Gingival response to mandibular incisor extrusion.

Area of Science:

• Periodontology
• Orthodontics
• Gingival biology

Background:

• Orthodontic extrusion of mandibular incisors is used to correct open bites.
• Understanding accompanying gingival changes is crucial for treatment planning.
• Gingival width and position can influence aesthetic outcomes.

Purpose of the Study:

• To evaluate gingival movement during orthodontic extrusion of mandibular incisors.
• To assess changes in attached gingiva (AG) and keratinized gingiva (KG) width.
• To analyze alterations in clinical crown length and sulcus depth.

Main Methods:

• 10 subjects with mandibular incisor extrusion for open bite correction.
• Measurement of AG and KG widths, periodontal indices, and clinical crown length pre- and post-treatment.
• Radiographic determination of gingival margin (GM) and mucogingival junction (MGJ) movement using a metal device.

Main Results:

• Significant increases in AG and KG widths, and clinical crown length observed (P <0.05).
• Gingival margin (GM) and mucogingival junction (MGJ) moved with teeth (80% and 52.5% respectively).
• Significant decrease in sulcus depth noted (P <0.05).

Conclusions:

• Orthodontic extrusion promotes increased AG and KG width.
• Gingival displacement occurs in the direction of tooth movement, but to a lesser extent.
• Increased gingival width may contribute to gummy smiles; corrective procedures carry root exposure risks. Long-term follow-up is recommended.