Tongue thickness is associated with masticatory performance of perioral muscles: Ultrasonographic study of perioral muscle characteristics in healthy young subjects

Reliability of Measuring Geniohyoid Cross-Sectional Area with B-Mode Ultrasound

B-mode ultrasound is a safe noninvasive procedure that has been used to characterize aspects of the oropharyngeal swallow. The submental suprahyoid muscles are often investigated with ultrasound because of their contributions to hyolaryngeal elevation. There are several techniques for positioning the ultrasound transducer in the coronal plane, however, there is limited research on how reliability of measurement of the cross-sectional area (CSA) of the geniohyoid differs across transducer placement technique. This study examined three methods of transducer placement in the coronal plane by two examiners to determine the reliability of measurement of CSA of the geniohyoid muscle. Forty healthy adults participated in the study. Each participant's geniohyoid muscles were imaged using B-mode ultrasound under three transducer placement conditions in the coronal plane by two examiners. Geniohyoid CSA was measured from each ultrasound image. A three-way mixed-methods ANOVA was used to determine whether there were significant differences in geniohyoid CSA among transducer position conditions, trials, and examiners. There were significant differences among the transducer placement conditions, indicating that each condition was measuring a different portion of the muscle. There were no significant differences among repeated trials nor between examiners within each method of transducer placement. All three conditions of transducer placement were reliable at measuring geniohyoid CSA across trials and examiners. This study emphasizes the need for consistency of placement, whichever method is selected. It also highlights the need for researchers to provide a precise description of methods for positioning the transducer so that placement is reproducible.

Evaluation of the thickness and internal structure of the masseter muscle with ultrasonography in female bruxism patients

OBJECTIVES

The aim of this study was to evaluate the differences in the thickness and internal structure of the masseter muscle in individuals with and without bruxism by ultrasonography.

MATERIALS AND METHODS

A total of 60 female patients with and without bruxism whose ages were ranging between 20 and 35 were included in the study. The masseter muscle thickness was measured during rest and maximum bite position. Ultrasonographic internal structure of the masseter muscle is classified according to the visibility of echogenic bands. In addition, the echogenic internal structure of the masseter muscle was evaluated with quantitative muscle ultrasound.

RESULTS

The masseter muscle thickness was significantly higher in both positions in patients with bruxism (p < 0.05). There was no significant difference between two groups in the evaluation of echogenicity (p > 0.05).

CONCLUSIONS

Ultrasonography is a useful and important diagnostic method for evaluating masseter muscle without using radiation.

Overview of Ultrasound in Dentistry for Advancing Research Methodology and Patient Care Quality with Emphasis on Periodontal/Peri-implant Applications

BACKGROUND

Ultrasound is a non-invasive, cross-sectional imaging technique emerging in dentistry. It is an adjunct tool for diagnosing pathologies in the oral cavity that overcomes some limitations of current methodologies, including direct clinical examination, 2D radiographs, and cone beam computerized tomography. Increasing demand for soft tissue imaging has led to continuous improvements on transducer miniaturization and spatial resolution. The aims of this study are (1) to create a comprehensive overview of the current literature of ultrasonic imaging relating to dentistry, and (2) to provide a view onto investigations with immediate, intermediate, and long-term impact in periodontology and implantology.

METHODS

A rapid literature review was performed using two broad searches conducted in the PubMed database, yielding 576 and 757 citations, respectively. A rating was established within a citation software (EndNote) using a 5-star classification. The broad search with 757 citations allowed for high sensitivity whereas the subsequent rating added specificity.

RESULTS

A critical review of the clinical applications of ultrasound in dentistry was provided with a focus on applications in periodontology and implantology. The role of ultrasound as a developing dental diagnostic tool was reviewed. Specific uses such as soft and hard tissue imaging, longitudinal monitoring, as well as anatomic and physiological evaluation were discussed.

CONCLUSIONS

Future efforts should be directed towards the transition of ultrasonography from a research tool to a clinical tool. Moreover, a dedicated effort is needed to introduce ultrasonic imaging to dental education and the dental community to ultimately improve the quality of patient care.

Association between masticatory performance and oral conditions in adults: A systematic review and meta-analysis

OBJECTIVES

To give an overview of the evidence on the associations between oral condition factors and masticatory performance of adults, and to evaluate the direction and level of the associations.

DATA/SOURCES

Medline (PubMed), Embase (Ovid) and CINAHL Plus (EBSCOhost) were searched up to May 2022 for cross-sectional studies on oral conditions and masticatory performance in adults. Methodological quality of the included studies was independently evaluated based on the Joanna Briggs Institute critical appraisal checklist for analytical cross-sectional studies. Data on the associations between oral condition factors and masticatory performance were extracted. Meta-analysis was conducted on correlation coefficients.

STUDY SELECTION

Of the 8,035 records identified, 97 articles (88 studies) were included in the qualitative synthesis, and 18 studies were included in the meta-analyses. Among the oral condition factors that had associations with masticatory performance, the number of natural/remaining teeth or functional tooth pairs was reported by the largest number of studies, followed by perioral muscle status, dental prosthetic status, oral moisture status and periodontal status. Results of the meta-analyses showed that the positive association with the number of natural/remaining teeth was the strongest (pooled correlation coefficient: 0.51, 95%CI: 0.48 to 0.54), followed by the number of functional tooth pairs, maximum tongue force/pressure, while the association with the oral moisture status was the weakest.

CONCLUSIONS

Number of natural/remaining teeth and functional tooth pairs, perioral muscle status, oral moisture status, dental prosthetic status and periodontal status are the main oral condition factors influencing masticatory performance. Based on the limited evidence available, among these factors, the number of natural/remaining teeth has the strongest positive association, with a very low quality of evidence.

CLINICAL SIGNIFICANCE

This study provides valuable information on the oral condition factors associated with masticatory performance, which would be important for policymakers and clinical practitioners when deciding on the strategies for improving the masticatory performance of adults. This review highlights the need for standardization of measures and classifications of masticatory performance and oral conditions.

REGISTRATION

PROSPERO (registration number: CRD42021256824).

Visual evaluation for the elasticity of suprahyoid muscles using sonographic elastography during tongue pressure measurement: A pilot study

BACKGROUND

Suprahyoid muscles behavior during the tongue lifting movement has not yet been elucidated.

OBJECTIVE

The purpose of this study was to investigate the potential of elastography imaging to examine developmental oral dysfunction in children and oral hypofunction in older adults using sonography.

METHODS

Tongue pressure was measured using a manometer with a probe. The tongue pressure was measured with simultaneously scanning the geniohyoid muscle (GHM) and the anterior belly of the digastric muscle (DGM) using sonographic elastography. Sagittal images of the GHM and coronal images of the DGM were used for the strain ratio measurement. The strain ratio of the muscles was measured three times for each subject with the tongue pressure values of 0-30 kPa.

RESULTS

The strain ratio of the GHM were higher than those of the DGM at tongue pressure of 10, 20 and 30 kPa. The strain ratio of the GHM increased as the tongue pressure increased in all participants. In contrast, the strain ratio of the DGM tended to slowly decrease as tongue pressure increased in female participants.

CONCLUSION

Sonographic elastography is useful for visual and quantitative evaluation of elastic properties in suprahyoid muscles during tongue lifting movements.

Relationship between chewing ability and malnutrition, sarcopenia, and frailty in older adults

BACKGROUND

Several studies reported that impaired nutrition is associated with reduced muscle mass, muscle strength, and physical performance. Chewing ability is essential to maintain balanced oral nutrient intake. The study was designed to define the possible relationship between chewing ability and nutrition-related problems (malnutrition, sarcopenia, and frailty) in a holistic perspective.

METHODS

This cross-sectional study recruited adults aged ≥65 years. All patients were evaluated with comprehensive geriatric assessment. Sarcopenia was diagnosed according to European Working Group on Sarcopenia in Older People criterion. Malnutrition was determined according to body mass index, calf circumference, and Mini Nutritional Assessment short form (MNA-SF). Frailty status was diagnosed with the Clinical Frailty Scale. Masseter and gastrocnemius muscle thicknesses (MTs) were measured via ultrasonography imaging. Oral examinations were carried out by a dentist, and chewing performance was examined with a color-changeable chewing gum.

RESULTS

Overall, 135 older adults (76 females) were analyzed. Mean ± SD age was 75.7 ± 7.2 years; 37.0% of the patients were frail, 3.7% were malnourished, 12.6% were sarcopenic, and 20.0% had poor chewing function. In the poor chewing function group, age and frailty scores were increased and the MNA-SF scores, handgrip strength, skeletal muscle index, and masseter MT were reduced (all P < 0.05). After adjusting for confounders, regression analysis showed that low grip strength and low gastrocnemius MT were independently associated with poor chewing ability.

CONCLUSIONS

Chewing ability was related to sarcopenia. Age and low grip strength in females and low cognitive scores and having low gastrocnemius MT in males were independent variables affecting chewing ability.

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

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

The results of this study suggested that the measurement of EI could be an important indicator for assessing the tongue function in the elderly.

Quantification of the Masseter Muscle Hardness of Stroke Patients Using the MyotonPRO Apparatus: Intra- and Inter-Rater Reliability and Its Correlation with Masticatory Performance

BACKGROUND Chewing dysfunction is one of the most common serious complications after a stroke. It may be influenced by the hardness of the masseter muscle and masticatory performance; however, the association between these 2 factors is not explicit. Thus, it is meaningful to explore the functional status of the masseter muscle among stroke patients. The main objectives of this study were to examine the intra- and inter-rater reliability of the MyotonPRO apparatus in measuring masseter muscle hardness in stroke patients and to investigate the correlation between the bilateral masseter muscle hardness and masticatory performance in these patients. MATERIAL AND METHODS A total of 20 stroke patients participated in our study. The hardness of the masseter muscle was measured by 2 physiotherapists using the MyotonPRO apparatus. Overall, each patient masticated 2 pieces of red-blue bicolor chewing gum for 20 chewing cycles each. The chewing pieces were analyzed using ViewGum software for masticatory performance. RESULTS The intra- and inter-rater reliability of the MyotonPRO apparatus for measuring bilateral masseter hardness of stroke patients was excellent. The correlation analysis showed that the hardness index of the masseter muscle on the affected side was moderately correlated with the masticatory performance of the same side. CONCLUSIONS The MyotonPRO device can be used for measuring the masseter muscle hardness of stroke patients, with excellent reliability. This study established the construct validity between the stiffness of the masseter muscle and masticatory performance.

Validation of masticatory function and related factors in maxillectomy patients based on the concept of "oral hypofunction": A retrospective cross-sectional study

PURPOSE

Although oral functions have been evaluated by various methods in maxillectomy patients, there exists substantial difficulty in the assessment procedures. The purpose of this study was to evaluate masticatory function, maximum occlusal force (MOF), and maximum tongue pressure (MTP) in maxillectomy patients objectively as per the "oral hypofunction" criteria, and examine the factors that correlate with masticatory function.

METHODS

This retrospective cross-sectional study included 50 maxillectomy patients with maxillofacial prostheses (23 males and 27 females, median age, 72 years; interquartile range (IQR), 63.75-77). The records of masticatory function, MOF, and MTP as per the "oral hypofunction" criteria and their profiles (age, number of occlusal supports, and maxillary defect configuration) were reviewed. The number of patients who exceeded a threshold value of "oral hypofunction" and the effects of occlusal support and defect configuration on masticatory function and MOF were calculated. Multiple regression analysis was performed to assess the associations between masticatory function and other variables.

RESULTS

The median value of masticatory function (114 mg/dL, IQR: 73-167.5) exceeded a threshold value, but not MOF (229.2 N, IQR: 110.2-419.6) and MTP (25.9 kPa, IQR: 21.4-29.0). The number of patients who exceeded each threshold value was 27 (masticatory function), 8 (MOF), and 12 (MTP), respectively. The influence of the number of occlusal supports, but not the defect configuration, was statistically significant. Multiple regression analysis revealed that MOF was independently related to masticatory function (P=0.042).

CONCLUSIONS

Within the limitations of this study, the median value of masticatory function in maxillectomy patients could exceed a threshold and MOF might be an independent predictor of masticatory function.

Ultrasonography Shows Age-related Changes and Related Factors in the Tongue and Suprahyoid Muscles

OBJECTIVES

To investigate age and other factors related to the deterioration of the muscles used for swallowing, including the tongue and suprahyoid muscles.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

This study included 146 participants: 47 younger adults (23 men and 24 women; age range 23-44 years) recruited from a dental hospital and 99 community-dwelling older adults (37 men and 62 women, age range 65-86 years).

METHODS

Age (<65 years or ≥65 years), body mass index (BMI), skeletal muscle mass index (SMI), and tooth loss (Eichner classification) were measured. The cross-sectional areas (CSAs) of the tongue, geniohyoid muscle, and anterior belly of the digastric muscle were measured using an ultrasonic diagnostic apparatus. The correlation between each muscle's CSA and strength was examined. Multiple regression analyses were performed separately for each sex using each muscle CSA as the dependent variable and age, BMI, SMI, and the Eichner classification as explanatory variables.

RESULTS

Older men had a significant positive correlation between tongue pressure and CSA (r = 0.35, P = .031). Jaw opening force was positively correlated with geniohyoid muscle CSA (r = 0.41, P = .001) in older women. In the multiple regression analysis, age, BMI, and SMI were significantly associated with tongue CSA in men. Age was significantly and inversely associated with suprahyoid muscle CSA in both men and women. No explanatory variables were significantly associated with geniohyoid muscle CSA except age.

CONCLUSIONS AND IMPLICATIONS

The tongue increased in volume, and the suprahyoid muscles underwent atrophy with age. The study results suggest that interventions to prevent dysphagia associated with aging should be tailored toward specific muscles. Direct muscle training is required for the suprahyoid muscles, whereas the maintenance of tongue muscle mass and function, as well as training for the tongue, requires attention to ensure optimal nutritional status and whole-body skeletal muscle mass.