Relationship between perception of tongue position and measures of tongue force on the teeth

Differences between Maximum Tongue Force in Women Suffering from Chronic and Asymptomatic Temporomandibular Disorders-An Observational Study

Background: Temporomandibular disorders are craniofacial disorders characterized by the presence of chronic pain in masticatory muscles, with higher incidence in the women population. There is little research that has studied tongue force related to temporomandibular disorders, but there are a lot of studies that have demonstrated the impact of tongue force in vital functions, such as chewing, swallowing, phonation, or breathing. According to this, the aim of this study was to compare the maximum force of the tongue between females with chronic temporomandibular disorders and asymptomatic females. We also wanted to establish whether any relationship existed between the pain and fatigue versus the maximum force developed in females with chronic temporomandibular disorders. Material and methods: A cross-sectional study of 67 women between the ages of 18 and 65 years old was performed. The included women were assigned to one of two groups, according to whether they had chronic temporomandibular disorders or not. The procedure was the same for both groups. Outcome measures included the maximum tongue force, intensity of perceived orofacial pain, and intensity of perceived orofacial fatigue. Results: The results showed significant statistical differences for the maximum tongue force measurement between the chronic temporomandibular disorders group and the control group (p < 0.05) for all the movements, except the lip pressure measurement. Furthermore, the analysis revealed significant statistical differences between the intensity of perceived orofacial fatigue between the groups (p < 0.05). Moreover, the data showed no significant correlations between variables. Conclusion: The study found significant differences in maximum tongue force when comparing women with chronic temporomandibular disorders and asymptomatic women (being superior in these). Likewise, we found that the intensity of perceived orofacial fatigue after tongue exercises showed significant differences between groups. However, this study reveals no correlations between the intensity of perceived orofacial pain and fatigue and the maximum tongue force.

A Method for the Tribological Assessment of Oral Pharmaceutical Liquids

OBEJECTIVE Patient acceptance of pediatric formations is critical to compliance and consequently therapeutic outcomes; thus, having an in vitro method to evaluate sensory perception of pharmaceutical products would be beneficial. The objective of this research is to develop a sensitive and reproducible tribological method to characterize pharmaceutical suspensions at low force and sliding speeds.METHODS The discriminating potential of the method was examined using tribology profiles (coefficient of friction (COF) vs sliding speed) for commercially available products and products made for this study with widely varying sweetness, thickness and grittiness; these formulations were used to judge the sensitivity of the method. Samples were measured using 3M Transpore™ surgical tape to simulate the tongue surface, steel half ring geometry, constant gap setting, target axial force of 2 N in a 600 second exponential ramp for rotation speed.RESULTS The COF ranged from 0.1 to 0.6. For the speeds studied, the high viscosity commercial suspension Ibuprofen Drops and Acetaminophen suspension show a classic Stribeck Curve with an increasing COF at the higher rotation speeds, which indicates these formulations entered the hydrodynamic lubrication phase, while the lower viscosity suspensions only reached the mixed lubrication phase.CONCLUSIONS The contribution of particles seems to affect the COF in a dynamic pattern compared to products that are categorized as either low gritty or high viscosity. These results are important as they provide a potentially rapidly in vitro method for screening pediatric medications and help to identify the factors that affect the palatability of pediatric formulations.

Evaluation of periodontal parameters and gingival crevicular fluid cytokines in children with anterior open bite receiving passive orthodontic treatment with a spur

Objective

To evaluate clinical parameters and gingival crevicular fluid (GCF) cytokines in children with anterior open bite receiving passive orthodontic treatment with spurs.

Methods

Twenty children with indications for interceptive orthodontic treatment, an anterior open bite, and good oral hygiene and periodontal health were included in this study. GCF samples were collected from the mandibular and maxillary central incisors before (baseline) and 24 hours and 7 days after spur bonding. Clinical and periodontal examinations and cytokine analyses were performed.

Results

At 7 days after spur attachment, gingival bleeding in the mandibular group was increased relative to that in the maxillary group. Visible plaque was correlated with gingival bleeding at 7 days and the GCF volume at 24 hours after spur attachment. Compared with those at baseline, interleukin (IL)-8 levels in the maxillary group and IL-1β levels in both tooth groups increased at both 24 hours and 7 days and at 7 days, respectively. At 24 hours, IL-8, IL-1β, and IL-6 levels were higher in the maxillary group than in the mandibular group. Cytokine production was positively correlated with increased GCF volume, but not with gingival bleeding, visible plaque, or probing depth.

Conclusions

Although orthodontic treatment with spurs in children resulted in increased gingival bleeding around the mandibular incisors, IL levels were higher around the maxillary incisors and not correlated with periodontal parameters. Increased cytokine levels in GCF may be associated with the initial tooth movement during open bite correction with a passive orthodontic appliance in children.

Open bite

Self-perception of tongue tip constriction in alveolar fricatives produced by young women with and without normal tongue positioning

PURPOSE

This study investigated the self-perception of 49 women, monolingual speakers of Brazilian Portuguese, about their tongue position for the alveolar articulation of the fricatives [s] and [z].

METHODS

The video recording of speech samples of these 49 women (ages 18 to 28) were analyzed by three Speech-Language Pathologists. They were classified into two groups: Group 1 (G1, n=25), with no alterations in the tongue position during the production of [s] and [z], and Group 2 (G2, n=24), with alterations in the tongue position during the production of [s] and [z]. The tongue position self-perception experiment required the participants to identify the specific tongue constriction point in the production of [s] and [z] (apical, laminal, or "other") during the reading of 24 words and 24 pseudowords. The Friedman test, with posterior paired comparisons, was used for the intragroup analysis. The Mann-Whitney test was used for intergroup comparisons. The statistical significance adopted was 5% (p<0.05).

RESULTS

G1 reported apical and laminal tongue constrictions while GE reported these constrictions plus other tongue adjustments. The presence of other tongue adjustments differentiated the groups, G1 and G2 (p=0,002). There were significant differences between [s] and [z] for G1, with the laminal position occurring more often in [s] compared to [z].

CONCLUSION

Women with and without alteration in the tongue position reported apical and laminal constrictions. Howerer, other tongue adjustments were self-perceived in the presence of altered tongue position.

Tribology provides an in vitro tool that correlated to in vivo sensory data on the mouthfeel of coated tablets

Tribology is an emerging technique in the pharmaceutical field for texture and mouthfeel studies. Due to its relevance to oral sensory perception, tribology supports the development of novel products in the food industry. This study explores tribology as a tool to optimise the mouthfeel and ease of swallowing of pharmaceutical coatings and coated tablets. We measured the lubricating properties of eight pharmaceutical coatings using two methods: surface tribology and thin film tribology. As food science is more advanced in texture and mouthfeel studies, methods were developed from this field with the intention to mimic tablet ingestion. Further, the link between tribological measurements and the sensory evaluation of the coated tablets obtained by a human panel was explored. We have demonstrated that discrimination of tablets with different coatings using tribology is feasible. The viscosity, solubility and composition of the coating formulations played an important factor in lubrication. For the first time, tribology was used to analyse the lubricating properties of conventional tablet coatings and a linear relationship between tribology and the oral sensory perception, i.e. slipperiness and stickiness, was demonstrated. Tribology has the potential to become a valuable formulation tool to characterise the lubricating behaviour of coated tablets in the context of oral sensory perception.

Influence of the Craniocervical Posture on Tongue Strength and Endurance

Tongue strength has an important role in the swallowing process, and previous research has suggested that tongue position, concerning the craniomandibular region, could affect the oral function. This study aimed to evaluate the strength and endurance of three areas of the tongue in three experimentally induced craniocervical postures. A cross-sectional study with a nonprobabilistic sample of 37 participants (mean age: 3.85 ± 3.64 years; 20 men, 17 women) was performed. Tongue strength and endurance were assessed using a pressure device entitled Iowa Oral Performance Instrument (IOPI), in three different craniocervical positions: neutral head position (NHP), anterior head translation-or forward head position (FHP), and posterior head translation-or retracted head position (RHP). Measurements taken using the IOPI system showed significant differences in tongue strength for the anterior (p = 0.015) and middle areas of the tongue (p = 0.01). Significant differences were observed in analysis of variance (ANOVA) in the FHP (p = 0.02) and NHP (p = 0.009). The results of tongue endurance measurements showed statistically significant differences for FHP (p = 0.001), NHP (p = 0.00), and RHP (p = 0.007). The craniocervical position influences tongue strength, especially in the anterior and middle tongue areas, concerning the posterior, and, in the anterior and neutral head posture, regarding the retracted position. No differences were found in tongue resistance between the various craniocervical positions, but differences were found in resistance between the different tongue areas.

Osseous Loading by a Volume-Reduced Tongue During Muscle Contractions

PURPOSE

To investigate how tongue volume reduction affects loads on surrounding bone surfaces produced by neuromuscular stimulation of the tongue.

MATERIALS AND METHODS

Of each pair of same-gender minipig siblings, 1 received tongue reduction and 1 underwent sham surgery. Either immediately (acute, 6 pairs) or 1 month (chronic, 5 pairs) after surgery, bone surface and/or suture strains and pressures were recorded from the following locations when the hypoglossal nerve trunk, hypoglossal nerve medial branch, hypoglossal nerve lateral branch, genioglossus, and styloglossus (SG) were electrically stimulated: 1) three rosette strain gauges on the premaxillary palatal surface (premaxilla [PM]) and lingual surfaces of the mandibular alveolus at anterior (mandibular incisor [MI]) and posterior (mandibular molar [MM]) locations; 2) two single-element strain gauges over the palatal surface of the premaxillary-maxillary suture and the lingual surface of the mandibular symphysis; and 3) two pressure transducers on the palatal surface of the maxilla (palatal process) and the lingual surface of the mandibular alveolus (mandibular corpus).

RESULTS

Compared with the sham animals in the acute study, reduction animals showed significantly decreased PM and MI strains, as well as palatal process pressure. With muscle contractions, mandibular symphysis and MM strains were enhanced significantly with a more dorsal orientation. In the chronic study, reduction animals showed decreased PM and increased MM strains. On comparison of chronic versus acute studies, PM, MI, and MM strains under SG stimulation were significantly smaller whereas MM strain was significantly larger under hypoglossal nerve trunk, hypoglossal nerve lateral branch, and SG stimulations.

CONCLUSIONS

Muscle contractions from a volume-reduced tongue produce lower and higher loads in the anterior and posterior mouth, respectively. However, although the effects on reducing loads in the anterior mouth are persisting over time, compensatory load enhancement in the posterior mouth diminishes owing to surgical healing.