Root Proximity During Mini-Screw Insertion Using a Digital Three-Dimensional Printed Guide

Orthodontic Appliance Complication

Surgical guide, Surgical stent, orthodontic mini screw, temporary anchorage device

Although mini screw insertion is considered as a simple and non-invasive technique, it's a critical procedure which requires precision and accuracy. The placement of mini-screw poses a challenge to the orthodontist, particularly if the space available for mini-screws is limited.4 The proximity to the vital structures surrounding the proposed mini-screw position necessitates the precise knowledge of the anatomy of the insertion area.5 The incidence of mini-screw to tooth contact in the placement of inter-radicular region was 27%.6 Although failure of mini screw is considered a multi-factorial concern, many studies reported the proximity of a mini-screw to tooth structures is a major risk factor for failure, especially in the inter-radicular inserted mini-screws. guided insertion was believed to give more favorable results. Above all, the recent technology of the scanning and three-dimensional printing could pave the way to construct a simple accurate guide. Additionally all previous studies assessed the insertion accuracy using CBCT post-operatively, that can't be applied on human subjects for ethical reasons. Thus a non-invasive method for assessment of mini-screw insertion should be implemented.

PICOs P: Adult orthodontic patients need mini screws in maxillary arch bilaterally for anchorage I: Three dimensional printed digital guide for mini screw insertion C: Conventional free hand insertion technique \- O: Primary outcome: Root proximity Secondary outcomes: * Patient discomfort during insertion 17 * Insertion accuracy * Angular deviation * Linear deviation * Failure 18 S: Split Mouth Randomized clinical Trial