The Genetic Population Structure of Robinson Crusoe Island, Chile.

Studies examining genetic conditions common in Latin America are highly underrepresented in the scientific literature. Understanding of the population structure is limited, particularly Chile, in part due to the lack of available population specific data. An important first-step in elucidating disease mechanisms in Latin America countries is to understand the genetic structure of isolated populations. Robinson Crusoe Island (RCI) is a small land mass off the coast of Chile. The current population of over 900 inhabitants are primarily descended from a small number of founders who colonized the island in the late 1800s. Extensive genealogical records can trace the ancestry of almost the entire population. We perform a comprehensive genetic analysis to investigate the ancestry of the island population, examining ancestral mitochondrial and Y chromosome haplogroups, as well as autosomal admixture. Mitochondrial and Y chromosome haplogroups indicated a substantial European genetic contribution to the current RCI population. Analysis of the mitochondrial haplogroups found in the present-day population revealed that 79.1% of islanders carried European haplogroups, compared to 60.0% of the mainland Chilean controls from Santiago. Both groups showed a substantially lower contribution of indigenous haplogroups than expected. Analysis of the Y chromosome haplogroups also showed predominantly European haplogroups detected in 92.3% of male islanders and 86.7% of mainland Chilean controls. Using the near-complete genealogical data collected from the RCI population, we successfully inferred the ancestral haplogroups of 16/23 founder individuals, revealing genetic ancestry from Northern and Southern Europe. As mitochondrial and Y investigations only provide information for direct maternal and paternal lineages, we expanded this to investigate genetic admixture using the autosomes. Admixture analysis identified substantial indigenous genetic admixture in the RCI population (46.9%), higher than that found in the Santiago mainland Chilean controls (43.4%), but lower than a more representative Chilean population (Chile_GRU) (49.1%). Our study revealed the Robinson Crusoe Island population show a substantial genetic contribution for indigenous Chileans, similar to the level reported in mainland Chileans. However, direct maternal and paternal haplogroup analysis revealed strong European genetic contributions consistent with the history of the Island.

Candidate gene variant effects on language disorders in Robinson Crusoe Island.

Background: Robinson Crusoe Island is a geographically and socially isolated settlement located over 600 km west of the Port of Valparíso, Chile. An unusually high incidence (30%) of the Chilean equivalent of developmental language disorder (in Spanish, trastorno especifico de lenguaje (TEL)), has been reported in Islander children, with 90% of these affected children found to be direct descendants of a pair of original founder-brothers, therefore strongly suggesting a shared genetic basis. Aim: This study reports a comprehensive examination of 34 genes that have been previously directly implicated in language-related mechanisms. It utilises whole-genome sequencing to investigate potential underlying variants in seven TEL affected and 10 unaffected islanders. The aim was to identify the underlying genetic cause of the TEL phenotype under two inheritance model paradigms; Mendelian monogenic and complex susceptibility. Subjects and methods: A targeted candidate gene approach was used to look for rare, shared variants that may underlie the diagnosis of TEL in a Mendelian genetic model. This study tested whether an overall burden of rare variants is enriched in individuals affected by TEL or with Islanders related to the founder-brother lineage. It further examined if any variants segregate with affection status or with founder-brother-related status and, therefore, may increase risk of developing a language disorder as part of a complex model. Finally, gene-based tests were performed to evaluate relationships between combined variation across candidate genes and TEL affection status. Results: No single pathogenic rare variant segregated with either affection or founder-related status within the 34 candidate genes. Additionally, no evidence was found of an overall increased variant burden in TEL individuals compared to those with TLD. Gene-based analysis found no clear association between the combined effects of variants across the 34 genes and affection status or founder-brother-relatedness. Conclusion: The high prevalence of language disorders found on Robinson Crusoe Island is not caused by either a shared high-impact variant, or an increased burden of variants within candidate genes previously implicated in language disorders. We have comprehensively tested for 'low hanging fruit' in genes implicated in language disorders. Therefore, the underlying cause of TEL on Robinson Crusoe lies outside of these known language disorder genes, or within a complex susceptibility model.

Family aggregation of language impairment in an isolated Chilean population from Robinson Crusoe Island.

BACKGROUND: It has been reported that the inhabitants of the Chilean Robinson Crusoe Island have an increased frequency of specific language impairment (SLI) or developmental language disorder (DLD). AIMS: To explore the familial aggregation of DLD in this community. METHODS & PROCEDURES: We assessed the frequency of DLD amongst colonial children between the ages of 3 and 8;11 years (50 individuals from 45 nuclear families). Familial aggregation rates of language disorder were calculated by assessing all available first-degree relatives (n = 107, 77 parents, 25 siblings, five half-siblings) of the probands. OUTCOMES & RESULTS: We found that 71% of the child population performed significantly below expected in measures of phonological production or expressive and receptive morphology. The majority of these children presented with severe expressive and/or receptive language difficulties. One-quarter of language-disordered probands primarily had phonological difficulties. Family members of affected probands experienced a higher risk of language disorder than those of typically developing probands. This increased risk was apparent regardless of non-verbal IQ. CONCLUSIONS & IMPLICATIONS: The study substantiates the existence of a familial form of speech and language disorder on Robinson Crusoe Island. Furthermore, we find that the familiarity is stable regardless of non-verbal IQ, supporting the recent movement to reduce the importance of non-verbal IQ criterion in DLD diagnoses.

Dental morphological markers as a proxy for ethnicity in Robinson Crusoe Islanders / Marcadores morfológicos dentarios en la estimación de la etnicidad poblacional de la Isla Robinson Crusoe

Chilean Robinson Crusoe Island is a semi-isolated location with unusually high rates of both consanguinity and language disorder. The current population of 633 inhabitants is descended almost exclusively from the colonization at the end of the 19th century, as there were few preceding immigrations to the island. This study investigates the genetic composition and degree of miscegenation within the island population, using dental morphological markers. The universe of island children was studied (n= 128, 3 to 15 years of age) using clinical exams, dental cast, and identification of each individual within a previously-constructed extensive genealogy for the island. The frequencies for Carabelli's cusp (61.7%), shovel-shaped incisor (9.4%), and sixth cusp (2.3%), along with the absence of seventh cusp, are consistent with a primarily Caucasian population. The estimated degree of miscegenation suggests an Amerindian component of 4.3%, which is consistent with the extensive known genealogies of the founders. Characterizing the genetic profile of Robinson Crusoe Island, a location with a remarkably high prevalence of language disorder, facilitates the comparison of the genetic variants underlying this pathology with those identified in European populations.

La isla chilena Robinson Crusoe es un semiaislado geográfico de alta consanguinidad. Su población actual de 633 habitantes proviene de la última colonización ocurrida a finales del siglo XIX y pocas migraciones posteriores, en quienes recientemente se ha descrito una alta incidencia de trastorno de lenguaje. Este estudio estimó el componente genético y grado de miscegenación de la población isleña usando marcadores morfológicos dentarios. Se estudió al universo de niños isleños (n= 128, 3 a 15 años de edad) con exámenes clínicos, modelos dentales y ubicación de cada individuo en genealogías extensas confeccionadas previamente. La frecuencia de Tubérculo de Carabelli fue 61,7%, Diente en Pala 9,4%, tubérculo sexto 2,3% y ausencia del rasgo tubérculo séptimo, lo que concuerda con una población eminentemente caucásica. El grado de miscegenación estima que el componente amerindio de esta población es de 4,3%, que también se evidencia al analizar las genealogías extensas originadas por los colonizadores. La descripción del perfil genético de esta población, donde se han reportado altas prevalencias de trastorno de lenguaje, permitirá comparar con las variantes genéticas subyacentes a esta patología descritas para poblaciones europeas.

Exome sequencing in an admixed isolated population indicates NFXL1 variants confer a risk for specific language impairment.

Children affected by Specific Language Impairment (SLI) fail to acquire age appropriate language skills despite adequate intelligence and opportunity. SLI is highly heritable, but the understanding of underlying genetic mechanisms has proved challenging. In this study, we use molecular genetic techniques to investigate an admixed isolated founder population from the Robinson Crusoe Island (Chile), who are affected by a high incidence of SLI, increasing the power to discover contributory genetic factors. We utilize exome sequencing in selected individuals from this population to identify eight coding variants that are of putative significance. We then apply association analyses across the wider population to highlight a single rare coding variant (rs144169475, Minor Allele Frequency of 4.1% in admixed South American populations) in the NFXL1 gene that confers a nonsynonymous change (N150K) and is significantly associated with language impairment in the Robinson Crusoe population (p = 2.04 × 10-4, 8 variants tested). Subsequent sequencing of NFXL1 in 117 UK SLI cases identified four individuals with heterozygous variants predicted to be of functional consequence. We conclude that coding variants within NFXL1 confer an increased risk of SLI within a complex genetic model.

PIAHO: una herramienta para la prevención de hábitos orales deletéreos (protocolo de incorporación apropiada de hábitos orales) / PIAHO: a tool to prevent bad oral habits occurrence (protocol of appropriate inclusion of oral habits)

Objetivo presentar una herramienta de prevención de malos hábitos orales, llamado PIAHO. Métodos se comparan los diagnósticos obtenidos de la prueba subjetiva PeNaF con los diagnósticos de resistencia nasal obtenidos por la prueba objetiva de rinomanometria. Se estudian las relaciones entre la incorporación de consistencias, herramientas y elección de posturas durante la alimentación y los diferentes tipos de deglución. Basados tanto en, los resultados obtenidos y publicados de investigaciones realizadas en población chilena; como enla revisión de la literatura internacional. Resultados una nueva estrategia y plan de acción para una oportuna incorporación de consistencias y utensilios de alimentación, también enfocado en una correcta higiene nasal. Conclusión Contribuir a la prevención de alteraciones miofuncionales, y evitar la instauración de malos hábitos orales. .

Purpose to present a tool to prevent bad oral habits ocurrance, this protocol is called PIAHO. Methods comparing the diagnoses obtained by PeNaF subjective test with nasal resistance diagnoses obtained by the objective test of rhinomanometry. It was explored the relationships between the incorporation of consistencies, tools and choice of positions during feeding and swallowing different types. Based on both, the results obtained and published research in Chilean population; as in the international literature review. Results a new strategy and guidelines for a early inclusion of consistencies and feeding tools, also focus in a good nasal hygiene. Conclusion to contribute to the prevention of orofacial myofunctional disorders and avoiding oral bad habits occurrence. .

Consanguinity on Robinson Crusoe Island, an isolated Chilean population.

The population of Robinson Crusoe Island is estimated at 633 inhabitants. The current population has a common origin from the first eight families who colonized the island at the end of the 19th century. The objective of this study was to determine the rates of consanguinity, the average coefficients of inbreeding, the types of consanguineous marriages and the inbreeding evolution between 1900 and 2000 on the island. All marriages registered on the island, from the last colonization until 2000 (417 in total), were included in the analysis. In addition, extended genealogies were obtained. The consanguinity rate was 14.9% and the average coefficient of inbreeding (α) 54.05 × 10(-4). The most frequent type of consanguineous marriages was between second cousins, followed by first cousins. The average value of the first/second cousin ratio was 1.11. The population of Robinson Crusoe Island has a high rate of inbreeding. The unique characteristic of the island - its small current population, originating from just a few families, with small rate of gene flow - could explain the observed high and increasing consanguinity.

Genome-wide analysis of genetic susceptibility to language impairment in an isolated Chilean population.

Specific language impairment (SLI) is an unexpected deficit in the acquisition of language skills and affects between 5 and 8% of pre-school children. Despite its prevalence and high heritability, our understanding of the aetiology of this disorder is only emerging. In this paper, we apply genome-wide techniques to investigate an isolated Chilean population who exhibit an increased frequency of SLI. Loss of heterozygosity (LOH) mapping and parametric and non-parametric linkage analyses indicate that complex genetic factors are likely to underlie susceptibility to SLI in this population. Across all analyses performed, the most consistently implicated locus was on chromosome 7q. This locus achieved highly significant linkage under all three non-parametric models (max NPL = 6.73, P = 4.0 × 10(-11)). In addition, it yielded a HLOD of 1.24 in the recessive parametric linkage analyses and contained a segment that was homozygous in two affected individuals. Further, investigation of this region identified a two-SNP haplotype that occurs at an increased frequency in language-impaired individuals (P = 0.008). We hypothesise that the linkage regions identified here, in particular that on chromosome 7, may contain variants that underlie the high prevalence of SLI observed in this isolated population and may be of relevance to other populations affected by language impairments.

Association of D16S515 microsatellite with specific language impairment on Robinson Crusoe Island, an isolated Chilean population: a possible key to understanding language development.

Specific language impairment (SLI) is a developmental language disorder that occurs for no known reason. The disorder affects 2-8% of children. Some scientific evidence suggests that genetic factors are implicated in the etiology of SLI. The disorder is genetically complex. Two novel loci, SLI1 on chromosome 16q24 (MIM 606711) and SLI2 on chromosome 19q13 (MIM 606712), have been found to be highly correlated with SLI. Four genes have been identified as susceptibility genes. SLI occurs at an unusually elevated incidence (35%) among the population of Robinson Crusoe Island (Chile), which also has a high consanguinity rate. This finding supports the influence of genetic mechanisms in the transmission of SLI based on a founder effect. To investigate further the genetic involvement in this population, we collected blood samples from 115 islanders from 13 families with a language-impaired proband and from 18 families with a normal-language proband. The analysis of micro satellite marker D16S515, located in locus SLI1, demonstrated that the 230-bp allele was correlated with SLI and that the 232-bp allele was correlated with normal language development. The domain containing the D16S515 marker, therefore, may play a role in language development.

Articulación de fones en individuos clase esqueletal I,II y III / Speech patterns in skeletal class I, II and III subjects

OBJETIVO: determinar los patrones de articulación de fones consonánticos en sujetos de habla española chilena clases I, II y III esqueletal; comparar las diferencias fonéticas que existan entre clases esqueletales. MÉTODOS: se seleccionaron 54 individuos que cumplían con los criterios de inclusión determinados mediante un examen clínico intraoral y a través del análisis de Ricketts, y se conformaron los grupos de estudio de pacientes clases esqueletales I, II y III. Se les realizó un examen fonoarticulatorio estandarizado para determinar los fones modificados y el patrón articulatorio compensatorio realizado. RESULTADOS: se observaron cambios en el punto de articulación de fones consonánticos en las tres clases esqueletales, con diferencias significativas en los grupos de fones anteriores y medios entre pacientes clases I y II, sólo en el grupo de los fones anteriores entre pacientes I y III. Entre pacientes clases II y III no se observaron diferencias significativas. Se reportan modificaciones y compensaciones cualitativamente distintas entre las clases esqueletales. CONCLUSIONES: en relación a pacientes clase I, los pacientes clase II o III, presentan distinto grado de modificación en el punto de articulación de fones consonánticos. Las diferencias observadas se relacionan con los patrones esqueletales propios de cada clase.

PURPOSE: to determine the consonant phonemes articulation patterns in Chilean skeletal class I, II and III Spanish speakers and compare their phonetic differences. METHODS: fifty-four skeletal class I, II and III subjects were selected, based on intraoral clinical examination and Ricketts cephalometric analysis, constituting the study groups. A standardized phonoarticulatory test was applied to each patient to determine the modified phonemes and their compensatory patterns. RESULTS: the findings indicate changes in articulation in all three groups. Significant differences were found in anterior and medium phonemes between skeletal class I and II and only in the anterior phonemes between skeletal class I and III. There were no significant differences between II and III skeletal groups. Qualitatively different modifications and compensations between skeletal classes are reported. CONCLUSION: different degree of modification in consonant phonemes articulation is shown in class II and III patients when compared to class I skeletal subjects. These differences are related to the skeletal patterns.

[High prevalence of specific language impairment in Robinson Crusoe Island. A possible founder effect]. / Alta prevalencia de trastorno específico de lenguaje en isla Robinson Crusoe y probable efecto fundador.

BACKGROUND: Specific language impairment (SLI) occurs in 2% to 8% of preschool children. Major and candidate genes are probably involved. Genetic drift is a cause for the presence of high frequencies of deleterious alíeles of a specific disease and the founder effect is one of its forms. Robinson Crusoe Island has 633 inhabitants and its actual population began with 8 families that repopulated the island at the end of XIXth century. AIM: To assess the frequency of specific language impairment among children living in Robinson Crusoe Island. MATERIAL AND METHODS: All 66 children aged between 3 and 9 years living in the island, were studied. Parents were interviewed and in children, non verbal intelligence, audiometric parameters, comprehension and expression of oral language were assessed. Extended genealogies were also performed. RESULTS: Forty children had at least one parent that was descending of founder families. Among these, 35% had SLI. Eighth five percent of SLI affected children came from the same colonizer family. CONCLUSIONS: The prevalence of SLI in Robinson Crusoe Island is higher than that reported in mainland Chile and abroad. This high prevalence, associated to a high frequency of consanguinity, supports the influence of genetic mechanisms in SLI transmission, based on a founder effect.

Alta prevalencia de trastorno específico de lenguaje en isla Robinson Crusoe y probable efecto fundador / High prevalence of specific language impairment in Robinson Crusoe Island. A possible founder effect

Specific language impairment (SLI) occurs in 2 percent to 8 percent of preschool children. Major and candidate genes are probably involved. Genetic drift is a cause for the presence of high frequencies of deleterious alíeles of a specific disease and the founder effect is one of its forms. Robinson Crusoe Island has 633 inhabitants and its actual population began with 8 families that repopulated the island at the end ofXIXth century. Aim To assess the frequency of specific language impairment among children living in Robinson Crusoe Island. Material and methods: All 66 children aged between 3 and 9 years living in the island, were studied. Parents were interviewed and in children, non verbal intelligence, audiometric parameters, comprehension and expression of oral language were assessed. Extended genealogies were also performed. Results: Forty children had at least one parent that was descending of founder families. Among these, 35 percent had SLI. Eighth five percent of SLI affected children came from the same colonizer family. Conclusions: The prevalence of SLI in Robinson Crusoe Island is higher than that reponed in mainland Chile and abroad. This high prevalence, associated to a high frequency of consanguinity, supports the influence of genetic mechanisms in SLI transmission, based on a founder effect.

Modificaciones en la articulación de fones en pacientes con aparato ortodóncico fijo lingual / Speech changes in lingual orthodontic appliances patients

OBJETIVO: el presente trabajo pretende evaluar el efecto de los aparatos ortodóncicos fijos linguales en la articulación de los fones, en pacientes que hablen español chileno, y la adaptación a estos efectos dentro del primer mes de uso de los aparatos. MÉTODOS: la muestra consistió en 13 pacientes que acudieron para instalación de aparato ortodóncico fijo lingual. Se realizó un examen fonoarticulatorio en condiciones estandarizadas, en 5 momentos diferentes: previo a la instalación de los aparatos fijos (E0), inmediatamente después de realizada esta (E1), a las 24 horas posteriores (E2), a los 7 días (E3) y un mes después de la instalación (E4). Se determinaron los fones afectados en los distintos momentos de examen respecto a la línea base dada por el examen previo, y se analizó su resolución. RESULTADOS: se observaron cambios significativos en el punto de articulación de los fones [d], [s] y [r] Los fones [d] y [s] mostraron una resolución favorable dentro del primer mes de uso de los aparatos. El fone vibrante múltiple [r] no mostró una recuperación de la alteración una vez cumplido un mes de uso de los aparatos ortodóncicos. CONCLUSIONES: la instalación de aparato ortodóncico fijo lingual produce modificaciones en el punto de articulación de los fones consonánticos, las cuales tienden a mejorar dentro del primer mes de uso de los aparatos, con excepción del fone vibrante múltiple [r].

PURPOSE: this study evaluated the effect of lingual orthodontics appliances on speech performance in native Chilean spanish speakers, and their adaptation to these effects during the first month. METHODS: phone production was recorded in a standardized test, in 13 patients with lingual orthodontic brackets, in 5 different times: before (E0), immediately after (E1), within 24 hours after (E2), within 7 days after (E3) and 1 month after (E4) the placement of fixed orthodontic lingual appliances, for assessment by speech professionals. RESULTS: statistically significant changes were observed in the articulation of [d], [s] and [r] phones. Sounds [d] and [s] showed an improvement within first month of use of the appliances. Phone alveolar vibrant [r] did not show a significant reduce of sound impairment performance. CONCLUSION: lingual appliances placement induce impairment in sound performance but these changes show an improvement within the first month of use, with exception of alveolar vibrant [r] phone.

Parámetros de estética facial y gradiente sociogenético en niños chilenos / Facial esthetics and sociogenetic gradient parameters in chilean children

Objetivo: determinar valores antropométricos de estética facial de niños de 5 y 8 años de edad, concaracterísticas físicas y oclusales normales, pertenecientes a diferentes grupos sociogenéticos deSantiago de Chile, debido a que es un país con marcada mezcla indígena, y compararlos entre sísegún sexo y estrato para cada grupo etáreo y con los valores norteamericanos utilizados internacionalmentepublicados por Farkas. Metodos: se realizó un análisis facial basado en Arnett y Farkas,utilizando fotografía digital apoyada por examen clínico, en cuatro muestras, clasificadas según denticióny estrato. Resultados: no existen diferencias entre sexo ni estrato en Chile, ni tampoco cuando estasson comparadas con las medidas norteamericanas. Conclusiones: las mediciones antropométricasfaciales determinadas para los distintos grupos sociogenéticos en Santiago Chile no difieren entre sini con las publicadas por Farkas, por lo que estas pueden ser utilizadas en la clínica en Santiago conpoblaciones étnicamente mixtas.

Purpose: to compare anthropometric measurements of facial esthetics in 5 and 8 years old children,with normal physical and occlusal characteristics, belonging to different sociogenetic groups fromSantiago de Chile (mixed ethnic population); and with north American Caucasian parameters publishedby Farkas. Methods: a facial analysis based on Arnett and Farkas was carried out, using digitalphotography supported by a clinical examination, in four samples, according to the dentition andsociogenetic stratum. Results: the results show no differences in Chile according to sex and stratum,neither with Caucasian measurements. Conclusion: the anthropometric measurements of facialaesthetics in sociogenetic groups from Santiago are not different with Farkas Caucasian measurementsand can be used for clinical purposes in mixed ethnically Chilean populations.

Aprendizaje basado en problemas: un enfoque innovador en el currículo de fonoaudiología / Problem based learning: an innovative approach in a speech, language and hearing science curricula

El aprendizaje basado en problemas (ABP) surgió hace 20 años como respuesta al sistema de educación basado en clases magistrales o en casos clínicos. El uso de ABP es cada vez más frecuente en la enseñanza de profesiones de la salud y otras disciplinas. Se realiza una introducción al Programa de ABP, la descripción y evaluación de su aplicación en la División de Ciencia de la Audición y el Lenguaje de la Universidad de Hong Kong al currículo de pre grado de Fonoaudiología. Se discute el desarrollo y puesta en marcha del plan, importancia del trabajo independiente, rol del tutor, del grupo y una integración entre objetivos, problemas y evaluaciones. Se comenta la utilidad del ABP y su eventual implementación en el programa de la Escuela de Fonoaudiología de la Universidad de Chile.

Electromiografía en músculos infrahioídeos: una visión fonoaudiológica / Electromyography in infrahyoid muscles: a phonoaudiological vision

El presente artículo es una revisión bibliográfica acerca de la participación de la musculatura infrahioídea en diversas actividades motoras relacionadas con la producción de la voz, el habla y la deglución. Se revisa la técnica de la electromiografía (EMG) en este grupo muscular y se relaciona la información que aporta para la actividad clínica fonoaudiológica. Se discute la utilidad que implica conocer la fisiología de la musculatura infrahioídea mediante le procedimiento de la EMG para optimizar la rehabilitación de los trastornos de la voz, el habla y la deglución en lo relativo a la evaluación y a la terapia.

Bases genéticas del trastorno específico del lenguaje / Genetic basis of specific language disorder

El propósito del presente trabajo es ofrecer una revisión de la evidencia existente sobre las bases genéticas del trastorno específico del lenguaje (TEL). Estudios de afiliación, de comparación en mellizos monocigóticos y dicigóticos con TEL, y de genealogía indican que esta condición presenta una alta heredabilidad o transmisión genética. Además, estudios de ligamiento y análisis molecular aportan evidencia sobre la localización de algunos genes involucrados en la condición. Regiones de los cromosomas 7,13,16 y 19 parecen ser los mejores candidatos. Estos últimos hallazgos han sido posibles gracias a avances en el diagnóstico del TEL. El mejor criterio parece ser la búsqueda de marcadores fenotípicos o indicadores clínicos precisos del TEL. De acuerdo con lo anterior, se discuten las proyecciones de los hallazgos señalados.

Expansión palatina rápida y respiración bucal / Rapid maxillary expansion and oral breathing

Publicaciones muy antiguas ya habían señalado que la respiración bucal se relaciona con la presencia de adenoides o compresiones maxilares con sus numerosas implicancias clínicas. La expansión palatina rápida (EPR), es una terapia muy utilizada en ortodoncia como tratamiento de compresiones maxilares severas. Se ha descrito que muchos de los problemas causados por la respiración bucal se revierten si la compresión se corrige, debido al crecimiento craneofacial, por lo que el momento oportuno para el tratamiento es importante. Este estudio determina la condición clínica en 15 pacientes con compresiones maxilares, sometidos al tratamiento de expansión palatina rápida. A cada paciente se les aplicó el test de Rosenthal para determinar su permeabiloidad nasal, se hicieron mediciones cefalométricas y sus padres contestaron una encuesta referida a sus hábitos respiratorios, previo y posteriormente al tratamiento de 3 meses. Se observó un significativo crecimiento transversal, especialmente de la zona anterior del maxilar. Este cambio esqueletal permitió un significativo aumento de la permeabilidad nasal en todos los pacientes, tanto en la evolución con el test de Rosenthal como en la apreciación de sus padres. Estos resultados señalan que la expansión palatina rápida mejora la permeabilidad nasal de los individuos con comprensión maxilar, respaldando el tratamiento multidisciplinario de estos pacientes

Efecto del tipo respiratorio y la posición corporal en la actividad electromiográfica de los músculos cervicales / The effect of respiratory mode and body posture on the electromiographic activity of cervical muscles

El propósito de este estudio fue comparar la actividad electromiográfica (EMG) de los músculos Esternocleidemastoideo y trapecio entre individuos con respiración de tipo diafragmático y tipo costal, durante la inspiración en reposo, en las posiciones de pie y sentada. Se seleccionaron 20 sujetos jóvenes adultos, mediante la utilización de una ficha ad-hoc y examen clínico fonoaudiológico y odontológico, los cuales fueron divididos en dos grupos: Grupo estudio o tipo respiratorio costal, constituido por 9 individuos (promedio de 21,4 años); Grupo Control o tipo respiratorio diafragmático, constituido por 11 individuos (promedio de 22,6 años). Se registró la actividad EMG de los músculos Esternocleidomastoideo y trapecio izquierdo, utilizando electrodos de superficie mediante técnica bipolar, en las posiciones sentada y de pie en reposo. En la posición sentada no se observaron diferencias significativas en la actividad EMG entre los tipos respiratorios costal y diafragmático (p > 0.05). En la posición de pie, se observó una significativa mayor actividad EMG en ambos músculos, en los sujetos con tipo respiratorio costal en comparación con los sujetos con tipo respiratorio diafragmático (p < 0.05). Este hallazgo podría ser de gran importancia clínica debido a que una hiperactividad crónica de los músculos cervicales puede determinar espasmos ante situaciones de stress y patrones de dolor referido en la unidad cráneo-cérvico-facial