Orthodontic treatment of openbite and deepbite high-angle malocclusions

Area of Science:

• Dentistry
• Orthodontics
• Craniofacial Biology

Background:

• High-angle malocclusion, characterized by a hyperdivergent mandibular plane, presents challenges in orthodontic treatment.
• Dentoskeletal morphology and overbite compensation mechanisms in children with high-angle malocclusions require further investigation.

Purpose of the Study:

• To evaluate the impact of orthodontic treatment on dentoskeletal morphology in children with openbite and deepbite high-angle malocclusions.
• To compare the treatment effects and underlying mechanisms between openbite and deepbite subgroups.

Main Methods:

• Analysis of pre- and post-treatment lateral cephalograms in 54 children with mixed dentition and high-angle malocclusion (NSL/ML ≥ 40°).
• Subgrouping based on pretreatment overbite: openbite (<0 mm), normal overbite (0-4 mm), and deepbite (>4 mm).
• Assessment of changes in jaw-base relationships, dentoalveolar heights, and mandibular plane angle.

Main Results:

• Orthodontic treatment successfully corrected overbite in 82% of openbite and 90% of deepbite cases.
• The mandibular plane angle remained unchanged in both openbite and deepbite groups.
• Openbite correction involved a decrease in the interjaw-base angle and comparable increases in anterior/posterior dentoalveolar heights.
• Deepbite correction primarily involved controlling incisor eruption with minimal skeletal changes and a greater increase in posterior dentoalveolar height.

Conclusions:

• Orthodontic treatment effectively corrects overbite in high-angle malocclusions without altering the mandibular plane angle.
• Treatment mechanisms differ: openbite correction involves skeletal changes (maxillary rotation), while deepbite correction focuses on dentoalveolar compensation (incisor control).
• A majority of high-angle cases exhibit some degree of overbite, indicating compensation for jaw-base hyperdivergency.