The Effect of Orofacial Myofunctional Therapy on Neuromuscular Outcomes and Orofacial Function in Children and Adolescents in Estonia

The aim of the present study is to evaluate the effects of semi-standardized myofunctional therapy on the functional and neuromuscular characteristics of the orofacial system in children and adolescents aged 7-14 years using a longitudinal study design and a unified assessment protocol. Myofunctional therapy is a treatment method for functional disorders of the oral, lingual, and facial regions. The study approaches the orofacial system holistically by linking functional characteristics with anatomical structures, including palatal morphology and skeletal and dentoalveolar occlusal relationships, while also considering the impact of treatment adherence on outcomes.

Participants' orofacial functions and neuromuscular characteristics will be assessed before, during, and after therapy using standardized clinical measurements. The study will analyze the dynamics of changes, individual variability, and associations with craniofacial phenotype and treatment adherence.

Despite the widespread use of myofunctional therapy in Estonia, systematic evidence regarding therapy effectiveness, treatment dynamics, and factors influencing outcomes is limited, and unified assessment and intervention standards are lacking. The study aims to address this knowledge gap and support evidence-based implementation of myofunctional therapy, clinical decision-making, and healthcare resource planning.

Study Overview

• Status: Not yet recruiting
• Conditions: Orofacial Myofunctional Disorders
• Intervention / Treatment: Behavioral: Semi-standardized Orofacial Myofunctional Therapy

Detailed Description

This is a prospective longitudinal clinical interventional study conducted at the Department of Paediatric Dentistry, Stomatology Clinic, Tartu University Hospital, Estonia. The study will include up to 80 children and adolescents aged 7-14 years who have been referred for orofacial myofunctional therapy and meet the study eligibility criteria.

Participants will receive semi-standardized orofacial myofunctional therapy as part of their clinical treatment. The study period for each participant is approximately nine months, including an eight-month therapy intervention with eight therapy sessions conducted at intervals of approximately 4-6 weeks.

Standardized clinical assessments are performed at baseline (T0, visit 1), during therapy (T4, visit 5), and after completion of the intervention (T8, visit 9). The assessments include neuromuscular and orofacial functional measurements. Treatment adherence is assessed throughout the intervention period using standardized questionnaires completed from the perspectives of the child, parent or legal representative, and therapist.

The study also evaluates craniofacial and dentoalveolar characteristics as exploratory factors in relation to treatment response.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Pille Eikner, MSc; Phone Number: +3725056787; Email: pille.eikner@kliinikum.ee

Study Locations

• Estonia
  • Tartu, Estonia, 50406
    • Tartu University Hospital, Clinic of Dentistry
    • Contact: Pille Eikner, MSc; Phone Number: +3725056787; Email: pille.eikner@kliinikum.ee

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 7-14 years at the time of enrollment.
• Referred for orofacial myofunctional therapy.
• Diagnosed with an orofacial myofunctional disorder.
• Willingness to participate in therapy and assessments according to the study protocol.
• Written informed consent from a parent or legal guardian for the child's participation in the study.
• Written informed assent from the child to participate in the study.
• Written consent from a parent or legal guardian to participate in the study by completing the questionnaire assessing their child's treatment adherence.
• Sufficient proficiency in Estonian to participate in the study and understand the study procedures.

Exclusion Criteria:

• Structural craniofacial anomalies or syndromes (e.g., cleft lip and/or palate).
• A medical condition that prevents safe participation in therapy or study assessments.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Orofacial Myofunctional Therapy; Participants receive semi-standardized orofacial myofunctional therapy for 8 months, with a total of 8 therapy sessions.

Behavioral: Semi-standardized Orofacial Myofunctional Therapy; Participants receive semi-standardized orofacial myofunctional therapy over an 8-month period, consisting of 8 therapy sessions at approximately 4-6-week intervals. Individually tailored exercises target tongue strength and mobility, lip strength and closure, swallowing pattern, tongue resting posture, nasal breathing and reduction of mouth breathing, and other orofacial functional patterns. Exercises are practiced under therapist supervision and performed at home once daily according to an individualized exercise program. Simple non-invasive aids, including a spatula and a button attached to a string, may be used during exercises. The intervention corresponds to routine clinical care and does not involve invasive or painful procedures.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in normalized sEMG Area of the mylohyoid region during swallowing	Surface electromyographic (sEMG) activity of the bilateral mylohyoid region is recorded during swallowing. The sEMG Area during swallowing is normalized to the sEMG Area recorded during maximal tongue-palate pressure using the Iowa Oral Performance Instrument (IOPI) bulb. Normalized Area (%) is calculated as: sEMG Area during swallowing / sEMG Area during maximal tongue-palate pressure × 100. Change in normalized Area is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in tongue strength measured using the Iowa Oral Performance Instrument (IOPI)	Maximum tongue strength is measured using the Iowa Oral Performance Instrument (IOPI) and expressed in kilopascals (kPa). Change in maximum tongue strength is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in lingual swallowing pressure measured using the Iowa Oral Performance Instrument (IOPI)	Lingual swallowing pressure (LSP) is measured using the Iowa Oral Performance Instrument (IOPI) and expressed in kilopascals (kPa). Change in lingual swallowing pressure is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in lip strength measured using the Iowa Oral Performance Instrument (IOPI)	Lip strength is measured using the Iowa Oral Performance Instrument (IOPI) and expressed in kilopascals (kPa). Change in lip strength is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in tongue-to-incisive papilla opening (TIP)	Tongue-to-incisive papilla opening (TIP) is measured in millimeters (mm) with the tongue tip in contact with the incisive papilla. Change in TIP is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in lingual-palatal suction opening (LPS)	Lingual-palatal suction opening (LPS) is measured in millimeters (mm) during lingual-palatal suction. Change in LPS is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in overall orofacial function assessed using a modified Orofacial Myofunctional Evaluation with Scores (OMES)	Orofacial function is assessed using a modified Orofacial Myofunctional Evaluation with Scores (OMES). The modified total score ranges from 34 to 98 points, with higher scores indicating better orofacial function. Change in the modified total OMES score is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG mean frequency of the mylohyoid region during standardized solid-food swallowing	Surface electromyographic (sEMG) mean frequency (MF) of the bilateral mylohyoid region is recorded during standardized swallowing of an approximately 5 g apple slice and expressed in hertz (Hz). One practice trial is performed before measurement, and the mean of two measurement trials is used for analysis. Change in MF is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG mean frequency of the mylohyoid region during swallowing	Surface electromyographic (sEMG) mean frequency (MF) of the bilateral mylohyoid region is recorded during swallowing and expressed in hertz (Hz). Change in MF is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG mean power frequency of the mylohyoid region during swallowing	Surface electromyographic (sEMG) mean power frequency (MPF) of the bilateral mylohyoid region is recorded during swallowing and expressed in hertz (Hz). Change in MPF is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG Area of the mylohyoid region during swallowing	Surface electromyographic (sEMG) Area of the bilateral mylohyoid region is recorded during swallowing and expressed in microvolt-seconds (µV·s). Change in sEMG Area is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG mean frequency of the masseter region during swallowing	Surface electromyographic (sEMG) mean frequency (MF) of the bilateral masseter region is recorded during swallowing and expressed in hertz (Hz). Change in MF is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG mean power frequency of the masseter region during swallowing	Surface electromyographic (sEMG) mean power frequency (MPF) of the bilateral masseter region is recorded during swallowing and expressed in hertz (Hz). Change in MPF is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG Area of the masseter region during swallowing	Surface electromyographic (sEMG) Area of the bilateral masseter region is recorded during swallowing and expressed in microvolt-seconds (µV·s). Change in sEMG Area is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG mean power frequency of the mylohyoid region during standardized solid-food swallowing	Surface electromyographic (sEMG) mean power frequency (MPF) of the bilateral mylohyoid region is recorded during standardized swallowing of an approximately 5 g apple slice and expressed in hertz (Hz). One practice trial is performed before measurement, and the mean of two measurement trials is used for analysis. Change in MPF is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG Area of the mylohyoid region during standardized solid-food swallowing	Surface electromyographic (sEMG) Area of the bilateral mylohyoid region is recorded during standardized swallowing of an approximately 5 g apple slice and expressed in microvolt-seconds (µV·s). One practice trial is performed before measurement, and the mean of two measurement trials is used for analysis. Change in sEMG Area is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG mean frequency of the masseter region during standardized solid-food swallowing	Surface electromyographic (sEMG) mean frequency (MF) of the bilateral masseter region is recorded during standardized swallowing of an approximately 5 g apple slice and expressed in hertz (Hz). One practice trial is performed before measurement, and the mean of two measurement trials is used for analysis. Change in MF is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG mean power frequency of the masseter region during standardized solid-food swallowing	Surface electromyographic (sEMG) mean power frequency (MPF) of the bilateral masseter region is recorded during standardized swallowing of an approximately 5 g apple slice and expressed in hertz (Hz). One practice trial is performed before measurement, and the mean of two measurement trials is used for analysis. Change in MPF is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)
Change in sEMG Area of the masseter region during standardized solid-food swallowing	Surface electromyographic (sEMG) Area of the bilateral masseter region is recorded during standardized swallowing of an approximately 5 g apple slice and expressed in microvolt-seconds (µV·s). One practice trial is performed before measurement, and the mean of two measurement trials is used for analysis. Change in sEMG Area is assessed across the study period.	Baseline (T0), 4 months (T4), and 8 months (T8)

Collaborators and Investigators

• Sponsor: Tartu University Hospital
• Collaborators: University of Tartu
• Investigators: Study Chair: Triin Jagomägi, PhD, University of Tartu

Study record dates

Study Major Dates

• Study Start (Estimated): September 14, 2026
• Primary Completion (Estimated): March 31, 2028
• Study Completion (Estimated): March 31, 2028

Study Registration Dates

• First Submitted: September 8, 2026
• First Submitted That Met QC Criteria: September 15, 2026
• First Posted (Actual): September 18, 2026

Study Record Updates

• Last Update Posted (Actual): September 18, 2026
• Last Update Submitted That Met QC Criteria: September 15, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: Treatment adherence; Children and adolescents; Surface electromyography; Orofacial myofunctional therapy; Iowa Oral Performance Instrument; Orofacial function; Craniofacial phenotype; Tongue Range of Motion Ratio; Orofacial Myofunctional Evaluation with Scores
• Additional Relevant MeSH Terms: Behavior; Health Behavior; Treatment Adherence and Compliance
• Other Study ID Numbers: TEET295

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared with other researchers. Study data are processed in pseudonymized form in accordance with the approved study protocol and applicable data protection requirements. Study results will be reported only in aggregated and anonymized form.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No