While the biomechanics of retraction are well-understood on paper, clinical cases rarely proceed without surprises. Even in well-planned treatment, side effects can arise—often silently—derailing your ideal outcomes.
In this article, we explore three of the most common complications in orthodontic retraction: open bite development, midline deviation, and anchorage burnout. We’ll dive into how these problems arise, how to detect them early, and what strategies can prevent or correct them.
1. Open Bite Development
Problem: During space closure, anterior teeth may extrude or posterior teeth may intrude, causing an anterior open bite.
Why It Happens:
- Vertical bowing of the archwire (bowing effect)
- Incorrect force vector (especially with sliding mechanics)
- Excessive use of Class II elastics
- Improper vertical anchorage control
Warning Signs:
- Incisors no longer touch by mid-retraction
- Smile arc begins to flatten
- Posterior bite deepens
How to Prevent It:
- Use reverse curve archwires for vertical control
- Incorporate TADs for molar intrusion or incisor anchorage
- Monitor overjet and overbite at each appointment
- Activate loops with vertical force control
How to Fix It:
- Intrude anterior teeth with TADs or utility arch
- Eliminate elastics temporarily and reassess bite
- Level occlusal plane with proper wire sequence
2. Midline Shift
Problem: Dental midlines deviate from the facial or skeletal midline during or after space closure.
Why It Happens:
- Asymmetrical extraction space closure
- Uneven force application (e.g., one chain tighter than the other)
- Unilateral anchorage loss
- Class II/III elastic misuse
Warning Signs:
- Midline shift >1mm by mid-treatment
- Unilateral canine or molar class discrepancies
How to Prevent It:
- Symmetrical activation of retraction springs or power chains
- Use midline elastic only with strict anchorage control
- Consider staggered retraction to maintain symmetry
- Monitor with progress photos or digital scans
How to Fix It:
- Re-open space slightly on one side and reattempt closure symmetrically
- Use midline elastic with opposing TAD anchorage
- Shift anterior segment using sectional wires
3. Anchorage Burnout
Problem: Posterior teeth drift mesially instead of anterior teeth retracting—leading to space closure without esthetic improvement.
Why It Happens:
- No skeletal anchorage or poorly reinforced anchorage
- Over-reliance on group ligation or TPAs
- Inadequate force calibration (too low, too variable)
- Poor compliance with headgear or elastics
Warning Signs:
- Incisors remain protrusive despite space closure
- Molar Class I becomes Class II
- Midline shifts or arch symmetry deteriorates
How to Prevent It:
- Plan anchorage needs from the start (e.g., use mini-screws)
- Monitor posterior molar position with cephalometric or model analysis
- Use passive ligation and minimize friction in sliding mechanics
How to Fix It:
- Reinforce anchorage with TADs mid-treatment
- Reopen extraction space with open coil springs
- Retract anterior segment using sectional or loop mechanics with fixed anchorage
Bonus: Other Notable Retraction Side Effects
- Root Resorption – Excessive force or prolonged retraction phase; monitor with radiographs
- Rotational Relapse – Poor finishing; use interproximal reduction (IPR) and retention
- Smile Arc Flattening – Bowing effect; consider anterior torque preservation and vertical control
Monitoring Strategies to Catch Side Effects Early
- Use progress cephalometrics every 4–6 months
- Take clinical photos from standardized angles
- Perform model superimpositions or digital scans
- Document midline, overbite, and arch width progression
Proactive tracking transforms unexpected problems into manageable challenges.
Final Thoughts
Orthodontic retraction is rarely a straight road. Open bites, midline shifts, and anchorage burnout are common—but not inevitable. With proactive diagnosis and biomechanical mastery, most issues can be avoided or reversed before they become irreversible.
“You can’t control what you don’t measure. But once you see it, you can shape it.”
Next Episode: Retraction in Challenging Cases – Deep Bite, High Angle, and Periodontally Compromised Patients
