21 - Anatomical assessment of intra-alveolar miniscrews for therapeutic use in orthodontics

Abstract

Background

Absolute anchorage in orthodontics has significantly advanced with the use of intra-alveolar miniscrews (MTIs), offering predictable control of tooth movement with reduced dependence on patient cooperation.

Objectives

To analyze the anatomical, physical, and clinical considerations that influence the safe and effective use of MTIs in the maxilla and mandible, aiming to guide clinical decision-making and minimize complications.

Methods

A literature review was conducted, integrating recent scientific articles and anatomical sources to evaluate insertion zones, angulation, miniscrew dimensions, materials, and clinical indications or contraindications for MTIs.

Results

The interradicular region between the second premolar and first molar is the safest for MTI insertion. Ideal angulation ranges from 30°–45° buccally and 0°–20° palatally in the maxilla, and 20°–40° in the posterior mandible. Preferred MTIs measure 1.5–2.0 mm in diameter and 6–9 mm in length. Titanium is recommended for thin bone; stainless steel for dense bone. Self-drilling or self-tapping systems should be selected based on cortical thickness. Indications include intrusion, distalization, retraction, and verticalization. Contraindications include active periodontal disease, anatomical restrictions, and systemic conditions like uncontrolled diabetes or bisphosphonate use.

Conclusions

The success of MTIs relies on detailed anatomical planning via 3D imaging, proper screw selection, and thorough evaluation of patient-specific factors. A comprehensive understanding of these variables enhances primary stability, reduces risks, and supports predictable orthodontic outcomes.