Tongue Function Research Articles

Efficacy of soft palatal augmentation prosthesis for oral functional rehabilitation in patients with dysarthria and dysphagia: a protocol for a randomised controlled trial

IntroductionPalatal augmentation prosthesis (PAP) is used in patients with articulation and swallowing disorders caused by postoperative loss of tongue tissue due to tongue cancer, cerebrovascular disease sequelae and age-related hypofunction....

A Strength Endurance Exercise Paradigm Mitigates Deficits in Hypoglossal-Tongue Axis Function, Strength, and Structure in a Rodent Model of Hypoglossal Motor Neuron Degeneration.

The tongue plays a crucial role in the swallowing process, and impairment can lead to dysphagia, particularly in motor neuron diseases (MNDs) resulting in hypoglossal-tongue axis degeneration (e.g., amyotrophic lateral sclerosis and progressive bulbar palsy). This study utilized our previously established inducible rodent model of dysphagia due to targeted degeneration of the hypoglossal-tongue axis. This model was created by injecting cholera toxin B conjugated to saporin (CTB-SAP) into the genioglossus muscle of the tongue base for retrograde transport to the hypoglossal (XII) nucleus via the hypoglossal nerve, which provides the sole motor control of the tongue. Our goal was to investigate the effect of high-repetition/low-resistance tongue exercise on tongue function, strength, and structure in four groups of male rats: (1) control + sham exercise (n = 13); (2) control + exercise (n = 10); (3) CTB-SAP + sham exercise (n = 13); and (4) CTB-SAP + exercise (n = 12). For each group, a custom spout with adjustable lick force requirement for fluid access was placed in the home cage overnight on days 4 and 6 post-tongue injection. For the two sham exercise groups, the lick force requirement was negligible. For the two exercise groups, the lick force requirement was set to ∼40% greater than the maximum voluntary lick force for individual rats. Following exercise exposure, we evaluated the effect on hypoglossal-tongue axis function (via videofluoroscopy), strength (via force-lickometer), and structure [via Magnetic Resonance Imaging (MRI) of the brainstem and tongue in a subset of rats]. Results showed that sham-exercised CTB-SAP rats had significant deficits in lick rate, swallow timing, and lick force. In exercised CTB-SAP rats, lick rate and lick force were preserved; however, swallow timing deficits persisted. MRI revealed corresponding degenerative changes in the hypoglossal-tongue axis that were mitigated by tongue exercise. These collective findings suggest that high-repetition/low-resistance tongue exercise in our model is a safe and effective treatment to prevent/diminish signs of hypoglossal-tongue axis degeneration. The next step is to leverage our rat model to optimize exercise dosing parameters and investigate corresponding treatment mechanisms of action for future translation to MND clinical trials.

Spontaneous Regression of Lymphatic Malformation -A Rare Case of Transient Macroglossia

Lymphatic malformation (LM) is a rare benign proliferation of dilated lymphatic vessels with inappropriate communication, filled with lymphatic fluid and lined by endothelial cells. Its occurrence is rare in the oral cavity; however, inside the oral cavity most common site is anterior two-thirds on the dorsum of the tongue, presenting as macroglossia. Macroglossia compromises the airway, often leads to obstructive sleep apnea, malocclusion, and speech and mastication difficulty. The main objective of tongue LM treatment is to preserve the taste sensation, restoration of the tongue size for articulation and cosmesis. We report a rare case of transient intermittent macroglossia due to LM. The patient presented with painful swelling of the tongue, relative macroglossia. There was spontaneous regression of LM with antibiotics and corticosteroids. LM can grow suddenly due to infection or hemorrhage and can shrink spontaneously. Upon treatment of the infection, there is spontaneous regression, total or partial. Therefore, expectant management should be considered in the treatment of tongue LM, to preserve the functions of tongue.

Tied to the Top: A Case Report on an Isolated Ankyloglossia Superior

ABSTRACT Objective: To report a case of isolated ankyloglossia superior in a one-month-old boy. Methods: Design: Case Report Setting: Tertiary Government Training Hospital Patient: One Results: A one-month-old boy with failure to thrive, feeding difficulties and a palatoglossal band that limited mouth opening and anterior posturing of the tongue was diagnosed to have non-syndromic ankyloglossia superior and underwent surgical transection of the fibrous ankylosis under intravenous sedation due to difficulty of insinuating an endotracheal tube orally. Direct latch breastfeeding was successfully adapted from the second to tenth postoperative day before they were lost to follow up. Conclusion: Despite a complicated pediatric airway, coordinated surgical and anesthesia management successfully restored tongue function and mouth opening to allow effective feeding.

A Case of Schwannoma at Tongue

Schwannoma is a benign peripheral nerve sheath tumor. Although rarely found in the oral cavity, it is most commonly found on the tongue, followed by the palate, palate, buccal mucosa, and mandible. Because schwannoma of the base of the tongue is so rare, it is often not included in the differential diagnosis immediately, delaying identification and treatment. We report a case of schwannoma at the base of the tongue misdiagnosed as lingual thyroid, along with a literature review. A 28-year-old man presented with a tongue mass, which was first discovered a month ago. The preoperative diagnosis was lingual thyroid gland on physical findings and computed tomography findings. The permanent pathological report of the mass was schwannoma. After surgery, the patient had no problems with tongue function and wound healing.

Contribution and safety of the side-to-end hypoglossal-to-facial transfer in multidisciplinary facial reanimation.

This study evaluates facial and tongue function in patients undergoing side-to-end hypoglossal-to-facial transfer (HFT) with additional techniques. Thirty-seven patients underwent a side-to-end HFT. Twelve had additional cross-face grafts, and 9 had an additional masseter-to-facial transfer. Facial was assessed with House-Brackmann (HB), Sunnybrook Facial Grading Scale (SFGS), and eFACE. Martins scale and the Oral-Pharyngeal Disability Index (OPDI) were used to assess tongue function. Ninety-four percent of cases reached HB grades III-IV. Mean total SFGS score improved from 16 ± 15 to 59 ± 11, while total eFACE score from 52 ± 13 to 80 ± 5. Dual nerve transfers were a predictor for a better eFACE total score p=0.034, β=2.350 [95% CI, 0.184-4.516]), as well as for a higher SFGS total score (p=0.036, β=5.412 [95% CI, 0.375-10.449]). All patients had Martin's grade I. Mean postoperative OPDI scores were 84 ± 17 (local physical), 69 ± 16 (simple and sensory motor components), 82 ± 14 (complex functions), and 73 ± 22 (psychosocial). The side-to-end HFT offers predictable facial function outcome and preserves tongue function in nearly all cases. Dual nerve transfers appear to improve the final outcome.

Relationship between Rate of Force Development of Tongue Pressure and Physical Performance.

In the assessment of skeletal muscle strength, rate of force development (RFD) is clinically identified as a functional index that reflects the effects of aging, but there are few reports on RFD of the tongue. The purpose of this study was to examine the relationship between RFD of tongue pressure (RFD-TP) and oral and whole-body physical performance in older adults, and to clarify its characteristics. We enrolled adults aged ≥65 years with pathological occlusal contact in premolar and molar regions of teeth in the Tamba-Sasayama area, Japan, from 2017 to 2018. Maximum tongue pressure (MTP) and the speed to reach the maximum tongue pressure (RFD-TP) were evaluated as measures of tongue function. Oral functions related to objective measures of tongue function, such as repetitive saliva swallowing test, oral diadochokinesis, and physical status or performance, such as mini mental state examination, body mass index, skeletal mass index, knee extension force, one-leg standing time, grip strength, walking speed, timed up-and-go test, and five-time chair stand speed was evaluated. No significant correlation was found between MTP and age, but RFD-TP had a significant negative correlation with age. Neither RFD-TP nor MTP showed a significant correlation with oral function. RFD-TP was associated with physical performance, such as knee extension force and one-leg standing time. RFD-TP is more sensitive to aging than MTP. In addition, RFD-TP is related to physical performance and may be useful for the early detection of frailty.

Colorimetric photonic tongue for metal ions screening

<h2>Summary</h2> Screening of metal ions in body fluid is vital for monitoring human health. Here, inspired by taste-sensing functions of human tongue, we reported a novel colorimetric photonic tongue for multiple metal ions screening by using spherical structural color hydrogel particles (SCHPs) as sensory units. As SCHPs are composed of acrylic acid (AA)-based skeleton, the sensory units could respond to metal ions with color variations like receptors in taste buds. Thus, through analyzing all units' sensory information, a colorimetric "fingerprint" for each metal ion could be obtained in a database. Based on this, we constructed a portable, reusable, and biocompatible device by integrating SCHP arrays into a test-strip microchip for real-time monitoring of metal ions. The target ions could be distinguished by multivariate data analysis for pattern recognition. These features indicated that the proposed photonic tongue is valuable for metal ions screening in biological samples and promising for clinical disease diagnosis.

Facial nerve-sublingual nerve parallel bridge anastomosis for facial nerve injury caused by closed temporal bone fractures

To investigate the effectiveness of facial nerve-sublingual nerve parallel bridge anastomosis for facial nerve injury resulting from closed temporal bone fractures. Between January 2017 and December 2019, 9 patients with facial nerve injury resulting from closed temporal bone fracture caused by head and face trauma were treated. Among them, 5 patients were treated with facial nerve-sublingual nerve parallel bridge anastomosis (operation group), and 4 patients were treated with neurotrophic drugs combined with rehabilitation exercise (conservative group). There was no significant difference in gender, age, side, cause of injury, duration of facial nerve injury before surgery, House-brackmann grading (hereinafter referred to as HB grading) of facial nerve injury, and other general information between 2 groups ( P>0.05). HB grading was used to evaluate the improvement of facial nerve function before and after treatment. At the same time, facial nerve neuroelectrophysiological test was performed to evaluate the electrical activity of facial muscles before and after treatment. Tongue function, atrophy, and tongue deviation were evaluated after nerve anastomosis according to the tongue function scale proposed by Martins et al. Patients in both groups were followed up 12-30 months, with an average of 25 months. None of the 5 patients in the operation group showed symptoms such as tongue muscle atrophy, tongue extension deviation, hypoglossal nerve dysfunction (mainly including slurred speech, choking with water), postoperative infection, bleeding, lower limb muscle atrophy or lower limb motor dysfunction after sural nerve injury. Postoperative skin sensory disturbance in lateral malleolus area was found, but gradually recovered to normal. During the follow-up, facial nerve and sublingual motor neurons were innervated to paralyzed facial muscle in the operation group. At last follow-up, the HB grading of 5 patients in the operation group improved from preoperative grade Ⅴ in 2 cases, grade Ⅵ in 3 cases to grade Ⅱ in 3 cases, grade Ⅲ in 1 case, and grade Ⅳ in 1 case. And in the conservative group, there were 1 patient with grade Ⅴ and 3 patients with grade Ⅵ before operation, facial asymmetry continued during follow-up, and only 2 patients improved from grade Ⅵ to grade Ⅴ at last follow-up. There was significant difference in prognosis HB grading between the two groups ( t=5.693, P=0.001). In the operation group, the amplitude and frequency of F wave were gradually improved, and obvious action potential could be collected when the facial muscle was vigorously contracted. On the contrary, there was no significant difference in neuroelectrophysiological results before and after treatment in the conservative group. Facial nerve-sublingual nerve parallel bridge anastomosis can effectively retain the integrity of the facial nerve, while introducing the double innervation of the sublingual nerve opposite nerve, which is suitable for the treatment of severe incomplete facial nerve injury caused by closed fracture.

Functional comparison of pacifiers using finite element analysis

BackgroundPacifiers have been shown to affect maxillary growth related to the anatomic structure of the palate and forces placed upon it during sucking. This study compares and evaluates the mechanical behavior of pacifiers of different design and size (i.e., fit), identified by brand and size, positioned in age-specific palatal models with respect to both contact area and force when subjected to peristaltic tongue function and intraoral pressure related to non-nutritive sucking.MethodsNonlinear finite element analyses were used to simulate dynamic mechanical interaction between the pacifiers and palates. Time-varying, external pressure loads were applied which represent intraoral pressure arising from non-nutritive sucking and peristaltic behavior of the tongue. The silicone rubber pacifier bulb was represented using a hyperelastic material model.ResultsResults from the finite element analyses include deformation, stress, strain, contact area, and contact force. Mechanical interaction was evaluated in terms of the spatial distribution of the contact area and force between the pacifier and the palate. The resulting palatal interaction profiles were quantitatively compared to assess how pacifier fit specifically affects the support provided to two areas of the palate, the palatal vault and the Tektal wall.ConclusionsPacifiers interact with the palate differently based on their fit (i.e., design and size) regardless of whether they are labeled conventional or orthodontic. Finite element analysis is an effective tool for evaluating how a pacifier’s design affects functional mechanics and for providing guidance on biometric sizing.

Relationship between Dental Occlusion and Maximum Tongue Pressure in Preschool Children Aged 4-6 Years.

Tongue function is regarded as a primary factor in the etiology of malocclusion, but details of the relationship remain unknown. The purpose of the present study was to investigate maximum tongue pressure, in preschool children to examine its relationship with dental occlusion. A total of 477 healthy children (248 boys, 229 girls, aged 4–6 years) were recruited. Dental occlusion was assessed visually to record sagittal, vertical, and transverse malocclusion, and space discrepancies. Maximum tongue pressure was measured using a balloon-based tongue pressure measurement device. Additionally, 72 children (37 boys, 35 girls, aged 4–5 years) were recruited for a 1-year follow-up study. Approximately half of the children (53.5%) showed some type of malocclusion in the present study. Maximum tongue pressure was highest in the 6-year-old children. The results of a two-way ANCOVA show that the effect of age was significant (p < 0.001); however, the effects of sex and dental occlusion, or the interactions among these variables, did not reach significance. Additionally, maximum tongue pressure increased significantly in the 1-year follow-up study (p < 0.001), especially in the normal occlusion group. Maximum tongue pressure increases markedly with growth in the preschool years and can be associated with some types of malocclusion in preschool children.

Comparison of Tongue Characteristics Classified According to Ultrasonographic Features Using a K-Means Clustering Algorithm.

The precise correlations among tongue function and characteristics remain unknown, and no previous studies have attempted machine learning-based classification of tongue ultrasonography findings. This cross-sectional observational study aimed to investigate relationships among tongue characteristics and function by classifying ultrasound images of the tongue using a K-means clustering algorithm. During 2017–2018, 236 healthy older participants (mean age 70.8 ± 5.4 years) were enrolled. The optimal number of clusters determined by the elbow method was 3. After analysis of tongue thickness and echo intensity plots, tongues were classified into three groups. One-way ANOVA was used to compare tongue function, tongue pressure, and oral diadochokinesis for /ta/ and /ka/ in each group. There were significant differences in all tongue functions among the three groups. The worst function was observed in patients with the lowest values for tongue thickness and echo intensity (tongue pressure [P = 0.023], /ta/ [P = 0.007], and /ka/ [P = 0.038]). Our results indicate that ultrasonographic classification of tongue characteristics using K-means clustering may aid clinicians in selecting the appropriate treatment strategy. Indeed, ultrasonography is advantageous in that it provides real-time imaging that is non-invasive, which can improve patient follow-up both in the clinic and at home.

Measurement of ultrasonic echo intensity predicts the mass and strength of the tongue muscles in the elderly.

The purpose of this study was to investigate the relationship between the echo intensity (EI) on ultrasound images of the tongue, tongue thickness, and tongue pressure to examine the effectiveness of EI measurement for assessing the tongue function. A total of 100 elderly outpatients were enrolled. Tongue thickness and EI were measured using ultrasonography. The distance from mylohyoid muscle surface to dorsal surface of the tongue was measured for tongue thickness. Subsequently, this area was vertically divided into four areas: top of tongue dorsal side (DT), bottom of tongue dorsal side (DB), top of basal tongue side (BT), and bottom of basal tongue side (BB), and the EI was measured in each area. The mean EIs of DT and DB were lower than those of BT and BB. In the three areas apart from BB, the EI decreased with an increase in tongue thickness. In particular, a significant correlation between the EI in DB and tongue thickness was found. In all areas, the EI decreased with an increase in tongue pressure. The results of this study suggested that the measurement of EI could be an important indicator for assessing the tongue function in the elderly.

Patients with mild cognitive impairment diagnosed at dementia clinic display decreased maximum occlusal force: a cross-sectional study

BackgroundPrevious research indicates that patients with mild cognitive impairment (MCI) are more likely to have poor oral health and impairments in oral functions, which may be due to few remaining teeth and impaired tongue and lip motor function. However, the oral health of those patients following comprehensive cognitive assessment by a dementia specialist has not been sufficiently investigated. Therefore, this study aimed to clarify the oral function of patients with MCI and the association between oral health and lower cognitive function.MethodsThis cross-sectional study included 96 participants (men: 35; women: 61; mean age: 73.3 ± 8.5 years) who visited a dementia clinic between December 2017 and January 2020. Participants’ cognitive function was assessed by a dementia specialist using neuropsychological and hematological tests and neuroimaging immediately after enrollment. The participants were divided into the healthy and MCI groups according to comprehensive cognitive assessment. Participants’ age, sex, body mass index, primary disease, education level, drinking habits, smoking habits, living environment, employment status, and exercise habits were evaluated. Moreover, oral outcomes, including the number of existing teeth, number of functional teeth (natural and prosthetic teeth which were occluded with antagonists), denture use, oral dryness, tongue and lip motor function, tongue pressure, occlusal force, masticatory ability, and swallowing ability were recorded. The Mann–Whitney U test, χ2, and Fisher’s exact tests were used for between-group comparisons. Furthermore, logistic regression analysis using MCI diagnosis as the target variable was performed.ResultsA comprehensive evaluation of the cognitive function of the study participants by the dementia specialist revealed that 48 participants (mean age: 69.8 ± 8.8 years) were healthy and 48 (mean age: 76.9 ± 6.7 years) had MCI. MCI participants were significantly older (p < 0.001) and had significantly fewer existing teeth (p = 0.031) and lower maximum occlusal force (p = 0.019) than healthy participants. Age (odds ratio: 1.126, p = 0.002) and maximum occlusal force (odds ratio: 0.978, p = 0.048) were significantly associated with lower cognitive function.ConclusionsPatients with MCI had poorer oral health than healthy individuals. Decreased maximum occlusal force was independently associated with lower cognitive function, even when adjusted for age and sex.

Tongue-tie – development, evolution and treatment

Over the past decade, there has been an exponential increase in the number of children diagnosed and treated with ankyloglossia, a condition where the lingual frenulum attaches near the tip of the tongue (anterior tongue-tie) or at the root of the tongue (posterior tongue-tie) and may be short, tight and thick. There have been immense controversies regarding clinical significance of this condition. Recent studies suggest that speech, solid feeding, and sleep difficulties may be linked to restricted tongue function. This article presents the latest evidence on the diagnosis and management of tongue-tie.

Oral diadochokinesis and associated oro-facial function in young and old German mother-tongue speakers: A cross-sectional study.

ObjectivesThe aims of this study were to compare oral diadochokinesis and to test associations with oro‐facial functional parameters in healthy young and old German speakers.BackgroundOral diadochokinesis is a key component in the concept of oro‐facial hypofunction and relates to tongue and lip motor function but may depend on the linguistic background.Materials and methodsHealthy German speakers with a minimum of 20 teeth were recruited to form a young (<60 years) and an older group (≥60 years). Oral diadochokinesis was assessed as the number of repetitions/s for the monosyllables /pa/, /ta/ and /ka/ to evaluate movement capacity of the lip, the anterior region of the tongue and the posterior region of the tongue, respectively. Maximum voluntary lip force, maximum voluntary bite force, masticatory performance, maximum voluntary tongue pressure, xerostomia and swallowing function were assessed with validated instruments. Results are presented as median (IQR).ResultsSixty participants formed the younger group (n = 35, 30.0 years [24.0‐49.0]) and the older group (n = 25, 64.0 years [62.0‐72.0]). Counts/s of /ta/ were different between age groups (younger group: 6.0 vs older group: 5.4) but not for syllables /pa/ (younger group: 6.0 vs older group: 5.8) and /ka/ (younger group: 5.6 vs older group: 5.0). The oral diadochokinesis with /pa/ was overall associated with maximum voluntary lip force; oral diadochokinesis performed with /ta/ was associated with tongue pressure, and oral diadochokinesis with /ka/ with swallowing function. Masticatory performance was not associated with oral diadochokinesis but with maximum voluntary bite force, xerostomia and with maximum voluntary tongue pressure.ConclusionsThe published thresholds for oral diadochokinesis should be reconsidered in non‐Japanese mother‐tongue speakers. However, they still play an important role in the overall concept of oro‐facial functional assessment.

Effect of maximal voluntary tongue pressure and mechanical properties of gels on tongue pressure production when squeezing gels

Soft foods like gels, which are often used as care foods, are usually processed with the tongue (i.e, squeezing) by elderly consumers with chewing difficulty. However, little is known about squeezing, especially the relationship between individual tongue function and squeezing behavior, such as average tongue pressure per squeezing cycle (ATPS) and the number of squeezes until swallowing. The aim of this study was to evaluate squeezing behavior from both the aspects of individual tongue function and the mechanical properties of gels. Fourteen healthy young men were recruited. A 0.1-mm-thick pressure sensor sheet with five measuring points was used to measure tongue pressure when squeezing 5 ml of gels with four different fracture force and strain. Maximal amplitude, duration and area of tongue pressure during squeezing, ATPS, the number of squeezes until swallowing were evaluated. The maximal voluntary tongue pressure (MVTP) was also evaluated. Differences of the tongue pressure when squeezing four gels were statistically analyzed. The relationship between MVTP, ATPS and the number of squeezes were also analyzed. All evaluation items concerning squeezing gels increased as the fracture force increased. MVTP was positively correlated with ATPS and negatively correlated with the number of squeezes. Furthermore, MVTP and the fracture properties of gels were associated with ATPS and the number of squeezes. These results suggest that individual tongue function and the mechanical properties of gels have an influence on the squeezing behavior, and MVTP has potential as a biomarker for selecting care foods that can be safely ingested.

Hydrophilic and opened canals in honey bee tongue rods endow elastic structures with multiple functions

The honey bee (Apis mellifera L.) tongue is a sophisticated and dexterous probing device that can bend and twist, adapting to various surfaces for liquid imbibition and/or gustatory sensing. The tongue exhibits remarkable extendibility, flexibility, and durability, which may be essentially ascribed to the internal elastic rod that supports the entire tongue. However, neither the material composition nor the structural features of the rod, especially a peculiar inner canal that facilitates feeding, have been studied in relation to their function. Herein, by combining a set of imaging techniques, including optical microscopy, high-speed videography, scanning electron microscopy, micro-computed tomography (micro-CT), and confocal laser scanning microscopy, we characterize the spatial morphology, surface wettability and material composition of honey bee tongue rods. By performing mechanical testing, including atomic force microscopy, fracture testing, and finite element analysis, we provide the first evidence that the internal canal of the rod may represent a specialized structure for water retention due to the specific chemistry of resilin, which is an elastomeric protein that dominates the entire rod and renders it highly elastic, compliant and robust. Numerical simulations also suggest that the opening of the canal may facilitate larger deformations in twisting, extending the flexibility of the rod. Statement of significanceThe honey bee is one of the most important pollinators around the world and is capable of foraging a wide spectrum of liquid sources by dipping into them with a miniature hairy tongue. However, there are no direct muscles distributed inside the tongue, instead, there is a conspicuous elastic rod with a hollow core. The rod extends for its full length and, according to our study, structurally reinforces the entire tongue to achieve functional versatility, and suggests a water containing function of the rod canal for maintaining the elasticity of the protein (resilin) that constitutes the rod. Our results broaden understandings of the relationship among morphology, materials science, and function of a honey bee tongue.

Sensorimotor tongue evaluation and rehabilitation in patients with sleep-disordered breathing: a novel approach.

To evaluate tone, apraxia and stereognosis dysfunctions in patients with SDB compared with healthy controls, and to monitor the effectiveness of Airway Gym® as an easy-to-use myofunctional therapy (MT) modality in terms of the tongue's motor and sensory responses, comparing results before and after therapy. This was a prospective, non-randomised pilot study of 25 patients with moderate to severe obstructive sleep apnoea-hypopnoea syndrome (OSAHS), 25 patients with primary snoring (PS) and 20healthy controls. Qualitative and quantitative instruments-Iowa Oral Performance Instrument (IOPI), lingual apraxia and stereognosis tests were used to assess tongue sensorimotor function. 22 patients with PS, 21 with OSAHS and all 20 controls ended the therapy. In OSAHS, the Epworth Sleepiness Scale score decreased from 16±7.3 to 12±4.5 after therapy (p=0.53). In PS and OSAHS groups, the IOPI scores increased significantly. These measures did not change significantly in the controls. Lingual apraxia testing showed that controls performed all the manoeuvres, whereas PS 5.6±1.4 and OSAHS 4.5±1.9 (p=0.14). In the stereognosis test, the mean number of figures recognised was 2.6±2.2 in OSAHS, 3.3±1.2 in PS and 5.7±0.9 in control group (p<0.05). Patients with OSAHS recognised circles and ovals less often. Using the Airway Gym® app produced improvements in sensorimotor tongue function in patients with SDB, due to continuous stimulation of the brain based on proprioceptive training required to localise responses when doing the exercises.

Tongue cleaning in the elderly and its role in the respiratory and swallowing functions: Benefits and medical perspectives.

Oral dysfunction, including oral uncleanness and decline in tongue motor function, tongue pressure and swallowing function, precedes frailty. The tongue's dorsum is a reservoir of oral microbiota, desquamated epithelial mucosa and leukocytes due to the multi-papillate anatomy, and leads to tongue coating. The tongue coating is frequently found in older adults because of hyposalivation, immunity's hypoactivity, diminished motor function and compromised tongue's pressure with age. Anaerobe-driven volatile sulphur compounds in tongue coating are a major cause of intra-oral malodor. Dysbiosis of the tongue-coating microbiome rather than the amount of microorganisms is associated with a risk of aspiration pneumonia. Daily tongue cleaning with a brush or scraper is an easy way to control tongue coating deposits and quality. Using mouth wash or rinse-containing germicides is also a way to control the microbiota of tongue coating. The tongue function is closely related to swallowing. Tongue and suprahyoid muscles are linked with respiratory muscles through the endothoracic fascia. The mechanical stimulation during the cleaning of the tongue may stimulate the respiratory muscles. An intervention trial revealed that tongue cleaning by mucosal brush improves tongue pressure, swallowing and respiratory function in old residents of nursing homes, suggesting a rehabilitative effect of tongue cleaning on the swallowing and respiratory functions, preventing aspiration pneumonia. This narrative review assesses the tongue-cleaning benefits for respiratory and swallowing functions and the possibility of preventing aspiration pneumonia.