Assessment of Masticatory Muscle Function in Patients with Bilateral Complete Cleft Lip and Palate and Posterior Crossbite by means of Electromyography

Electromyographic Evaluation of Masticatory Muscle Activity in Individuals with and without Cleft Lip/Palate: A Systematic Review and Meta-analysis

OBJECTIVE

This study aims to systematically review and meta-analyze the electromyographic activity of masticatory muscles in cleft palate and non-cleft patients, and identify influencing factors.

DESIGN

Systematic Review and Meta-analysis.

PATIENTS AND EXPOSURES

Patients with cleft lip/ palate.

COMPARISON

Patients without CL/P.

MAIN OUTCOME MEASURES

Electrical activity of masseter and temporalis muscles at rest and during peak activation.

RESULTS

After a comprehensive search in MEDLINE, Web of Science, EMBASE, Scopus, and Cochrane's CENTRAL up to December 2022, without language or date restrictions. Eligible trials were selected based on the PECO question and assessed for bias using Cochrane's ROBINS-E tool. Eight clinical trials with 474 participants were included in the review. Then relevant data was extracted from included studies using customized forms. A random-effects meta-analysis was performed to combine the results of the studies, meta-analyses showed that CL/P patients have elevated electrical activity in the masseter (P = .01) and temporalis (P = <.01) muscles at rest compared to non-cleft control patients. During maximum bite force, cleft patients exhibited a statistically significant decrease in electrical activity in both the masseter (P = .03) and temporalis (P = <.01) muscles.

CONCLUSIONS

According to our meta-analysis, cleft patients exhibited increased resting muscle activity but decreased activity during maximum bite force, indicating reduced efficiency of masticatory muscles compared to non-cleft patients. These differences can be attributed to anatomical variations, compensatory mechanisms, and previous treatments.

Mandibular Radiomorphometric Characteristics of Individuals with Bilateral or Unilateral Cleft Lip and Palate

OBJECTIVE

This study aimed to investigate and compare the mandibular radiomorphometric characteristics of patients with unilateral or bilateral cleft lip and palate (CLP) with those of individuals without CLP and to determine whether there was a difference.

DESIGN

Retrospective cohort study.

SETTING

Orthodontic Department in Faculty of Dentistry.

PATIENTS AND INTERVENTIONS

Mandibular cortical bone thickness was measured on high-quality panoramic radiographs taken from 46 patients with unilateral or bilateral CLP aged 13-15 years and 21 control patients.

MAIN OUTCOME MEASURES

Three radiomorphometric indices [antegonial index (AI), mental index (MI), and panoramic mandibular index (PMI)] were measured bilaterally. AutoCAD software was used for MI, PMI, and AI measurements.

RESULTS

Left MI values were significantly lower in individuals with unilateral cleft lip and palate (UCLP; 0.029 ± 0.04) than in individuals with bilateral cleft lip and palate (BCLP; 0.033 ± 0.07). In addition, right MI values of individuals with right UCLP (0.26 ± 0.06) were significantly lower than those of individuals with left UCLP (0.34 ± 0.06) or BCLP (0.32 ± 0.08). No difference was observed between individuals with BCLP and left UCLP. These values did not differ between groups.

CONCLUSIONS

Antegonial index and PMI values did not differ between individuals with different types of CLP or when compared with control patients. In patients with UCLP, cortical bone thickness was found to be reduced on the cleft side compared to the intact side. Patients with UCLP with a right-sided cleft had a more substantial decrease in cortical bone thickness.

Electromyographic Study of Masticatory Muscle Function in Children with Down Syndrome

This study assessed the electrical activity of the masticatory muscles in both children with down syndrome (DS) and healthy children. After applying the inclusion and exclusion criteria, 30 patients aged between 7.9 and 11.8 years participated in the study. They were divided into two groups of 15: DS and non-DS. A DAB-Bluetooth device (Zebris Medical GmbH, Germany) was used to record the electromyographical (EMG) activity of the right and left temporal and of the right and left masseter muscles at rest and during maximum voluntary clenching (MVC). The asymmetry index between right and left masticatory muscle EMG activity was calculated for each position. The Mann–Whitney U test was applied to analyze the study results. There were no differences in the electrical activity of the temporal and masseter muscles at rest between the groups. During MVC, the asymmetry index for the masseter muscles was significantly higher in subjects with DS. The electrical potentials of the temporal and masseter muscles in children with DS were significantly lower compared to the corresponding parameters for healthy children when clenching.

The Electrical Activity of the Orbicularis Oris Muscle in Children with Down Syndrome-A Preliminary Study

The aim of this study was to assess the electrical activity of the superior (SOO) and inferior (IOO) orbicularis oris muscles in children with Down syndrome (DS) and in children without DS. After applying the inclusion and exclusion criteria, 30 subjects were eligible to participate in the later stages of the research—15 subjects with DS (mean age 10.1 ± 1.1) and 15 healthy controls (mean age 9.8 ± 1.0). The electrical potentials of the SOO and IOO muscles were recorded using a DAB-Bluetooth electromyography machine (Zebris Medical GmbH, Germany) during the following tasks: At clinical rest, saliva swallowing, lip protrusion, lip compression, and production of the syllable/pa/. The Mann–Whitney U test was conducted to compare the study results between the groups. An analysis of the electromyographical (EMG) recordings showed that the electrical activity of the orbicularis oris muscle in children with DS and lip incompetence was significantly higher compared to healthy children during saliva swallowing, lip compression, and when producing the syllable/pa/, and this may suggest greater muscular effort due to the need to seal the lips during these functional conditions.

Superior Orbicularis Oris Muscle Activity in Children Surgically Treated for Bilateral Complete Cleft Lip and Palate

The aim of this cross-sectional study was to evaluate the electromyographic activity of the superior orbicularis oris muscle both in children surgically treated for bilateral complete cleft lip and palate (BCCLP) as well as in subjects without BCCLP. The study comprised 77 children aged 6.6 to 12.5 years. All the patients with clefts had previously undergone lip and palate surgery. The upper lip electromyographic (EMG) assessments were made with a DAB-Bluetooth device (Zebris Medical GmbH, Germany) at rest, while swallowing saliva, protruding lips and compressing lips. EMG measurements were also made when the subjects produced phonemes /p/, /b/, and /m/ with the vowel /a/. The Mann-Whitney U test was applied to statistically analyze the EMG values. Significantly higher median upper lip EMG activity under working conditions such as swallowing saliva, lip compression, and production of the phoneme /p/ with the vowel /a/ was observed in patients with BCCLP compared to those without a cleft. The results of the study showed that the upper lip muscle activity increases in children with BCCLP when swallowing saliva, compressing lips and during some speech movement tasks. This may be important in the aspect of the effect of surgical lip repair on the craniofacial growth.