Comparison of Root Resorption in Modified Corticotomy-Assisted and Conventional Canine Retraction (MCA-CR)

Comparison of External Apical Root Resorption in Modified Corticotomy-Assisted and Conventionally Retracted Maxillary Canines Using Frictionless T-Loop Mechanics: A Randomized Controlled Clinical Trial

This randomized controlled clinical trial will compare external apical root resorption in patients undergoing maxillary canine retraction using modified corticotomy-assisted frictionless T-loop mechanics versus conventional frictionless T-loop mechanics. Sixty orthodontic patients requiring extraction of maxillary first premolars will be randomly assigned to two groups. Changes in canine root length will be measured on panoramic radiographs taken before and after retraction to determine the extent of external apical root resorption. The study will evaluate whether modified corticotomy-assisted retraction results in different root resorption outcomes compared to conventional retraction.

Study Overview

• Status: Not yet recruiting
• Conditions: External Apical Root Resorption in Maxillary Canines During Orthodontic Retraction
• Intervention / Treatment: Procedure: Modified Corticotomy assisted frictionless canine retraction; Procedure: Conventional Frictionless Canine retraction

Detailed Description

External apical root resorption is a known complication of orthodontic treatment and may be influenced by the magnitude and duration of orthodontic force. Methods that accelerate tooth movement may reduce overall treatment time and potentially influence the extent of root resorption.

Corticotomy-assisted orthodontics is based on the regional acceleratory phenomenon, which enhances bone remodeling and facilitates tooth movement. Modified corticotomy techniques involve limited surgical injury to the cortical bone to stimulate accelerated movement while minimizing postoperative morbidity. Frictionless mechanics using T-loops allow controlled canine retraction with reduced frictional resistance between the bracket and archwire.

This single-center randomized controlled clinical trial will enroll 60 patients aged 12 to 30 years who require bilateral extraction of maxillary first premolars as part of orthodontic treatment. Participants will be randomly allocated in a 1:1 ratio to:

Group A: Modified corticotomy-assisted canine retraction with frictionless T-loop mechanics Group B: Conventional frictionless T-loop canine retraction

All participants will be treated using 0.022 × 0.028-inch preadjusted edgewise appliances. Standardized T-loop activation delivering controlled force will be performed at three-week intervals until canine retraction is completed.

External apical root resorption will be assessed by measuring linear changes in root length from the canine cusp tip to the root apex on calibrated pre- and post-retraction panoramic radiographs using digital measurement software. The primary outcome measure will be the mean change in root length between baseline and post-retraction assessments. Statistical analysis will compare the magnitude of root resorption between the two groups.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Dr. Menal Khurshid, BDS; Phone Number: 0333-5303397; Email: menal.15@iideas.edu.pk
• Study Contact Backup: Name: Prof. Dr. Haroon Shahid Qazi, BDS, MS, MCPS (HPE),; Phone Number: 0300-5001774; Email: haroon77@gmail.com

Study Locations

• Pakistan
  • Federal
    • Islamabad, Federal, Pakistan, 45720
      • Islamabad Dental Hospital
      • Contact: Menal Khurshid, BDS; Phone Number: 0333-5303397; Email: menal.15@iideas.edu.pk

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Patients aged 12-30 years requiring canine retraction into maxillary first premolar extraction spaces
• Patients with normal vertical skeletal pattern (mandibular plane angle 32° ± 5°)
• Patients with healthy periodontium

Exclusion Criteria:

• Syndromic patients
• Patients with systemic conditions requiring long-term medication affecting orthodontic tooth movement (e.g., NSAIDs, bisphosphonates, anticonvulsants)
• Mixed dentition cases
• Patients with pre-existing root resorption
• Patients who fail to attend scheduled appointments

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Modified Corticotomy Assisted Canine Retraction; Description: Participants will undergo modified corticotomy procedure followed by canine retraction using frictionless T-loop mechanics after extraction of maxillary first premolars. Intervention: Procedure: Modified Corticotomy; Procedure: Frictionless T-loop canine retraction.	Procedure: Modified Corticotomy assisted frictionless canine retraction; A surgical procedure in which a buccal flap is elevated and two vertical corticotomy cuts are made in the maxillary cortical bone adjacent to the extraction site to accelerate orthodontic tooth movement.
Active Comparator: Conventional T-loop Canine Retraction; Description: Participants will undergo conventional canine retraction using frictionless T-loop mechanics without any surgical intervention after extraction of maxillary first premolars. Intervention: Frictionless T-loop canine retraction.	Procedure: Conventional Frictionless Canine retraction; Orthodontic space closure using 17×25 TMA T-loops activated to deliver approximately 200 g of force for frictionless canine retraction into maxillary first premolar extraction spaces.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Loss of Canine Root Length (mm)	External apical root resorption measured as the difference in root length (in millimeters) from canine cusp tip to root apex on calibrated pre-treatment and post-retraction OPG radiographs using ViewBox software.	- Before retraction (baseline) - From baseline to completion of canine retraction (approximately 4-6 months)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Root Width at Mesial and Distal Apex (mm)	Difference in mesial and distal root width measured 1 mm short of the root apex on calibrated OPG radiographs before and after canine retraction.	From baseline to completion of canine retraction (approximately 4-6 months)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Degree of External Apical Root Resorption According to Sharpe Classification	SHARPE ET AL. CLASSIFICATION OF EXTERNAL ROOT RESORPTION 0 = No apical root resorption; Slight blunting of the root apex; Moderate resorption of root apex beyond blunting and up to one-third of root length.; Excessive (severe) resorption of the root apex beyond one-third of the root length.	At completion of canine retraction (approximately 4-6 months)

Collaborators and Investigators

• Sponsor: Islamabad Medical and Dental College
• Investigators: Study Chair: Prof. Dr. Haroon Shahid Qazi, BDS, MS, MCPS (HPE), Islamabad Medical & Dental Hospital

Publications and helpful links

General Publications

• Hatrom AA, Zawawi KH, Al-Ali RM, Sabban HM, Zahid TM, Al-Turki GA, Hassan AH. Effect of piezocision corticotomy on en-masse retraction. Angle Orthod. 2020 Sep 1;90(5):648-654. doi: 10.2319/092719-615.1.
• Alikhani M, Raptis M, Zoldan B, Sangsuwon C, Lee YB, Alyami B, Corpodian C, Barrera LM, Alansari S, Khoo E, Teixeira C. Effect of micro-osteoperforations on the rate of tooth movement. Am J Orthod Dentofacial Orthop. 2013 Nov;144(5):639-48. doi: 10.1016/j.ajodo.2013.06.017.
• Sondeijker CFW, Lamberts AA, Beckmann SH, Kuitert RB, van Westing K, Persoon S, Kuijpers-Jagtman AM. Development of a clinical practice guideline for orthodontically induced external apical root resorption. Eur J Orthod. 2020 Apr 1;42(2):115-124. doi: 10.1093/ejo/cjz034.

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: March 3, 2026
• First Submitted That Met QC Criteria: March 3, 2026
• First Posted (Actual): March 9, 2026

Study Record Updates

• Last Update Posted (Actual): March 9, 2026
• Last Update Submitted That Met QC Criteria: March 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Maxillary Canine Retraction; External Apical Root Resorption; Frictionless Mechanics; Modified Corticotomy
• Other Study ID Numbers: IDH123; IDH-ORTHO-2026 (Other Identifier: Islamabad Medical & Dental College)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: IPD will not be shared to maintain participant confidentiality and due to institutional data protection policies.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No