Clinical trial NCT06949527: Effects of Open Bite Activator and Skeletal Anchorage-Supported Vertical Elastics on the Masseter Muscle
Official title: Ultrasonographic and Sonoelastographic Evaluation of the Effects of Open Bite Activator and Anterior Skeletal Anchorage-Supported Vertical Elastics on the Masseter Muscle in Skeletal Open Bite Cases
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hyperdivergent Facial Pattern
Skeletal Open Bite
Hyperdivergent Growth Pattern
Anterior Open Bite
Keywords: Open Bite Treatment
Masseter Muscle
Ultrasound Imaging
Sonoelastography
Skeletal Anchorage
Vertical Elastics
Functional Orthodontic Appliance
Cephalometric Analysis
Lead sponsor: Ankara University
Sponsor class: OTHER
First posted: 2025-04-29
Enrollment: 24
Sex: ALL
Minimum age (years): 12
Maximum age (years): 14
Standard ages: CHILD
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: Participants received treatment with an open bite activator combined with vertical elastics supported by anterior skeletal anchorage in a single group.
Primary purpose: TREATMENT

Brief summary: This clinical trial aims to evaluate the effects of a combined treatment involving an open bite activator and anterior skeletal anchorage-supported vertical elastics on the masseter muscle in children with skeletal open bite. A total of 24 growing individuals with increased vertical skeletal pattern were treated with a functional appliance and intermaxillary vertical elastics supported by miniscrews placed in the anterior region. Ultrasonographic and sonoelastographic assessments were performed at baseline, 6 months, and 12 months to measure changes in masseter muscle thickness and stiffness. Cephalometric radiographs were also used to evaluate dentofacial structural changes. This study aims to provide insight into the soft tissue changes associated with functional orthopedic treatment in hyperdivergent patients.

Detailed description: This prospective clinical study investigates the dentofacial and muscular effects of a combined orthopedic treatment method in patients with skeletal open bite. The intervention includes the use of an open bite activator appliance along with anterior skeletal anchorage-supported vertical elastics. The study was conducted at Ankara University Faculty of Dentistry, Orthodontics Department, and received ethical approval (Approval No: 36290600/78).

A total of 24 growing individuals (14 females, 10 males) with increased vertical facial pattern (GoGn/SN ≥ 36°) were treated over a 12-month period. Patients received custom-made open bite activators designed to eliminate occlusal contact in the anterior region and redirect functional forces posteriorly. Miniscrews were placed between the lateral and canine teeth in both the maxilla and mandible, and vertical elastics were applied between these skeletal anchorage points with a force of 150 grams on each side, worn for 20-22 hours daily.

Masseter muscle changes were assessed using ultrasonography and sonoelastography at three time points: baseline (T0), interim (6 months, T1), and end of treatment (12 months, T2). Muscle thickness and stiffness (elasticity) were measured bilaterally during rest and maximal clenching. Cephalometric radiographs were obtained at T0 and T2 to evaluate skeletal and dentoalveolar changes, including SNA, SNB, ANB angles, overbite, U1-PP, L1-MP, and other relevant vertical and angular measurements.

Statistical analysis revealed significant increases in masseter muscle thickness during the treatment period, especially between T0 and T1. Stiffness values peaked at T1 and slightly decreased at T2, but remained higher than baseline. Cephalometric findings showed improvements in overbite and reductions in vertical growth tendencies, including significant changes in GoGn/SN and PP-MP angles.

This study demonstrates that combined functional appliance and skeletal anchorage-based vertical control therapy can positively influence muscle structure and dentofacial morphology in hyperdivergent skeletal open bite cases. Ultrasonography and sonoelastography proved to be reliable, non-invasive methods for assessing soft tissue changes in orthodontic treatment.

Eligibility criteria: Inclusion Criteria:

* GoGn/SN angle ≥ 36°
* Decreased overbite (dental open bite)
* In active growth phase (confirmed by hand-wrist radiograph)
* Good oral hygiene
* No prior orthodontic or orthognathic treatment

Exclusion Criteria:

* Presence of systemic disease or craniofacial deformity
* Poor oral hygiene
* Non-compliance with appliance wear
* Previous use of skeletal anchorage devices

Primary outcomes:
measure: Change in masseter muscle thickness measured by ultrasonography
timeFrame: Baseline, 6 months, and 12 months
Secondary outcomes:
measure: Change in masseter muscle stiffness assessed by sonoelastography
timeFrame: Baseline, 6 months, and 12 months
Other outcomes:
Locations:
city: Ankara
country: Turkey
facility: Ankara University Faculty of Dentistry
state: Çankaya
Study officials:
affiliation: Ankara University
name: Murat K Erdem, PhD, DDS
role: PRINCIPAL_INVESTIGATOR
References: