Bimaxillary proclination refers to a condition where both the upper and lower incisors are protruded, often leading to a convex facial profile, lip incompetence, and an increased incisor display. Treatment aims to improve dental alignment, facial esthetics, and occlusal function. The management depends on the severity, skeletal pattern, and patient-specific needs.
1. Diagnosis and Assessment
- Clinical Examination: Evaluates lip strain, lip incompetence, and facial profile.
- Cephalometric Analysis: Measures incisor angulation, interincisal angle, and skeletal pattern.
- Model Analysis: Checks crowding, spacing, and arch form.
- Soft Tissue Considerations: Assesses lip support and balance.
2. Treatment Approaches
A. Orthodontic Camouflage (Non-Surgical Approach)
Used when the skeletal discrepancy is mild to moderate.
- Extraction Therapy:
- Premolar Extraction (Usually 1st or 2nd Premolars): Creates space for retraction of incisors.
- Molar Anchorage Considerations: Use of TADs (Temporary Anchorage Devices) or headgear to maintain anchorage.
- Fixed Orthodontic Appliances:
- MBT or Roth Prescriptions: Used to control torque and inclination of incisors.
- En Masse Retraction with Mini-Screws: Ensures effective incisor retraction.
- Retraction Mechanics: Use of power chains, coil springs, or NiTi wires.
- Non-Extraction Approach (If Space Permits):
- Interproximal Reduction (IPR): Minor enamel stripping to gain space.
- Expansion of Arches: If indicated and feasible.
- Use of Functional Appliances: If a mild skeletal component exists.
B. Orthognathic Surgery (For Severe Skeletal Cases)
- Indicated when there is significant skeletal protrusion that cannot be corrected by orthodontics alone.
- Surgical Procedures:
- Bilateral Sagittal Split Osteotomy (BSSO): For mandibular setback.
- LeFort I Osteotomy: For maxillary repositioning.
- Segmental Osteotomy: To manage severe dental protrusion without full orthognathic surgery.
3. Retention and Post-Treatment Considerations
- Retention Phase: Use of bonded retainers or Hawley retainers to prevent relapse.
- Soft Tissue Adaptation: Lips may take time to adapt to the new position.
- Post-Treatment Stability: Regular follow-ups to ensure stability.
Conclusion
The management of bimaxillary proclination depends on the severity and underlying skeletal structure. Mild-to-moderate cases can often be treated with extractions and orthodontic retraction, while severe cases may require orthognathic surgery. A thorough diagnosis and individualized treatment plan ensures optimal esthetic and functional outcomes.