Electromyographic analysis of superior orbicularis oris muscle function in children surgically treated for unilateral complete cleft lip and palate

Detection of Lip, Tongue, Masseter, and Temporalis Muscle Contractions with Electromyography Tools as an Early Diagnostic Medium for Dentoalveolar Malocclusion

OBJECTIVES

 This study aims to detect early class I, II, and III malocclusions through the muscle strength of the lips, tongue, masseter, and temporalis.

MATERIALS AND METHODS

 The study subjects were 30 pediatric patients with predetermined criteria. The subjects were divided into class I, II, and III malocclusions where each classification of malocclusion amounted to 10 people. Subjects were differentiated according to gender and age. Tongue pressure during swallowing was recorded by a palatal measurement sensor system. The strength of the activity was assessed when the lip muscles resisted as hard as possible the traction plate placed between the teeth and the lips, then the force was connected to an electromyograph (EMG) to be measured. Temporal and masseter muscle contractions were assessed when the muscles performed swallowing, chewing, mouth opening, resting, mouth closing, and biting movements.

STATISTICAL ANALYSIS

 Data analysis using the SPSS application was performed with the ANOVA test if the data distribution was normal, and if the data distribution was not normal, then the Kruskal-Wallis test was used. Significant data were evaluated by post-hoc tests using least significant difference if the data distribution was normal or the Mann-Whitney test if the data distribution was not normal.

RESULTS

 It was found that there was a significant difference in the left masseter muscle and left temporalis muscle.

CONCLUSION

 EMG can be considered as a tool to detect class I, II, and III malocclusions through muscle contraction. Biting and chewing positions have satisfactory EMG examination results for malocclusion detection. Age and gender of the child may affect the results of EMG examination in certain conditions.

Change in Lower Lip Position After Le Fort I Advancement in Patients with Bilateral vs. Unilateral Cleft Lip and Palate

To compare lower lip changes after Le Fort I advancement surgery in patients with a cleft.

Single institution, retrospective review.

Academic tertiary referral hospital.

Skeletally mature patients with a cleft who underwent one-piece Le Fort I advancement surgery who had a lateral cephalogram or cone-beam computed tomography (CBCT) scan preoperatively and at least 6 months postoperatively. Patients who underwent concomitant mandibular surgery or genioplasty were excluded. 64 patients were included: 45 male and 19 female, 25 with BCLP and 39 with UCLP. The mean age at surgery was 18.4 years.

Single jaw one-piece Le Fort I advancement surgery.

Standard lateral cephalometric landmarks of the bony skeleton and soft tissue were compared before and after Le Fort I advancement. Pearson correlation coefficients (r) were calculated to measure the correlation between lower lip position and other soft and hard tissue changes.

After comparable maxillary advancements [BCLP: 7.2 mm (95% CI: 6.2-8.3 mm), UCLP: 6.4 mm (95% CI: 5.7-7.0 mm)] the horizontal upper-to-lower lip discrepancy significantly improved in both groups. The lower lip became thinner and more posteriorly positioned. Changes in lower lip position correlated strongly with mandibular bony landmarks and moderately with upper lip position, but poorly with maxillary landmarks.

Le Fort I advancement results in posterior displacement of the lower lip and better lip competence, thereby improving facial harmony. This lower lip change is not predictable by degree of maxillary advancement, and does not differ in patients with BCLP vs. UCLP.

The oral microbiome of children in health and disease-a literature review

The oral microbiome is a complex community of microorganisms residing in the oral cavity interacting with each other and with the host in a state of equilibrium. Disruptions in this balance can result in both oral and systemic conditions. Historically, studying the oral microbiome faced limitations due to culture-dependent techniques that could not capture the complexity and diversity of the microbial community. The emergence of advanced genomic technologies and the ease of sample collection from the oral cavity has revolutionized the understanding of the oral microbiome, providing valuable insights into the bacterial community in both health and disease. This review explores the oral microbiome in children, discussing its formation and dynamics in both states of health and disease, its role in various conditions such as dental caries, periodontal disease, oral cancer, cleft lip and palate, and explores its connection to several systemic consequences.

Comparison of Peri-Oral and Masticatory Muscle Activity between Repaired Unilateral Cleft Lip and Palate and Non-Cleft Individuals - A Systematic Review

Surgical intervention in patients with repaired unilateral cleft lip and palate (UCLP) leads to altered muscular activity and hinders the normal growth of the maxilla. To compare the activity of superior orbicularis oris and masticatory muscles between repaired unilateral cleft lip and palate and non-cleft individuals. A literature search was carried out on MEDLINE/PubMed, Cochrane Library, Science Direct, Semantic Scholar, and Google Scholar databases upto January 2024 resulting in 1320 studies. Specified inclusion/exclusion criteria guided the selection of five relevant articles. Study selection, assessment of the outcome of articles, and subsequent Risk of Bias (RoB) assessment were done independently by three authors. In case of any disparity, the fourth and fifth authors were consulted. All five studies were observational cross-sectional studies. The majority of the studies reported an altered muscular activity in repaired UCLP patients compared to normal individuals, which may affect the normal growth of the maxilla. Patients with repaired UCLP show an increased muscle activity compared to non-cleft subjects, which may lead to altered masticatory efficiency in such patients.

Measurement of surface electromyography activity during swallowing in paediatrics: a scoping literature review

Surface electromyography (sEMG) could be used for diagnostic and therapeutic purposes in various health conditions. For example, sEMG biofeedback is shown to be beneficial in adults with swallowing disorders (dysphagia), whereas there are no easily identifiable studies to support such evidence in paediatrics. The current review aimed to evaluate the feasibility of implementing sEMG during swallowing tasks in paediatric populations with various diagnoses. Additionally, the review aimed to describe findings in publications involving participants with cerebral palsy (CP) and dysphagia. Paediatric-related publications were sourced using English keywords and phrases across the following seven databases: PubMed, EMBASE, CINAHL, Web of Science, PsycINFO, and ProQuest Dissertations and Theses Global. The search included all available publications without language and date restrictions. Publications using sEMG during chewing tasks were also accepted in the review as chewing is considered to be part of the act of swallowing. The feasibility of measuring sEMG during swallowing in children with various health conditions was supported by 116 publications (n = 6 literature reviews) that met the inclusion criteria for the final full-text review. However, a few publications described some difficulties occurring directly during the sEMG data collection sessions. The review identified 15 publications involving 177 participants with CP who underwent sEMG while swallowing (n = 1 publication focused solely on the assessment of chewing). Ten publications described studies that recruited children with dysphagia. Children with CP who had dysphagia were recruited in five of these studies.

CONCLUSIONS

The acquisition of sEMG measurements while performing swallowing tasks was shown to be feasible in children with various diagnoses including those who have CP and dysphagia. Future studies should investigate the implementation of sEMG as a part of paediatric dysphagia therapy alongside biofeedback swallowing skill training.

WHAT IS KNOWN

• Surface electromyography (sEMG) could be implemented for diagnostic and therapeutic purposes in various health conditions. • Biofeedback using sEMG is beneficial in adults with swallowing disorders (dysphagia).

WHAT IS NEW

• Implementation of sEMG was shown to be feasible during swallowing tasks in paediatric populations with various diagnoses, including dysphagia and cerebral palsy. • The usage of sEMG biofeedback as a part of paediatric dysphagia management should be investigated in future studies.

Outcome Comparisons of Two Different Orbicularis Oris Muscle Reconstruction Techniques in Patients with Unilateral Incomplete Cleft Lip

BACKGROUND

The long-term postoperative outcomes of two different orbicularis oris muscle reconstruction techniques in patients with unilateral incomplete cleft lip were compared.

METHODS

Forty-seven patients with unilateral incomplete cleft lip were assessed in this study, where 23 underwent a traditional method of reconstruction and 24 underwent a novel method. Preoperative measurements, postoperative results, and 3-year follow-up outcomes were measured by photographic anthropometric analysis. Five upper lip measurement indices and 8 nostril indices were included.

RESULTS

The postoperative outcomes showed that the shape of the lip and nose was more symmetric with the new surgical method compared with the conventional technique. Long-term outcomes after 3 years, although characterized by minimal changes during maxillofacial development, showed better maintenance of lip and nostril symmetry in the novel-method group.

CONCLUSION

The novel technique seeks to balance the perinasal and perioral muscles, resulting in improved symmetry compared with the traditional reconstruction technique.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Investigating oral microbiome profiles in patients with cleft lip and palate compared with the healthy control

BACKGROUND

Patients with cleft lip and palate (CLP) have an oronasal communication differed from the closed state in healthy individuals, leading to a unique oral microbiome. This study aimed to determine if variances in the oral microbiota persist among CLP patients who have received treatments for the closure of these fistulas compared to the microbiota of healthy individuals.

METHODS

Saliva samples were collected from a cohort comprising 28 CLP patients (CLP group) and 30 healthy controls (HC group). Utilizing 16S rRNA sequencing on the Illumina NovaSeq platform, we conducted a comprehensive analysis of the diversity and composition of the oral microbiota.

RESULTS

The analysis of the microbiota in the saliva samples revealed a total of 23 microbial phyla, 38 classes, 111 orders, 184 families, 327 genera and 612 species. The alpha diversity with microbial abundance and evenness indicated the significant difference between the CLP and HC groups. Principal coordinate analysis (PCoA) and the ADONIS test further supported the presence of distinct microorganisms between the two groups. The CLP group displayed elevated abundances of Neisseria, Haemophilus, Porphyromonas, and Granulicatella, as indicated by LefSe analysis. Conversely, Rothia, Veillonella, and Pauljensenia exhibited significant reductions in abundance in the CLP group. The results of the PICRUSt analysis indicated significant differences in the relative abundance of 25 KEGG pathways within the CLP group. Through Spearman correlation analysis, strong associations between Rothia, Veillonella, and Pauljensenia and 25 functional pathways linked to CLP were identified.

CONCLUSION

Findings of this study offer a thorough comprehension of the microbiome profiles of CLP patients after the restoration of oronasal structure and are anticipated to present innovative concepts for the treatment of CLP.

Relation between Maximum Oral Muscle Pressure and Dentoalveolar Characteristics in Patients with Cleft Lip and/or Palate: A Prospective Comparative Study

BACKGROUND

Perioral muscle function, which influences maxillofacial growth and tooth position, can be affected in patients with oral clefts due to their inherent anatomical characteristics and the multiple surgical corrections performed. This research aims to (1) compare the maximum oral muscle pressure of subjects with and without isolated cleft palate (CP) or unilateral cleft lip and palate (UCLP), (2) investigate its influence on their dentoalveolar characteristics, and (3) investigate the influence of functional habits on the maximum oral muscle pressure in patients with and without cleft.

MATERIAL AND METHODS

Subjects with and without CP and UCLP seeking treatment at the Department of Orthodontics of University Hospitals Leuven between January 2021 and August 2022 were invited to participate. The Iowa Oral Performance Instrument (IOPI) was used to measure their maximum tongue, lip, and cheek pressure. An imbalance score was calculated to express the relationship between tongue and lip pressure. Upper and lower intercanine (ICD) and intermolar distance (IMD) were measured on 3D digital dental casts, and the presence of functional habits was reported by the patients. The data were analyzed with multivariable linear models, correcting for age and gender.

RESULTS

44 subjects with CP or UCLP (mean age: 12.00 years) and 104 non-affected patients (mean age: 11.13 years) were included. No significant differences in maximum oral muscle pressure or imbalance score were detected between controls and clefts or between cleft types. Significantly smaller upper ICDs and larger upper and lower IMDs were found in patients with clefts. A significant difference between controls and clefts was found in the relationship between oral muscle pressure and transversal jaw width. In cleft patients, the higher the maximum tongue pressure, the wider the upper and lower IMD, the higher the lip pressure, the smaller the upper and lower ICD and IMD, and the higher the imbalance score, the larger the upper and lower IMD and lower ICD. An imbalance favoring the tongue was found in cleft patients. The influence of functional habits on the maximum oral muscle pressure was not statistically different between clefts and controls.

CONCLUSION

Patients with CP or UCLP did not present reduced maximum oral muscle pressure compared with patients without a cleft. In cleft patients, tongue pressure was consistently greater than lip pressure, and those who presented a larger maxillary width presented systematically higher imbalance scores (favoring the tongue) than those with narrow maxillae. Therefore, the influence of slow maxillary expansion on maximum oral muscle pressure in cleft patients should not be underestimated.

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.

Surface Electromyography as a Method for Diagnosing Muscle Function in Patients with Congenital Maxillofacial Abnormalities

Electromyography (EMG) is the most objective and reliable method available for imaging muscle function and efficiency, which is done by identifying their electrical potentials. In global surface electromyography (sEMG), surface electrodes are located on the surface of the skin, and it detects superimposed motor unit action potentials from many muscle fibers. sEMG is widely used in orthodontics and maxillofacial orthopaedics to diagnose and treat temporomandibular disorders (TMD) in patients, assess stomatognathic system dysfunctions in patients with malocclusions, and monitor orthodontic therapies. Information regarding muscle sEMG activity in subjects with congenital maxillofacial abnormalities is limited. For this reason, the aim of this review is to discuss the usefulness of surface electromyography as a method for diagnosing muscle function in patients with congenital malformations of the maxillofacial region. Original papers on this subject, published in English between 1995 until 2020, are located in the MEDLINE/PubMed database.

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

Aim

The aim of this study was to evaluate the electrical activity of the masticatory muscles in children with a bilateral complete cleft lip and palate (BCCLP) and posterior crossbite as well as in noncleft subjects with no malocclusion. Another purpose of the study was to examine the possible factors associated with this muscle activity.

Methods

The study included 52 children with mixed dentition and Class I occlusions (20 patients with nonsyndromic BCCLP and 32 subjects with no clefts). All the cleft patients had posterior crossbite. The surface electromyography (sEMG) was used to identify the electrical potentials of the temporalis and masseter muscles. The electromyographical (EMG) recordings were taken with a DAB-Bluetooth Instrument (zebris Medical GmbH, Germany) at rest and during maximum voluntary clenching (MVC). The relationships between muscle EMG activity and independent variables were identified through multivariate logistic regression analysis.

Results

The EMG activity of the temporalis muscles at rest was significantly higher in BCCLP patients with malocclusion in comparison with the noncleft subjects with normal occlusion. During MVC, significantly lower electrical potentials of the temporalis and masseter muscles were observed in cleft patients compared to the noncleft group. The presence of BCCLP, unilateral posterior crossbites, increased vertical overlap, and increased overjet are factors strongly associated with higher temporalis muscle EMG activity at rest.

Conclusion

The use of surface electromyography in imaging muscle function showed that children with BCCLP and posterior crossbite exhibited altered masticatory muscle potentials at rest and during clenching. The presence of unilateral posterior crossbites, increased vertical overlap, and increased overjet had a significant impact on temporalis muscle activity in cleft patients. This knowledge is important in the aspect of early and proper diagnosis and orthodontic treatment of malocclusions, thereby achieving correct occlusion and improvement in muscle function.

Effects of Age, Sex, Disease, and Exercise Training on Lip Muscle Strength

Lip muscle strength has been shown to influence daily functional activities such as facial expression, speech production, and eating. In this review, recent literature regarding lip strength and exercise training responses are summarized, highlighting the influence of sex, age, and disease (e.g., stroke). A search using five electronic databases was conducted. Twelve studies were identified from the search, which included five studies using healthy adults and seven studies using patients with diseases or chronic ailments. Regardless of the population, lip strength training multiple times a day for a relatively short term (<24 weeks) has resulted in improvements of lip muscle strength. This change in lip strength has been observed in both young and old participants. Although changes in strength have been observed in both men and women, we are unaware of any studies that have tested whether there are sex differences in this response. The same directional change can be expected for patients with stroke and patients with lip incompetence, but the magnitude of the training effect seems to be higher in healthy people.

Etiology of Cleft Lip Lower Lip Deformity: Use of an Objective Analysis to Measure Severity

OBJECTIVE

Measure lower lip thickness and eversion in patients with cleft lip and palate (CLP) and maxillary hypoplasia. The specific aims were to (1) compare lower lip thickness/eversion in patients with CLP to noncleft controls with maxillary hypoplasia, (2) determine differences between patients with unilateral CLP (UCLP) and bilateral CLP (BCLP), and (3) document changes in the lower lip that occur with Le Fort I advancement.

DESIGN

Retrospective case-control study.

SETTING

Tertiary care center.

PATIENTS/PARTICIPANTS

Patients with available pre- and postoperative CT scans and 2D lateral photographs who had a Le Fort I advancement between 2009 and 2017. There were 32 patients with CLP (17 females; mean age 17.7 ± 1.9 years) and 33 noncleft controls (21 females; mean age 18.8 ± 2.6 years).

MAIN OUTCOME MEASURES

Lower lip thickness and eversion.

RESULTS

Patients with CLP and maxillary hypoplasia have a significantly thicker lower lip (P = .019) and outward rotation of the vermilion border (P = .003) compared to noncleft controls. The lower lip was significantly thicker in patients with BCLP than in those with UCLP (P = .035). Lower lip thickness and rotation did not change after maxillary advancement.

CONCLUSIONS

Patients with CLP and maxillary hypoplasia have a thicker and more everted lower lip than noncleft controls. Patients with BCLP have a significantly thicker lower lip than those with UCLP. Strain of the lower lip musculature appears to be an important contributor to the development of the cleft lip lower lip deformity.

Fractional CO2 laser treatment for post-surgical lip scars in cleft lip and palate patients

Post-surgical scars of cleft lip patients can lead to abnormal lip activity, which causes deficient maxillary growth. The aim of the present study was to assess the effect of laser therapy on the appearance and electrical activity of the upper lip in cleft lip and palate patients. Twelve patients with cleft lip and palate participated in this study. All patients had surgically repaired the cleft lip at the age of about 3-6 months. The lip scars underwent five fractional CO₂ laser treatment sessions with a 4-week interval. Improvement of the quality of the skin texture was recorded according to quartile grading scale based on photographs taken before and 1 month after treatment. Patients' satisfaction survey was also recorded using Patient Scar Assessment Questionnaire (PSAQ) before and after laser therapy. Moreover, the EMG activity of the upper lip muscle was measured before and after treatment. According to dermatologists, the improvement of scar appearance ranged from 0.5 to 3, with a mean of 1.29 ± 0.86. Mean scores of the scar appearance (p < 0.001), symptoms (p = 0.003), and scar consciousness (p < 0.001) subscales of the PSAQ questionnaire had significantly increased after treatment. The EMG recording of the upper lip had decreased significantly after laser treatment at rest (p = 0.009) and maximum lip compression (p = 0.007). The fractional CO₂ laser is an effective method for treating old scars of the cleft lip with a significant change in the opinion of patients about their scar appearance. Also, the therapy can help to reduce the EMG activity of the upper lip at rest.

The Electrical Activity of Masseter and Anterior Temporal Muscles in Patients With Unilateral Cleft Lip and Palate

This study aimed to determine the electrical activity of masseter and anterior temporal muscles in patients with unilateral cleft lip and palate (CLP) and compare it with healthy volunteers. The study involved 20 female patients (mean age 20 ± 4 years) with unilateral cleft lip and palate who had undergone lip and palate surgery in childhood and finished the first-phase orthodontic therapy with level and align teeth. Twenty age- and sex-matched volunteers with no cleft lip and palate were involved as controls. Electromyographic (EMG) signals of masseter and anterior temporal muscles were recorded at rest position, during swallowing and during maximum bite force (MBF). EMG signals at different test conditions were compared between the cleft and noncleft sides of CLP patients and between CLP patients and healthy individuals. The EMG potentials of masseter (rest, swallowing, MBF) and temporal (rest, MBF) muscles were significantly higher in the cleft than the noncleft side of CLP patients (P value <0.001). Generally, patients with unilateral cleft lip and palate experienced a significant increase in the electrical activity of the masseter and temporal muscles in both sides compared to the control group (P <0.05). In conclusion, patients with unilateral cleft lip and palate exhibit overall greater masticatory muscle activity compared to healthy individuals. The asymmetric masticatory function in subjects with unilateral cleft lip and palate may be associated with severe consequences such as asymmetric facial growth, implying the importance of early diagnosis and orthodontic treatment to achieve a favorable environment for balanced facial growth in CLP affected patients.

The Diagnostic Value of Electromyography in Identifying Patients With Pain-Related Temporomandibular Disorders

Introduction: Orofacial pain disorders can be divided into several subgroups. One of them is temporomandibular disorders (TMD) with recognizable signs such as joint noises, limitations in the range of motion, or mandibular deviation during function and symptoms-pain in the muscles or joint. Surface electromyography (sEMG) is a diagnostic tool that ensures reliable and valid evaluation of muscle activity. sEMG detects electrical potentials and on this account may conceivably be employed in the TMD recognition. The aim of this study was to assess the sensitivity, specificity, and accuracy of electromyography in diagnosing subjects with temporomandibular disorders, including pain-free TMD and pain-related TMD. Methods: The sample comprised 88 patients with cleft lip and palate and mixed dentition. TMD has been recognized on the grounds of Axis I of the Research Diagnostic Criteria for TMD (RDC/TMD). To evaluate the electrical activity of the temporal and masseter muscles in the rest position and during maximum voluntary contraction, a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany) was used. The analysis of the receiver operating characteristic (ROC) curve gave information about accuracy, cut-off point value, sensitivity and specificity of the normalized sEMG data. Results: The highest diagnostic efficiency of sEMG in terms of identifying subjects with TMD and pain-related TMD was observed for the mean values of temporal and masseter muscle activity as well as the Asymmetry Index of the masseter muscles in a rest position. A moderate degree of EMG accuracy in differentiating between pain-related TMD and non-TMD children was observed for the mean values of masseter muscle activity and the Asymmetry Index of the masseter muscles at rest. Conclusion: An evaluation of electromyography exhibits its diagnostic usability in recognition of patients with pain-related TMD and it could be used as an adjunctive tool in the identification of this disorder. Clinical Trial Registration: This clinical research was registered in the ClinicalTrials.gov database under the number NCT03308266.

Electromyographic Analysis of Masticatory Muscles in Cleft Lip and Palate Children with Pain-Related Temporomandibular Disorders

Aim

The aim of this study was to assess the electrical activity of temporalis and masseter muscles in children with cleft lip and palate (CLP) and pain-related temporomandibular disorders (TMD-P).

Methods

The sample consisted of 31 CLP patients with a TMD-P (mean age 9.5 ± 1.8 years) and 32 CLP subjects with no TMD (mean age 9.2 ± 1.7 years). The children were assessed for the presence of temporomandibular disorders (TMD) using Axis I of the Research Diagnostic Criteria for TMD (RDC/TMD). Electromyographical (EMG) recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany) in the mandibular rest position and during maximum voluntary contraction (MVC).

Results

The rest activity of the temporalis and masseter muscles was significantly higher in TMD-P group compared with non-TMD children. A significant decrease in temporalis muscle activity during MVC was observed in TMD-P patients. There was a significant increase in the Asymmetry Index for temporalis and masseter muscle rest activity in the TMD-P group.

Conclusion

Cleft children diagnosed with TMD-P have altered masticatory muscle activity, and this can affect their muscle function.

The electrical activity of the masticatory muscles in children with cleft lip and palate

BACKGROUND

Information regarding masticatory muscle function in children with cleft lip and palate (CLP) is limited. As a consequence, research on masticatory muscle activity in cleft subjects is needed.

AIM

To assess masticatory muscle activity in children surgically treated for CLP as well as identify the possible factors associated with this activity.

DESIGN

The sample comprised 82 children with mixed dentition and Class I occlusions (25 children with unilateral CLP and 57 subjects with no cleft abnormalities). A DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany) was used to take electromyographical (EMG) recordings of the temporal and masseter muscles both in the mandibular rest position and during maximum voluntary contraction (MVC).

RESULTS

Patients with clefts showed a significant increase in temporal muscle activity at rest compared with the controls. The presence of clefts and unilateral posterior crossbites are factors strongly associated with increased temporal muscle EMG potentials during rest position.

CONCLUSIONS

Children with clefts have altered temporal muscle function. The presence of posterior crossbites affects the temporal muscle activity in cleft subjects. Early diagnosis and orthodontic treatment of malocclusions are necessary to achieve functional improvement in these patients.