Tongue Placement Research Articles

Orofacial Myofunctional Therapy for Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis.

Orofacial myofunctional therapy (OMT) is an alternative form of treatment of obstructive sleep apnea (OSA), that incorporates various exercises to optimize tongue placement and increase oropharyngeal tone. The objective of this systematic review and meta-analysis is to determine the efficacy of OMT in OSA patients. PubMed/Medline, EMBASE, Cochrane, Web of Science. Using PRISMA guidelines, a directed search strategy was performed for randomized control trials (RCTs) published prior to March 24, 2023, featuring 10+ patients with OSA undergoing mono-therapeutic OMT. The primary outcome of interest was apnea-hypopnea index (AHI). Secondary outcomes included subjective sleepiness, sleep-related quality-of-life, and snoring frequency. Of the 1244 abstracts that were identified, 7 RCTs involving 310 patients met inclusion criteria. Adult OMT patients had a statistically significant improvement in AHI (MD -10.2; 95% CI, -15.6, -4.8, p < 0.05), subjective sleepiness (Epworth Sleepiness Scale; MD -5.66; 95% CI, -6.82, -4.5, p < 0.05), sleep-related quality-of-life (Pittsburgh Sleep Quality Index; MD -3.00; 95% CI, -4.52, -1.49, p < 0.05), and minimum oxygen saturation (MD 2.71; 95% CI, 0.23, 5.18, p < 0.05) when compared with sham OMT or no therapy. Within the single RCT featuring pediatric OMT patients, patients had poor compliance (<50%) and did not show any improvements in AHI, minimum oxygen saturation, or snoring frequency. OMT may provide a reasonable alternative for OSA patients who cannot tolerate CPAP or other more established treatment options. OMT benefits appear limited in children due to poor compliance. More studies are required to evaluate compliance and the long-term effects of OMT on OSA outcomes. 1 Laryngoscope, 134:480-495, 2024.

Impacts of Development, Dentofacial Disharmony, and Its Surgical Correction on Speech: A Narrative Review for Dental Professionals.

Speech is a communication method found only in humans that relies on precisely articulated sounds to encode and express thoughts. Anatomical differences in the maxilla, mandible, tooth position, and vocal tract affect tongue placement and broadly influence the patterns of airflow and resonance during speech production. Alterations in these structures can create perceptual distortions in speech known as speech sound disorders (SSDs). As craniofacial development occurs, the vocal tract, jaws, and teeth change in parallel with stages of speech development, from babbling to adult phonation. Alterations from a normal Class 1 dental and skeletal relationship can impact speech. Dentofacial disharmony (DFD) patients have jaw disproportions, with a high prevalence of SSDs, where the severity of malocclusion correlates with the degree of speech distortion. DFD patients often seek orthodontic and orthognathic surgical treatment, but there is limited familiarity among dental providers on the impacts of malocclusion and its correction on speech. We sought to review the interplay between craniofacial and speech development and the impacts of orthodontic and surgical treatment on speech. Shared knowledge can facilitate collaborations between dental specialists and speech pathologists for the proper diagnosis, referral, and treatment of DFD patients with speech pathologies.

Impaired tongue motor control after temporomandibular disorder: A proof-of-concept case-control study of tongue print.

BackgroundTemporomandibular disorder (TMD) perturbs the tongue motor control and consequently impairs oral function, but strength training reduces this impairment. However, tongue motor control is widely reduced to a matter of strength.ObjectivesTo investigate the accuracy of the tongue placement as a measure of tongue motor control in patients with TMD compared with age‐ and sex‐matched healthy participants.Material and MethodsThis proof‐of‐concept case‐control study was prospective, observational, and part of the TMIQ study (NCT04102306). After pointing against a wood stick while maintaining the tongue as sharp as possible, the examinator drew the contour of the tongue print on the wood stick, which was then scanned for image analyses to compute the area for each participant using ImageJ.ResultsA total of 94 participants were included, all patients with TMD (n = 47) diagnosed with myalgia, 61% with intra‐articular joint disorder accordingly to the DC/TMD. The median (IQR) tongue print area was 117 (111) mm2 for the TMD group and 93.5 (76.2) mm2 for the control group (V = 352, p = .04) and the median [95% confidence interval] difference was 25.4 [1.3; 51.0] mm². Overlapping of the 95% confidence intervals of the area evidenced no significant difference between the categories of the DC/TMD. The corrected each area–total correlation (r = .24) suggests a reasonably homogenous thus valid measure.ConclusionThe results suggest that TMD impairs the motor control of the tongue. Therefore, the sharpest tongue pointing test may constitute a simple and accessible clinical tool to assess the accuracy of tongue placement in TMD patients. The study was registered on ClinicalTrial.gov with identification number NCT04102306.

Articulatory and acoustic analysis of voice acting

Voice actors are an under-utilized population for linguistic study. Looking at voice actors' novel productions of typical speech sounds can tell us more about over which muscles we have volitional control. This can help test models of speech production, inform speech therapy, and create better pedagogy for teaching vocal performance. While there have been several studies analyzing the acoustics produced by voice actors (Teshigawara, 2001; 2003; 2004; 2009; 2011; Teshigawara et al., 2007; Uchida, 2007) there are fewer studies that have investigated the articulation of voice acting (Teshigawara &amp; Murano, 2004). This study used acoustic analysis, 3D ultrasound, and electroglottography to investigate the speech produced by six professional and amateur voice actors (2 female, 4 male). Measures of average fundamental frequency (F0) and F0 range were collected from each actor speaking in their regular adult voice and a simulated child voice. 3D ultrasound was used to look at tongue placement and horizontal kymograms of the ultrasound images were also used to infer hyoid bone movement. Additionally, acoustic estimates of vocal tract length were compared to electroglottography measurements of laryngeal raising for two of the subjects. This presentation will describe the within-subject variation across each actor’s adult and simulated child voices.

Optimal design of multi-blade centrifugal fan based on partial coherence analysis

Considering that there are many design variables in multi-blade centrifugal fans, the complicated design parameters and internal flow uncertainty increase the difficulty of studying fan noise mechanisms. This study adopted the impact noise between the airflow at the impeller outlet inside the fan and the volute tongue as the research object. Based on the influence of mutual interfering noise sources on the system noise, a partial coherence function was introduced to establish a system noise model. The correlation between the static pressure of the impeller outlet in the volute tongue area of the centrifugal fan and far-field noise of the fan was analyzed and obtained. The peak values of fundamental frequency and average sound pressure level of a far-field noise receiving points were selected as the optimization goals, taking the volute tongue placement angle θ1, volute tongue radius R, and center distance L1 as the optimization objects. The Latin hypercube sampling was used to select 35 groups of sampling points and a Kriging agent model was established. The NSGA-II genetic algorithm was used to optimize the volute tongue profile. The results showed that the flow rate was increased by 1.2 m3/min, the far field noise of the centrifugal fan was reduced by 1.9 dB, while the fan efficiency increased by 3%, static pressure increased by 27 Pa, and peak values of fundamental frequency reduced by 8%.

EFFICACY OF CAPNOMETRY IN PATIENTS WITH RESPIRATORY DYSFUNCTION

Резюме. Згідно з зарубіжними та вітчизняними джерелами розповсюдженість зубощелепних аномалій у дітей віком 6-9 років сягає 63-80 % у різних регіонах [1, 4]. Потужним етіопатогенетичним чинником виникнення патології є порушення носового типу дихання. Причиною виникнення дисфункції дихальних шляхів нерідко є гіпертрофія піднебінних та глоткових мигдалин чи респіраторні алергози. Перехід від нормального типу дихання до змішаного чи ротового призводить до зміни міодинамічної рівноваги та провокує формування патології прикусу; за наявності інших функціональних порушень відхилення лише посилюються та поглиблюються [2, 11].&#x0D; Метою дослідження є своєчасне та більш детальне вивчення дихальної дисфункції у пацієнтів віком 6-9 років, створення комплексного плану лікування, зменшення термінів лікування, забезпечення більш стабільного результату.&#x0D; Нами було прийнято на лікування 92 дитини віком 6-9 років з дистальним прикусом, пацієнти були розподілені на 2 групи відповідно до проведених методик лікування. В І основну групу увійшли пацієнти, лікування яких проводили за допомогою міофункціональної апаратури; в ІІ – діти, яких лікували за допомогою механічно діючої апаратури.&#x0D; Кожному пацієнту було проведено стандартну ортодонтичну діагностику: збір анамнезу, фотопротокол, виготовлення КДМ, ортопантомограму та запропонований нами метод обстеження – капнометрію. Всі дані були зафіксовані та підкріплені до особистої ортодонтичної картки пацієнта.&#x0D; У ході дослідження ми проводили оцінку проміжних результатів капнометрії та розширеного фотопротоколу. У результаті, відсоток успішного лікування в групі, де корекцію патології проводили за допомогою запропонованої методики, становив 93,5 %, у групі стандартної методики лікування – 86,2 %.

Evaluation of a Wireless Tongue Tracking System on the Identification of Phoneme Landmarks.

Evaluate the accuracy of a tongue tracking system based on the localization of a permanent magnet to generate a baseline of phoneme landmarks. The positional variability of the landmarks provides an indirect measure of the tracking errors to estimate the position of a small tracer attached on the tongue. The creation of a subject-independent (universal) baseline was also attempted for the first time. 2,500 tongue trajectories were collected from 10 subjects tasked to utter 10 repetitions of 25 phonemes. A landmark was identified from each tongue trajectory, and tracking errors were calculated by comparing the distance of each repetition landmark to a final landmark set as their mean position. In the subject-dependent baseline, the tracking errors were found to be generally consistent across all phonemes, and subjects, with less than 25% of the errors reported to be greater than 5.8mm (median: 3.9mm). However, the inter-subject variability showed that current limitations of our system resulted in appreciable errors (median: 55mm, Q3: 65mm). The tracking errors reported in the subject-dependent case demonstrated the potential of our system to generate a baseline of phoneme landmarks. We have identified areas of improvement that will reduce the gap between the subject-dependent, and universal baseline, while lowering tracking errors to be comparable to the gold standard. Creating a baseline of phoneme landmarks can help people affected by speech sound disorders to improve their intelligibility using visual feedback that guides their tongue placement to the proper position.

Children's Consonant Acquisition in 27 Languages: A Cross-Linguistic Review.

The aim of this study was to provide a cross-linguistic review of acquisition of consonant phonemes to inform speech-language pathologists' expectations of children's developmental capacity by (a) identifying characteristics of studies of consonant acquisition, (b) describing general principles of consonant acquisition, and (c) providing case studies for English, Japanese, Korean, and Spanish. A cross-linguistic review was undertaken of 60 articles describing 64 studies of consonant acquisition by 26,007 children from 31 countries in 27 languages: Afrikaans, Arabic, Cantonese, Danish, Dutch, English, French, German, Greek, Haitian Creole, Hebrew, Hungarian, Icelandic, Italian, Jamaican Creole, Japanese, Korean, Malay, Maltese, Mandarin (Putonghua), Portuguese, Setswana (Tswana), Slovenian, Spanish, Swahili, Turkish, and Xhosa. Most studies were cross-sectional and examined single word production. Combining data from 27 languages, most of the world's consonants were acquired by 5;0 years;months old. By 5;0, children produced at least 93% of consonants correctly. Plosives, nasals, and nonpulmonic consonants (e.g., clicks) were acquired earlier than trills, flaps, fricatives, and affricates. Most labial, pharyngeal, and posterior lingual consonants were acquired earlier than consonants with anterior tongue placement. However, there was an interaction between place and manner where plosives and nasals produced with anterior tongue placement were acquired earlier than anterior trills, fricatives, and affricates. Children across the world acquire consonants at a young age. Five-year-old children have acquired most consonants within their ambient language; however, individual variability should be considered. https://doi.org/10.23641/asha.6972857.

Clinico-Statistical Study Concerning the use of Classical Orthodontic Appliances Among Orthodontists

Objective: The purpose of this study was to establish a statistics on the contemporary use of classical mobile orthodontic appliances, anchorage means and certain procedures (functional exercises) among orthodontic specialists. Material and Methods: The present study was based on a questionary comprising 15 questions addressed to 55 postgraduate, specialist and senior orthodontists concernig the use of classical orthodontic methods. The questionary was delivered online by means of Google Forms and intermediated by the National Dentists‘ Association of Tirgu Mures, Romania. The sole inclusion criteria was the specialty of orthodontics. Results: 92,7% of the orthodontists use removable appliances (palatal plate with expansion screw), 90,9 % recommend functional exercises (correct palatal tongue placement), 89,1% exploit space maintainers, 87,3% provide lingual cribs for functional reeducation, 80% apply functional devices and the Goshgarian arch as an anchorage method, 72,2% use the Delaire mask and 69,8% the headgear and 58,2 apply the Hawley plate as a contention mean. Conclusions: A very high percentage of resident, specialist and senior doctors utilize classical removable and functional appliances and methods.

An ultrasound investigation of how accurately people follow tongue movement instructions

In an analytic-linguistic approach to teaching segmental pronunciation and articulatory setting, teachers and voice coaches give explicit instructions on tongue placement and movements. Instructors assume that learners can do exactly as instructed. This assumption was tested in research by Wilson and Horiguchi (2012, PSLLT), who showed that phonetically untrained participants were very poor at following explicit tongue movement instructions. In their study, both the magnitude and direction of movement of the tongue’s centre of gravity were calculated from 2D ultrasound images. However, by only measuring changes in the centre of gravity, it is possible that movements were found to be smaller than they really were, especially if participants focused on the front of the tongue rather than the whole tongue body. In this study, we reanalyzed the original data, this time focusing on the surface of the tongue, rather than the centre of gravity. We made tongue traces using EdgeTrak software (Li et al., 2005), and compared them using a Smoothing-Spline ANOVA method (Davidson, 2006). Results differed from the original study, showing that participants were more conscious of what the front of the tongue was doing rather than the whole tongue body. Implications for segmental pronunciation teaching will be discussed.In an analytic-linguistic approach to teaching segmental pronunciation and articulatory setting, teachers and voice coaches give explicit instructions on tongue placement and movements. Instructors assume that learners can do exactly as instructed. This assumption was tested in research by Wilson and Horiguchi (2012, PSLLT), who showed that phonetically untrained participants were very poor at following explicit tongue movement instructions. In their study, both the magnitude and direction of movement of the tongue’s centre of gravity were calculated from 2D ultrasound images. However, by only measuring changes in the centre of gravity, it is possible that movements were found to be smaller than they really were, especially if participants focused on the front of the tongue rather than the whole tongue body. In this study, we reanalyzed the original data, this time focusing on the surface of the tongue, rather than the centre of gravity. We made tongue traces using EdgeTrak software (Li et al., 2005), and...

Remediating abnormal oral cavity motor strategies in a horn player using RT-MRI: a case study

This study uses real-time (cine) MRI to examine how orofacial myofunctional disorders (OMDs) affect muscle function during speech and horn playing. Dynamic MRI images were captured of an OMD subject and control subjects reciting a speech task and sustaining a note on an MRI-compatible horn. A following visual feedback session allowed the OMD subject to view and react to their (cine) MRI next to the image of an elite subject. Profile lines created in MATLAB allowed analysis of muscle function and changes in oral cavitation between the OMD and control subjects. In both the speech and horn films, the OMD subject consistently utilized maladaptive muscle movements, resulting in low and forward tongue position against the front teeth. Both control subjects had tongue placement free of the front teeth, and the horn control subject could elevate the tongue to narrow the air stream and play higher pitches. The MRI films suggest a connection between speech disorders and compromised horn-playing technique. OMDs limit the ability of the tongue to make the changes in oral cavitation used to play different pitches on the horn.

Sibilant production in Hebrew-speaking adults: Apical versus laminal

ABSTRACTThe Hebrew IPA charts describe the sibilants /s, z/ as ‘alveolar fricatives’, where the place of articulation on the palate is the alveolar ridge. The point of constriction on the tongue is not defined – apical (tip) or laminal (blade). Usually, speech and language pathologists (SLPs) use the apical placement in Hebrew articulation therapy. Some researchers and SLPs suggested that acceptable /s, z/ could be also produced with the laminal placement (i.e. the tip of the tongue approximating the lower incisors). The present study focused at the clinical level, attempting to determine the prevalence of these alternative points of constriction on the tongue for /s/ and /z/ in three different samples of Hebrew-speaking young adults (total n = 242), with typical articulation. Around 60% of the participants reported using the laminal position, regardless of several speaker-related variables (e.g. tongue-thrust swallowing, gender). Laminal production was more common in /s/ (than /z/), coda (than onset) position of the sibilant, mono- (than di-) syllabic words, and with non-alveolar (than alveolar) adjacent consonants. Experiment 3 revealed no acoustical differences between apical and laminal productions of /s/ and of /z/. From a clinical perspective, we wish to raise the awareness of SLPs to the prevalence of the two placements when treating Hebrew speakers, noting that tongue placements were highly correlated across sibilants. Finally, we recommend adopting a client-centred practice, where tongue placement is matched to the client. We further recommend selecting targets for intervention based on our findings, and separating between different prosodic positions in treatment.

The use of ultrasound to determine the most effective placement cues for /s/ during articulation therapy

Although two distinct normal tongue configurations for /s/ have been documented for many years (Borden &amp; Gay, 1978), estimates of the frequency of tongue tip up vs. tongue tip down /s/ articulation in the general population vary. Therapy procedures often focus exclusively on one or the other of the two tongue postures. Given that /s/ is one of the most frequently misarticulated sounds in English, clinicians may need guidance in determining which tongue placement is most natural for each client. In recent years, portable ultrasound devices have become more widely accessible for use in speech therapy. In such cases, ultrasound has generally been used as a visual feedback technique for clients (Bernhardt, Gick, Bacsfalvi &amp; Adler-Bock, 2005; Cleland, Scobbie &amp; Wrench, 2015). The current study investigates the use of ultrasound imaging as a preliminary information gathering tool for clinicians to guide decisions regarding /s/ therapy techniques and procedures. In this investigation, students utilized ultrasound to attempt to determine tongue tip configuration during /s/ production for various individuals. Results indicate that ultrasound can provide clinicians with enough initial information to determine the most natural tongue configuration for /s/ production for most clients, thus potentially reducing therapy time and increasing therapy effectiveness.

Ultrasound visual feedback in articulation therapy following partial glossectomy

Disordered speech is common following treatment for tongue cancer, however there is insufficient high quality evidence to guide clinical decision making about treatment. This study investigated use of ultrasound tongue imaging as a visual feedback tool to guide tongue placement during articulation therapy with two participants following partial glossectomy.A Phase I multiple baseline design across behaviors was used to investigate therapeutic effect of ultrasound visual feedback during speech rehabilitation. Percent consonants correct and speech intelligibility at sentence level were used to measure acquisition, generalization and maintenance of speech skills for treated and untreated related phonemes, while unrelated phonemes were tested to demonstrate experimental control. Swallowing and oromotor measures were also taken to monitor change.Sentence intelligibility was not a sensitive measure of speech change, but both participants demonstrated significant change in percent consonants correct for treated phonemes. One participant also demonstrated generalization to non-treated phonemes. Control phonemes along with swallow and oromotor measures remained stable throughout the study. This study establishes therapeutic benefit of ultrasound visual feedback in speech rehabilitation following partial glossectomy.Learning outcomes: Readers will be able to explain why and how tongue cancer surgery impacts on articulation precision. Readers will also be able to explain the acquisition, generalization and maintenance effects in the study.

Tongue Dynamics in Childhood Apraxia of Speech: A Case Study

Childhood Apraxia of Speech (CAS) is a subtype of speech sound disorder with unique features that include deficits in speech sound accuracy, prosody, coarticulatory transitions, and consistency on repeated attempts. Articulatory errors are abundant in apraxia such as articulatory groping, perseverative errors, and speech initiation difficulties. There are few studies conducted to see the articulatory pattern of CAS. Present study aimed to analyse the prime articulator, i.e. tongue dynamics in CAS in different place of articulation comparing with typically developing children. One child with CAS and one typically developing age matched control subject were participated in the study. The test material consisted of three meaningful words consisting stops in three different places of articulation including dental /t?/, retroflex/?/ and velar /k/. The instrument Mindray ultrasound 6600 with Articulate Assistant Advanced (AAA) ultrasound module Version 2.14 was used for data collection and analysis. The overall results showed variation across trials in CAS and this disparity between the trails were less in typical speaker’s utterances compared to CAS. The placement of tongue was diverse across subject during the articulation of /k/ with respect to the tongue height and advancement. Variations were more evident in the tongue front and posterior tongue body region compared to anterior tongue body. In the case of retroflex stop /?/ tongue front and posterior tongue body image was not prominent in all repetition of CAS. But in normal speaker all the three divisions were prominent and variations across trails were less. This information can be useful to set the treatment plans for CAS to resolve the articulatory errors.

Differences in EPG contact dynamics between voiced and voiceless lingual fricatives

Achieving voicing during fricatives is complex because voicing and frication require opposite production strategies that must be managed effectively at the supralaryngeal level. Previous research has suggested that there are differences in tongue-to-palate contact patterns that are conditioned by voicing. However, findings have been restricted to a single time point and have been generally inconclusive. This study used electropalatography (EPG) to investigate differences in the dynamics of contact in voiced and voiceless lingual fricatives. Participants were six typically speaking Croatian adults. The speech material consisted of symmetrical VCV sequences, where C was /s zʃ ʒ/. EPG measures were taken throughout the fricatives and indices were used to quantify place of articulation (CoG), groove width and target configuration onset. The EPG measures showed similar results for voiced and voiceless fricatives during their central portions. However, there were notable differences at the periphery of the fricative period, the most significant being that the voiceless fricatives reached a stable period in terms of tongue placement and groove configuration later than the voiced fricatives. The results support aerodynamic evidence that voiced and voiceless fricatives differ in the onset and the offset of turbulence.

Speech–language pathologists’ knowledge of tongue/palate contact for consonants

Speech–language pathologists (SLPs) rely on knowledge of tongue placement to assess and provide intervention. A total of 175 SLPs who worked with children with speech sound disorders (SSDs) drew coronal diagrams of tongue/palate contact for 24 English consonants. Comparisons were made between their responses and typical English-speaking adults’ contact established by electropalatography (EPG). SLPs were most accurate for consonants with no contact (h, p, f), then velar consonants (g, k, ng). The remaining consonants were rarely accurate (from most to least accurate: l, t, r, z, n, sh, s, zh, y, v, th(voiceless), d, m, b, w, th(voiced), ch, j). SLPs demonstrated good knowledge of contact along the midline, but poor knowledge of contact along lateral margins of the palate. Importantly, SLPs did not show awareness of: lateral bracing (‘horseshoe’ contact) for alveolar consonants (t, d, n, s, z); the groove for s, z, sh, zh; or posterior lateral contact for most other consonants. Accuracy was not influenced by the following: length of time as SLP, location of SLP training, location of current workplace, proportion of caseload with SSD or childhood apraxia of speech, amount of time spent reading, or exposure to EPG. Awareness of coronal tongue placement for consonant production needs targeting in SLP education.

The review of Pierre Robin sequence

The Pierre Robin sequence (PRS)is a congenital abnormality which is not only causally heterogeneous but also with a group of physical findings, characterized by the presence of the combination of underdeveloped(micrognathia) or retropositioned(retrognathia) mandible,glossoptosis that leads to respiratory tract obstruction with or without cleft palate. PRS is clinically defined by obstruction of the upper airways, feeding difficulties, inspiration pneumonia and some accompany with multiple -anomalies that are more frequent and more severe during the immediate postnatal and neonatal period. Diagnosis of PRS may be made immediately when a neonate presents in respiratory distress with micrognathia. Further examination may show the posterior placement of the tongue and possibly a cleft palate. Now that the strong association of PRS with many multiple - anomaly syndromes is recognized, treatment must be individualized to optimize the outcome. Most PRS children have failure to thrive,and long -term outcomes vary greatly,depending on whether the PRS is an isolated occurrence or part of an associated syndrome and on whether the infant experienced any obstructive-hypoxic episodes. Key words: Pierre Robin sequence; Micrognathia; Glossoptosis; Cleft palate

Articulatory characteristics of coronal consonants in Argentine Spanish: An electropalatographic study.

Previous articulatory investigations of Spanish have been largely limited to its Peninsular varieties. This study uses electropalatography (EPG) to investigate articulatory characteristics of coronal consonant contrasts in Argentine Spanish as part of a larger project examining phonetic variation across Spanish dialects. Simultaneous EPG and acoustic data were collected from four female speakers of Buenos Aires Spanish reading sentences with various intervocalic coronal consonants. Results revealed consistent differences in terms of anterior/posterior tongue placement and the amount of linguopalatal contact with the primary distinction between (denti-)alveolar and post-alveolar articulations within the classes of stops/affricates, fricatives, nasals, and laterals/rhotics. Inter-speaker variation was observed, however, in the articulation of some consonants, namely, in the apical or laminal realization of the post-alveolar fricative and in the palatal or palatalized alveolar realization of the post-alveolar nasal. These findings diverge from those reported for Peninsular Spanish [A. M. Fernández Planas, Estudios de fonética experimental, 16, 11–80 (2007)], revealing some dialectal differences in the degree of fronting of denti-alveolars. Additionally, results suggest a sound change in progress in Argentine Spanish, such as the depalatalization of the palatal nasal. [Work supported by Connaught, University of Toronto.]

Effects of tongue position on mandibular muscle activity and heart rate function

A primary goal of pain management for muscle-related pain is to reduce masticatory muscle activity. This study aimed to investigate masticatory muscle group activity and heart rate variability change when the tongue was placed on the palate or the floor of the mouth in a healthy pain-free sample. Participants were 23 females and 18 males with a mean age of 19.6 years (standard deviation = 1.5). Muscle activity was measured using surface electromyography and heart period were measured using electrocardiography. The experimental protocol consisted of 3 periods: baseline, tongue placement on the floor of mouth, and tongue placement on palate. Results indicated significantly more activity in the temporalis and suprahyoid muscle regions as well as a significant reduction in heart rate variability when the tongue was positioned on the palate compared with tongue position on the floor of the mouth. Instructions to place the tongue on the roof of the mouth are not instructions that will promote reduced physiological functioning (i.e., relaxation) but rather promote small, but potentially important increases in overall activity as indexed by muscle tone and cardiac function.