Success Rate of the Miniscrews in the Mandibular Buccal Shelf

Evidence-based Selection of Orthodontic Miniscrews, Increasing Their Success Rate in the Mandibular Buccal Shelf: A Randomized, Prospective Clinical Trial

Stability of the orthodontic miniscrews placed in the mandible is still considered to bare higher risk of failure compared to other intraoral locations. The aim of our study was to determine the influence of the miniscrew size on their long-term stability, occurrence of oral mucosa inflammation and pain lasting over 48 hours after implantation.

Study Overview

• Status: Completed
• Conditions: Class III Malocclusion
• Intervention / Treatment: Procedure: Orthodontic miniscrew insertion in the mandibular buccal shelf

• Study Type: Interventional
• Enrollment (Actual): 100
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 50 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• generally healthy Caucasians
• mild Class III maloclussion that required an absolute anchorage for en-masse distalization in the mandible
• hypodivergent or normal angle between the maxillary and mandibular planes
• excellent oral hygiene

Exclusion Criteria:

• Hyperdivergent angle between the maxillary and mandibular planes
• unfavorable anatomical conditions - e.g. presence of a strong frenulum potentially irritating the miniscrew head during chewing and/or facial movement

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: SINGLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: SH2018-10 miniscrew side; We designed our project as a split-mouth study, therefore each patient received both SH2018-10 and SH1514-08 miniscrews, randomly assigned to either left or right side. To do so, our nurse divided both miniscrew types into two halves and assigned symbols appropriate for blinding the intervention. Thus, two combinations of miniscrew sets aroused: 1. SH1514-08R and SH2018-10L or 2. SH1514-08L and SH2018-10R, which were placed separately in opaque packages marked consecutively from "1" to "100" and stored on the tray with dividers. One hundred cards, labeled accordingly, were placed in an envelope, from which the nurse blindly pulled the card just before the miniscrew insertion, this way assigning the set number to every patient. Thus both: the placement side and the screw size were random for clinician.	Procedure: Orthodontic miniscrew insertion in the mandibular buccal shelf; Each patient received miniscrews in both sizes. The same orthodontist (M.S.) performed all the insertion procedures. Miniscrews were always placed in the mandibular buccal shelf, laterally to the first and second molar interproximal area, with angulation 30 degree to the bone surface, meaning that miniscrew angulation should be approximately the same as the axial inclination of the adjacent molar. Miniscrews were loaded with orthodontic force 2 weeks after the surgery. The investigated factors were: long-term success rate of the miniscrews in the buccal shelf of the mandible (miniscrews were considered long-term stable if they served as an anchorage until completion of mandibular distalization, at least 9 months);; peri-implantitis development (enlargement of the gingiva and/or redness and/or tendency to bleed);; the patient's report of pain lasting longer than 48 hours after miniscrew insertion.
EXPERIMENTAL: SH1514-08 miniscrew side; We designed our project as a split-mouth study, therefore each patient received both SH2018-10 and SH1514-08 miniscrews, randomly assigned to either left or right side. To do so, our nurse divided both miniscrew types into two halves and assigned symbols appropriate for blinding the intervention. Thus, two combinations of miniscrew sets aroused: 1. SH1514-08R and SH2018-10L or 2. SH1514-08L and SH2018-10R, which were placed separately in opaque packages marked consecutively from "1" to "100" and stored on the tray with dividers. One hundred cards, labeled accordingly, were placed in an envelope, from which the nurse blindly pulled the card just before the miniscrew insertion, this way assigning the set number to every patient. Thus both: the placement side and the screw size were random for clinician.	Procedure: Orthodontic miniscrew insertion in the mandibular buccal shelf; Each patient received miniscrews in both sizes. The same orthodontist (M.S.) performed all the insertion procedures. Miniscrews were always placed in the mandibular buccal shelf, laterally to the first and second molar interproximal area, with angulation 30 degree to the bone surface, meaning that miniscrew angulation should be approximately the same as the axial inclination of the adjacent molar. Miniscrews were loaded with orthodontic force 2 weeks after the surgery. The investigated factors were: long-term success rate of the miniscrews in the buccal shelf of the mandible (miniscrews were considered long-term stable if they served as an anchorage until completion of mandibular distalization, at least 9 months);; peri-implantitis development (enlargement of the gingiva and/or redness and/or tendency to bleed);; the patient's report of pain lasting longer than 48 hours after miniscrew insertion.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Assessing the stability of miniscrews	The mobility of the miniscrews was checked clinically with cotton tweezers at each visit. Miniscrews that could not sustain orthodontic force and required replacement because of mobility were considered failures.	The first evaluation was performed 2 weeks after miniscrew insertion and then every 4-6 weeks (at follow-up visits) throughout the duration of distalization (up to 2 years).
Assessing the presence of peri-implantitis	Hypertrophy of the gingiva and/or redness and/or tendency to bleed was noted as the inflammation presence.	The first evaluation was performed 2 weeks after miniscrew insertion and then every 4-6 weeks (at follow-up visits) throughout the duration of distalization (up to 2 years).
Assessing the presence of pain lasting longer than 48 hours after implantation.	Two weeks after the miniscrew implantation patients were surveyed upon pain incidence lasting longer than 48 hours.	two weeks

Collaborators and Investigators

• Sponsor: Wroclaw Medical University
• Investigators: Principal Investigator: Michał Sarul, Wroclaw Medical University

Publications and helpful links

General Publications

• Sarul M, Lis J, Park HS, Rumin K. Evidence-based selection of orthodontic miniscrews, increasing their success rate in the mandibular buccal shelf. A randomized, prospective clinical trial. BMC Oral Health. 2022 Sep 20;22(1):414. doi: 10.1186/s12903-022-02460-3.

Study record dates

Study Major Dates

• Study Start (ACTUAL): January 1, 2016
• Primary Completion (ACTUAL): January 1, 2019
• Study Completion (ACTUAL): January 1, 2019

Study Registration Dates

• First Submitted: January 10, 2022
• First Submitted That Met QC Criteria: March 5, 2022
• First Posted (ACTUAL): March 15, 2022

Study Record Updates

• Last Update Posted (ACTUAL): March 15, 2022
• Last Update Submitted That Met QC Criteria: March 5, 2022
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Keywords: orthodontics; miniscrew; skeletal anchorage
• Additional Relevant MeSH Terms: Congenital Abnormalities; Musculoskeletal Diseases; Stomatognathic Diseases; Tooth Diseases; Stomatognathic System Abnormalities; Jaw Abnormalities; Jaw Diseases; Maxillofacial Abnormalities; Craniofacial Abnormalities; Musculoskeletal Abnormalities; Mandibular Diseases; Malocclusion; Prognathism; Malocclusion, Angle Class III
• Other Study ID Numbers: 293/2007

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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