Clinical Performance of Infrazygomatic Crest Miniscrews Placed Without Surgical Guides: A Retrospective Study with 30-Month Follow-Up

Background: Infrazygomatic crest (IZC) miniscrews provide reliable extra-alveolar skeletal anchorage for orthodontic tooth movement while minimizing dependence on patient compliance. Although guided insertion techniques have been proposed to improve placement accuracy, freehand insertion remains widely used because of its simplicity and clinical practicality. This retrospective study evaluated the clinical performance and survival of freehand-placed IZC miniscrews over a minimum follow-up period of 30 months. Materials and Methods: A retrospective observational study was conducted on 23 consecutive patients receiving a total of 30 IZC miniscrews between January 2022 and July 2024. All miniscrews were placed freehand by the same experienced orthodontist following individualized radiographic planning based on panoramic radiography and/or cone-beam computed tomography (CBCT), according to the patient’s anatomical requirements. Miniscrews were immediately loaded using light orthodontic forces (<100 g), with progressive force increases during subsequent appointments based on treatment objectives. Patients were reviewed at approximately 30–35-day intervals. Clinical records were analyzed to assess miniscrew survival, timing of failure, and procedure-related complications using descriptive statistical analysis. Results: Twenty-seven of the 30 miniscrews remained clinically stable throughout treatment, corresponding to an overall success rate of 90.0%. Three failures occurred during the early treatment phase, while no late failures were observed. Because of the limited number of failure events, potential contributing factors—including screw dimensions, mechanical interference, and deterioration of oral hygiene during treatment—were evaluated descriptively and should be interpreted with caution. No major surgical or radiographic complications were detected during follow-up. Conclusions: Within the limitations of this retrospective observational study, freehand placement of IZC miniscrews demonstrated favorable clinical performance when performed by an experienced operator following appropriate radiographic planning. However, the relatively small sample size, absence of a control group, and descriptive nature of the analysis preclude definitive conclusions regarding factors influencing miniscrew failure or the comparative effectiveness of freehand versus guided insertion. Larger prospective controlled studies are warranted to validate these preliminary findings. Clinical relevance Manual IZC miniscrew insertion represents a predictable, efficient, and cost-effective alternative to guided approaches in orthodontic practice.