Anterior Open Bite, Hyperdivergent Facial Pattern, Hyperdivergent Growth Pattern, Skeletal Open Bite
Conditions
Keywords
Open Bite Treatment, Masseter Muscle, Ultrasound Imaging, Sonoelastography, Skeletal Anchorage, Vertical Elastics, Functional Orthodontic Appliance, Cephalometric Analysis
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.
Interventions
A custom-made acrylic open bite activator was fabricated for each participant, with the bite registered 3-4 mm above freeway space. Miniscrews were placed between the lateral and canine teeth in both jaws. Vertical elastics (150g force) were applied bilaterally between miniscrews and the appliance. The intervention aimed to reduce vertical growth in posterior regions and stimulate anterior dentoalveolar development while improving masseter muscle morphology.
Sponsors
Murat Kaan Erdem
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Participants received treatment with an open bite activator combined with vertical elastics supported by anterior skeletal anchorage in a single group.
Eligibility
Sex/Gender
ALL
Age
12 Years to 14 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in masseter muscle thickness measured by ultrasonography | Baseline, 6 months, and 12 months | Masseter muscle thickness (in millimeters) will be measured at rest and during maximal clenching using ultrasonography at three time points: baseline (T0), 6 months (T1), and 12 months (T2). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in masseter muscle stiffness assessed by sonoelastography | Baseline, 6 months, and 12 months | The ratio of stiff (red) areas to total cross-sectional area of the masseter muscle will be evaluated using shear wave sonoelastography at T0, T1, and T2. |
Countries
Turkey (Türkiye)
Outcome results
None listed