Posttreatment and postretention changes following orthodontic therapy

Area of Science:

• Orthodontics
• Dental Arch Dimensions
• Retention Stability

Background:

• Orthodontic treatment aims to correct malocclusions and improve dental aesthetics.
• Understanding long-term stability of orthodontic corrections is crucial for treatment success.

Purpose of the Study:

• To evaluate changes in mandibular arch dimensions after orthodontic treatment and retention.
• To compare dimensional changes between nonextraction and extraction cases.

Main Methods:

• Study included 103 orthodontic cases (74 nonextraction, 29 extraction).
• Full-banded edgewise bioprogressive technique was used.
• Measurements of intercanine, inter-first premolar, inter-second premolar, inter-first molar widths, and incisor-to-molar distance were taken pre-treatment, post-treatment, and post-retention (average 5.2 years).

Main Results:

• Intercanine width expanded during treatment but returned to baseline post-retention.
• Inter-first premolar width showed significant increase with minimal post-retention decrease.
• Intermolar width increased in nonextraction cases and decreased in extraction cases, with no post-retention changes.
• Incisor-to-molar distance decreased during treatment and slightly more post-retention.

Conclusions:

• Mandibular arch dimension changes vary between nonextraction and extraction cases.
• Intercanine width shows a tendency towards relapse.
• Inter-first premolar and intermolar widths demonstrate good long-term stability post-retention.