Dento-Alveolar Changes in Maxillary Incisors After En-Masse Retraction Using Two Power-Arm Heights

NCT07259720 | Completed

• 1 other identifier: AZH-ORTHO-RET-2025
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to evaluate the dento-alveolar changes associated with en-masse retraction of the maxillary anterior teeth using two different power-arm lengths to produce two distinct levels of force application. Twenty patients were randomly assigned into two equal groups. Group I received en-masse retraction using a 5-mm power arm, while Group II was treated using a 9-mm power arm. Cone-beam computed tomography (CBCT) was used to measure changes in buccal bone thickness at 3 mm, 6 mm, and 9 mm levels before and after retraction. The purpose of the study is to assess the influence of power-arm length on force direction, bone remodeling, and the safety of anterior tooth movement.

Conditions

Malocclusion, Angle Class II, Division 1

Keywords

En-masse retraction Power arm lenghth CBCT Bone remodeling

Outcome Measures

Primary Outcomes (1)

• Dentoalveolar changes of maxillary incisors after en-masse retraction using different power arm heights

  Evaluation of maxillary incisor dentoalveolar changes following orthodontic en-masse retraction using temporary anchorage devices (TADs) with different power arm heights. Measurements include incisor inclination, root position, buccal and palatal alveolar bone thickness, and alveolar crest level changes assessed by CBCT.

  Baseline (before retraction) and after space closure (approximately 6-9 months)

Study Arms (2)

Group 1: 5 mm Power Arm

EXPERIMENTAL

Orthodontic en-masse retraction using temporary anchorage devices (TADs) with a 5 mm power arm height for force application. Maxillary incisors are retracted as a single unit following first premolar extraction.

Procedure: TAD-supported En-masse Retraction

Group 2: 9 mm Power Arm

EXPERIMENTAL

Orthodontic en-masse retraction using temporary anchorage devices (TADs) with a 9 mm power arm height for force application. Maxillary incisors are retracted as a single unit following first premolar extraction.

Procedure: TAD-supported En-masse Retraction

Interventions

TAD-supported En-masse Retraction PROCEDURE

Orthodontic en-masse retraction of maxillary incisors using temporary anchorage devices (TADs) with different power arm heights following first premolar extraction. The intervention involves controlled retraction mechanics using a 0.017×0.025 stainless steel archwire and vertical power arms to alter the moment-arm and force system.

Group 1: 5 mm Power Arm; Group 2: 9 mm Power Arm

Eligibility Criteria

• Age: 18 Years - 25 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• \. Aged from 18 to 25 years. 2. Patients indicated for extraction of maxillary first premolars (those with Angle's Class I bimaxillary protrusion or Angle's Class II Division I malocclusion).
• \. Good oral hygiene. 4. Healthy compliant and motivated patient. 5. Full dentition in maxillary arch except wisdom teeth.

You may not qualify if:

• \. Previous orthodontic treatments. 2. Any systemic or bone diseases. 3. Smoking history. 4. Presence of periodontal diseases.

Sponsors & Collaborators

• Faculty of Dental Medicine for Girls: lead

Study Sites (1)

Orthodontic Department, Faculty of Dentistry - Al-Azhar University

Cairo, Egypt

Location

Related Links

• CBCT-based evaluation of en-masse retraction biomechanics.

MeSH Terms

Conditions

Malocclusion, Angle Class II

Condition Hierarchy (Ancestors)

Malocclusion; Tooth Diseases; Stomatognathic Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Postgraduate Student - Orthodontics

Model Details: Participants were randomly assigned into two parallel groups receiving different power-arm lengths (5 mm vs 9 mm) during en-masse retraction. Each group followed the same orthodontic protocol except for the intervention difference.

Study Record Dates

• First Submitted: November 21, 2025
• First Posted: December 2, 2025
• Study Start: November 1, 2023
• Primary Completion: November 1, 2023
• Study Completion: November 1, 2025
• Last Updated: December 2, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

EG (1)