Evaluation of Muscle Activity in Unilateral Posterior Crossbite

NCT04962685 | Unknown

• 1 other identifier: CER202108
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

Posterior crossbite (PCB) is defined as the presence of one or more teeth of the posterior group (canine to third molar) in an inverted buccolingual relationship, where the vestibular cusp of the upper tooth is in contact with the central fossa of its lower antagonist tooth. 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. It can be bilateral (MCPB) or unilateral (MCPU). In 71-84% of cases, CCM in growing patients appears as a functional CCBM and is therefore associated with a functional mandibular deviation. The hypothesis of this study is, that unilateral posterior crossbite correction by Rapid Maxillary expansion achieves improved symmetry and muscle activation potential in treated patients. The objective of this study is to evaluate the muscle activity of masticatory muscles in patients with unilateral posterior crossbite with superficial electromyography before and after treatment with rapid maxillary expansion. Superficial electromyography will be measured in masseter and temporalis muscle before treatment, when the patients bite is corrected and after the treatment. Three static and two dynamic tasks will be measured.

Conditions

Malocclusion; Muscle Activity; Maxillary Expansion

Outcome Measures

Primary Outcomes (8)

• Muscle activity (microVolts)

  sEMG is a NON-invasive method that measures the electrical activity of the muscle generated by the passage of the nerve impulse, which causes depolarization of the muscle cell membrane during excitation. Once the muscle is contracted and receives electrical signals, the electrodes pick up these signals and record them on the device application.

  change between baseline and 1 week follow-up; change between baseline and 6 months follow-up.

• percentage of overlapping coefficient (%)

  The standardized EMG waves of the left and right anterior temporalis (AT) and masseters (MM) were compared by computing a percentage overlapping coefficient (POC, unit: %, range: 0-100 per cent, norm values 85 per cent ≤ POC ≤ 100 per cent). If the muscles contract with perfect symmetry, a POC of 100 per cent (perfect symmetry) is expected. Conversely, a value corresponding to 0 per cent indicates the absence of concurrent activation of paired muscles (no symmetry). Three indices were computed for each subject (POC AT, POC MM and POC medium).

  change between baseline and 1 week follow-up; change between baseline and 6 months follow-up.

• torque coefficient

  This index is obtained by measuring the overlapping activity (standardized EMG waves) between the left MM and right AT and the right MM and left AT. The higher muscular activity of one couple (i.e. left MM and right AT) over the other (i.e. right MM and left AT) results in a torquing effect on the lower jaw. TC ranges between 0 per cent (no symmetric activation of the couples, greatest torquing effect) and 100 per cent (perfect symmetric activation of the couples, no torquing effect). Normal values are 90 per cent ≤ TC ≤ 100 per cent.

  change between baseline and 1 week follow-up; change between baseline and 6 months follow-up.

• Total standardized muscle activity

  This index is computed as the integrated area of the EMG standardized potentials of both MM and AT over time (5 seconds MVC). Norm values are 85 per cent ≤ IC ≤ 115 per cent. Lower values indicate that the EMG standardized potentials were reduced during the clenching tasks, and that the maximal EMG activity could not be expressed

  change between baseline and 1 week follow-up; change between baseline and 6 months follow-up.

• Asymmetry index

  This index is calculated by comparing the activity of the right couple (right AT and right MM) to the left couple (left AT and left MM). ASIM ranges from -100 per cent and +100 per cent; a value of 0 per cent depicts a perfect symmetric activation of the two couples. A negative value indicates greater activity of the left couple; conversely, a positive value indicates a greater activity of the right couple. Norm values are -10 per cent ≤ ASIM ≤ +10 per cent.

  change between baseline and 1 week follow-up; change between baseline and 6 months follow-up.

• Symmetrical mastication index

  assess whether the left and the right side chewing tests were performed with symmetrical muscular patterns. It indicates the distance between the centre of the chart and the centre of the ellipse in a graph that describes the prevalence of one side over the other during mastication. SMI ranges between 0 per cent (no symmetry) and 100 per cent (symmetrical muscular pattern). Normal values are 70 per cent ≤ SMI ≤ 100 per cent.

  change between baseline and 1 week follow-up; change between baseline and 6 months follow-up.

• side of prevalent mastication

  in case of SMI values lower than 70 per cent, the dominant side of mastication was identified as side of prevalent mastication. Three categories could be identified, that is right, left and symmetric.

  change between baseline and 1 week follow-up; change between baseline and 6 months follow-up.

• frequency index

  measures the frequency of masticatory cycles during the chewing experimental tasks and was reported in hertz (Hz: bites per second)

  change between baseline and 1 week follow-up; change between baseline and 6 months follow-up.

Study Arms (2)

Unilateral Posterior Crossbite

EXPERIMENTAL

Other: Rapid Maxillary Expansion

Normal occlusion

NO INTERVENTION

Interventions

Rapid Maxillary Expansion OTHER

Subjects in the experimental group (with unilateral posterior crossbite) will be treated with Maxillary Rapid Expansion using a disjunctor fixed with two bands on the upper first permanent molars and a mesh cemented to the upper first premolars or upper first primary molars (depending on the eruptive stage of the patient). The breaker screw will be activated twice a day 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 light-curing flowable resin and the patient will wear the cemented disjunctor as a retainer for a minimum of six months.

Unilateral Posterior Crossbite

Eligibility Criteria

• Age: 9 Years - 15 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Mixed or early permanent dentition.
• Complete eruption of the first four permanent molars.
• Angle Class I ±1 mm.

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 orthodontic treatment.

Sponsors & Collaborators

• Universitat Internacional de Catalunya: lead

Study Sites (1)

Universitat Internacional Catalunya

Barcelona, Sant Cugat, 08195, Spain

Location

MeSH Terms

Conditions

Malocclusion

Condition Hierarchy (Ancestors)

Tooth Diseases; Stomatognathic Diseases

Central Study Contacts

Albert Pérez-Bellmunt, Dr.

CONTACT

636817297; aperez@uic.cat

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: June 22, 2021
• First Posted: July 15, 2021
• Study Start: November 1, 2021
• Primary Completion: July 1, 2022
• Study Completion: December 30, 2023
• Last Updated: October 22, 2021

Record last verified: 2021-10

Locations

ES (1)