The effects of Class II elastics on masticatory muscles responses

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

TCTR

Registry ID

TCTR20200814005

Enrollment

Unknown

Registered

2020-08-14

Start date

2019-02-01

Completion date

Unknown

Last updated

2026-08-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy adults Class II malocclusion Masticatory muscles masseter muscle temporal muscle electromyography dental occlusion dentition

Interventions

All subjects will be treated with conventional orthodontic treatment. After leveling phase&#44

the main arch wire of 0.016â€x0.022â€ stainless steel will be used. Before Class II elastics is applied in experimental group&#44

each subject will be evaluated right before Class II elastics application (T0without)&#44

and immediately after (T0with) and also with and without Class II elastics 1 months (T1with&#44

T1without)&#44

and 3 months (T2with&#44

T2without) after. Then&#44

discontinue intermaxillary elastics for 3 months and measure (T3),All subjects will be treated with conventional orthodontic treatment. After leveling phase&#44

the main arch wire of 0.016â€x0.022â€ stainless steel will be used. No any mechanics will be applied for 3 months and the data will be collected in the same protocol as the experimental group

Experimental Device,Active Comparator No treatment

Class II elastics during orthodontic treatment,Orthodontic treatment without any other mechanic but main arch wire

Eligibility

Sex/Gender

All

Age

18 Years to 40 Years

Inclusion criteria

Inclusion criteria: 1. Plans to / has been treated with conventional orthodontic treatment 2. Complete dentition (excluding the third molars) 3. Molar class II relationship not exceed 3 mm. 4. Skeletal Class I (ANB = 3Âº Â± 2Âº), normodivergent pattern (FMA = 23 Âº Â± 4 Âº) 5. Adult (18-40 years old), able to comply with the protocol

Exclusion criteria

Exclusion criteria: 1. Transverse discrepancies e.g. crossbite, laterognathia 2. Acute dental disease and/or periodontal disease 3. Cuspal-coverage dental restoration 4. Sign and symptom of TMD (according to DC/TMD, 2014112), parafunction habit 5. Cranio-mandibular anomalies 6. Systemic muscle or joint disorder 7. Use neuromuscular-effected medication i.e. muscle relaxant, Botulinum toxin (Botox)

Design outcomes

Primary

Measure	Time frame
Masticatory muscle activity Initial, 1 month, 3 months and 6 months Surface electromyography	—

Secondary

Measure	Time frame
Occlusal contact area Initial, 1 month, 3 months and 6 months Silicone bite registration	—

Countries

Thailand

Contacts

Public ContactNapat Nalamliang

Faculty of Dentistry, Prince of Songkla University

a_luvis@hotmail.com+66818886611

Outcome results

None listed

Source: TCTR (via WHO ICTRP) · Data processed: Aug 9, 2026