sucking tongue on palate and the occurrence of lingual tremor. Quantitative evaluation was accomplished using the FORLING instrument. It is composed of a piston/cylinder assembly attached to a mouthguard and to a drive shaft. The force applied by the tongue to the drive shaft is hydraulically transmitted to a pressure sensor. Mann-Whitneys test was used to verify whether there were differences in average and maximum forces according to the characteristics assessed. The test was performed at a 5% level of significance. RESULTS The aspects with the most frequent alteration were sucking tongue on palate and tongue vibration. Tremor had a higher occurrence during tongue movements. Elevation of the floor of the mouth in sucking tongue on palate was the only aspect associated with quantitative evaluation. CONCLUSION The association between elevation of the floor of the mouth during sucking tongue on palate and quantitative evaluation can provide insight into the higher participation of the suprahyoid muscles in some participants in both tasks.

Electromyography of muscles involved in feeding premature infants

PURPOSE To measure and compare the electrical activity of masseter, temporal, and suprahyoid muscles in premature newborn infants during breast-feeding and cup-feeding. METHODS This cross-sectional observational study was carried out by the electromyographic assessment of 36 preterm infants, 53% of whom were male, with mean gestational age of 32 weeks and birth weight of 1,719 g, fed via oral route, by full breast-feeding and supplementation of diet, through cup with expressed breast milk, until 15 days after hospital discharge. Children with neurological disorders, genetic syndromes, oral-motor, and/or congenital malformations were excluded. The different methods of feeding and the variables gestational age at birth, corrected gestational age, chronological age, birth weight and size, head circumference, and Apgar scores at 1 and 5 minutes were analyzed and compared by appropriate statistical analysis. RESULTS No difference was observed between breast-feeding and cup-feeding in the analysis of the temporal and masseter muscles. However, higher activity of suprahyoid musculature was observed during cup-feeding (p=0.001). The other variables were not correlated with the electrical activity of the muscles during the different feeding methods. CONCLUSION There may be a balance between the activity of the temporal and masseter muscles during breast-feeding and cup-feeding. There was higher activity of suprahyoid musculature during cup-feeding. This can be explained by the greater range of tongue movement, as premature infants usually perform tongue protrusion to get the milk from the cup.

Comparação da atividade elétrica dos músculos supra-hióideos durante a realização de diferentes exercícios linguais

Purpose To analyze the electric activity of suprahyoid muscles in eight different isometric exercises and to suggest the most appropriate exercise for data normalization.Methods Twenty two female volunteers, ages between 19 and 38 years (Avg=24,1 and SD=3,8) participated of the study. At first, the participants underwent a clinical evaluation of the tongue. Electric activity of submental region was recorded, by means of the electromyographic assessment, with the participant keeping the tongue in rest position and accomplishing the following exercises: tongue suction on the palate; tongue pressure on the palate; tongue apex pressure against the palate; tongue apex pressure against incisive papilla; exaggerated tongue retraction; tongue lateralization; and tongue protrusion. The exercises were randomly accomplished by the participants. Collected data were analyzed using Kruskal Wallis and Mann-Whitney tests. It was adopted as the significance level for all analyzes value of p≤0.05.Results Electromyographic activity of all the exercises was different from the one recorded in rest position. There was no statistical significant difference between different exercises.Conclusion There was no difference in submental electrical activation in different exercises. Therefore none was more appropriate then the other for data normalization.

Reproducibility assessment of an instrument for measuring the axial force of the tongue

PURPOSE Evaluate the reproducibility of Forling, a portable instrument for measuring axial tongue force. METHODS Axial force of the tongue was measured in 49 individuals (30 women and 19 men) aged 18-25 years using the Forling portable instrument. Measurements were performed in three days at intervals of 7±2 days. On each day, three 7-second measurements were performed with one-minute intervals between them. The coefficient of variation, Wilcoxon paired test, and intraclass correlation coefficient were used in the statistical analysis of the data. Maximum and mean tongue force values were analyzed, and comparison between them was performed using three approaches: the mean of the three values; the mean of the two highest values; the highest value of each measurement. RESULTS In the analysis of mean tongue force, the coefficient of variation was considered desirable and the intraclass correlation coefficient was acceptable. Significant differences were observed regarding the maximum value between the second and third days, mean of the two highest values and mean of the three values between the first and second days and the second and third days. In the analysis of maximum tongue force, the coefficient of variation and the intraclass correlation coefficient were acceptable. Significant difference was found only in the comparison between the second and third days. CONCLUSION Good reproducibility of the data obtained with the use of the Forling portable instrument was observed.

Correlation between tongue pressure and electrical activity of the suprahyoid muscles

Mailing address: Andréa Rodrigues Motta Faculdade de Medicina da UFMG Av. Professor Alfredo Balena, 190 sala 251 Santa Efigênia – Belo Horizonte, Minas Gerais, Brasil CEP: 30130-100 E-mail: andreamotta@ufmg.br ABSTRACT Objective: to investigate the correlation between the tongue pressure and the electrical activity of the suprahyoid muscles. Methods: a across-sectional, observational and analytical study conducted with 15 men and 22 women. Each participant underwent simultaneous assessment of maximal tongue pressure through the Iowa Oral Performance Instrument (IOPI) and the surface electromyography of the suprahyoid muscles. They were asked to press the tongue against the hard palate in the anterior and posterior region, with and without IOPI. The adopted significance level of the performed analyses was 5%. Results: there was a moderate and significant correlation only between suprahyoid electrical activity and tongue pressure in the posterior region. It was verified that the measured electrical potentials, when using the IOPI, were greater in the tasks of anterior pressure than in the tasks of the posterior one, bilaterally. Without using the IOPI, the electrical potentials were greater in the posterior pressure than in the anterior one, bilaterally. Finally, the values of lingual pressure were compared with the bulb positioned in the anterior and posterior parts, and the anterior tongue pressure was higher. Conclusion: there was a moderate correlation between tongue pressure and electrical potential of the suprahyoid muscles, researched by the surface electromyography, only when performing activities with the posterior portion of the tongue.