Cephalometric and electromyographic study of patients of East African ethnicity with and without anterior open bite

Changes in the electromyographic activity of masticatory muscles in patients undergoing bimaxillary surgery

OBJECTIVE

The aim of this study is to investigate short-term changes in the electromyographic (EMG) activity of masticatory muscles in individuals with skeletal Class III malocclusion undergo double-jaw orthognathic surgery.

MATERIAL AND METHODS

In patients with skeletal Class III anomaly, EMG activity changes in the anterior temporalis and masseter muscles were measured before T0 and at 3 (T1) and 6 (T2) months after bimaxillary orthognathic surgery. Recordings were obtained using the 'MP100' device and circular Ag-AgCl electrodes during closure, clenching, chewing and swallowing. Data from 26 individuals (12 males, 14 females) with a mean age of 21.7 years were analysed using the Friedman test.

RESULTS

A significant decrease was observed in the right/left masseter muscles during clenching/chewing from T1 to T0 (right and left masseter clenching: p < 0.001, left masseter chewing: p < 0.01, right masseter chewing: p < 0.05), while a significant increase was noted in the right masseter's clenching function from T2 to T1 (p < 0.01). The EMG activity of the right anterior temporal muscle decreased during clenching at T1-T0 (p < 0.001), increased at T2-T1 (p < 0.05), and decreased during chewing/swallowing at T1-T0 (chewing: p < 0.001, swallowing: p < 0.05) and T2-T0 (p < 0.05). The left anterior temporal muscle showed decreased EMG activity during clenching at T1-T0 (p < 0.001), increased at T2-T1 (p < 0.05), and decreased during chewing at T1-T0 (p < 0.001). During swallowing, a decrease was observed at T2-T0 (p < 0.001).

CONCLUSIONS

Partial changes in EMG activity were observed during some functions in the 3-month period; however, no significant overall change was recorded in the 6-month period.

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.

Prevalence of Malocclusion Traits in Primary Dentition, 2010-2024: A Systematic Review

The present review was aimed to describe the prevalence and the regional distribution of malocclusion among preschool children worldwide. Two independent reviewers performed a systematic literature search to identify English publications from January 2010 to May 2024 using PubMed, ISI Web of Science and Embase. Search MeSH key words were "malocclusion", "primary dentition" and "child, preschool". The reporting quality was assessed by the modified Newcastle-Ottawa Quality Assessment Scale. We identified 2599 publications and recruited 47 articles. Fourteen of the included studies were conducted in Asia, four in Europe, twenty-eight in South America and one in Africa. The prevalence of malocclusion ranged from 28.4% to 83.9%, and half of the reported prevalences were higher than 50%. The highest percentage was in Asia (61.81%), followed by Europe (61.50%), South America (52.69%) and Africa (32.50%). Statistically significant differences existed in deep overbite, anterior open bite, posterior crossbite, edge-to-edge incisor relationship and distal step between continents (p < 0.05). Europe showed the highest prevalence (33.08%) of deep overbite. Africa showed the highest prevalence (18.60%) of anterior open bite. Europe showed the highest prevalence (15.38%) of posterior crossbite. The most common malocclusion traits were increased overjet and deep overbite. To conclude, malocclusion remained prevalent in the primary dentition and varied between countries.

Impacts of Skeletal Anterior Open Bite Malocclusion on Speech

Introduction

Articulation problems are seen in 80-90% of dentofacial deformity (DFD) subjects compared with 5% of the general population, impacting communication and quality of life, but the causal link is unclear. We hypothesize there are both qualitative (perceptual) and quantitative (spectral) differences in properties of stop (/t/ or /k/), fricative (/s/ or /∫/), and affricate (/t∫/) consonant sounds and that severity of anterior open bite (AOB) jaw disharmonies correlates with degree of speech abnormality.

Methods

To test our hypotheses, surgical orthodontic records and audio recordings were collected from DFD patients (n=39 AOB, 62 controls). A speech pathologist evaluated subjects and recordings were analyzed using spectral moment analysis (SMA) to measure sound frequency distortions.

Results

Perceptually, there is a higher prevalence of auditory and visual speech distortions in AOB DFD patients when compared to controls. Quantitatively, a significant (p<0.01) increase in the centroid frequency (M1) was seen in the /k/, /t/, /t∫/, and /s/ sounds of AOB subjects compared to the controls. Using linear regression, correlations between AOB skeletal severity and spectral distortion were found for /k/ and /t/ sounds.

Conclusions

A higher prevalence of qualitative distortion and significant quantitative spectral distortions in consonant sounds were seen in AOB patients compared to controls. Additionally, severity of skeletal AOB is correlated with degree of distortion for consonant sounds. These findings provide insight into how the surgical and/or orthodontic treatment of AOB may impact speech.

Effect of malocclusion on jaw motor function and chewing in children: a systematic review

Objective

To investigate the effects of dental/skeletal malocclusion and orthodontic treatment on four main objective parameters of chewing and jaw function (maximum occlusal bite force [MOBF], masticatory muscle electromyography [EMG], jaw kinematics, and chewing efficiency/performance) in healthy children.

Materials and methods

Systematic searches were conducted in MEDLINE (OVID), Embase, and the Web of Science Core Collection. Studies that examined the four parameters in healthy children with malocclusions were included. The quality of studies and overall evidence were assessed using the Joanna Briggs Institute and GRADE tools, respectively.

Results

The searches identified 8192 studies; 57 were finally included. The quality of included studies was high in nine studies, moderate in twenty-three studies, and low in twenty-five studies. During the primary dentition, children with malocclusions showed similar MOBF and lower chewing efficiency compared to control subjects. During mixed/permanent dentition, children with malocclusion showed lower MOBF and EMG activity and chewing efficiency compared to control subjects. The jaw kinematics of children with unilateral posterior crossbite showed a larger jaw opening angle and a higher frequency of reverse chewing cycles compared to crossbite-free children. There was a low to moderate level of evidence on the effects of orthodontic treatment in restoring normal jaw function.

Conclusions

Based on the limitations of the studies included, it is not entirely possible to either support or deny the influence of dental/skeletal malocclusion traits on MOBF, EMG, jaw kinematics, and masticatory performance in healthy children. Furthermore, well-designed longitudinal studies may be needed to determine whether orthodontic treatments can improve chewing function in general.

Clinical relevance

Comprehensive orthodontic treatment, which includes evaluation and restoration of function, may or may not mitigate the effects of malocclusion and restore normal chewing function.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04356-y.

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.

Botulinum toxin-A injection into the anterior belly of the digastric muscle for the prevention of post-operative open bite in class II malocclusions: a case report and literature review

Background

Class II malocclusion patients with hyperdivergent facial types are characterized by short mandibular body lengths and anterior open bite. Accordingly, the treatment for hyperdivergent skeletal class II malocclusion is a lengthening of the mandibular body length and a counterclockwise rotation of the mandible. To prevent post-operative relapse, botulinum toxin-A (BTX-A) injection can be a retention modality.

Case presentation

A class II open-bite patient received BTX-A injection to the anterior belly of her digastric muscle for the prevention of post-operative relapse. The relapse was evaluated via a clinical examination and a lateral cephalometric radiograph after the completion of post-surgical orthodontic treatment. The patient showed stable occlusion without any signs of relapse at 15 months post-operatively.

Conclusion

In this case presentation, a single injection into the anterior belly of the digastric muscle was sufficient for the prevention of post-operative open bite.

Electromyographic evaluation in children orthodontically treated for skeletal Class II malocclusion: Comparison of two treatment techniques

OBJECTIVE

To compare the clinical efficacy of two techniques for fabricating a Bimler device by assessing the patient's surface electromyography (sEMG) activity at rest before treatment and six months after treatment.

METHODS

Twenty-four patients undergoing orthodontic treatment were enrolled in the study; 12 formed the test group and wore a Bimler device fabricated with a Myoprint impression using neuromuscular orthodontic technique and 12 formed the control group and were treated by traditional orthodontic technique with a wax bite in protrusion. The "rest" sEMG of each patient was recorded prior to treatment and six months after treatment.

RESULTS

The neuromuscular-designed Bimler device was more comfortable and provided better treatment results than the traditional Bimler device.

CONCLUSION

This study suggests that the patient group subjected to neuromuscular orthodontic treatment had a treatment outcome with more relaxed masticatory muscles and better function versus the traditional orthodontic treatment.

Influence of non-orthodontic intervention on digit sucking and consequent anterior open bite: a preliminary study

OBJECTIVES

This study aimed to assess behavioural and occlusal outcomes of non-orthodontic intervention (NOI) in a sample of children, 4-12 years of age, in Australia, in order to establish clinical relevance.

MATERIALS AND METHODS

Data from 91 patient records of 4- to 12-year-old children reporting a habit of digit sucking, from two clinics in north-eastern Australia, were de-identified and used. Each patient had been examined at two visits, separated by an interval of 4 months, using standard clinical procedures.

RESULTS

Of the 77 children who received a 4-month NOI, 69 (89.6%) had ceased their digit sucking habit by the end of the NOI period [χ2=67.0, degrees of freedom (d.f.)=1, P<0.001]. Of the 72 subjects who had front teeth, the number with anterior open bite decreased from 37 (51.4%) to 12 (16.7%) upon completion of NOI (χ2=21.3, d.f.=1, P<0.001). Among the 32 patients with a measurable overjet, the mean overjet was found to decrease from 4.2±2.4 mm to 3.1±1.9 mm after implementation of NOI (t=5.8, d.f.=31, P<0.001). Children who received NOI were more likely to quit the digit sucking habit in the 4-month period (P<0.001, OR=51.8, 95% CI: 9.8-273.9) and were more likely to appear without anterior open bite at a 4-month recall (P<0.001, OR=30.0, 95% CI: 5.9-151.6).

CONCLUSIONS

This study demonstrated clinical relevance of NOI on the cessation of a digit sucking habit, closure of anterior open bite and reduction of overjet. Further investigations are indicated.

Association between facial growth pattern and facial muscle activity: A prospective cross-sectional study

OBJECTIVE

To evaluate the relationship between facial growth pattern and electromyography (EMG) of facial muscles: anterior temporalis, masseter, buccinators, orbicularis oris, mentalis and anterior digastric.

PATIENTS AND METHODS

The sample consisted of 77 subjects aged between 18-28 years (mean age 21.10±2.03), with dental Class I relationship, normal overjet and overbite, balanced facial profile, no signs of temporomandibular disorders, and no previous orthodontic treatment. Facial growth pattern was determined on the lateral cephalograms according to the Björk sum (sum of the N-S-Ar, S-Ar-Go, and Ar-Go-Me angles) dividing the sample into three groups: horizontal facial pattern group (24 subjects), normal facial pattern group (41 subjects), and vertical facial pattern group (12 subjects). The EMG of anterior temporalis, masseter, buccinator, orbicularis oris, mentalis and anterior digastric muscles were examined for each patient in the rest position and in functional positions (central maximum intercuspation, chewing on right side, chewing on left side and swallowing). Mean values and standard deviation of EMG were obtained and compared between the three groups.

RESULTS

At rest, the EMG of the masseter, orbicularis oris and anterior digastric were higher in the vertical facial pattern group compared with the other two groups, with a moderate positive correlation between the EMG of these muscles and the Björk sum (P<.01). In contrast, during central maximum intercuspation, the activity of the anterior temporalis, masseter and buccinator was significantly lower in the vertical facial pattern group compared with the two other groups, with a moderate negative correlation between the Björk sum and EMG in the maximum central intercuspation position of these muscles (P<.01).

CONCLUSIONS

A significant relationship was found between facial muscle activity and facial growth pattern. The findings suggest that the activity of masticatory and perioral muscles could play a role in the direction of the facial growth.

Surface electromyography in orthodontics - a literature review

Electromyography is the most objective and reliable technique for evaluating muscle function and efficiency by detecting their electrical potentials. It makes it possible to assess the extent and duration of muscle activity. The main aim of surface electromyography is to detect signals from many muscle fibers in the area of the detecting surface electrodes. These signals consist of a weighted summation of the spatial and temporal activity of many motor units. Hence, the analysis of the recordings is restricted to an assessment of general muscle activity, the cooperation of different muscles, and the variability of their activity over time.

This study presents the main assumptions in the assessment of electrical muscle activity through the use of surface electromyography, along with its limitations and possibilities for further use in many areas of orthodontics. The main clinical uses of sEMG include the diagnostics and therapy of temporomandibular joint disorders, an assessment of the extent of stomatognathic system dysfunctions in subjects with malocclusion, and the monitoring of orthodontic therapies.

Non-nutritive sucking habits, anterior open bite and associated factors in Brazilian children aged 30-59 months

The aim of the present study was to investigate the prevalence of non-nutritive sucking habits and anterior open bite as well as their main causes (associated factors) in Brazilian children aged 30-59 months. A cross-sectional study was carried out during the National Immunization Day for polio in the city of Recife in the northeastern region of Brazil. The sample was made up of 1,308 children. Data were collected from interviews with mothers or guardians as well as from clinical examinations carried out by previously trained dental students. The chi-square test was used for statistical analysis at 5% significance level. The prevalence of non-nutritive sucking habits was 40%, and the habits were associated with gender (p=0.001), age (p=0.003) and feeding type (p<0.001). Anterior open bite was detected in 30.4% of children, and it was significantly associated with feeding type (p<0.001) and non-nutritive sucking habits (p<0.001). The variables found to be associated factors in the present study for the occurrence of non-nutritive sucking habits and anterior open bite emphasize the need to establish strategies that include orientation regarding health promotion based on the "common determining factors" approach. Public health policies should be adopted to encourage a longer duration of breastfeeding, thereby contributing towards reducing the prevalence of non-nutritive sucking habits and anterior open bite.