Comparison of Maxillary Protraction Biomechanics in Mild to Moderate Retrognathism - Tooth-Borne versus Skeletal Anchorage

Abstract

AIM: To compare two anchorage techniques in facilitating maxillary forward development in mild to moderate maxillary retrognathism.

METHODS: An electronic search of the literature was systematically reviewed using PubMed/Medline, followed by a manual search. The search was refined by time and English language criteria. Keywords and MeSH terms included Cephalometric, Palatal expansion, mini plates, micro-screws, mini implants, skeletal anchorage, orthodontic anchorage. The search yielded 291 articles, which were narrowed down to 10 relevant quality studies, several moderate quality studies, and 4 systematic reviews based on inclusion and exclusion criteria.

RESULTS: The initial database search yielded 1305 records; 32 studies passed the first review phase, and 10 studies were finally selected. Dental anchorage designs consistently demonstrated maxillary skeletal advancement of 2-4mm, accompanied by maxillary forward and upward rotation, and increased vertical dimension. Bone-anchored protraction techniques showed greater forward movement (1 mm more), with fewer unwanted side effects.

CONCLUSION: Skeletal anchorage mechanics produced more skeletal effect in maxillary protraction with less dentoalveolar component compared to dental anchorage techniques. Despite the advantages of skeletal bone anchorage in maxillary protraction mechanics, evidence-based research is limited.