Maximum Clinical Insertion Torque and Its Association With the Success Rate of Orthodontic Miniscrews (MTtorque)

Orthodontic miniscrews provide temporary skeletal anchorage but are lost prematurely in a proportion of cases despite correct placement. The insertion torque generated when a miniscrew is seated has been proposed as a marker of primary stability, but its relationship with clinical success remains uncertain and the existing evidence is limited. This prospective observational cohort study evaluated orthodontic miniscrews placed for skeletal anchorage during routine fixed orthodontic treatment at the postgraduate orthodontic clinic of Universidad de los Andes, Santiago, Chile. The primary objective was to determine whether the maximum clinical insertion torque measured at placement is associated with miniscrew success. Maximum insertion torque and patient-, device-, site-, and treatment-related characteristics were recorded, and each miniscrew was followed until elective removal or failure.

Study Overview

• Status: Completed
• Conditions: Malocclusion
• Intervention / Treatment: Device: microscrew

Detailed Description

Orthodontic miniscrews are widely used to provide temporary skeletal anchorage, yet the prognostic value of the insertion torque generated at placement remains uncertain. In this single-center prospective cohort, miniscrews placed for skeletal anchorage during routine fixed orthodontic treatment were followed under real-world clinical conditions. All miniscrews were placed by a single experienced operator following a standardized clinical protocol. Maximum clinical insertion torque was recorded at final seating using a calibrated manual disk-type torque wrench as the reference measurement, with a digital torque meter used for corroboration at sites with difficult access or when values exceeded the manual gauge range. Each miniscrew was monitored at routine orthodontic visits from placement until elective removal or failure, and its observation time was recorded. The study evaluates the association between maximum insertion torque and miniscrew outcome, accounting for the clustering of multiple miniscrews within patients, and describes insertion torque across anatomical insertion sites.

• Study Type: Observational
• Enrollment (Actual): 63

Contacts and Locations

Study Locations

• Chile
  • Santiago Metropolitan
    • Santiago, Santiago Metropolitan, Chile, vitacura
      • Valentina Risso

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Patients with indication for insertion of orthodontic mini-screws as an orthodontic anchorage device, attended at the Postgraduate Orthodontic Clinic of CESA, Universidad de los Andes, San Bernardo, Chile.

Description

Inclusion Criteria:

• - Patients undergoing orthodontic treatment and who have a clinical indication for skeletal anchorage using mini-screws.
• Patients who freely and voluntarily accept the procedure as part of their orthodontic treatment.
• Patients who freely and voluntarily consent or agree to the use of their TM installation and evolution data as part of their orthodontic treatment.

Exclusion Criteria:

• - Patients with craniofacial syndromes.
• Patients with uncontrolled systemic disease.
• Patients with active periodontal disease.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
MT success rate	A MT that provides the necessary orthodontic anchorage prior to its removal, or that its permanence in the mouth is ≥4 months, will be considered successful.	1 year

Collaborators and Investigators

• Sponsor: Universidad de los Andes, Chile
• Investigators: Principal Investigator: rodrigo oyonarte, orthodontics, Universidad de los Andes, Chile

Study record dates

Study Major Dates

• Study Start (Actual): August 7, 2020
• Primary Completion (Actual): May 1, 2022
• Study Completion (Actual): September 1, 2022

Study Registration Dates

• First Submitted: March 17, 2022
• First Submitted That Met QC Criteria: August 19, 2026
• First Posted (Actual): August 21, 2026

Study Record Updates

• Last Update Posted (Actual): August 21, 2026
• Last Update Submitted That Met QC Criteria: August 19, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: orthodontics; skeletal anchorage; mini-screw; TADS; insertion torque
• Additional Relevant MeSH Terms: Stomatognathic Diseases; Tooth Diseases; Malocclusion
• Other Study ID Numbers: MT Maximum insertion torque

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes