Morphological characterization of extra-alveolar anchorage sites for orthodontic anchorage through miniscrews: A scoping review.

BACKGROUND

Extra-alveolar anchorage sites, particularly the infrazygomatic crest (IZC) and the mandibular buccal shelf (MBS), are increasingly used for orthodontic anchorage. Although cone-beam computed tomography (CBCT) is widely employed to evaluate these regions, the available evidence shows substantial methodological heterogeneity.

OBJECTIVE

To map the CBCT-based evidence on the morphological characteristics of the infrazygomatic crest and mandibular buccal shelf as extra-alveolar anchorage sites for orthodontic miniscrews.

METHODS

A scoping review was conducted following PRISMA-ScR guidelines. Searches were conducted in PubMed, Scopus, and the Cochrane Library through June 2025. Observational studies reporting CBCT-based anatomical measurements of the IZC and/or MBS were included and charted descriptively.

RESULTS

Of the 58 initially identified records, 13 studies were finally included. Considerable heterogeneity was observed in CBCT acquisition protocols, measurement approaches, anatomical reference points, and studied populations, limiting direct comparability across studies.

CONCLUSIONS

Current CBCT-based evidence on the morphology of extra-alveolar anchorage sites is highly heterogeneous. This scoping review provides a structured overview of the existing literature on the IZC and MBS and underscores the need for greater standardization of morphological measurement protocols.