Newly designed flat surface artificial tongue system for speech improvement in glossectomy patients: A preliminary study.

PURPOSE: To design an efficient tongue prosthesis with reproducibility and to objectively evaluate improvement in speech function. METHODS: A silicon anatomical artificial tongue (AT) and a flat surface artificial tongue system (FTS) were used in our study. Twenty healthy participants (10 males and 10 females, 26.3 ± 1.8 years) were fitted with a tongue movement suppression appliance (TSA) that fit the dental arch to simulate the glossectomy condition. TSA, TSA + FTS, and TSA + AT simulated the state of glossectomy patients without artificial tongue, with normal artificial tongue, and newly designed artificial tongue, respectively. Three speech intelligibility tests were performed for each of the following conditions: pronouncing 100 Japanese monosyllables, 40 Japanese words, and reading a short story. One-way ANOVA, Wilcoxon signed-rank test, and Tukey-Kramer post-hoc test were used for statistical analyses. RESULTS: Significant differences were observed for 100 Japanese monosyllables and 40 Japanese words between the TSA + FTS, TSA, and TSA + AT conditions (p < 0.05). Regarding the speech intelligibility test for reading a short story, the TSA + FTS condition resulted in a significantly higher speech intelligibility than the TSA and TSA + AT conditions (p < 0.05). CONCLUSION: A flat surface artificial tongue system contributed to the improvement in speech function. This structure can be easily used in cases where conventional artificial tongue are applicable, regardless of variation in the oral condition; thus, making it a widely applicable treatment option for glossectomy patients.

Detection of muscle fatigue caused by repeated posterior tongue lift movement from neck surface EMG: a pilot study.

BACKGROUND: Fatigue is an important factor for muscle strengthening in rehabilitation medicine. Frequency analysis has been regarded as the gold standard for muscle fatigue assessment in surface electromyography (EMG). However, there are no experiments quantifying fatigue with grouped discharge (GD), which is one of the historical phenomena observed in patients having fatigue, by using high sampling rate recording of EMG. OBJECTIVE: To investigate the effect of fatigue, which is induced by repeated posterior tongue lift movement (TLM), on the occurrence of GD peaks, thus, to provide possible basis as a parameter for future fatigue evaluation. METHODS: Nineteen healthy adults (9 men and 10 women) participated in this study. The muscle fatigue protocol consisted of repetitive posterior TLM and maximum voluntary contractions (MVC). Bilateral N-EMG (Neck surface EMG for measuring the muscle activity of the posterior tongue) was recorded. RESULTS: Subjective tongue fatigue at the end of the protocol was significantly higher than at beginning throughout the muscle fatigue protocol (p < .01). The frequency of occurrence of GD peaks was 0.9 ± 1.2 (per second) at the baseline in 33 of 38 subject sides, and significantly increased depending on fatigue progression (p < .01). CONCLUSION: It was shown that fatigue due to repetitive posterior tongue lifting resulted in significant increase in the frequency of occurrence of GD peaks. Especially, the nature of GD, showing very few occurrences at non-fatigue condition, might work as an advantageous property for its use in future absolute evaluation of fatigue phenomena.

Parafunctional masseter muscle activity during waking is related to periodontitis progression: A pilot prospective cohort study.

AIM: The purpose of this pilot prospective cohort study was to investigate the effects of parafunctional masseter muscle activity on periodontitis progression among patients receiving supporting periodontal therapy (SPT). MATERIALS AND METHODS: We collected data of patients treated at Okayama University Hospital from August 2014 to September 2018. The progression group was defined as patients with ≥2 teeth demonstrating a longitudinal loss of proximal attachment of ≥3 mm during the 3-year study period and/or at least one tooth extraction due to periodontitis progression. Surface electromyography of masseter muscles at baseline was continuously recorded while patients were awake and asleep. RESULTS: We analysed 48 patients (36 females) aged 66.8 ± 9.1 years (mean ± SD). The rate of parafunctional masseter muscle activity during waking hours and sleeping hours at baseline was 60.4% and 52.1%, respectively. Cox's proportional hazards regression model showed that the incidence of periodontitis progression was significantly associated with number of teeth present (p = 0.001) and parafunctional masseter muscle activity during waking hours (p = 0.041). CONCLUSION: Our results suggest that parafunctional masseter muscle activity during waking hours is a risk factor for periodontitis progression among patients receiving SPT.

Characteristics of Grouped Discharge Waveforms Observed in Long-term Masseter Muscle Electromyographic Recording: A Preliminary Study.

We investigated the characteristics of grouped discharge (GD) waveforms obtained from long-term masseter electromyogram (EMG) recording in 6 female temporomandibular disorder (TMD) patients with myofascial pain and 6 healthy females. The EMG measurement was performed from the morning of the experiment day until the subject woke up the next day. We observed a significantly larger number of GD waveforms in the TMD group compared to the control group (p=0.002). Our results indicate that the existence of GD waveforms in masseter EMGs might be a predictor of future TMD with myofascial pain.

Novel treatment for chronic pododermatitis in an Indian elephant (Elephas maximus indicus) with Mohs' paste.

Asian and African elephants are frequently afflicted by foot disorders that can be very challenging to manage even with aggressive therapy. Such conditions may have indirect life-threatening effects. Mohs' paste (zinc chloride based escharotic agent) was used to treat a female Indian elephant (Elephas maximus indicus) aged 39 years with foot disorder at Kanazawa Zoological Gardens. Degenerated hyperplastic tissue was observed inside the hoofs of digits 2 and 5. Mohs' paste was applied on the lesions, which coagulated the hyperplastic tissue and restrained its proliferation. Subsequently, the hyperplastic tissue could be trimmed with little pain, and the disorder became manageable. Mohs' paste treatment was effective and is expected to be an alternative treatment for hoof disorder.

Relationship between severity of periodontitis and masseter muscle activity during waking and sleeping hours.

OBJECTIVE: This study was conducted to investigate whether the masseter muscle activity shows any specific pattern in relation to the severity of periodontitis. DESIGN: Sixteen subjects with no or mild periodontitis (NMP group) and 15 subjects with moderate or severe periodontitis (MSP group) were enrolled. Plasma IgG antibody titer was examined using Porphyromonas gingivalis as a bacterial antigen. Surface electromyography (EMG) of the masseter muscles was continuously recorded using an ambulatory surface EMG recording device while patients were awake and asleep. Masseter muscle activity was analyzed using intensities of 5%-10% maximal voluntary clenching (MVC), 10%-20% MVC, and >20% MVC. Furthermore, EMG levels of 20% MVC were adopted as the threshold for analysis of phasic, tonic, and mixed EMG activities. The cumulative duration of masseter muscle activity and bruxism episodes was calculated as duration per hour. RESULTS: There was no significant difference in plasma IgG antibody titers against P. gingivalis between the NMP and MSP groups (p = 0.423). During waking hours, the duration of masseter muscle activity with an intensity of >20% MVC was significantly longer in the MSP group than in the NMP group (p = 0.037). During sleeping hours, the duration of masseter muscle activity at all MVC intensities was significantly longer in the MSP group than in the NMP group (all p < 0.05). Additionally, the duration of phasic and mixed episodes was significantly longer in the MSP group than those in the NMP group while both awake and asleep (all p < 0.05). CONCLUSIONS: The results of this study suggested that masseter muscle activity might be related to the severity of periodontitis.

Properties of tonic episodes of masseter muscle activity during waking hours and sleep in subjects with and without history of orofacial pain.

PURPOSE: To provide a scientific data related to the tonic activity of masseter muscle in subjects with and without history of orofacial pain during their normal daily life. METHODS: Thirty-three subjects were divided into two groups, a pain history group (PHG) and a non-pain history group (non-PHG), based on their responses to the Research Diagnostic Criteria for Temporomandibular Disorders questionnaire. After excluding four subjects with incomplete recordings, full-day masseter muscle surface EMGs of 29 subjects (10 men, 19 women; mean age 24.1 years) were analyzed. Tonic episode (TE) was defined as continuous EMG activity with a duration at least 2s with intensities above twice the baseline noise level. TEs were classified into 6 strength categories (<7.5%, 7.5-10%, 10-15%, 15-25%, 25-40% and >40% of the maximum voluntary clenching (MVC)). The mean duration of activity observed in the non-PHG+2 SD was adopted as a cutoff for identifying sustained TE. RESULTS: During waking hours, the incidence of sustained TEs was significantly higher in the PHG than in the non-PHG (p<0.05). The incidence and total duration of sustained TEs were significantly higher in the PHG than in the non-PHG at intensities of 7.5-10% MVC, 10-15% MVC, and 15-25% MVC (p<0.05). No significant difference was observed during sleep. CONCLUSIONS: Within the limitations of this study, it would be concluded that sustained TEs may have a correlation with orofacial pain and the intensity range of 7.5-25% MVC would be an important range for future clenching studies.

Subcutaneous malignant mast cell tumor in a Japanese macaque (Macaca fuscata).

The histopathological, immunohistochemical, and ultrastructural morphologic characteristics of a tumor in the subcutaneous tissue of the chest of a 19-year-old female Japanese macaque were investigated. Consequently, the mass was diagnosed as a malignant mast cell tumor (MCT). Tumors were present in both mammary gland portions of the anterior thorax. Both tumors showed the same histopathological findings. The tumor tissue was defined by the presence of delicate connective tissue, and the tumor cells grew in a cord-like or cobblestone pattern. The tumor cell cytoplasm was very clear. The nuclei were relatively uniform and the cells showed a low nucleus-cytoplasm ratio. The cytoplasmic granules stained blue with Alcian blue and eosinophils had infiltrated into the tumor tissue. Furthermore, immunohistochemical analysis revealed that the tumor cell membrane was positive for the anti-c-kit antibody. In ultrastructural morphologic analyses, all tumor cells showed a rich cytoplasm and, occasionally, granules wrapped in a limiting membrane of high electron density. The tumor cells had metastasized to the axillary lymph nodes, the kidney, and the peritoneum. Based on these results, the mass was diagnosed as a malignant MCT originating from the subcutaneous tissue of the chest. Since cases of MCTs in macaques are very rare, this report presents important new knowledge of neoplastic lesions in this species.

Ipsilateral Molar Clenching Induces Less Pain and Discomfort than Contralateral Molar Clenching in Patients with Unilateral Anterior Disc Displacement of the Temporomandibular Joint.

AIMS: To assess the influence of clenching side and location (ie, tooth) on the bite force necessary to induce pain or discomfort in patients with unilateral anterior disc displacement (ADD) of the temporomandibular joint (TMJ). METHODS: A total of 17 patients with unilateral ADD diagnosed clinically and with magnetic resonance imaging were included. A bite force meter was positioned at each of four experimental positions: the mandibular first premolars and first molars, bilaterally. Subjects were instructed to clench on the bite force meter until they felt pain or discomfort in the orofacial area and to report the location of the pain. Differences in pain location (ADD side versus contralateral side) and in the bite force thresholds for eliciting pain or discomfort were assessed by means of the paired t test and Wilcoxon signed-rank test. RESULTS: Only 18% of subjects (3 out of 17) reported pain in the TMJ with ADD during clenching at the ipsilateral molar, whereas 65% (11 out of 17) reported joint pain during clenching on the contralateral molar (P = .005). At the molars, the mean ± standard deviation bite force necessary to induce pain was 241.2 ± 135.5 N on the side with ADD and 160.9 ± 78.0 N on the contralateral side. The mean molar bite force necessary to induce pain on the side with ADD was significantly higher than that on the contralateral side (P = .002). CONCLUSION: Patients with unilateral ADD had fewer reports of TMJ pain and discomfort when they were molar clenching on the ipsilateral side compared to molar clenching on the contralateral side.

IMMUNOLOCALIZATION OF INHIBIN/ACTIVIN SUBUNITS AND STEROIDOGENIC ENZYMES IN THE TESTES OF AN ADULT AFRICAN ELEPHANT (LOXODONTA AFRICANA).

In this case report, the authors investigated immunolocalization of inhibin α and inhibin/activin ßA and ßB subunits, as well as steroidogenic enzymes, in the testes of an African elephant. Testes were collected from a reproductively active male African elephant (24 yr old) at autopsy. Histologically, all types of spermatogenic cells including mature-phase spermatozoa were found in the seminiferous tubules. Positive immunostaining for inhibin α and inhibin/activin ßA and ßB subunits was observed in Sertoli and Leydig cells. In addition, P450scc, 3ßHSD, P450c17, and P450arom were also detected in the cytoplasm of Leydig cells. These results suggested that Leydig cells of adult African elephant testes have the ability to synthesize progestin, androgen, and estrogen, whereas both Sertoli and Leydig cells appear as a major source of inhibin secretion in the male African elephant.

Structure of a New Palatal Plate and the Artificial Tongue for Articulation Disorder in a Patient with Subtotal Glossectomy.

A palatal augmentation prosthesis (PAP) is used to facilitate improvement in the speech and swallowing functions of patients with tongue resection or tongue movement disorders. However, a PAP's effect is limited in cases where articulation disorder is severe due to wide glossectomy and/or segmental mandibulectomy. In this paper, we describe speech outcomes of a patient with an articulation disorder following glossectomy and segmental mandibulectomy. We used a palatal plate (PP) based on a PAP, along with an artificial tongue (KAT). Speech improvement was evaluated by a standardized speech intelligibility test consisting of 100 syllables. The speech intelligibility score was significantly higher when the patient wore both the PP and KAT than when he wore neither (p＝0.013). The conversational intelligibility score was significantly improved with the PP and KAT than without PP and KAT (p＝0.024). These results suggest that speech function can be improved in patients with hard tissue defects with segmental mandibulectomy using both a PP and a KAT. The nature of the design of the PP and that of the KAT will allow these prostheses to address a wide range of tissue defects.

Specific diurnal EMG activity pattern observed in occlusal collapse patients: relationship between diurnal bruxism and tooth loss progression.

AIM: The role of parafunctional masticatory muscle activity in tooth loss has not been fully clarified. This study aimed to reveal the characteristic activity of masseter muscles in bite collapse patients while awake and asleep. MATERIALS AND METHODS: Six progressive bite collapse patients (PBC group), six age- and gender-matched control subjects (MC group), and six young control subjects (YC group) were enrolled. Electromyograms (EMG) of the masseter muscles were continuously recorded with an ambulatory EMG recorder while patients were awake and asleep. Diurnal and nocturnal parafunctional EMG activity was classified as phasic, tonic, or mixed using an EMG threshold of 20% maximal voluntary clenching. RESULTS: Highly extended diurnal phasic activity was observed only in the PBC group. The three groups had significantly different mean diurnal phasic episodes per hour, with 13.29±7.18 per hour in the PBC group, 0.95±0.97 per hour in the MC group, and 0.87±0.98 per hour in the YC group (p<0.01). ROC curve analysis suggested that the number of diurnal phasic episodes might be used to predict bite collapsing tooth loss. CONCLUSION: Extensive bite loss might be related to diurnal masticatory muscle parafunction but not to parafunction during sleep. CLINICAL RELEVANCE SCIENTIFIC RATIONALE FOR STUDY: Although mandibular parafunction has been implicated in stomatognathic system breakdown, a causal relationship has not been established because scientific modalities to evaluate parafunctional activity have been lacking. PRINCIPAL FINDINGS: This study used a newly developed EMG recording system that evaluates masseter muscle activity throughout the day. Our results challenge the stereotypical idea of nocturnal bruxism as a strong destructive force. We found that diurnal phasic masticatory muscle activity was most characteristic in patients with progressive bite collapse. PRACTICAL IMPLICATIONS: The incidence of diurnal phasic contractions could be used for the prognostic evaluation of stomatognathic system stability.

A new posture measurement method for measuring intrinsic standing posture.

AIMS: Although body posture in relation to the dental condition has been of great interest in the dental profession, rumination bias has been a substantial obstacle to achieving a reliable objective evaluation of the intrinsic body posture. The aim of this study was to establish a posture control protocol that would minimize the effect of bias. METHODOLOGY: Fifteen healthy male volunteers (23-33 years of age) participated in this study. The posture movement was recorded for 10 seconds by a three-dimensional motion capture system. The experiment was performed on four different days. RESULTS: The posture was most stable at 4-5 seconds after the start of the front bulb gaze (the mean coefficient of variation ranged from 0.1 to 44.1). The intraclass correlation coefficients for four days were 0.871-0.975 (P < or = 0.001). CONCLUSIONS: It was concluded that the use of this measurement method helped in producing a reliable intrinsic standing posture where unbiased evaluation of the effect of any intervention on the body posture is researched.

Carcinosarcoma in a white Rhinoceros (Ceratotherium simum simum).

In Rhinocerotidae, there are very few reports of tumors and no reports of a mixed tumor. This paper reports the case of a male 33-year-old southern white rhinoceros. Grossly, there were two masses in the coelomic cavity and solid nodules in the liver. Histologically, all tumors had a biphasic pattern that consisted of malignant epithelial cells (cytokeratin- and E-cadherin-positive) and non-epithelial cells (vimentin-positive) with cartilage. In this case, the prostate could not be identified, and instead, the largest tumor mass was present at that site. Furthermore, since structures regarded as the prostate duct remained in this tumor, we considered that this tumor was very likely to be of prostate gland origin. This case is the first report of carcinosarcoma in Rhinocerotidae.

Domestication process of the goat revealed by an analysis of the nearly complete mitochondrial protein-encoding genes.

Goats (Capra hircus) are one of the oldest domesticated species, and they are kept all over the world as an essential resource for meat, milk, and fiber. Although recent archeological and molecular biological studies suggested that they originated in West Asia, their domestication processes such as the timing of population expansion and the dynamics of their selection pressures are little known. With the aim of addressing these issues, the nearly complete mitochondrial protein-encoding genes were determined from East, Southeast, and South Asian populations. Our coalescent time estimations suggest that the timing of their major population expansions was in the Late Pleistocene and significantly predates the beginning of their domestication in the Neolithic era (≈10,000 years ago). The ω (ratio of non-synonymous rate/synonymous substitution rate) for each lineage was also estimated. We found that the ω of the globally distributed haplogroup A which is inherited by more than 90% of goats examined, turned out to be extremely low, suggesting that they are under severe selection pressure probably due to their large population size. Conversely, the ω of the Asian-specific haplogroup B inherited by about 5% of goats was relatively high. Although recent molecular studies suggest that domestication of animals may tend to relax selective constraints, the opposite pattern observed in our goat mitochondrial genome data indicates the process of domestication is more complex than may be presently appreciated and cannot be explained only by a simple relaxation model.

Effect of transient occlusal loading on the threshold of tooth tactile sensation perception for tapping like the impulsive stimulation.

The objectives of this study were (1) to establish a reliable method for detecting the force threshold of the tooth tactile sensation while avoiding experimenter bias and (2) to examine the effect of occlusal force loading on the threshold for impulsive force stimulation in subjects with normal dentition. Twenty volunteers participated in this study (10 males and 10 females; mean age, 26.6 ± 2.9 years). To simulate the bite force during occlusal tapping, a force-loading device was designed to exert impulsive force to the occlusal surface in the direction parallel to the tooth axis. The impulsive force detection threshold of the periodontal sensation was measured before and after loading 98 N of occlusal force on the left upper first molar for 1 min. Transient mechanical loading of the upper first molar caused an increase in the absolute threshold for impulsive force. This increase did not vanish immediately, and the increment of the threshold was maintained during the remainder of the experiment. A computer-controlled method for the evaluation of tooth tactile sensation using impulsive stimulation was established. Transient occlusal force loading parallel to the tooth axis increases the threshold of periodontal sensation for mechanical impulsive stimulation.

Mechanomyographic activity in the human lateral pterygoid muscle during mandibular movement.

The activity of the lateral pterygoid muscle has been regarded to be related to the pathological condition of the temporomandibular joint (TMJ) in the craniomandibular disorders. Because the lateral pterygoid muscle is a deep muscle, a needle electrode is necessary for EMG recordings. The purpose of this study was to establish a non-invasive method for the evaluation of muscle activity of the lateral pterygoid muscle using mechanomyogram (MMG). In three male subjects, surface electromyogram (EMG) in the left masseter muscle, left anterior and posterior belly of the temporal muscle, left anterior belly of the digastric muscle and needle EMG of the inferior head of the lateral pterygoid were recorded during mandibular movement tasks simultaneously with the MMG derived from a condenser microphone in the external ear canal. There were significant positive correlations between the needle EMG signal of the lateral pterygoid muscle and the MMG signal for the tasks of static jaw opened position of 30 mm of interincisal distance (p=0.000, R(2)=0.725), static jaw opened position of 40 mm of interincisal distance (p=0.000, R(2)=0.753), 5mm protruded mandibular position (p=0.000, R(2)=0.653), the most protruded mandibular position (p=0.000, R(2)=0803). On the contrary, for the task of maximal clenching, there was no significant correlation between the EMG signal of the lateral pterygoid muscle and the MMG signal. These results suggest that the activity of the lateral pterygoid muscle could be evaluated by the MMG signals recorded in the external ear canal, unless jaw closing major muscles show active contraction.

Relationship between body temperature and ovarian cycle in Asian and African elephants.

The aim of the present study was to investigate whether changes in body temperature are related to the ovarian cycle in elephants. Rectal, tongue or fecal temperature was measured for 2 Asian and 5 African elephants using an electric thermometer. Evaluation of ovarian cycles was based on the changes in serum or fecal progestin. The mean +/- SD values of the rectal, tongue, and fecal temperatures were 36.3 +/- 0.3 (2 Asian), 36.2 +/- 0.5 (1 African) and 36.5 +/- 0.3 C (4 African), respectively; the fecal temperature was the highest of the 3 temperatures (P<0.01). The longitudinal changes in body temperatures correlated with the ovarian cycle, with higher temperatures occurring during the luteal phase. The fecal temperatures of one acyclic African elephant did not change cyclically. These results suggest that measurement of body temperature can be used to easily evaluate the ovarian cyclicity of an individual animal, although it might not be able to determine the ovarian cycle length.

Fatal Baylisascaris larva migrans in a colony of Japanese macaques kept by a safari-style zoo in Japan.

A colony of Japanese macaques (Macaca fuscata fuscata) kept by a safari-style zoo in Japan experienced 9 sporadic cases of fatal neurological diseases, such as epilepsy and posterior paralysis, during the 12 yr from 1989 to 2001. This macaque colony consisted of approximately 30 animals, on average, during this period, and the macaques shared their living space with II American black bears (Ursus americanus) harboring zoonotic roundworms (Baylisascaris transfuga). Close to this enclosure, a cote for 2-3 raccoons (Procyon lotor) was placed, and raw sewage from this cote ran into a shallow drain in the area for macaques and bears. However, fecal examinations in recent years did not detect the infection of raccoons with zoonotic roundworms (Baylisascaris procyonis). Postmortem histological examination of the latest 2 ill macaques detected multifocal malacia in the brain; 2 ascarid larvae of 60 microm maximum width were encapsulated in the cerebrum and lungs of 1 of the animals. To determine the causative ascarid species of the fatal larva migrans, we analyzed 2 additional encapsulated Baylisascaris larvae collected from formalin-fixed lungs by morphological and molecular approaches. This sporadic outbreak is the second record of Baylisascaris larva migrans in animals in Japan.