Malocclusion Class II
Conditions
Keywords
Class II, mandibular advancement, clear aligners, twin block, growing patients
Brief summary
To analyze mandibular advancement between the traditional Twin Block and the Angel Aligner A6 mandibular advancement clear aligners using cephalometric analysis in growing patients and a repeatable and reproducible digital measurement technique.
Detailed description
This study compared three early orthodontic treatments for Class II division 1 malocclusion in 60 growing patients (mean age: 12.4 ± 1.3 years): Twin Block, standard Angel Aligner, and Angel Aligner A6 with mandibular advancement. After 10 months, both Twin Block and A6 showed greater skeletal correction and mandibular advancement than standard aligners, achieving higher rates of Class I correction. The A6 group also had the shortest overall treatment time. Cephalometric analyses were performed using a digital and reproducible measurement technique. For each patient, lateral cephalograms were taken before treatment (T0) and after treatment (T1, after the functional phase or aligner completion). Thus, a total of 120 lateral cephalograms were analysed. The following skeletal, dental, and soft tissue parameters were analysed.
Interventions
DEVICEAngelAligner A6 Mandibular Advancer
Mandibular advancement with aligners is achieved using specially designed orthodontic aligners that incorporate built-in mandibular advancement features. These appliances posture the lower jaw forward in a controlled and incremental manner while simultaneously aligning the teeth. The forward positioning of the mandible helps stimulate mandibular growth in growing patients and improves the correction of Class II malocclusion by enhancing sagittal jaw relationship. Aligner replacement was performed at 10-day intervals.
DEVICETwin Block
The Twin Block is a removable functional orthodontic appliance used to correct Class II malocclusion by advancing the mandible. It consists of upper and lower acrylic plates with bite blocks that interlock at a specific angle, guiding the lower jaw forward during closure. It is most effective in growing patients to improve jaw relationship and facial profile. The Twin Block appliance, used for mandibular advancement (correction of skeletal class II), was usually worn for a period of 10 months, with a minimum of 14-16 hours per day, including night hours.
DEVICEClear aligners
Class II correction with aligners (without mandibular advancement) involves the use of clear sequential aligners to improve dental alignment and occlusion by moving teeth into a more favorable position. The correction is achieved through controlled tooth movements such as distalization, interproximal reduction, and vertical control, without actively repositioning the mandible forward.
Sponsors
University of Salamanca
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
The study is designed as a parallel-group interventional trial with three independent treatment arms. A total of 60 participants (mean age: 12.4 ± 1.3 years) will be enrolled and allocated equally into one of three orthodontic interventions (Twin Block, standard Angel Aligner, or Angel Aligner A6 with mandibular advancement), with 20 patients per group. Each participant receives only the assigned treatment throughout the study period, with no crossover between groups. Outcomes are assessed at baseline (T0) and after 10 months of treatment (T1) using digital cephalometric analysis.
Eligibility
Sex/Gender
ALL
Age
9 Years to 14 Years
Healthy volunteers
No
Inclusion criteria
* Aged between 9 and 14 years with late mixed or early permanent dentition * Class II/1 malocclusion (molar relationship ≥ half-cusp Class II and overjet ≥ 5 mm) * ANB angle greater than 5º * SNB lower than 78º * CVMS 2-3, a growing patients.
Exclusion criteria
* Previous orthodontic treatment or orthognathic surgery * Patients with severe malformations or syndromes * Extraction treatment.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| ANB (°) | 10 months | Point A-nasion-point B angle (ANB): relationship between the upper and lower jaws |
| Wits appraisal (AO-BO) | 10 months | projecting points A and B in two perpendicular lines, along the functional occlusal plane |
Countries
Spain
Outcome results
None listed