Maxillary protraction anchored on miniplates versus miniscrews: three-dimensional dentoskeletal comparison

Area of Science:

• Orthodontics and Dentofacial Orthopedics
• Craniofacial Biology
• Biomaterials in Orthodontics

Background:

• Skeletal Class III malocclusion presents a significant challenge in growing patients, often requiring orthopedic intervention to correct maxillary deficiency.
• Maxillary protraction techniques aim to advance the midface, improving facial aesthetics and function.
• Skeletal anchorage, using miniscrews or miniplates, offers a more controlled approach to maxillary protraction compared to traditional dental anchorage.

Purpose of the Study:

• To compare the three-dimensional (3D) treatment outcomes of miniscrew-anchored maxillary protraction (MAMP) and bone-anchored maxillary protraction (BAMP) in growing patients with skeletal Class III malocclusion.
• To evaluate and quantify the skeletal and dental changes induced by each protraction protocol.
• To assess differences in maxillary displacement and nasal cavity dimensions between the two skeletal anchorage methods.

Main Methods:

• Retrospective study comparing two skeletal anchored maxillary protraction protocols: MAMP (n=22) and BAMP (n=24).
• Patients with skeletal Class III malocclusion were treated with Class III elastics anchored to maxillary expanders and mandibular skeletal anchorage (miniscrews for MAMP, miniplates for BAMP).
• Three-dimensional displacements were analyzed using cone-beam computed tomography (CBCT) scans, superimposed on the cranial base. Statistical analysis included Analysis of Covariance (ANCOVA).

Main Results:

• Both MAMP and BAMP therapies resulted in significant improvements in skeletal Class III malocclusion.
• The MAMP group exhibited less anterior and 3D maxillary displacement compared to the BAMP group (MD: -1.09 mm and -1.27 mm, respectively).
• A significantly greater increase in nasal cavity width was observed in the MAMP group (MD: 2.36 mm) compared to the BAMP group. Mandibular changes were similar and negligible in both groups.

Conclusions:

• Both MAMP and BAMP are effective 3D skeletal anchorage methods for maxillary protraction in growing patients with Class III malocclusion.
• BAMP therapy demonstrated a greater degree of maxillary advancement.
• MAMP therapy showed a more pronounced effect on widening the nasal cavity, suggesting potential benefits for improving nasal respiration.