What's in a smile?: Quantification of the vertical smile of patients with myasthenia gravis

Consensus on the terminologies and methodologies for masticatory assessment

A large number of methodological procedures and experimental conditions are reported to describe the masticatory process. However, similar terms are sometimes employed to describe different methodologies. Standardisation of terms is essential to allow comparisons among different studies. This article was aimed to provide a consensus concerning the terms, definitions and technical methods generally reported when evaluating masticatory function objectively and subjectively. The consensus is based on the results from discussions and consultations among world‐leading researchers in the related research areas. Advantages, limitations and relevance of each method are also discussed. The present consensus provides a revised framework of standardised terms to improve the consistent use of masticatory terminology and facilitate further investigations on masticatory function analysis. In addition, this article also outlines various methods used to evaluate the masticatory process and their advantages and disadvantages in order to help researchers to design their experiments.

Efficacy of laser acupuncture for patients with chronic Bell's palsy: A study protocol for a randomized, double-blind, sham-controlled pilot trial

BACKGROUND

Bell's palsy is the most frequent cause of unilateral peripheral facial palsy, a common condition that third of patients can have inadequate recovery and subsequent physical and social impairments. The largely ineffective and even controversial nature of the various medical and surgical treatment options means that novel, alternative approaches are needed. In preclinical and clinical evidence, low-level laser therapy (LLLT) has demonstrated the ability to regenerate peripheral nerves. Laser acupuncture treatment (LAT), the stimulation of traditional acupoints with low-intensity, non-thermal laser irradiation, is a common treatment modality, but its efficacy in chronic Bell's palsy is undetermined. This study aims to evaluate the efficacy of LAT in patients experiencing inadequate recovery from Bell's palsy.

METHODS

This 2-armed, parallel, randomized, subject-assessor-blinded, single-center, sham-controlled pilot trial will randomly assign 32 eligible patients into either a real LAT group (n = 16) or a sham LAT group (n = 16). The real LAT group will receive 3 LAT sessions each week for 6 weeks (a total of 18 sessions), delivered to acupoints corresponding with the affected side of the face. The sham LAT group will receive the same treatment as the real LAT group, but with a sham laser device. The primary outcome measure will be the change from baseline at week 6 in the Facial Disability Index score. Secondary outcomes will monitor changes during treatment in the House-Brackmann and Sunnybrook facial nerve grading systems and stiffness scale, at weeks 1, 3, and 6.

DISCUSSION

To the best of our knowledge, this double-blind, randomized, sham-controlled trial is the first such investigation into the efficacy of LAT in chronic Bell's palsy. Clinical trials using LLLT have shown positive therapeutic effects in acute Bell's palsy, although as yet, the feasibility and efficacy of LAT remain unclear in patients experiencing inadequate recovery from Bell's palsy.

TRIAL REGISTRATION

This trial protocol has been approved by the Research Ethics Committee of the China Medical University Hospital, Taichung, Taiwan (Protocol ID: CMUH107-REC1-030) also registered at ClinicalTrials.gov (identifier no. NCT03592797).

[Clinical, endoscopical and manometric evaluation of swallowing in patients with acquired autoimmune myasthenia gravis]

Dysphagia, or difficulty swallowing, is a common problem following myasthenia gravis (MG) and may lead to aspiration of saliva, food or liquids. We herein present 22 MG patients, with complaint of dysphagia, evaluated by phonoaudiological evaluation, nasofibrolaryngoscopical analysis and manometry of upper esophageal sphincter. The main objective was to evaluate the phases of the swallowing process and anatomical and functional aspects of oropharyngeal musculature. The age of patients varied from 19 to 74 years; being 19 female and 3 male. The main data were: (1) statistically significant relation between the phonoaudiological clinical evaluation and nasofibrolaryngoscopical one; (2) stomatognatical system disorders present in 100%; (3) swallowing and chewing disorders present in 100%, when clinically evaluated, and in 81,8% when evaluated by the nasofibrolaryngoscopy; (4) statistically significant relation between penetration/aspiration and antecedents of pneumonia; (5) stomatognatical muscles very altered, difficulty controlling the bolus, collection of food in the pharynx or larynx and presence of penetration and/or aspiration showed significant correlation with weakness of a pharyngeal muscles. These findings justify the necessity to evaluate clinically the swallowing phases in MG patients, with the main purpose to prevent both aspiration and dehidration from inadequate oral intake.

Masticatory performance in patients with myasthenia gravis

Masticatory muscle electromyograms (EMGs) were recorded while patients with bulbar myasthenia gravis chewed artificial food and compared with those of patients with ocular myasthenia gravis, patients in clinical remission who had previously suffered from bulbar myasthenia gravis and healthy individuals. Masticatory performance and EMGs were significantly smaller in the bulbar group. There were no indications of subclinical masticatory muscle weakness in patients with bulbar myasthenia gravis in remission and in patients with ocular myasthenia gravis. Patients with bulbar myasthenia gravis barely compensated for muscular weakness by chewing at a higher percentage of their maximal EMG. These quantitative findings, when combined with subjective reports of masticatory muscle weakness, show that a need to support the jaw is characteristic of patients with bulbar myasthenia gravis who produce low EMG activity.

Controlled study of EMG activity of the jaw closers and openers during mastication in patients with myasthenia gravis

Mastication was evaluated in patients with bulbar myasthenia gravis and compared with that of patients with ocular myasthenia gravis, patients in remission who previously suffered from bulbar symptoms, and healthy controls. Bulbar myasthenia gravis may impair mastication due to weakness of the masticatory muscles. The aim of the study was to objectively evaluate the influence of myasthenia gravis on mastication. The subjects chewed a piece of breakfast cake and chewed 1 min on a piece of chewing gum. Surface EMG of the masseter muscle, temporalis muscle and jaw opener muscles was recorded. Statistical analysis revealed that bulbar patients produced significantly less EMG activity in the closing phase of a chewing cycle in both experiments. The EMG of the masseter muscle expressed as percentage of the maximum EMG during maximal clenching showed significantly higher values in the bulbar group than in the other groups. This was not found for the temporalis muscle. It was suggested that bulbar patients use a strategy of limited effort to produce a bolus that can be swallowed. The ocular patients and the patients in remission showed no subclinical impairments in muscle function during chewing.

Maximal bite force and surface EMG in patients with myasthenia gravis

Masticatory muscle strength was quantified in patients with bulbar myasthenia gravis and compared with that of patients with ocular myasthenia gravis, patients in clinical remission (whether or not pharmacological) who previously suffered from bulbar myasthenia gravis, and healthy subjects. Maximal bite force and maximal activity of the masseter and temporalis muscles and of the submental muscle complex were measured. Bite force was decreased in the patients with bulbar myasthenia gravis, but was normal in the patients in the clinical remission group and in the ocular group. These findings were consistent with the results of electromyographic data. Although subjective reports of masticatory muscle weakness provide valuable information, quantitative measurements provide more information about the degree of muscle weakness of individual muscles. This is especially important for longitudinal evaluation of therapy in individual patients and for pharmacotherapeutic research.