Assessment of Mandibular Buccal Shelf Area for Ideal Placement of Miniscrews: A Systematic Review and Meta-analysis

Abstract

Aim:

To determine the most favorable site for placing mini-implants within the mandibular buccal shelf (MBS) by evaluating buccal bone width and cortical bone thickness.

Background:

This review sought to analyze the MBS using cone-beam computed tomography (CBCT) data from diverse populations, including Caucasian, Asian, and South Asian adolescents and adults. Comparisons were made across potential insertion zones buccal to the first and second molars, with specific attention to the mesiobuccal and distobuccal aspects. The primary outcomes were buccal bone width, cortical thickness, and insertion angulation relevant to achieving predictable miniscrew stability.

Materials and Methods:

Conducted in accordance with PRISMA guidelines, the review protocol was registered on PROSPERO (CRD42021258738). A systematic search of PubMed, Embase, Web of Science, and Cochrane databases, supplemented by hand searching, identified 878 records. Eligible studies included randomized controlled trials and observational designs that reported MBS dimensions for miniscrew placement. Data were extracted on bone width, cortical thickness, and insertion angle. Quantitative synthesis was carried out using R statistical software, and study quality was evaluated with the QUAMAS tool.

Results:

Eight studies with comparable data were meta-analyzed. Significance was set at 0.05 for comparisons of bone width and cortical thickness. Risk-of-bias assessment identified nine studies as high quality and five as moderate. Findings consistently indicated the distobuccal cusp region of the mandibular second molar as the most favorable insertion site, followed by the mesiobuccal cusp area. Despite methodological differences across included studies, pooled analysis revealed significant differences (p < .05) among sites, with the second molar region demonstrating superior dimensions for achieving miniscrew stability.

Conclusion:

The MBS adjacent to the distobuccal cusp of the second molar provides the most advantageous bone morphology for miniscrew placement, offering greater buccal bone width and cortical thickness. This location supports enhanced stability and should be considered the preferred choice for orthodontic anchorage in clinical practice.