Speech Outcomes and Velopharyngeal Function in Children Undergoing Submucous Cleft Palate Repair.

OBJECTIVE: Describe and compare the results of speech and velopharyngeal function in children with classic and occult submucous cleft palate undergoing interdisciplinary treatment at the Gantz Foundation. METHODS: The clinical history of all patients born between 2012 and 2017 with a diagnosis of classic or occult submucous cleft palate was retrospectively reviewed. Preoperative and postoperative medical, surgical, and speech and language history were collected. RESULTS: Twenty-eight cases diagnosed at the age of 44.8±23.9 months were included. Of these, 71.4% presented classic submucous cleft, and 28.6% occult. Before primary surgery, 7.1% had a diagnosis of the syndrome, and 21.4% were under study. A total of 39.3% had hearing difficulties and 21.4% used tympanic ventilation tubes. A total of 60.7% had language problems, 39.3% had compensatory articulation, 17.9% had absent hypernasality, and 21.4% had absent nasal emission. The team indicated primary palate surgery in 71.4%, of which 85% performed the surgery at the mean age of 61.7±24.7 months. The surgical technique was Furlow in 88.2% of the cases and intravelar veloplasty in the remaining 11.8%. Then, 3 cases underwent velopharyngeal insufficiency surgery; 2 of them eliminated hypernasality and reduced nasal emission. The age of diagnosis ( P =0.021) and the performance of velopharyngeal insufficiency surgery ( P =0029) of the occult submucous cleft palate group was significatively later than the classic cleft palate group. CONCLUSIONS: Language, hearing, compensatory articulation, hypernasality, and nasal emission problems were recorded. A high percentage required primary surgery. Of these, a low proportion also required a velopharyngeal insufficiency surgery, which improved the velopharyngeal function of the children but did not completely adapt it. In this regard, early diagnosis is essential, as well as an analysis of each center primary closure protocol.

International Collaboration for the Prosthetic and Surgical Intervention of Velopharyngeal Insufficiency.

Interdisciplinary teamwork is essential for the rehabilitation of patients with cleft lip and palate, and therefore, the application of treatment techniques for velopharyngeal insufficiency, both surgical and prosthetic, depends on the experience of each rehabilitation team. For this reason, the following study consisting of the cooperation between interdisciplinary cleft lip and palate teams from Chile and Argentina, which succeeded in correcting velopharyngeal insufficiency in an adolescent, initially using a pharyngeal bulb prosthesis and speech therapy, and finally through pharyngeal flap surgery, is presented. This shows that international cooperation is a valuable tool for training, implementation, and follow-up of different treatment techniques for teams in formation.

Surgical and Speech Therapy Evaluation of Lingual Frenulum.

Interdisciplinary evaluation is essential to diagnose and define clinical conduct for children and adults presenting with an altered lingual frenulum; however, there are few reports on the subject in the literature. In this context, the following study exemplifies a proposed protocol for the surgical and SLT treatment of a lingual frenulum based on a review of the literature and the experience of speech and language therapists and maxillofacial surgeons from hospitals in Santiago de Chile. After its application, a history of breastfeeding with difficulties and a maintained preference for soft foods was reported. Upon anatomic examination, the lingual apex was heart-shaped, and the lingual frenulum was fixed in the upper third of the ventral side of the tongue, with a pointed shape, submerged up to the apex, and of adequate thickness. Meanwhile, upon functional examination, the tongue was descended at rest, performed tongue protrusion with restrictions (raising and clicking), did not achieve attachment or vibration, and presented distortion of the sounds / r/ and /rr/. With this information, an altered lingual frenulum was diagnosed, with the indication for surgery and postoperative speech and language therapy. The constructed instrument allowed for the standardization of the evaluation in different teams but should be validated in future research.

Planificación quirúrgica de colgajo faríngeo a medida para insuficiencia velofaríngea secundaria a fisura de paladar: reporte de caso y revisión de literatura / Surgical planning of a tailor-made pharyngeal flap for velopharyngeal insufficiency secondary to a cleft palate: case report and literature review

Resumen La insuficiencia velofaríngea (IVF) es una de las principales secuelas estructurales tras la palatoplastía primaria en casos de fisura de paladar. La IVF se caracteriza por la ausencia de tejido suficiente para lograr un cierre adecuado del mecanismo velofaríngeo durante el habla, lo que conlleva a una resonancia hipernasal y la emisión nasal de aire durante la producción de sonidos orales. Al respecto, el tratamiento ideal para corregir la IVF es quirúrgico, dentro de los cuales el colgajo faríngeo de pedículo superior es uno de los procedimientos más utilizados en nuestro país. Para su realización es fundamental determinar el ancho necesario, lo cual puede ser determinado mediante una videofluoroscopía multiplano (VFMP). Por esto, con el objetivo de potenciar el trabajo multidisciplinario en la corrección quirúrgica de la IVF, a continuación, se presentan los procedimientos de evaluación fonoaudiológica, videonasofaríngoscopía flexible y videofluoroscopía multiplano utilizados para la planificación quirúrgica de un colgajo faríngeo en un adolescente chileno diagnosticado con IVF secundaria a fisura palatina operada. Además, se describe el uso de la VFMP en la planificación quirúrgica del colgajo faríngeo mediante una revisión de literatura.

Abstract Velopharyngeal insufficiency (VPI) is one of the main structural sequelae after primary palatoplasty in cases of cleft palate. VPI is characterized by the absence of sufficient tissue to achieve adequate closure of the velopharyngeal mechanism (VFM) generating hyper-nasal resonance and nasal emission during the production of oral sounds. In cases of cleft palate, the ideal treatment to correct VPI is surgery. The upper pedicle pharyngeal flap is one of the most widely used procedures. To plan it, is essential to determine the appropriate width, which can be determined by means of multiplane videofluoroscopy (MPVF). For this reason, and with the aim of promoting multidisciplinary approach in the surgical correction of VPI, the following procedures such as speech and language evaluation, flexible videonasopharyngoscopy and multiplane videofluoroscopy used for the surgical planning of a pharyngeal flap, in a Chilean adolescent diagnosed with VPI secondary to operated cleft palate, will be presented. In addition, the use of MPVF in pharyngeal flap surgical planning is described through a literature review.

Valores de nasalancia para vocales, serie numérica y oraciones producidas por adultos hablantes de español chileno / Nasalance scores for vowels, number series and sentences produced by Chilean Spanish-speaking adults

Objetivo: El presente estudio tuvo como objetivo establecer y comparar valores de nasalancia en adultos de ambos sexos hablantes de español de Chile durante la producción de vocales sostenidas, una muestra de habla automática y la lectura de oraciones. Métodos: Participaron 46 adultos (25 mujeres y 21 hombres), con edad entre 18 y 29 años. Todos sin historia de tratamiento fonoaudiológico, patologías neurológicas, déficit intelectual, pérdida auditiva, síndromes u otras patologías que afectan la producción del habla. La adecuada función velofaríngea fue determinada en vivo a través de una evaluación perceptual de la resonancia. La nasalancia fue determinada con el Nasometer, modelo 6450, durante la producción sostenida de las vocales /a/, /i/, /u/, una repetición automática de la serie numérica 1-10 y la lectura de seis oraciones, cinco con consonantes orales de alta presión y una con consonantes nasales. La comparación entre ambos sexos fue realizada con el test de la U de Mann-Whitney. Resultados: La oración con sonidos nasales («Mi mamá me mima») presentó el porcentaje mayor de nasalancia, con un 66.36%, seguido de la serie numérica, con un 24.61%, y la vocal /i/, con un 23.57%. En tanto, las oraciones con sonidos orales y las vocales /a/ y /u/ sostenidas presentaron una nasalancia promedio que fluctuó entre un 10.5% (vocal /u/) y un 16.52% (oración: «Fifí fue feliz»). Por último, fue observado un promedio significativamente mayor en mujeres para tres oraciones orales: «Pipo patea la pelota» (p=.044), «Tito tapa tarros» (p=.041), y «Fifi fue feliz» (p=.027). Conclusión: Los valores de nasalancia obtenidos en adultos chilenos demostraron variaciones de acuerdo al estímulo de habla y el sexo de los hablantes.(AU)

Objective: The present study aimed to establish and compare nasalance scores in Spanish-speaking adults of both genders from Chile during the production of sustained vowels, an automatic speech sample and the reading of sentences. Methods: 46 adults participated, 25 women and 21 men, aged between 18 and 29 years. All without a history of speech therapy, neurological pathologies, intellectual deficit, hearing loss, syndromes or other pathologies that affect speech production. Adequate velopharyngeal function was determined in vivo through a perceptual evaluation of resonance. Nasalance was determined with the Nasometer, model 6450, during the sustained production of the vowels /a/, /i/ and /u/, an automatic repetition of the number series 1-10 and the reading of six sentences, five with consonants high pressure orals and one with nasal consonants. The comparison between both genders was made with the Mann-Whitney U test. Results: The sentence with nasal sounds («Mi mamá me mima») presented the highest percentage of nasalance with 66.36%, followed by the numerical series with 24.61% and the vowel /i/ with 23.57%. Meanwhile, sentences with oral sounds and sustained vowels /a/ and /u/ presented an average nasalance that fluctuated between 10.5% (vowel /u/) and 16.52% (sentence: «Fifi fue feliz»). Finally, a significantly higher average was observed in women for three oral sentences: «Pipo patea la pelota» (P=.044), «Tito tapa tarros» (P=.041), and «Fifi fue feliz» (P=.027). Conclusion: The nasalance values obtained in Chilean adults showed variations according to the speech stimulus and the gender of the speakers.(AU)

Normative nasalance scores in Chilean adults.

PURPOSE: The present study is aimed towards determining and comparing normative nasalance scores in Chilean Spanish-speaking adult men and women. METHODS: 40 women (age range 18 to 35, X = 25.79, SD = 5.83) and 36 men (age range 18 to 35, X = 26.45, SD = 4.08) were invited to participate, all of them without any previous speech therapy, neurological pathologies, intellectual deficits, hearing loss, syndromes, or other diagnosed pathologies that could impact speech production.A study of proper velopharyngeal function was performed, using a perceptual resonance evaluation. Nasalance was determined using a model 6450 Nasometer, during the reading of three standardized speech samples in Spanish: a nasal passage (NP), an oronasal passage (ONP), and an oral passage (OP). Also, the nasalance distance was calculated. Genders were compared using Wilcoxon tests for independent samples. RESULTS: The NP presented the highest percentage of nasalance, with 52.13% (± 4.73), followed by the ONP with 25.38% (± 3.7), and finally the OP, which presented the lowest value of 14.15% (± 5.03). Meanwhile, nasalance distance was 37.98% (± 5.32). Finally, no significant differences were observed when comparing the nasalance between genders (p >0.05). CONCLUSION: The nasalance values obtained were similar to those observed for other Spanish speakers. Also, male and women showed similar scores. The results of this study are a contribution to the indirect assessment of velopharyngeal function in Chilean adults.

Normative nasalance scores in Chilean adults / Valores normativos de nasalancia en adultos chilenos

ABSTRACT Purpose The present study is aimed towards determining and comparing normative nasalance scores in Chilean Spanish-speaking adult men and women. Methods 40 women (age range 18 to 35, X = 25.79, SD = 5.83) and 36 men (age range 18 to 35, X = 26.45, SD = 4.08) were invited to participate, all of them without any previous speech therapy, neurological pathologies, intellectual deficits, hearing loss, syndromes, or other diagnosed pathologies that could impact speech production. A study of proper velopharyngeal function was performed, using a perceptual resonance evaluation. Nasalance was determined using a model 6450 Nasometer, during the reading of three standardized speech samples in Spanish: a nasal passage (NP), an oronasal passage (ONP), and an oral passage (OP). Also, the nasalance distance was calculated. Genders were compared using Wilcoxon tests for independent samples. Results The NP presented the highest percentage of nasalance, with 52.13% (± 4.73), followed by the ONP with 25.38% (± 3.7), and finally the OP, which presented the lowest value of 14.15% (± 5.03). Meanwhile, nasalance distance was 37.98% (± 5.32). Finally, no significant differences were observed when comparing the nasalance between genders (p >0.05). Conclusion The nasalance values obtained were similar to those observed for other Spanish speakers. Also, male and women showed similar scores. The results of this study are a contribution to the indirect assessment of velopharyngeal function in Chilean adults.

RESUMEN Objetivo El presente estudio tiene como objetivo determinar y comparar puntajes normativos de nasalancia en hombres y mujeres chilenos de habla hispana. Método Participaron 40 mujeres (rango de edad de 18 a 35, X = 25.79, DE = 5.83) y 36 hombres (rango de edad de 18 a 35, X = 26.45, DE = 4.08), todos sin ningún antecedente de tratamiento fonoaudiológico, patologías neurológicas, déficit intelectual, hipoacusia, síndromes u otras patologías diagnosticadas que podrían afectar la producción del habla. La adecuada función velofaríngea fue determinada en vivo a través de una evaluación perceptual de la resonancia. La nasalancia se determinó utilizando un Nasometer modelo 6450, durante la lectura de tres muestras de habla estandarizadas en español: un párrafo nasal (PN), un párrafo oronasal (PON) y un párrafo oral (PO). Además, se calculó la distancia de nasalancia. La comparación entre ambos sexos fue realizada con el test de Wilcoxon para muestras independientes. Resultados El PN presentó el mayor porcentaje de nasalancia con 52.13% (± 4.73), seguido del PON con 25.38% (± 3.7), y finalmente el PO, que presentó el valor más bajo de 14.15% (± 5.03). En tanto, la distancia de nasalancia fue del 37.98% (± 5.32). Por último, no se observaron diferencias significativas al comparar entre ambos sexos (p> 0.05). Conclusión Los valores de nasalancia obtenidos fueron similares a los observados para otros hispanohablantes. Además, hombres y mujeres mostraron puntuaciones similares. Los resultados de este estudio son una contribución a la evaluación indirecta de la función velofaríngea en adultos chilenos.

Fisiología del esfínter velofaríngeo durante la deglución. Revisión sistemática de literatura

Resumen El objetivo de este artículo es describir el funcionamiento del esfínter velofaríngeo (EVF) durante la deglución, mediante una revisión de literatura. En febrero de 2020, las bases de datos electrónicas Medline, LILACS, SciELO e IBECS, fueron consultadas retrospectivamente, usando las palabras claves en inglés: "velopharyngeal sphincter" o "pharyngeal muscles". Fueron seleccionados artículos originales que describen la fisiología del EVF en la deglución de adultos sanos. Para este estudio fue creado un protocolo que contempla lo siguiente: autor, año, país, número y características de los participantes, actividades evaluadas, metodologías e instrumentos utilizados y principales resultados. Fueron encontrados 4.124 artículos. 3.863 fueron excluidos luego de la lectura de los títulos, 239 luego de lectura de los resúmenes y 8 luego de la revisión de los textos completos. Finalmente, 14 artículos fueron analizados en esta revisión. Se discuten eventos espaciales y temporales del EVF, la actividad electromiográfica de la musculatura del EVF y la presión velofaríngea durante la deglución en adultos sanos. Se concluye que el esfínter velofaríngeo cumple un rol importante en la fase faríngea de la deglución, que debe ser profundizado en futuras investigaciones.

Abstract The aim of this article is to describe the functioning of the velopharyngeal sphincter (VPS) during swallowing, through a literature review. In February 2020, the electronic databases Medline, LILACS, SciELO and IBECS were retrospectively consulted, using the key words in English: "velopharyngeal sphincter" or "pharyngeal muscles". Original articles were selected that describe the physiology of VPS in healthy adult swallowing. For this study it was created a protocol that includes the following items: author, year, country, number and characteristics of the participants, evaluated activities, methodologies and instruments used, and main results. 4124 articles were found. 3,863 were excluded after reading the titles, 239 after reading the abstracts and 8 after reviewing the full texts. Finally, 14 articles were analyzed in this review. Spatial and temporal events of the VPS, the electromyographic activity of the VPS musculature, and velopharyngeal pressure during swallowing in healthy adults are discussed. We conclude that the velopharyngeal sphincter plays an important role in the pharyngeal phase of swallowing, which should be studied in depth in future research.

Speech pathology telepractice intervention during the COVID-19 pandemic for Spanish-speaking children with cleft palate: A systematic review.

BACKGROUND: Due to the lockdown and quarantines caused by the COVID-19 pandemic, the need to study and use telepractice for providing speech pathology interventions for children with cleft palate has arisen. OBJECTIVE: To carry out a systematic review of the use of telepractice during the COVID-19 pandemic for providing speech pathology interventions for Spanish-speaking children with cleft palate. METHODS: In July and August 2020, the authors searched the electronic databases Medline, LILACS, SciELO, and the Cochrane Library using the following keywords in English (MeSH): Cleft palate combined with Early intervention, Speech therapy, Rehabilitation of speech and language disorders, Speech production measurement, Speech articulation tests and Telemedicine. Original articles were selected and analyzed, complemented by an analysis of flowcharts and recommendations by the GES Clinical Guide of Cleft Lip and Palate of Chile's Government and the authors' expert opinions. RESULTS: A total of 2680 articles were retrieved, of which 23 were critically analyzed and used to adapt the early stimulation, evaluation, and treatment of children with CP to speech therapy telepractice at the Gantz Foundation, a Hospital in Santiago de Chile. LIMITATIONS: Only three researchers carried out a quick review, which limited the depth of individual analysis of the studies included. Also, the suggestions and material presented should be evaluated in future investigations. CONCLUSION: This systematic review provides useful guidelines for providing speech pathology interventions through telepractice for children with cleft palate. Audiovisual materials seem to be extremely useful for families receiving the interventions. The use of interactive videos for Spanish-speaking children and educational videos for parents is manifest.

Evaluación perceptual de la insuficiencia velofaríngea en personas con fisura del paladar: una revisión integradora de literatura / Perceptual evaluation of velopharyngeal insufficiency in people with cleft palate: an integrative literature review

La insuficiencia velofaríngea (IVF) secundaria de fisura del paladar corresponde al cierre incompleto del mecanismo velofaríngeo durante el habla, debido a una falta de tejido en el paladar blando o las paredes de la faringe, lo cual genera una resonancia hipernasal y una emisión nasal de aire en los sonidos orales. Al respecto, en la literatura existen diversas propuestas para la evaluación perceptual de la IVF. Por esto, el objetivo del presente estudio es describir la evaluación perceptiva auditiva de la insuficiencia velofaríngea, mediante una revisión integradora de literatura. Para ello, en mayo de 2020 las bases de datos electrónicas PUBMED, LILACS, SciELO y Cochrane, fueron consultadas utilizando las palabras claves en inglés: "Velopharyngeal Sphincter", "Velopharyngeal Insufficiency", "Cleft Palate", "Speech Intelligibility", "Speech Production Measurement", "Speech Articulation Tests" y "Speech-Language Pathology" y sus respectivos equivalentes en portugués y español. Se seleccionaron artículos originales relacionados al tema, y se creó un protocolo específico para la extracción de los datos. En total se encontraron 2.385 artículos. De ellos, 2.354 fueron excluidos por el título, 13 por el resumen y 3 luego de la lectura del texto completo. Finalmente, a partir de la metodología desarrollada, en esta revisión fueron utilizados 33 artículos. A partir de la revisión realizada se concluye que los parámetros más utilizados en la evaluación son la hipernasalidad, la emisión nasal y la articulación compensatoria asociada a IVF. Estos parámetros son evaluados principalmente en oraciones, habla espontánea y palabras, por un fonoaudiólogo experto, en vivo y mediante grabaciones de audio.

Secondary Velopharyngeal insufficiency (VPI) to cleft palate corresponds to the incomplete closure of the velopharyngeal mechanism during speech, due to lack of tissue in the soft palate or the walls of the pharynx, which generates a hypernasal resonance and nasal air emission in oral sounds. In this regard, there are various proposals in the literature for the perceptual evaluation of VPI. For this reason, the objective of the present study is to describe the auditory perceptual evaluation of velopharyngeal insufficiency, through an integrative literature review. To this end, in May 2020 the electronic databases PUBMED, LILACS, SciELO and Cochrane were consulted using the key words in English: "Velopharyngeal Sphincter", "Velopharyngeal Insufficiency", "Cleft Palate", "Speech Intelligibility", "Speech Production Measurement", "Speech Articulation Tests" and "Speech-Language Pathology", and their equivalent properties in Portuguese and Spanish. Original articles related to the topic were selected, and a specific protocol for data extraction was created. In total, 2,385 articles were found. Of these, 2,354 were excluded due to the title, 13 due to the abstract and 3 after reading the full text. Finally, based on the methodology developed, 33 articles were used in this review. From the review carried out, it is concluded that the parameters most used in the evaluation are hypernasality, nasal emission and the compensatory joint associated with IVF. These parameters are evaluated mainly in sentences, spontaneous speech and words, by an expert speech therapist, live and through audio recordings.

Lactancia materna y factores asociados a la alimentación en bebés con fisura de paladar / Breastfeeding and factors associated to feeding in babies with cleft palate

Breastfeeding can be affected in babies with cleft palate, due to various factors associated with feeding. The objective of the study was to relate the time of breastfeeding and the time to express breast milk with factors associated with feeding in babies between 0 and 6 months with cleft palate. Electronic records of care of 36 babies with cleft palate from a public hospital in Chile were reviewed. Sociodemographic characteristics of the mother and father, perinatal and postnatal antecedents of the babies and general characteristics of feeding up to 6 months were extracted. The data were compared with the Mann-Whitney U test and relationships were established with the Pearson and Spearman correlations. In the time of direct breastfeeding (days), significant differences were observed in: the babies who used a nasogastric tube (p = 0.009), the indication to express breast milk (p = 0.017), the presence of manual extraction of breast milk (p = 0.005) and the presence of electrical extraction of breast milk (p = 0.002). In addition, a positive correlation (p = <.001; r = 0.538) was recorded between the time of direct breastfeeding and the time of expressed breast milk. It is concluded that the longer the breastfeeding time, the longer the breast milk extraction time. Meanwhile, the time of breastfeeding was influenced by the use of a nasogastric tube, the expression of breast milk as a personal option, and the manual and electrical expression of breast milk.

La lactancia materna puede afectarse en bebés con fisura de paladar, debido a diversos factores asociados a la alimentación. El objetivo del estudio fue relacionar el tiempo de lactancia materna y el tiempo de extracción de leche materna con factores asociados a la alimentación en bebés de entre 0 y 6 meses portadores de fisura de paladar. Se revisaron registros electrónicos de atenciones de 36 bebés portadores de fisura de paladar de un hospital público de Chile. Fueron extraídas características sociodemográficas de la madre y padre, antecedentes perinatales y postnatales de los bebés y características generales de la alimentación hasta los 6 meses. Se compararon los datos con el Test de la U de Mann-Whitney y se establecieron relaciones con las correlaciones de Pearson y Spearman. En el tiempo de lactancia materna directa (días) se observaron diferencias significativas en: los bebés que utilizaron sonda nasogástrica (p = 0.009), la indicación de extracción de leche materna (p = 0.017), la presencia de extracción manual de leche materna (p = 0.005) y la presencia de extracción eléctrica de leche materna (p = 0.002). Además, se registró una correlación positiva (p = < .001; r = 0.538) entre el tiempo de lactancia materna directa y el tiempo de leche materna extraída. Se concluye que a mayor tiempo de lactancia materna existe un mayor tiempo de extracción de leche materna. En tanto, el tiempo de lactancia materna fue influenciado por el uso de sonda nasogástrica, la extracción de leche materna como opción personal y la extracción de leche materna de manera manual y eléctrica.

Plasticidad muscular y fibras híbridas en la musculatura masticatoria: revisión de literatura / Muscle plasticity and hybrid fibers in the masticatory musculature: literature review

La musculatura masticatoria se caracteriza por presentar fibras híbridas que en los últimos años se han relacionado con el fenómeno de plasticidad muscular. El objetivo del estudio fue describir la relación entre la plasticidad muscular y las fibras musculares híbridas presentes en la musculatura masticatoria, mediante una revisión narrativa de literatura. Para esto, se realizó una búsqueda electrónica en PUBMED, ScienceDirect y BIREME, utilizando las palabras claves: "Muscle Plasticity", "Hybrid Muscle Fibers" y "Hybrid Fibers". Fueron seleccionados documentos que reportan las isoformas de cadena pesada de miosina (MHC) presentes en los músculos masticatorios de humanos y otros mamíferos, junto a los cambios vinculados a demandas funcionales. Se describe la presencia de fibras puras tipo I y tipo II, además de otras isoformas como la MHC-la, MHC-IIM, MHC-fetal y MHC-cardíaca. Sin embargo, un porcentaje considerable de fibras en la musculatura masticatoria son híbridas, es decir, expresan a más de una isoforma de MHC, las cuales también son diferentes a nivel intermuscular e intramuscular. Las influencias locales pueden contribuir a la variación de la expresión del tipo de fibra. En la musculatura masticatoria, el destete, la dureza de los alimentos, el bruxismo, la morfología craneofacial y el uso de prótesis dentales genera cambios a nivel de los músculos masticatorios, donde es común la presencia de fibras híbridas. Se concluye la presencia importante de fibras híbridas en la musculatura masticatoria y su relación con la plasticidad muscular a lo largo del ciclo vital, debido a cambios funcionales y patológicos. Es importante que los terapeutas de habla y motricidad orofacial profundicen en el conocimiento de la fisiología del comportamiento oromiofuncional.

The masticatory musculature is characterized by presenting hybrid fibers that in recent years have been related to the phenomenon of muscle plasticity. The objective of the study was to describe the relationship between muscle plasticity and the hybrid muscle fibers present in the masticatory muscles, through a narrative review. For this, an electronic search was conducted in PUBMED, ScienceDirect and BIREME, using the keywords: "Muscle Plasticity", "Hybrid Muscle Fibers" and "Hybrid Fibers". Documents that report the myosin heavy chain (MHC) isoforms present in the masticatory muscles of humans and other mammals were selected, along with the changes linked to functional demands. The presence of type I and type II pure fibers were described, in addition to other isoforms such as MHC-la, MHC-IIM, MHC-fetal and MHC-cardiac. However, a significant percentage of fibers in the masticatory muscles are hybrids, that is, they express more than one MHC isoform, which are also different at the intermuscular and intramuscular level. Local influences can contribute to the variation of fiber type expression. In the chewing muscles, weaning, the hardness of food, bruxism, craniofacial morphology and the use of dental prostheses generate changes at the level of the chewing muscles, where the presence of hybrid fibers is common. The important presence of hybrid fibers in the masticatory muscles and their relationship with muscle plasticity throughout the life cycle, due to functional and pathological changes, is concluded. It is important for Speech Therapy andMyofunctional Therapy to deepen their understanding of the physiology of oromyofunctional behavior.