Mandibular Sequential Distalization Versus Class III Elastics With Clear Aligners in Class III Patients

NCT06859606 | Completed DMC

• 1 other identifier: 75.23
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Distalizing mandibular molars may be indicated for patients with minor skeletal Class III discrepancies or in Class III subjects with mild crowding. Traditionally, mandibular molar distalization was accomplished using elastics, open coils, and the multiloop edgewise archwire technique. In recent years, several techniques have been developed to reduce the dependence on patient compliance, such as skeletal anchorage. Recently, several reports have been published on mandibular distal movement using miniscrews and some case reports have shown the possibility of obtaining Class III correction with sequential mandibular distalization in non-growing subjects by means of clear aligners. However, a sound clinical judgment should always be made on the basis of a higher level of evidence. Therefore, the purpose of the present prospective study is to provide a detailed analysis of the underlying skeletal and dental changes determined by mandibular distalization therapy with the sequential Invisalign protocol in permanent dentition. This will be accomplished by testing the following null hypothesis: mandibular molar distalization is not achievable with aligners without the application of TADs.

Conditions

Class III Malocclusion

Keywords

class III malocclusion; lower molar distalization; class III elastics; clear aligner treatment

Outcome Measures

Primary Outcomes (1)

• Lower molar positional changes expressed by means of linear and angular measurements (L6-MP mm; L6-MP angle; L6 - CoGo mm; L6 apex - CoGo mm)

  L6-MP mm: linear distance between the mesial cusp of lower first molar and Mandibular plane L6-MP angle: angle between long axis of lower first molar and Mandibular plane L6 - CoGo mm: linear distance between the mesial cusp of lower first molar and CoGo line L6 apex - CoGo mm: linear distance between the apex of lower first molar and CoGo line

  from the start of treatment to the end at 24 months

Secondary Outcomes (7)

• Changes in inclination of the lower incisors (IMPA angle)

  from the start of treatment to the and at 24 months

• Changes in position of the lower incisors (L1-CoGo mm; L1apex - CoGo)

  from the start of treatment to the and at 24 months

• Sagittal skeletal changes (SNA angle, SNB angle, ANB angle)

  from start of treatment to to the end at 24 months

• Sagittal skeletal changes (Wits appraisal)

  from start of treatment to to the end at 24 months

• Vertical skeletal changes (SN^MP angle, Gonial Angle)

  from the start of treatment to the end at 24 months

Study Arms (2)

Group 1 - Lower Distalization Protocol

EXPERIMENTAL

In Group 1 (Lower Distalization Protocol), all subjects underwent lower molar distalization combined with Class III elastics.

Other: Lower molar distalization

Group 2, Non-Distalization Protocol

EXPERIMENTAL

In Group 2 (Non-Distalization Protocol) all subjects were treated with dento-alveolar expansion and Class III elastics

Other: Class III elastics

Interventions

Lower molar distalization OTHER

Lower Distalization Protocol included extraction of the lower third molars before starting treatment and a 50% sequential lower distalization with two teeth being distalized at a time. The distalization started with the movement of lower second molars, followed by the first molars halfway through the process, and so on. Once the canine reached the right position, the "en masse" retraction of the four incisors completed the treatment plan. The protocol comprised the use of Class III intermaxillary elastics to support the distalization movement and to control the proclination of lower incisors

Group 1 - Lower Distalization Protocol

Class III elastics OTHER

Non-Distalization Protocol featured extraction of the lower third molars before starting treatment, transversal dento-alveolar coordination, strategic interproximal reduction (IPR) in the anterior segment of the lower arch, and the addition of Class III elastics

Group 2, Non-Distalization Protocol

Eligibility Criteria

• Age: 19 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• adult age (≥19 years)
• permanent dentition including second permanent molars
• skeletal Class I or slight Class III (-2° \< ANB \< +2°)
• normal skeletal divergency pattern (SN\^GoGn, 27°-37°)
• Class III canine and molar relationship at baseline (T0), moderate lower arch crowding (≤ +4 mm)
• good compliance with aligners and elastics (≥ 20 hours/day)

You may not qualify if:

• severe skeletal Class III malocclusion (ANB \< -2°)
• transversal maxillary deficiency
• use of Temporary Anchorage Devices (TADs)
• extraction treatments other than third molars
• periodontal disease or temporomandibular disorders (TMDs).

Sponsors & Collaborators

• Saint Camillus International University of Health Sciences: lead

Study Sites (1)

Saint Camillus International University of Health Sciences

Rome, 00131, Italy

Location

Related Publications (6)

• Martina H, Stefano Adriana A, Ernesto B, Alessandra I, Roberto AV, Gabriella G. Lower molar distalization using clear aligners: Is it effective? A systematic review. J Orthod Sci. 2024 Feb 16;13:11. doi: 10.4103/jos.jos_174_23. eCollection 2024.

  PMID: 38516119 BACKGROUND

• Rota E, Parrini S, Malekian K, Cugliari G, Mampieri G, Deregibus A, Castroflorio T. Lower molar distalization using clear aligners: bodily movement or uprighting? A preliminary study. Appl. Sci. 2022, 12(14), 7123.

  BACKGROUND

• Han J, Ning N, Du H, Zhou M, Cai C, Hong Y, et al. Efficacy of clear aligners on mandibular molar distalization: A retrospective study. Digit Med 2021; 7:1.

  BACKGROUND

• Padmanabhan A, Khan Y, Lambate V, K U, Naveed N, Singh M, Nagi PK. Efficacy of Clear Aligners in Treating Class III Malocclusion With Mandibular Molar Distalization: A Systematic Review. Cureus. 2023 Nov 1;15(11):e48134. doi: 10.7759/cureus.48134. eCollection 2023 Nov.

  PMID: 38046776 BACKGROUND

• Pavoni C, Gazzani F, Franchi L, Loberto S, Lione R, Cozza P. Soft tissue facial profile in Class III malocclusion: long-term post-pubertal effects produced by the Face Mask Protocol. Eur J Orthod. 2019 Sep 21;41(5):531-536. doi: 10.1093/ejo/cjz003.

  PMID: 30865768 BACKGROUND

• Gazzani F, Pavoni C, De Razza FC, Lugli L, Cozza P, Lione R. Clear aligner treatment in adult patients with class III malocclusion: lower distalization and class III elastics vs class III elastics alone - a RCT. Eur J Orthod. 2025 Jun 12;47(4):cjaf052. doi: 10.1093/ejo/cjaf052.

  PMID: 40600239 DERIVED

MeSH Terms

Conditions

Malocclusion, Angle Class III

Condition Hierarchy (Ancestors)

Malocclusion; Tooth Diseases; Stomatognathic Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Research Assistant

Study Record Dates

• First Submitted: February 11, 2025
• First Posted: March 5, 2025
• Study Start: December 1, 2022
• Primary Completion: December 1, 2024
• Study Completion: January 10, 2025
• Last Updated: March 5, 2025

Record last verified: 2025-03

Locations

IT (1)