Modified Herbst Approach to Improve Chin Projection
Class II Malocclusion
About this trial
This is an interventional treatment trial for Class II Malocclusion
Eligibility Criteria
Inclusion Criteria:
- Class II skeletal malocclusion based on PgOLp more than 85 mm and A-OLp more than 75 mm.
- Perceived potential improvement of facial convexity.
- At least end-to-end bilateral molar relationship.
- Early permanent dentition.
- No congenitally missing teeth.
Exclusion criteria:
- Class II skeletal malocclusion based on PgOLp less than 85 mm and A-OLp less than 75 mm.
- Only reasonable management option is surgery.
- Less than an end-to-end bilateral molar relationship.
- Mixed dentition dentition.
- Congenitally missing teeth.
Sites / Locations
- University of AlbertaRecruiting
Arms of the Study
Arm 1
Arm 2
Arm 3
Arm 4
Active Comparator
Active Comparator
Experimental
Experimental
Class II type A malocclusion - proclination of upper incisors indicated - No TADs
Class II type B malocclusion - proclination of upper incisors not indicated - No TADs
Class II type A malocclusion - proclination of upper incisors indicated - TADs
Class II type B malocclusion - proclination of upper incisors not indicated - TADs
A hybrid Herbst appliance approach will be used (current available conventional treatment). The upper jaw component will be a maxillary expander secured on the first molar bands. The lower arch would have an uncemented lower acrylic full-coverage splint-type. In between Herbst-type pistons will be used. Upper brackets will be initially bonded and upper incisors proclined until normal inclination values are attained.
A hybrid Herbst appliance approach will be used (current available conventional treatment). The upper jaw component will be a maxillary expander secured on the first molar bands. The lower arch would have an uncemented lower acrylic full-coverage splint-type. In between Herbst-type pistons will be used.
A modified hybrid Herbst appliance approach (same hybrid Herbst appliance approach but with the addition of temporary anchorage devices (TADs) in both arches) will be used (alternative treatment). In the upper arch, the TADs would be inserted in the paramedical palatal area. In the lower arch, they would be inserted buccally between the roots of the lower second premolar and the first permanent molar. Elastomeric chains will be used to link these TADs to the first molars in the upper arch and to a buccal bottom on the lower canines. Upper brackets will be initially bonded and upper incisors proclined until normal inclination values are attained.
CA modified hybrid Herbst appliance approach (same hybrid Herbst appliance approach but with the addition of temporary anchorage devices (TADs) in both arches) will be used (alternative treatment). In the upper arch, the TADs would be inserted in the paramedical palatal area. In the lower arch, they would be inserted buccally between the roots of the lower second premolar and the first permanent molar. Elastomeric chains will be used to link these TADs to the first molars in the upper arch and to a buccal bottom on the lower canines.