Success Rate of the Miniscrews in the Mandibular Buccal Shelf

Wroclaw Medical University100 enrolled

Overview

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 Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

100

Conditions

Class III Malocclusion

Interventions

Orthodontic miniscrew insertion in the mandibular buccal shelfPROCEDURE

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.

Eligibility

Sex: ALLMin age: 20 YearsMax age: 50 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

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.

Time frame: 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.

Time frame: 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.

Time frame: two weeks

Data from ClinicalTrials.gov

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