Effect of Maxillary Third Molar Extraction vs. Non-extraction on Distalization of First Molars in a Group of Adolescent Patients

Effect of Maxillary Third Molar Extraction vs Non-extraction on Distalization of First Molars in a Group of Adolescent Patients Using Infra-Zygomatic Gear Distalizer: A Randomized Clinical Trial

There is a scarcity in literature regarding the influence of maxillary third molar on distalization . This study aimed to compare the influence of unerupted maxillary third molars and their extraction on the bilateral distalization of upper first molars using the infra-zygomatic gear distalizer

Study Overview

• Status: Completed
• Conditions: Class II Malocclusion
• Intervention / Treatment: Procedure: Distalization combined with upper third molars extraction; Procedure: Distalization without upper third molars extraction

Detailed Description

Maxillary molar distalization is one of the non-extraction modalities for treating class II malocclusion. When distalizing maxillary molars In adults, it is not a problem to extract fully erupted third molars, and it may even be suggested that the extraction site may accommodate distalization. On the contrary, adolescents usually have unerupted third molars with partially formed roots, rendering the surgical extraction more difficult and traumatic. The necessity of surgically extracting upper third molar buds before distalization remains questionable. Therefore, this study was conducted to three-dimensionally assess the impact of maxillary third molar presence on distalizing maxillary molars in adolescent patients having Class II malocclusion.

• Study Type: Interventional
• Enrollment (Actual): 22
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Cairo, Egypt
    • Future University in Egypt

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 19 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Adolescent patients aged 16-19 years
• skeletal Class I
• bilateral Class II molar relationship. defined by at least an end-to-end molar relationship.
• normal vertical growth pattern.
• full permanent dentition with unerupted upper third molars.

Exclusion Criteria:

• skeletal Class II or Class III relationship.
• past orthodontic treatment.
• poor oral hygiene.
• Increased vertical dimension.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Third molar extraction group; After surgical extraction of unerupted upper third molars, the maxillary first molars were distalized using the infra-zygomatic gear distalizer, which is anchored to infra-zygomatic mini-implants inserted in the infra-zygomatic crest.	Procedure: Distalization combined with upper third molars extraction; After surgical extraction of unerupted upper third molars, the maxillary first molars were distalized using a labial bow with two soldered crimpable hooks distal to the upper lateral incisors. The labial bow fitted in the flying tube of the upper first molar bands. It was anchored bilaterally to the infra-zygomatic mini-implant by closed coil spring that applied a force of 300gm on each side
Experimental: Third molar presence group; Without extraction of unerupted upper third molars, the maxillary first molars were distalized using the infra-zygomatic gear distalizer, which is anchored to infra-zygomatic mini-implants inserted in the infra-zygomatic crest.	Procedure: Distalization without upper third molars extraction; The maxillary first molars were distalized , without extracting upper third molars, using a labial bow with two soldered crimpable hooks distal to the upper lateral incisors. The labial bow fitted in the flying tube of the upper first molar bands. It was anchored bilaterally to the infra-zygomatic mini-implant by closed coil spring that applied a force of 300gm on each side

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
distalization amount of maxillary firs molars at the crown and root levels	Anteroposterior changes in the position of maxillary first molars assessed on digitized models and cone beam computed tomography (CBCT) taken for each patient before and after distalization. Measurements were done by identifying landmarks, reference lines, and planes(measured in mm)	From pre to post distalization (an average of 8 months)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of maxillary first molar Distalization	Incremental changes in the antero-posterior position of maxillary first molars assessed on digitized models taken for each patient before and after distalization and in each follow up visit. Measurements were done by identifying landmarks, reference lines, and planes (measured in mm)	From pre- to post-distalization (an average of 8 months)
Tipping of maxillary first molar	Angular changes of maxillary first molar assessed on cone beam computed tomography (CBCT) taken for each patient before and after distalization. Measurements were done by identifying landmarks, reference lines, and planes(measurement of the angles in degrees).	From pre- to post-distalization (an average of 8 months)
Vertical position of maxillary first molar	vertical positional changes of maxillary first molar assessed on cone beam computed tomography (CBCT) taken for each patient before and after distalization. Measurements were done by identifying landmarks, reference lines, and planes (measured in mm)	From pre- to post-distalization (an average of 8 months)
Inter molar width	Changes in the transvers distance between the right and left upper first molars assessed on digitized models taken for each patient before and after distalization. Measurements were done by identifying landmarks, reference lines, and planes (measured in mm)	From pre- to post-distalization (an average of 8 months)
Molar rotation	Study models that are taken pre and post retraction (then digitalized) will be used to assess the rotation of the maxillary first molars in relation to a reference line (measurement of the angles in degrees)	From pre- to post-distalization (an average of 8 months)
Tipping of maxillary second molar	Angular changes of maxillary second molar assessed on cone beam computed tomography (CBCT) taken for each patient before and after distalization. Measurements were done by identifying landmarks, reference lines, and planes. (measured in of in degrees)	From pre- to post-distalization (an average of 8 months)
Tipping of maxillary third molar	Angular changes of maxillary third molar assessed on cone beam computed tomography (CBCT) taken for each patient before and after distalization. Measurements were done by identifying landmarks, reference lines, and planes (measurement of the angles in degrees)	From pre- to post-distalization (an average of 8 months)
Vertical position of maxillary third molar	Vertical positional changes of maxillary third molar assessed on cone beam computed (measured in mm)tomography (CBCT) taken for each patient before and after distalization. Measurements were done by identifying landmarks , reference lines, and planes (measured in mm)	From pre- to post-distalization (an average of 8 months)
Vertical position of upper incisors	Vertical positional changes of upper incisors assessed on cone beam computed tomography (CBCT) taken for each patient before and after distalization. Measurements were done by identifying landmarks, reference lines, and planes (measured in mm)	From pre- to post-distalization (an average of 8 months)
Anteroposterior position of upper incisors	Antero-posterior change in the anteroposterior position of upper incisors assessed on cone beam computed tomography (CBCT) taken for each patient before and after distalization. Measurements were done by identifying landmarks, reference lines, and planes (measured in mm)	From pre- to post-distalization (an average of 8 months)
upper incisors torque	Angular changes of upper incisors assessed on cone beam computed tomography (CBCT) taken for each patient before and after distalization. Measurements were done by identifying landmarks, reference lines, and planes (measurement of the angles in degrees)	From pre- to post-distalization (an average of 8 months)
Anteroposterior changes of upper first and second premolars	Antero-posterior change in the position of maxillary first and second premolars assessed on digitized models taken for each patient before and after distalization. Measurements were done by identifying landmarks, reference lines, and planes (measured in mm)	From pre- to post-distalization (an average of 8 months)

Collaborators and Investigators

• Sponsor: Future University in Egypt
• Investigators: Study Director: Yehya mostafa, Professor and chairman, Future University in Egypt

Study record dates

Study Major Dates

• Study Start (Actual): February 28, 2021
• Primary Completion (Actual): January 15, 2022
• Study Completion (Actual): January 15, 2022

Study Registration Dates

• First Submitted: November 25, 2022
• First Submitted That Met QC Criteria: December 8, 2022
• First Posted (Estimate): December 12, 2022

Study Record Updates

• Last Update Posted (Estimate): December 12, 2022
• Last Update Submitted That Met QC Criteria: December 8, 2022
• Last Verified: December 1, 2022

More Information

Terms related to this study

• Keywords: Infra-zygomatic mini-implant; Distalization; Infra-zygomatic crest; Digital models; molar tipping
• Additional Relevant MeSH Terms: Stomatognathic Diseases; Tooth Diseases; Malocclusion; Malocclusion, Angle Class II; Overbite
• Other Study ID Numbers: FUE.REC(14)/7-2019

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: All collected participant data (IPD)
• IPD Sharing Time Frame: Data will be available after publication
• IPD Sharing Supporting Information Type: Study Protocol; Statistical Analysis Plan (SAP); Informed Consent Form (ICF)

Drug and device information, study documents

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