Clinical Trial Details
— Status: Enrolling by invitation
Administrative data
| NCT number |
NCT05820438 |
| Other study ID # |
2023-EMGRME |
| Secondary ID |
|
| Status |
Enrolling by invitation |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
March 16, 2023 |
| Est. completion date |
July 30, 2024 |
Study information
| Verified date |
April 2024 |
| Source |
University of Pavia |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial 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).
Description:
Transverse maxillary constriction subsists when the distance between upper first molars
palatal cuspids is lower than the distance between lower first molars vestibular central
fossae. 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 general population. The hypothesis
of this study is that transverse maxillary constriction correction by Rapid Maxillary
Expander (RME) affects masticatory muscles activation potential and improves activation
symmetry in patient with unilateral crossbite. The aim of this study is to evaluate
electromyographic activity of masseters, anterior temporalis and suprahyoid muscles in
clenching, chewing and swallowing in patients undergoing maxillary expansion with RME. The
electromyographic evaluation is carried out before treatment (T0), at the end of the
expansion (T1) and 6 months later (T2). Detailed Description: Transverse maxillary
constriction subsists when the distance between upper first molars palatal cuspids is lower
than the distance between lower first molars vestibular central fossae. 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 general population. One of the most frequent
expression of transverse maxillary constriction is unilateral crossbite, that consists in an
inverted bucco-lingual relationship between one or more posterior teeth (canine to molars)
with their antagonists; it can be present both in deciduous and permanent dentition. There is
evidence that an altered relationship between upper and lower teeth is associated with
asymmetric masticatory function that has been related to asymmetric contraction of
masticatory muscles, decreased thickness of the cross-sided masseter muscle and altered
masticatory pattern. This condition could lead to an asymmetric development of the mandibular
bone during growth. Many authors conclude that early treatment of transverse maxillary
constriction with RME would be recommended to reduce the risk of development of skeletal
asymmetries and temporomandibular disorders (TMD). Muscle activity is commonly recorded by
means of surface electromyography (sEMG). However sEMG data can be affected by various
artifacts, resulting in questionable interpretation of the results. A standardisation
procedure allows to reduce variability of the assessment of masticatory muscle activity
during static and dynamic tasks.
- Page 2 of 6 [DRAFT] -
The hypotheses of this study are:
Patients with transverse maxillary constriction improve muscles activation potential after
rapid maxillary expansion; correction of unilateral posterior crossbite by rapid maxillary
expansion improves muscles activation potential symmetry.
The main objectives of this study are:
- to evaluate the activity of superficial masseters, anterior temporalis and suprahyoid
muscles in patients with traverse maxillary constriction, using surface electromyography
with a standardized protocol. The test consists of detecting muscles activity in maximum
clenching (on cottons and on teeth), during swallowing and chewing;
- to evaluate whether the presence of unilateral posterior crossbite is associated with
asymmetrical activation of superficial masseters, anterior temporalis and suprahyoid
muscles;
- to compare intra-patient results before and after traverse maxillary constriction
correction. The electromyograph that will be used is Easy-MYo EMG Tracer of 3 Technology
Srl; Udine, Italy. It records muscular activity of superficial masseters, anterior
temporalis and suprahyoid muscles. Disposable bipolar surface electrodes (21 × 41 mm, 20
mm inter-electrode distance; F3010; Fiab) 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 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 on the forehead of the patient.
The sEMG analysis will be composed of four parts:
Masticatory muscle standardisation procedures (repeated thrice):
two 10mm thick cotton rolls will be positioned on the mandibular posterior teeth of each
participant, and a 5 second maximum voluntary contraction will be recorded to standardize
anterior temporalis and superficial masseters sEMG signals. The mean sEMG potential obtained
in the first acquisition was set at 100%, and all further ssEMG potentials will be expressed
as a percentage of this value (μV/μV × 100); Maximum voluntary teeth clenching: patients will
be asked to clench their teeth in maximum intercuspation as hard as possible for 5 seconds.
Submental muscle standardisation procedures: participants will be asked to push their tongue
against the palate (without teeth clenching), and a 5 seconds sEMG suprahyoid muscles
activity will be recorded. All further sEMG potentials will be expressed as a percentage of
this value (μV/μV × 100).
Saliva swallowing: participants will be asked to keep their mouth open to accumulate saliva
and, when needed, to swallow "freely" (as usual) and a 5 seconds sEMG activity will be
recorded.
Three EMG sessions will be recorded:
1. before starting treatment with Rapid Maxillary Expander (RME) (T0);
2. at the end of RME activation (T1), established by the clinician, generally looking for
hypercorrection, that is contact between upper molar palatal cuspid and lower molar
buccal cuspid.
3. after 6 months from T1 (T2).
