Skeletally-anchored rapid maxillary expansion using the Dresden Distractor

Area of Science:

• Orthodontics
• Craniofacial Surgery
• Biomedical Engineering

Background:

• Surgically-assisted rapid maxillary expansion (RME) is used to correct maxillary hypoplasia.
• Tooth-borne RME devices can lead to undesirable dento-alveolar side effects.
• Bone-borne RME aims to minimize these side effects by applying forces directly to the bone.

Purpose of the Study:

• To perform a 3-D analysis of skeletal and dental changes during bone-borne RME with the Dresden Distractor (DD).
• To evaluate the efficacy of the DD in achieving skeletal expansion while minimizing dento-alveolar side effects.
• To compare the outcomes of bone-borne RME with the DD to traditional tooth-borne RME.

Main Methods:

• Twelve patients underwent 3-D computed tomography (CT) scans before and after RME with the DD.
• Standardized reference planes and the triple-0-ELSA were used for measurements.
• Quantification of skeletal and dental movements, including transverse expansion and tooth tipping.

Main Results:

• A 6.0 mm screw activation resulted in significant transverse expansion (5.55 mm premolar, 4.87 mm molar regions).
• Minimal buccal tipping of teeth (3.1-4.6 degrees premolars, 1.1-2.6 degrees molars) was observed.
• Significant skeletal expansion with uprighting of teeth and potential for mandibular autorotation was noted.

Conclusions:

• The bone-borne Dresden Distractor (DD) is effective for RME, achieving skeletal expansion.
• The DD minimizes adverse dento-alveolar effects like root resorption and excessive tooth tipping.
• This method facilitates stable occlusion and is suitable for patients with vertical growth patterns.