Development and growth of median structures in the human tongue: A histological study using human fetuses and adult cadavers.

Glossectomy is a surgical procedure performed to remove all or part of the tongue in patients with cancer. The removal of a significant part of the tongue has a marked effect on speech and swallowing function, as patients may lose not only the tongue muscles but also the median lingual septum (MLS). Therefore, to achieve successful tongue regeneration, it is necessary to investigate the developmental processes of not only the tongue muscles but also the MLS. This study was conducted to clarify the mutual development of the tongue muscles and the MLS in human fetuses. Serial or semi-serial histological sections from 37 embryos and fetuses (aged 5-39 weeks) as well as nine adults were analyzed. The MLS appeared at Carnegie stage 15 (CS15), and until 12 weeks of gestation, abundant fibers of the intrinsic transverse muscle crossed the septum in the entire tongue. However, in near-term fetuses and adults, the contralaterally extending muscles were restricted to the deepest layer just above the genioglossus muscle. This finding indicates that the crossing transverse muscle showed the highest density at mid-term. A thorough understanding of both the MLS and the tongue muscles is necessary for successful tongue regeneration.

Assessing Mode-Switching Strategies for Assistive Robotic Manipulators Using a Preliminary Version of the Novel Non-invasive Tongue-Computer Interface.

The inductive tongue-computer interface allows individuals with tetraplegia to control assistive devices. However, controlling assistive robotic arms often requires more than 14 different commands, which cannot always fit into a single control layout. Previous studies have separated the commands into modes, but few have investigated strategies to switch between them. In this feasibility study, we compare the efficiency of switching modes using buttons, swipe gestures and double taps using a preliminary version of a new non-invasive mouthpiece unit (nMPU), which includes an integrated activation unit and a single sensor board. Three participants controlled a JACO assistive robot to pick up a bottle using different mode-switching strategies. Compared with switching modes with buttons, switching modes with swipes and double taps increased the task completion time by 21% and 58% respectively. Therefore, we recommend that configurations with multiple modes for the non-invasive tongue-computer interface include buttons for mode-switching.Clinical relevance- Cumbersome mode-switching strategies can lower a control interface's responsiveness and contribute to end-user abandonment of assistive technologies. This study showed that using buttons to switch modes is more reliable. Moreover, this study will inform the development of future control layouts with improved usability.

[Conspicuous Conditions of the Tongue: Normal Variants vs. Pathological Findings].

INTRODUCTION: With its sensitivity, taste buds and complex anatomical structure of various muscles, the tongue is a central organ for speaking, tasting and food intake, especially oral food transport, chewing and swallowing. Changes in the tongue 's condition are frequent and often lead to uncertainty among patients and eventually to a visit to the family doctor, to the ear, nose and throat specialist, dentist or maxillofacial surgeon. The question whether the condition of the tongue is a lesion requiring treatment or just a variant can quite often prove a major challenge. The differential diagnoses are wide-ranging from harmless changes to alarming signs of disease. The time and duration of occurrence, the accompanying symptoms such as a burning sensation or taste disorders as well as risk factors such as nicotine and alcohol consumption are important anamnestic elements. Possible causes can be malnutrition, systemic diseases, inflammatory processes or malignancies. Accordingly, a blood test and a smear or a biopsy may be necessary as the first diagnostic step. The aim of this review is to explain the different types and causes of tongue problems and to explain in which cases further clarifications are necessary.

Radiation induced changes in profibrotic markers in the submental muscles and their correlation with tongue movement.

Swallowing impairment is a major complication of radiation treatment for oropharyngeal cancers. Developing targeted therapies that improve swallowing outcomes relies on an understanding of the mechanisms that influence motor function after radiation treatment. The purpose of this study was to determine whether there is a correlation between radiation induced changes in tongue movement and structural changes in irradiated submental muscles, as well as assess other possible causes for dysfunction. We hypothesized that a clinically relevant total radiation dose to the submental muscles would result in: a) quantifiable changes in tongue strength and displacement during drinking two months post treatment; and b) a profibrotic response and/or fiber type transition in the irradiated tissue. Sprague-Dawley adult male rats received radiation to the submental muscles at total dose-volumes known to provoke dysphagia in humans. A clinical linear accelerator administered 8 fractions of 8Gy for a total of 64Gy. Comparisons were made to sham-treated rats that received anesthesia only. Swallowing function was assessed using videofluoroscopy and tongue strength was analyzed via force lickometer. TGFß1 expression was analyzed via ELISA. The amount of total collagen was analyzed by picrosirius red staining. Immunofluorescence was used to assess fiber type composition and size. Significant changes in licking function during drinking were observed at two months post treatment, including a slower lick rate and reduced tongue protrusion during licking. In the mylohyoid muscle, significant increases in TGFß1 protein expression were found post radiation. Significant increases in the percentage of collagen content were observed in the irradiated geniohyoid muscle. No changes in fiber type expression were observed. Results indicate a profibrotic transition within the irradiated swallowing muscles that contributes to tongue dysfunction post-radiation treatment.

The Physiological Function of Deglutition and Swallowing in Patients With Maxillary Protrusion After Mandibular Advancement.

The objective of this study was to determine the tongue-palatal contact changes in patients with skeletal maxillary protrusion after sagittal split ramus osteotomy (SSRO) during swallowing. In this study, 15 patients with maxillary protrusion and 10 normal subjects participated. Before and 3 months after surgery, tongue-palatal contact patterns during swallowing of patients with maxillary protrusion as well as controls were evaluated by electropalatography. The electrode contact number in the alveolar, palatal, and velar parts was examined. The swallowing duration of each phase was also evaluated. In the lateral area of the velar part, incomplete electrode contact was shown at 0.3 seconds in patients with maxillary protrusion. The electrode contact number in the velar part at 0.3 seconds before tongue-palatal complete contact was significantly less in the preoperative patients compared with the controls ( P < 0.05). A small increase in the electrode contact number of the velar part was shown in the postoperative patients at 0.3 and 0.2 seconds before tongue-palatal complete contact ( P < 0.05). The pharyngeal phase duration was significantly larger in the patients with maxillary protrusion before SSRO compared with the controls ( P < 0.05). After SSRO, the pharyngeal phase duration was significantly shortened. It was shown that the tongue-palatal contact pattern during swallowing in patients with maxillary protrusion improved after orthognathic surgery, and the pharyngeal phase duration was also shortened. It is suggested that the changes in the mesiodistal mandibular position by orthognathic surgery can improve tongue posture and movement during swallowing.

Beyond the boundaries of compartmental hemiglossectomy: a proposal for an anatomically based classification of surgical approaches to advanced oral tongue squamous cell carcinoma.

INTRODUCTION: In the last decade, compartmental surgery (CTS) has been the surgical approach of choice for advanced tumors of the tongue and oral floor. METHODS: Advanced tumors (cT3-T4) oral tongue squamous cell carcinoma (OTSCC) may extend beyond the lingual septum and involve the contralateral hemitongue, developing along the intrinsic transverse muscle. The disease may then involve the genioglossus muscle and, more laterally, the hyoglossus muscle. RESULTS: The surgical approach to the contralateral tongue must be guided by anatomic and anatomopathological principles to achieve a safe oncological resection based on the principles of CTS. CONCLUSION: We propose a schematic classification of glossectomies that extend to the contralateral hemitongue based on the anatomy and pathways of tumor spread.

Optogenetic activation of the tongue in spontaneously breathing mice.

Inadequate tongue muscle activation contributes to dysarthria, dysphagia, and obstructive sleep apnea. Thus, treatments which increase tongue muscle activity have potential clinical benefit. We hypothesized that lingual injection of an adeno-associated virus (AAV) encoding channelrhodopsin-2 (ChR2) would enable light-induced activation of tongue motor units during spontaneous breathing. An AAV serotype 9 vector (pACAGW-ChR2-Venus-AAV9, 8.29 × 1011 vg) was injected to the posterior tongue in adult C57BL/6J mice. After 12 weeks, mice were anesthetized and posterior tongue electromyographic (EMG) activity was recorded during spontaneous breathing; a light source was positioned near the injection site. Light-evoked EMG responses increased with the intensity and duration of pulses. Stimulus trains (250 ms) evoked EMG bursts that were comparable to endogenous (inspiratory) tongue muscle activation. Histology confirmed lingual myofiber transgene expression. We conclude that intralingual AAV9-ChR2 delivery enables light evoked lingual EMG activity. These proof-of-concept studies lay the groundwork for clinical application of this novel approach to lingual therapeutics.

Association between sarcopenia and oral functions in community-dwelling older adults: A cross-sectional study.

BACKGROUND: Few studies have examined the state of oral function in older adults with sarcopenia. We assessed the oral functions of community-dwelling older adults with sarcopenia from multiple perspectives to clarify their potentially low oral function. METHODS: A total of 1517 (86.2%; 990 women, 527 men; mean age 76.1 ± 7.6 years) participants were included in this study. Grip strength, gait speed and skeletal muscle mass index were assessed, and sarcopenia was evaluated according to the criteria of the Asian Working Group for Sarcopenia 2019. The degree of tongue coating, oral moisture, occlusal force, tongue-lip motor function, tongue pressure, masticatory function and swallowing function were assessed. The criteria for oral hypofunction (a disease that is a combination of multiple low oral functions) were used to assess oral function. Statistical analyses were performed using Kolmogorov-Smirnov test, unpaired t-test, Mann-Whitney U test, χ2 test, and univariate and multivariable logistic regression analyses, with each oral function as the dependent variable and sarcopenia as one of the independent variables. The significance level was set at P < 0.05. RESULTS: The prevalence rates of sarcopenia and severe sarcopenia were 14.2% and 3.8%, respectively. The prevalence of oral hypofunction was 39.9%. Compared with the robust group, the sarcopenia and severe sarcopenia groups tended to have a higher frequency of the following components (all P < 0.01): low occlusal force, low tongue-lip motor function, low tongue pressure, low masticatory function, low swallowing function and oral hypofunction. Univariate logistic regression analysis showed that sarcopenia was associated with low occlusal force, low tongue-lip motor function, low tongue pressure, low masticatory function, low swallowing function and oral hypofunction. The odds ratios and 95% confidence intervals of sarcopenia for each oral function were 2.62 [2.00, 3.43], 2.21 [1.69, 2.89], 3.66 [2.79, 4.81], 3.23 [2.46, 4.25], 1.66 [1.26, 2.20] and 3.59 [2.72, 4.72], respectively. Multivariable logistic regression analysis showed that sarcopenia was associated with low occlusal force (1.63 [1.10, 2.40]), low tongue pressure (2.28 [1.65, 3.15]), low masticatory function, (1.94 [1.27, 2.97]), low swallowing function (1.64 [1.17, 2.28]) and oral hypofunction (2.17 [1.52, 3.09]). CONCLUSIONS: This study demonstrated that multiple aspects of oral function were low among community-dwelling older adults with sarcopenia. The potential decline in oral functions in older adults with sarcopenia may have been overlooked until now. This study indicates the need for dental perspectives in intervening with older adults with sarcopenia and the need to encourage them to see dental professionals.

Oral Dysfunction in Patients with Oral Cancer Could Occur Before Treatment and Require Early Nutritional Improvement: A Cross-Sectional Study.

Patients with oral cancer have poor nutritional status before treatment. However, there have been no reports of the detailed evaluation of preoperative oral function in patients with oral squamous cell carcinoma (OSCC). Therefore, this study aimed to evaluate the preoperative oral function of patients with OSCC and examine the relationship with nutritional status. Oral function measurements (microorganisms, oral dryness, occlusal force, tongue pressure, masticatory function, Eating Assessment Tool, and Postoperative Oral Dysfunction Scale) and Mini Nutritional Assessment-Short Form (MNA-SF) data were collected from 51 patients with OSCC (men: 37, women: 14, mean age: 72.1 years) who visited the Shimane University Hospital, Department of Oral and Maxillofacial Surgery, from September 2019 to September 2021. The tongue was the most prevalent primary gingiva site [22 patients (43.1%)], and 36 patients (70.6%) had advanced cancer. Comparisons between nutritional status and each related factor revealed significant differences in the number of individuals in the household, cancer stage, presence of pulmonary disease, number of teeth, microorganisms (grade), and masticatory function (mg/dL) (p < 0.05). Multiple regression analysis using the total MNA-SF score as the dependent variable with adjustment for confounding factors showed significant association between oral dryness and tongue pressure (p < 0.05). No significant association was found for the Eating Assessment Tool or Postoperative Oral Dysfunction scale. Patients with OSCC may have decreased oral function because of the tumor at the time of diagnosis, which causes a decline in nutritional status. Preoperative interventions are necessary to improve nutrition based on the state of oral function.

Identificação perceptiva do posicionamento da língua na produção de [s] por acadêmicos em Fonoaudiologia / Identificación perceptiva del posicionamiento de la lengua de la producción de [s] por académicos en Fonoaudiología / Perceptual analysis of the tongue position in the production of [s] by SLP students

Introdução: a identificação visual do posicionamento dos articuladores e o resultado auditivo na produção de [s] são necessários para decisões clínicas e monitoramento de tratamento. Para avaliadores não treinados esta tarefa pode ser desafiadora. Objetivo: verificar se avaliadores não treinados são capazes de identificar visualmente posições normal e alterada da língua na produção do [s] e perceber, auditivamente, produções normais e alteradas; bem como buscar quais ajustes da língua são mais difíceis de serem percebidos visualmente e quais resultados auditivos são mais facilmente identificados. Método: dez acadêmicos de Fonoaudiologia analisaram 20 amostras de fala gravadas, 10 com produção normal e 10 alterada do fone [s], sendo as respostas comparadas a uma avaliação padrão-ouro. Na análise foi utilizada a concordância Kappa, o teste Qui-quadrado, o Anova de Medidas repetidas e o teste t Student, com 5% de significância. Resultados: houve associação e concordância com a avaliação padrão-ouro para a posição da língua, com porcentagem média de 40% de respostas corretas para a posição normal, 17,5% quando a língua estava contra os dentes e 10% quando interposta. No resultado auditivo, a maioria dos avaliadores não apresentou associação e concordância com o padrão-ouro, sendo a porcentagem média de 50% de respostas corretas na ausência de distorção e com redução significativa quando presente (18,5%). Conclusão: os acadêmicos tiveram dificuldade na identificação visual da posição da língua, particularmente, quando alterada, bem como na identificação auditiva das produções normal ou alterada, sendo maior quando a distorção estava presente.

Introduction: thevisual identification of articulator positioning and auditory perception in the phoneme [s] are needed for clinical decisions and treatment monitoring. This can be challenging for untrained evaluators. Objective: to verify whether untrained evaluators are able to visually identify typical and atypical tongue positions in the production of phoneme [s] and to auditorily perceive typical and atypical productions; as well as to understand which tongue adjustments are more difficult to be visually perceived and which auditory productions are more easily identified. Methods: ten speech-language pathology students analyzed 20 recorded speech samples, being 10 with typical speech production and 10 atypical speech production regarding the [s] movement, and the answers were compared with a gold-standard evaluation. The Kappa agreement, Chi-squared test, Anova repeated measures and Student ́s t-test were used with 5% of significance. Results: there was an association and agreement with the gold standard evaluation for tongue positioning, with a mean percentage of 40% for correct answers regarding typical position, 17.5% when the tongue was against the teeth and 10% when interposed. In the auditory perception; most evaluators did not show association and agreement with the gold standard evaluation, with an average percentage of 50% for correct answers in the absence of distortion and a significant reduction in the presence (18.5%). Conclusion: the students had difficulty in the visual identification of the tongue positioning for atypical speech productions, as well as in the auditory identification of typical or atypical productions, and the greater difficulty occurred when there was distortion.

Introducción: identificar visualmente el posicionamiento del articulador y el resultado auditivo en la producción del [s] son necesarios para tomar decisiones clínicas y monitorear el tratamiento. Objetivo:verificar si los evaluadores no capacitados pueden identificar visualmente las posiciones normales y alteradas de la lengua en la producción del [s] y percibir auditivamente las producciones normales y alteradas; además buscar qué ajustes de la lengua son más difíciles de percibir visualmente y qué resultados auditivos se identifican más fácilmente. Método: estudiantes de Fonoaudiología analizaron 20 muestras de habla grabadas, 10 con producción normal y 10 con producción del fono [s] alterado. Compararon las respuestas con una evaluación patrón oro. En el análisis utilizaron la concordancia Kappa, la prueba Chi-cuadrado, el Anova de Medidas repetidas y la prueba t de Student, con 5% de significancia. Resultados:hubo asociación y concordancia con la evaluación patrón oro para la posición de la lengua, con media de 40% de respuestas correctas para la posición normal, 17,5% con la lengua contra los dientes y 10% cuando interpuesta. En el resultado auditivo, la mayoría de los evaluadores no presentaron asociación y concordancia con el patrón oro, con media de 50% de aciertos en ausencia de distorsión y con reducción significativa cuando presente (18,5%). Conclusión: los estudiantes tuvieron dificultad en identificar visualmente la posición de la lengua, particularmente cuando alterada, y en la identificación auditiva de producciones normales o alteradas, siendo mayor con la distorsión presente.

Development of inductive sensors for a robotic interface based on noninvasive tongue control.

Tongue based robotic interfaces have shown the potential to control assistive robotic devices developed for individuals with severe disabilities due to spinal cord injury. However, current tongue-robotic interfaces require invasive methods such as piercing to attach an activation unit (AU) to the tongue. A noninvasive tongue interface concept, which used a frame integrated AU instead of a tongue attached AU, was previously proposed. However, there is a need for the development of compact one-piece sensor printed circuit boards (PCBs) to enable activation of all inductive sensors. In this study, we developed and tested four designs of compact one-piece sensor PCBs incorporating inductive sensors for the design of a noninvasive tongue-robotic interface. We measured electrical parameters of the developed sensors to detect activation and compared them with a sensor of the current version of the inductive tongue-computer interface (ITCI) by moving AUs with different contact surfaces at the surface of the sensors. Results showed that, the newly developed inductive sensors had higher and wider activation than the sensor of ITCI and the AU with a flat contact surface had 3.5 - 4 times higher activation than the AU with a spherical contact surface. A higher sensor activation can result in a higher signal to noise ratio and thus a higher AU tracking resolution.

Acute effects of radiation treatment to submental muscles on burrowing and swallowing behaviors in a rat model.

Swallowing impairments are a major complication of radiation treatment for oropharyngeal cancers, influencing oral intake and quality of life. The timing and functional consequences of radiation treatment on the swallowing process is not clearly understood. A rodent radiation injury model was used to investigate the onset of oral and pharyngeal dysfunctions in deglutition related to radiation treatment. This study tested the hypothesis that (Wall et al., 2013) alterations in normal biting, licking, and swallowing performance would be measurable following 64Gy of fractionated radiation to the submental muscles; and (Kotz et al., 2004) radiation will affect the animal's general well-being as measured via burrowing activity. Seven rats received radiation using a clinical linear accelerator given in 8 fractions of 8Gy and another seven animals received sham anesthesia only treatment. Swallowing bolus transit/size was assessed via videofluoroscopy, tongue movement during drinking was measured via an electrical lick sensor, and biting was analyzed from acoustic recordings of a vermicelli pasta test. Burrowing activity was measured by the amount of gravel substrate displaced within a container. Measurements were taken at baseline, during treatment (1-4 weeks), and after completion of treatment (weeks 5 & 6). Decreases in licking frequency and increases in inter-lick interval were observed 5- and 6-weeks post-treatment. Significant decreases in burrowing performance, swallowing frequency, and inter-swallow interval were observed starting the last week of treatment and continuing up to 2-weeks after completion. Results suggest that tongue dysfunction is one of the first treatment related feeding problems to present immediately after the completion of radiation to the submental muscles.

Long latency responses in tongue muscle elicited by various stimulation sites in anesthetized humans - New insights into tongue-related brainstem reflexes.

BACKGROUND: Long Latency Responses (LLR) in tongue muscles are a scarcely described phenomenon, the physiology of which is uncertain. OBJECTIVES: The aim of this exploratory, observational study was to describe tongue-LLR elicited by direct trigeminal nerve (DTNS), dorsal column (DoColS), transcranial electric (TES) and peripheral median nerve (MNS) stimulation in a total of 93 patients undergoing neurosurgical procedures under general anesthesia. METHODS: Bilateral tongue responses were derived concurrently after each of the following stimulations: (1) DTNS applied with single monophasic or train-of-three pulses, ≤5 mA; (2) DoColS applied with a train-of-three pulses, ≤10 mA; (3) TES consisting of an anodal train-of-five stimulation, ≤250 mA; (4) MNS at wrist consisting of single or train-of-three monophasic pulses, ≤50 mA. Polyphasic tongue muscle responses exceeding the latencies of tongue compound muscle action potentials or motor evoked potentials were classified as LLR. RESULTS: Tongue-LLR were evoked from all stimulation sites, with latencies as follows: (1) DTNS: solely ipsilateral 20.2 ± 3.3 msec; (2) DoColS: ipsilateral 25.9 ± 1.6 msec, contralateral 25.1 ± 4.2 msec; (3) TES: contralateral 55.3 ± 10.2 msec, ipsilateral 54.9 ± 12.0 msec; (4) MNS: ipsilateral 37.8 ± 4.7 msec and contralateral 40.3 ± 3.5 msec. CONCLUSION: The tongue muscles are a common efferent in brainstem pathways targeted by trigeminal and cervical sensory fibers. DTNS can elicit the "trigemino-hypoglossal-reflex". For the MNS elicited tongue-LLR, we propose the term "somatosensory-evoked tongue-reflex". Although the origin of the TES related tongue-LLR remains unclear, these data will help to interpret intraoperative tongue recordings.

Methodology for eliciting the brainstem trigeminal-hypoglossal reflex in humans under general anesthesia.

OBJECTIVE: Brainstem trigeminal-hypoglossal reflexes (THRs), also known as the jaw-tongue reflexes, coordinate the position of the tongue in the mouth in relation to the jaw movement during oromotor behaviors such as mastication, swallowing, vocalization, and breathing. Their use in brainstem surgery however, has never been assessed in spite of its potential benefit possibly due to the lack of a methodology to elicit these reflexes under general anesthesia. METHODS: We proposed a technique to elicit the THRs during total intravenous anesthesia (TIVA) consisting on a V3 infrazygomatic train stimulation paradigm and recording from the Styloglossus (31 patients) and the Genioglossus (21 patients) muscles to elicit long latency responses. RESULTS: The THR was successfully recorded using the V3 stimulation point in 82.1% of patients, of which 96.9% presented a response on the Styloglossus muscle (Jaw-opening reflex) while 0.06% presented a response on the Genioglossus muscle instead (Jaw-closing reflex). CONCLUSIONS: The THRs can be successfully recorded in surgery under general anaesthesia with the predominant reflex seen being the jaw-opening reflex. SIGNIFICANCE: We provide a novel method to elicit the THRs during general anesthesia, which could be of aid in brainstem surgery.

Personalized biomechanical tongue models based on diffusion-weighted MRI and validated using optical tracking of range of motion.

For advanced tongue cancer, the choice between surgery and organ-sparing treatment is often dependent on the expected loss of tongue functionality after treatment. Biomechanical models might assist in this choice by simulating the post-treatment function loss. However, this function loss varies between patients and should, therefore, be predicted for each patient individually. In the present study, the goal was to better predict the postoperative range of motion (ROM) of the tongue by personalizing biomechanical models using diffusion-weighted MRI and constrained spherical deconvolution reconstructions of tongue muscle architecture. Diffusion-weighted MRI scans of ten healthy volunteers were obtained to reconstruct their tongue musculature, which were subsequently registered to a previously described population average or atlas. Using the displacement fields obtained from the registration, the segmented muscle fiber tracks from the atlas were morphed back to create personalized muscle fiber tracks. Finite element models were created from the fiber tracks of the atlas and those of the individual tongues. Via inverse simulation of a protruding, downward, left and right movement, the ROM of the tongue was predicted. This prediction was compared to the ROM measured with a 3D camera. It was demonstrated that biomechanical models with personalized muscles bundles are better in approaching the measured ROM than a generic model. However, to achieve this result a correction factor was needed to compensate for the small magnitude of motion of the model. Future versions of these models may have the potential to improve the estimation of function loss after treatment for advanced tongue cancer.

Cross motor innervation of the hypoglossal nerve-a pilot study of predictors for successful opening of the soft palate.

PURPOSE: Selective hypoglossal nerve stimulation has proven to be a successful treatment option in patients with obstructive sleep apnea. The aim of this pilot study was to investigate if there is a cross-innervation of the hypoglossal nerve in humans and if patients with this phenotype show a different response to hypoglossal nerve stimulation compared to those with ipsilateral-only innervation METHODS: Nineteen patients who previously received a selective hypoglossal nerve stimulation system (Inspire Medical Systems, Golden Valley, USA) were implanted with a nerve integrity system placing electrodes on both sides of the tongue. Tongue motions were recorded one and two months after surgery from transoral and transnasal views. Polysomnography (PSG) was also performed at two months. Electromyogram (EMG) signals and tongue motions after activation were compared with PSG findings. RESULTS: Cross-innervation showed significant correlation with bilateral tongue movement and bilateral tongue base opening, which were associated with better PSG outcomes. CONCLUSION: Cross motor innervation of the hypoglossal nerve occurs in approximately 50% of humans, which is associated with a positive effect on PSG outcomes. Bilateral stimulation of the hypoglossal nerve may be a solution for non-responding patients with pronounced collapse at the soft palate during drug-induced sleep endoscopy.

Compartmental Surgery for Oral Tongue Cancer: Objective and Subjective Functional Evaluation.

OBJECTIVE: To assess functional outcomes in patients treated by compartmental tongue surgery (CTS) and reconstruction for advanced oral tongue/floor-of-mouth cancer. STUDY DESIGN: Retrospective case series. METHODS: A retrospective cohort of patients (n = 48) treated by CTS and free flap reconstruction was prospectively evaluated concerning postoperative functional outcomes at different time points (6 months and 1 year). Swallowing was studied by videonasal endoscopic evaluation (VEES) and videofluoroscopy (VFS), testing various food consistencies and grading the results with the Donzelli scale. Speech articulation, lingual strength, and endurance were studied by phone call and Iowa Oral Performance Instrument (IOPI). Subjective tests (EORTC H&N35 and UWQOL) were administered. RESULTS: After 1 year, VEES showed a Donzelli scale of 67% level 1, 23% level 2, and 10% level 3. Vallecular pouch was present in 81% of patients. VFS showed levels 1, 2, and 3 in 42%, 25%, and 33%, respectively, with liquids (L); 48%, 19%, and 33%, with semi-liquids (SL); and 54%, 33%, and 13%, with semi-solids (SS). Vallecular pouch residue was present in 69% with L, 73% with SL, and 87% with SS. The mean number of words recognized at phone call was 56 of 75 (range, 27-74). IOPI showed a mean tongue strength of 19.2 kPa (range, 0-40), and a mean endurance of 16.2 seconds (range, 0-60). CONCLUSION: CTS does not significantly affect speech. Sub-clinical food aspiration and vallecular pouch are present in a significant proportion of patients, especially when adjuvant treatments are administered. Residual tongue strength is not affected when proper reconstruction is performed. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E176-E183, 2021.

Age and Sex-Dependent ADNP Regulation of Muscle Gene Expression Is Correlated with Motor Behavior: Possible Feedback Mechanism with PACAP.

The activity-dependent neuroprotective protein (ADNP), a double-edged sword, sex-dependently regulates multiple genes and was previously associated with the control of early muscle development and aging. Here we aimed to decipher the involvement of ADNP in versatile muscle gene expression patterns in correlation with motor function throughout life. Using quantitative RT-PCR we showed that Adnp+/- heterozygous deficiency in mice resulted in aberrant gastrocnemius (GC) muscle, tongue and bladder gene expression, which was corrected by the Adnp snippet, drug candidate, NAP (CP201). A significant sexual dichotomy was discovered, coupled to muscle and age-specific gene regulation. As such, Adnp was shown to regulate myosin light chain (Myl) in the gastrocnemius (GC) muscle, the language acquisition gene forkhead box protein P2 (Foxp2) in the tongue and the pituitary-adenylate cyclase activating polypeptide (PACAP) receptor PAC1 mRNA (Adcyap1r1) in the bladder, with PACAP linked to bladder function. A tight age regulation was observed, coupled to an extensive correlation to muscle function (gait analysis), placing ADNP as a muscle-regulating gene/protein.

Coordination between lingual motion and pressure production during dipper/tipper type swallows.

BACKGROUND: Tongue motor biomechanics during swallowing was not fully elucidated due to the technical difficulty. OBJECTIVE: To evaluate the relationship between tongue motion and tongue pressure production by simultaneously measuring tongue motion and tongue pressure during water swallowing. METHODS: In 12 healthy male participants (mean age, 30.8 ± 4.2 years), tongue pressure and tongue motion trajectory during dipper- and tipper-type swallows of 3 mL of water were measured using a sensor sheet system equipped with five sensing points and an electromagnetic articulography, respectively. The temporal correlation between motion of anterior/posterior tongue and tongue pressure production during swallowing was evaluated on the synchronised waveforms. RESULTS: In the dipper-type swallow, a similar up-and-down motion pattern in vertical direction was observed among all participants before tongue pressure production. Those motion patterns were common at the anterior and posterior tongue locations with a temporal difference in some segment of tongue motion. On the other hand, tongue directly attached to hard palate with temporal synchronicity between the anterior and posterior parts. In both types of swallow, a strong temporal correlation was found between the timing of tongue-palate contact and the Onset of tongue pressure by intra-class correlation coefficients. CONCLUSION: From the simultaneous measurement of tongue motion and tongue pressure production, the tongue motion pattern during water swallowing and the temporal correlation between tongue motion and tongue pressure production were elucidated.

Assessment of axonal sprouting and motor performance after hypoglossal-facial end-to-side nerve repair: experimental study in rats.

Hypoglossal-facial nerve anastomosis (HFA) aims to reanimate denervated mimic muscles with hypoglossal axons when the transected facial nerve is not accessible. The aim of this study was to evaluate the recovery of HFA using a "Y" tube in two variants: (1) the proximal stump of the hypoglossal nerve was entubulated to the "Y" tube (classic "Y" tube HFA) and (2) the "Y" tube was sutured to an epineurial window of a slightly damaged hypoglossal nerve (end-to-side "Y" tube HFA). A total of 48 adult female rats were divided into four groups: intact controls (group 1), sham operated (group 2), classic "Y" tube HFA (group 3) and end-to-side "Y" tube HFA (group 4). The abdominal aorta with both common iliac arteries of isogeneic male rats served as the Y-tube conduit. Animals from group 4 recovered better than those from group 3: the degree of collateral axonal branching (3 ± 1%) was significantly lower than that determined in group 3 (13 ± 1%). The mean deviation of the tongue from the midline was significantly smaller in group 4 (6 ± 4°) than that measured in animals from group 3 (41 ± 6°). In the determination of vibrissal motor function in group 3 and group 4, a decrease in amplitude was found to be - 66% and - 92%, respectively. No differences in the reinnervation pattern of the target muscles were detected. As a result, these surgical models were not determined to be able to improve vibrissal movements. It was concluded that performance of end-to-side "Y" tube HFA diminishes collateral axonal branching at the lesion site, which in turn, promotes better recovery of tongue- and vibrissal-motor performance.