One versus two anterior miniscrews for correcting upper incisor overbite and angulation: a retrospective comparative...

Area of Science:

• Orthodontics
• Dental Mechanics
• Skeletal Anchorage

Background:

• Miniscrews are established for upper incisor intrusion.
• Treatment mechanics vary based on objectives.
• Adult patients with deep overbite require effective correction strategies.

Purpose of the Study:

• To evaluate the efficacy of one versus two anterior miniscrews for upper incisor correction in adult overbite and angulation cases.
• To compare treatment outcomes between single and dual miniscrew anchorage systems.

Main Methods:

• Forty-four adults with deep overbite were divided into two groups: one miniscrew (group 1) or two miniscrews (group 2).
• Lateral cephalograms measured incisor intrusion and length pre-treatment, post-treatment, and during retention.
• Forces (90g) were applied via elastomeric chains; ANOVA analyzed significance.

Main Results:

• Mean root resorption was 2.15 mm, ceasing post-treatment.
• Overbite correction was -3.23 mm with no significant relapse.
• Group 2 (two miniscrews) showed significantly greater overbite correction and incisor intrusion compared to group 1.
• Root resorption correlated positively with overbite correction; no mandibular plane rotation occurred.

Conclusions:

• Upper incisor intrusion effectively corrects overbite without mandibular plane rotation.
• Two miniscrews yield superior incisor intrusion and overbite correction compared to one.
• Increased buccal angulation of upper incisors was noted with a single miniscrew.
• Root resorption is dose-dependent on intrusion extent; stability is achieved with both methods.