External Apical Root Resorption in Maxillary Canines During Orthodontic Retraction
Conditions
Keywords
Maxillary Canine Retraction, External Apical Root Resorption, Frictionless Mechanics, Modified Corticotomy
Brief summary
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.
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.
Interventions
PROCEDUREModified 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.
PROCEDUREConventional 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.
Sponsors
Islamabad Medical and Dental College
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Masking description
The investigator responsible for measuring root length and width on calibrated OPG radiographs using ViewBox software will be blinded to group allocation. Radiographs will be coded to prevent identification of the intervention group.
Intervention model description
Participants will be randomly assigned in a 1:1 ratio to one of two parallel groups: modified corticotomy-assisted canine retraction with frictionless T-loop mechanics or conventional frictionless T-loop canine retraction.
Eligibility
Sex/Gender
ALL
Age
12 Years to 30 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mean Loss of Canine Root Length (mm) | - Before retraction (baseline) - From baseline to completion of canine retraction (approximately 4-6 months) | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Root Width at Mesial and Distal Apex (mm) | From baseline to completion of canine retraction (approximately 4-6 months) | Difference in mesial and distal root width measured 1 mm short of the root apex on calibrated OPG radiographs before and after canine retraction. |
Countries
Pakistan
Contacts
CONTACTDr. Menal Khurshid, BDS
CONTACTProf. Dr. Haroon Shahid Qazi, BDS, MS, MCPS (HPE),
STUDY_CHAIRProf. Dr. Haroon Shahid Qazi, BDS, MS, MCPS (HPE)
Islamabad Medical & Dental Hospital
Outcome results
None listed