Evaluation of Masticatory Muscle Activity in Pediatric Patients Undergoing Rapid Maxillary Expansion

NCT05820438 | Completed

• 1 other identifier: 2023-EMGRME
• Study Type: interventional
• Target: 34
• Locations: 1 country
• Sites: 1

Brief Summary

Transverse maxillary constriction is a malocclusion that subsists when the distance between the upper first molars palatal cuspids is lower than the distance between the lower first molars vestibular center fossae. Consequently it can be clinically expressed with a narrow and high palatal vault, a unilateral or bilateral crossbite, dental crowding, and/or reduced volume of the nasal cavities. It is one of the most common malocclusions in children, with a prevalence of 8 to 22% among orthodontic patients in primary and mixed dentition and 5 to 15% among the general population. The hypothesis of this study is that transverse maxillary constriction correction by Rapid Maxillary Expansor achieves improved muscles activation potential in treated patients and improved symmetry in patient with unilateral crossbite. The aim of this study is to evaluate electromyographic activity of the masseter, anterior temporalis and suprahyoid muscles in clentching, chewing and swallowing in patients undergoing expansion therapy of the maxillary with rapid palatal expander. The electromyographic evaluation is carried out before the treatment (T0), at the end of the expansion (T1) and after 6 months from T1 (T2).

Conditions

Maxillar Hypoplasia

Outcome Measures

Primary Outcomes (5)

• Change in Percentage Overlapping Coefficient - POC %

  Indicates in % the ratio between the activation of the left muscle compared to the right one and its value is between 0 and 100%. A POC of 100% identifies two muscles that activate symmetrically. A lower value shows a greater asymmetry of muscles activation. There were 95% of subjects without muscular imbalances of dental origin who had POC values between 80 and 90% (Ferrario et al, 2000). The POC detected are: TA, MM and mean.

  Baseline (T0), end of activations - approximately 14-30 days - (T1), after 6 months from T1 (T2)

• Change in Asymmetry index - ASIM %

  It compares the influence of dental contacts on the total activity of the right MM and TA with respect to the left MM and TA. Its value varies between -100% and +100%. A negative value indicates a greater differential activity of the left muscles; conversely, a positive value indicates a greater differential activity of the right muscles. There was a total of 95% of subjects without muscular imbalances of dental origin having values of asymmetry between ± 10% (Ferrario et al, 2000);

  Baseline (T0), end of activations - approximately 14-30 days - (T1), after 6 months from T1 (T2)

• Change in Activation Index - ATTIV %

  It compares the influence of dental contacts on the TA activity in relation to MM activity. A negative value implies greater differential recruitment of TA, while a positive value implies greater differential recruitment of the MM. There was a total of 95% of subjects without muscular imbalances of dental origin having activation values between ± 10% (Ferrario et al, 2000);

  Baseline (T0), end of activations- approximately 14-30 days - (T1), after 6 months from T1 (T2)

• Change in TORQUE %

  Torque measures the differential activity of the right TA and left MM in relation to the antagonist torque. A prevalence of the right TA and left MM muscles, or right MM and left TA, may result in twisting forces on the jaw resulting in latero-deviation. This index ranges between -100% and +100%. -100% indicates the total prevalence of left TA and right MM, + 100% indicates the total prevalence of right TA and left MM. There was a total of 95% of subjects without muscular imbalances of dental origin having torque values between ±10% (Ferrario et al, 2000).

  Baseline (T0), end of activations- approximately 14-30 days - (T1), after 6 months from T1 (T2)

• Change in IMPACT %

  It quantifies the total muscular activity performed during MVC relative to the standardization clenching on cotton rolls.

  Baseline (T0), end of activations - approximately 14-30 days - (T1), after 6 months from T1 (T2)

Study Arms (1)

Patients requiring orthopedic treatment with Rapid Maxillary Expander

EXPERIMENTAL

Patients will be treated with Rapid Maxillary Expander with two bands on the upper first permanent molars or upper second primary molars (depending on the eruptive stage of the patient). The screw will be activated according to clinitian's indication until a transverse overcorrection of 2 mm is achieved in the first permanent molars. When the active disjunction phase is completed, the screw will be blocked out with a metal legature and the patient will wear the cemented RME for retentions at least for six months.

Device: Electromyography

Interventions

Electromyography DEVICE

Disposable bipolar surface electrodes will be used. The patient's skin will be clean with cotton gauze soaked in alcohol before electrodes placement to reduce skin impedance. The operator will palpate the muscle belly while the patient clenches his teeth and will position surface electrodes in parallel to the muscular fibres.Doing so the position of the electrodes results as follows: Masseters electrodes will be fixed parallel to the exocanthion-gonion line and with the upper pole of the electrode under the tragus-labial commissural line. Temporalis electrodes will be positioned along the anterior margin of the muscle (corresponding to the frontoparietal suture). Suprahyoid muscles electrodes will be placed in the submental area nearly 1 cm posterior to the mental symphysis, paramedian to the midline and lightly diverging. A reference electrode will be applied to the forehead of the patient.

Patients requiring orthopedic treatment with Rapid Maxillary Expander

Eligibility Criteria

• Age: 6 Years - 18 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Transverse maxillary constriction
• Patients needing maxillary expansion with Rapid Maxillary Expander (RME)

You may not qualify if:

• Systemic diseases or congenital anomalies affecting craniofacial growth or development.
• Signs or symptoms of temporomandibular disorder (TMD).
• Dental pain.
• Previous orthopedic/orthodontic treatment/s.

Sponsors & Collaborators

• University of Pavia: lead

Study Sites (1)

Unit of Orthodontics and Pediatric Dentistry - Section of Dentistry - Department of Clinical, Surgical, Diagnostic and Pediatrics - University of Pavia

Pavia, Lombardy, 27100, Italy

Location

MeSH Terms

Conditions

Retrognathia

Interventions

Electromyography

Condition Hierarchy (Ancestors)

Jaw Abnormalities; Jaw Diseases; Musculoskeletal Diseases; Maxillofacial Abnormalities; Craniofacial Abnormalities; Musculoskeletal Abnormalities; Stomatognathic Diseases; Mandibular Diseases; Stomatognathic System Abnormalities; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Intervention Hierarchy (Ancestors)

Electrodiagnosis; Diagnostic Techniques and Procedures; Diagnosis; Myography

Study Officials

• Andrea Scribante, DDS, PhD, Mac

  University of Pavia

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor, Principal Investigator

Study Record Dates

• First Submitted: March 14, 2023
• First Posted: April 19, 2023
• Study Start: March 16, 2023
• Primary Completion: March 20, 2025
• Study Completion: March 30, 2025
• Last Updated: September 25, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

IT (1)