The Correlation Between Surface Electromyography and Bite Force of Mastication Muscles in Asian Young Adults

Type of correlation between bite force and EMG activity of the temporalis and masseter muscles during maximal and submaximal clenching

INTRODUCTION

Maximal bite force is an important determinant of masticatory function and is essential for the estimation of dental status. Bite force is usually measured by gnathodynamometry.

Recent trends in aroma release and perception during food oral processing: A review

The dynamic and complex peculiarities of the oral environment present several challenges for controlling the aroma release during food consumption. They also pose higher requirements for designing food with better sensory quality. This requires a comprehensive understanding of the basic rules of aroma transmission and aroma perception during food oral processing and its behind mechanism. This review summarized the latest developments in aroma release from food to retronasal cavity, aroma release and delivery influencing factors, aroma perception mechanisms. The individual variance is the most important factor affecting aroma release and perception. Therefore, the intelligent chewing simulator is the key to establish a standard analytical method. The key odorants perceived from the retronasal cavity should be given more attention during food oral processing. Identification of the olfactory receptor activated by specific odorants and its binding mechanisms are still the bottleneck. Electrophysiology and image technology are the new noninvasive technologies in elucidating the brain signals among multisensory, which can fill the gap between aroma perception and other senses. Moreover, it is necessary to develop a new approach to integrate the relationship among aroma binding parameters, aroma concentration, aroma attributes and cross-modal reactions to make the aroma prediction model more accurate.

Does Maximum Voluntary Clenching Force Pose a Risk to Overloading Alloplastic Temporomandibular Joint Replacement?-A Prospective Cohort Study

PURPOSE

The amount of maximum voluntary clenching (MVC) force may influence functional loading at the polyethylene/metal bearing surfaces in alloplastic total temporomandibular joint replacement (TMJR). The aim of this study was to measure ipsilateral MVC and estimate the risk for revision due to overloading of the TMJR.

METHODS

A prospective cohort study design was used to study patients who underwent alloplastic TMJR. The primary predictor was time after TMJR, the secondary predictors were age at TMJR placement, coronoidectomy, prior ipsilateral TMJ surgeries, TMJR design (custom, stock), and bite location. The primary outcome variable was MVC, the secondary outcome was need for TMJR revision. Data were collected preoperatively (T0), and 1 year (T1), 2 to 3 years (T2) and ≥4 years postoperatively (T3). Analysis of variance (ANOVA) with post hoc Tukey-HSD and regression analysis was used for statistical analysis. P < .05 was considered significant.

RESULTS

Thirty-seven patients (58 TMJR) with unilateral (n = 16) and bilateral (n = 21) TMJR were enrolled; 8 males (12 TMJR) and 29 females (46 TMJR). Average age was 46.4 ± 14.9 years. MVC increased significantly over the observation period (P = .000). At all observation time points, age at TMJR placement and bite location significantly influenced MVC (P = .000). Coronoidectomy and prior ipsilateral TMJ surgeries did not demonstrate a significant influence on MVC. TMJR design influenced MVC significantly at T3 (P = .006). Regression analysis identified age as a significant factor for higher MVC. No TMJR required revision or replacement.

CONCLUSIONS

Based on this study, ipsilateral MVC increases significantly after TMJR. However, since MVC is significantly lower than in healthy test-patients, a considerably lower functional loading at the polyethylene/metal bearing surfaces can be assumed. Lower loading at the TMJR bearing surfaces and at the cortical screw fixation sites suggest a potential longer lifespan compared to other artificial joints like hip and knee prostheses.

Decreased Length of Postoperative Drain Use, Parenteral Opioids, Length of Stay, and Complication Rates in Patients Receiving Meshed versus Unmeshed Acellular Dermal Matrix in 194 Submuscular Tissue Expander-Based Breast Reconstructions: A Single-Surgeon Cohort Study

BACKGROUND

Studies have cited possible complications and increased fluid accumulation in implant-based breast reconstruction using acellular dermal matrix. The authors propose a novel approach, manually meshing acellular dermal matrix using a skin graft mesher before use in expander-based breast reconstruction. The authors investigated postoperative drain time, complication rates, pain, and length of hospital stay in meshed versus unmeshed acellular dermal matrix cohorts.

METHODS

One hundred fourteen patients and 194 reconstructed breasts were included overall. Of these, 99 patients were included in the pain and postoperative length of hospital stay analysis. Independent t test and chi-square analyses were used for bivariate comparisons. Multiple linear regression analyses were used to further delineate impact of meshing acellular dermal matrix on drain time, postoperative parenteral narcotic requirements, and length of stay between the two cohorts.

RESULTS

The meshed acellular dermal matrix cohort had lower overall complication rates compared with the unmeshed cohort. Multiple linear regression analyses showed meshing the acellular dermal matrix alone decreased drain time by 7.3 days, and decreased postoperative parenteral narcotic requirements by 77 percent (20 mg morphine). Furthermore, it was the only significant predictor for a decrease in length of stay.

CONCLUSIONS

Meshing acellular dermal matrix significantly decreased the time needed for postoperative drains. Statistical analysis showed significantly decreased overall and minor complication rates in the meshed cohort. Meshing significantly decreased parenteral narcotic requirements and, importantly, also decreased length of stay. All of these factors have important implications regarding cost and quality of care in expander-based breast reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Bite Force Evaluation in Complete Denture Wearer with Different Denture Base Materials: A Randomized Controlled Clinical Trial

AIM

The aim of this study is to evaluate the maximum bite force (MBF) with different denture base materials in completely edentulous patients.

MATERIALS AND METHODS

MBF was evaluated in randomly selected 100 completely edentulous patients. Patients were selected from the Outpatient Clinic, College of Dentistry, Aljouf University, Saudi Arabia. The patients were randomly divided into two equal groups: Group I (control group): Patient received a conventional heat-cured acrylic complete denture (Vertex™ Regular, Vertex-Dental B.V., The Netherlands) and Group II (experimental group): Patient received a thermoplastic complete denture (Vertex™ ThermoSens, Vertex-Dental B.V., The Netherlands). MBF measurements were taken at the time of new denture placement and after 6 months of denture use. Statistics were analyzed using independent t-test to compare the MBF measurements between both groups.

RESULTS

At the time of denture placement, there was no significant difference in bite force measurements between both groups. Bite force is increasing considerably after 6 months of denture use, and it was higher than MBF recorded at the time of new prosthesis placement in the same group. The MBF values were considerably higher in patients with a thermoplastic denture than patients with conventional acrylic denture with statistically significant difference after 6 months of denture use.

CONCLUSION

After 6 months of denture use, patients with a thermoplastic denture have a higher biting force than patients with a conventional acrylic denture. Therefore, it could be considered a treatment plan option according to the ridge nature and quality to solve the problem of diminished bite force in old age patients.

Bite force and electromyography evaluation after cranioplasty in patients with craniosynostosis

OBJECTIVE

This long-term follow-up investigation aimed to assess masticatory muscle function in 15 patients with craniosynostosis with detachment of the temporal muscle during fronto-orbital advancement 6 years after cranioplasty compared with a non-operative stomatognathic healthy cohort in the same age group (n = 25).

STUDY DESIGN

The follow-up assessment for the operated children occurred on average 5.2 ± 1.7 years after surgery at the age of 7 ± 1.6 years. The maximum bite force was assessed, in addition to the bilateral function of both temporal and masseter muscles, which were analyzed using superficial electromyography.

RESULTS

The maximum bite force was 257 ± 89 N 255 ± 88 N (right/left), respectively, in the group of operated children and 212 ± 61 N and 203 ± 57 N (right/left), respectively, in the control group, without clinical relevant difference between groups. The surface electromyography signal of the temporal muscle correlated positively with the bite force and showed a slightly lower average resting tone activity in the control group, whereas muscle fatigue occurred slightly faster in the operated children in both muscles without statistically significant difference between the 2 groups.

CONCLUSIONS

There was no measurable dysfunction in the temporal muscle after the operative correction of craniosynostosis compared with a healthy population of children.