An interventional study of Activator + LIPUS and Activator + LLLT in CLASS II DIVISION 1 MALOCCLUSION, sponsored by Damascus University. Completed at 1 site in Syria. Open to participants aged 10 Years to 12 Years. Per ClinicalTrials.gov, last updated 2026-10-05.
Sponsored by Damascus University · Not applicable, Interventional, and Treatment
Pain, discomfort, and functional limitations are common during functional orthodontic treatment and may affect appliance acceptance, compliance, and treatment satisfaction. This randomized clinical trial will compare patient-reported outcomes associated with low-intensity pulsed ultrasound (LIPUS) and low-level laser therapy (LLLT) as adjuncts to functional orthopedic treatment of skeletal Class II malocclusion.
Forty growing patients with skeletal Class II Division 1 malocclusion will be randomly allocated to a LIPUS-assisted Modified Schmuth Activator group or an LLLT-assisted Modified Schmuth Activator group, with 20 patients in each group.
All patients will be treated using a standardized Modified Schmuth Activator, which will be worn for 18 hours per day. LIPUS will be applied bilaterally over the temporomandibular joint regions, whereas LLLT will be administered to five points around the condylar region on each side. Patient-reported outcomes will be assessed using a Visual Analog Scale questionnaire evaluating soft-tissue tension, muscle pain, temporomandibular joint pain, difficulty in mouth opening, and overall satisfaction. Assessments will be performed at 7 days, 14 days, 6 weeks, 3 months, and 6 months after appliance insertion.
Functional treatment is a well-established approach for growing patients with skeletal Class II malocclusion, particularly when mandibular retrognathia is the predominant skeletal component. By guiding the mandible into a more advanced position, functional orthopedic appliances aim to improve skeletal and dentoalveolar relationships during the growth period. However, despite their clinical effectiveness, functional appliances may be associated with treatment-related pain, discomfort, and temporary functional limitations, particularly during the early stages of appliance wear. These patient-related experiences may influence appliance acceptance, compliance, and overall satisfaction, making patient-centered outcomes an important component of evaluating functional treatment.
In recent years, non-invasive biophysical modalities such as low-intensity pulsed ultrasound (LIPUS) and low-level laser therapy (LLLT) have attracted increasing attention as adjuncts to orthodontic and functional orthopedic treatment. Both modalities have been investigated because of their potential biological effects, including modulation of inflammatory responses, enhancement of tissue repair, and reduction of treatment-associated pain and discomfort. Previous randomized clinical trials have reported that combining LIPUS or LLLT with functional orthopedic therapy may improve treatment-related skeletal and dentoalveolar outcomes and potentially reduce overall treatment duration. However, these studies have primarily focused on skeletal, dental, and treatment-duration outcomes, while the patient's experience during functional treatment has received considerably less attention.
This randomized clinical trial will be conducted at the Department of Orthodontics, Faculty of Dentistry, Damascus University. Forty growing patients with skeletal Class II Division 1 malocclusion will be randomly allocated equally to one of two treatment groups: a low-intensity pulsed ultrasound-assisted Modified Schmuth Activator group (LIPUS-Act) or a low-level laser therapy-assisted Modified Schmuth Activator group (LLLT-Act). The Modified Schmuth Activator will be standardized for all participants and will be fabricated using the same general design and construction protocol. The appliance will consist of an acrylic body with upper and lower splints, labial bows, a Coffin spring, and an acrylic cap for retention of the lower incisors. A standardized construction bite will be recorded using a single-step mandibular advancement with a vertical opening of 5-6 mm in the premolar region. Patients will be instructed to wear the appliance for 18 hours per day under parental supervision. The active treatment phase will be considered complete when a Class I molar relationship, normal overjet and overbite, and absence of posterior chin displacement are achieved.
The two treatment groups will differ only in the adjunctive biophysical intervention applied during functional therapy. In the LIPUS-Act group, LIPUS will be used as the adjunctive intervention, whereas LLLT will be used in the LLLT-Act group. Both adjunctive interventions will follow the same treatment schedule: twice weekly during the first month, once every two weeks during the second month, and once every three weeks thereafter until completion of active treatment.
Rather than evaluating treatment solely according to clinical or skeletal outcomes, the present study will specifically focus on the patient's experience during functional orthopedic therapy. Patient-reported outcomes will be assessed using a structured questionnaire adapted from previously developed instruments and converted to a Visual Analog Scale (VAS) format to allow quantitative assessment of symptom intensity. Five patient-centered domains will be evaluated: soft-tissue tension, muscle pain, temporomandibular joint pain, difficulty in mouth opening, and overall treatment satisfaction.
The primary purpose of this study will be to directly compare LIPUS and LLLT as adjuncts to functional orthopedic treatment with regard to patient-centered experiences during treatment. Particular attention will be given to the early treatment period, when discomfort and functional adaptation may be most pronounced, as well as to the subsequent changes in treatment-related symptoms and patient satisfaction throughout the follow-up period.
124 studies on the registry are indexed under Malocclusion, Angle Class II; 18 are open to participants now.
This study's enrollment of 40 is above the median of 32 across 112 interventional studies indexed under Malocclusion, Angle Class II.
Browse Malocclusion, Angle Class II studies →Damascus University is the lead sponsor of 206 studies on the registry; 10 are open to participants now.
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Exclusion Criteria:
Participants will be treated using the Modified Schmuth Activator with low-intensity pulsed ultrasound
Device: Activator + LIPUS
Participants will be treated using the Modified Schmuth Activator with low-level laser therapy
Device: Activator + LLLT
• In this group, low-intensity pulsed ultrasound (LIPUS) will be applied bilaterally to the temporomandibular joint (TMJ) region using the US PRO 2000™ 2nd Edition device. The device will generate 200-µs bursts of a 1-MHz sine wave at a pulse repetition frequency of 100 Hz, with a temporal average intensity of 0.03 W/cm². LIPUS will be administered twice weekly during the first month, once every two weeks during the second month, and subsequently once every three weeks until completion of active treatment. All sessions will be performed by the principal investigator to ensure consistency of the treatment protocol.
In this group, low-level laser therapy (LLLT) will be applied bilaterally around the condylar region using the Mercury™ laser device, with a power output of 0.20 W and a wavelength of 810 nm. The laser will be applied to five points on each side: the anterior, superior, inferior, and posterior regions of the condyle, as well as along the external auditory canal. Each point will receive 4 J of laser energy for 20 seconds. LLLT will be administered according to the same treatment schedule as LIPUS: twice weekly during the first month, once every two weeks during the second month, and subsequently once every three weeks until completion of active treatment.
Change in the levels of soft tissue tension
Assessment will be performed using questionnaires via the Visual Analog scale (VAS). The Visual Analog Scale is a 100 mm horizontal line with two focal points at its beginning and end (0: no tension - 100: the worst tension).
Time frame: Time 1: 1 week after the insertion of the appliance; Time 2: 2 weeks; Time 3: 6 weeks; Time 4: 3 months; Time 5: 6 months following the treatment initiation.
Change in the levels of muscle pain
Assessment will be performed using questionnaires via the Visual Analog Scale (VAS). The Visual Analog Scale is a 100 mm horizontal line with two focal points at its beginning and end (0: no pain - 100: the worst pain).
Time frame: Time 1: 1 week after after the insertion of the appliance; Time 2: 2 weeks; Time 3: 6 weeks; Time 4: 3 months; Time 5: 6 months following the treatment initiation.
Change in the levels of TMJ pain
Assessment will be performed using questionnaires via the Visual Analog Scale (VAS). The Visual Analog Scale is a 100 mm horizontal line with two focal points at its beginning and end (0: no pain - 100: the worst pain).
Time frame: Time 1: 1 week after the insertion of the appliance; Time 2: 2 weeks; Time 3: 6 weeks; Time 4: 3 months; Time 5: 6 months following the treatment initiation.
Change in the levels of difficulties in mouth opening.
Assessment will be performed using questionnaires via the Visual Analog Scale (VAS). The Visual Analog Scale is a 100 mm horizontal line with two focal points at its beginning and end (0: no difficulties - 100: the worst difficulties).
Time frame: Time 1: 1 week after the insertion of the appliance; Time 2: 2 weeks; Time 3: 6 weeks; Time 4: 3 months; Time 5: 6 months following the treatment initiation
Change in the levels of satisfaction.
Assessment will be performed using questionnaires via the Visual Analog Scale (VAS). The Visual Analog Scale is a 100 mm horizontal line with two focal points at its beginning and end (0: no satisfaction - 100: the highest satisfaction).
Time frame: Time 1: 1 week after the insertion of the appliance; Time 2: 2 weeks; Time 3: 6 weeks; Time 4: 3 months; Time 5: 6 months following the treatment initiation.
Plan to share: No
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Damascus University