Danz JC et al. European Journal of Orthodontics. 2014;36:522–530
🔑 STUDY AT A GLANCE
| Parameter | Finding |
|---|---|
| Study design | Retrospective long-term follow-up |
| Original sample | 855 former orthodontic patients |
| Eligible deep bite cases | 185 |
| Final analyzed complete-treatment sample | 43 |
| Relapse cases | 4/43 |
| Median follow-up | 11.9 years |
| Relapse definition | Incisor overlap <50% after treatment → ≥50% at follow-up |
| Relapse prevalence | 10.3% |
| Median increase in overlap in relapse group | 6.7% |
| Range of increase | 3.2–19.8% |
| Stable cases | ~90% |
| Major conclusion | Long-term vertical relapse was low and clinically small |
📌 DEEP BITE — QUICK BASICS
Definition
Increased vertical overlap of maxillary and mandibular incisors
Measured as:
- Absolute: mm
- Relative: % incisor overlap
- Qualitative: Dental/gingival/palatal contact
Etiology
1. Dentoalveolar
- Incisor overeruption
- Altered incisor inclination
2. Skeletal
- Reduced lower facial height
- Low mandibular plane angle
- Hypodivergent growth pattern
⚠️ WHY DOES DEEP BITE RELAPSE?
Potential contributors
Growth
→ Mandibular growth rotation
Function
→ Muscular and functional influences
Dental changes
→ Incisor overeruption
→ Loss of arch form
→ Lower incisor crowding
→ Upper anterior spacing
Periodontal remodeling
→ Reorganization of periodontal tissues
Retention
→ Inadequate or absent retention
Treatment outcome
→ Incomplete leveling
→ Persistent deep bite
→ Poor incisor contact
Other factors
→ Lower lip pressure
→ Sagittal relapse
→ Bolton discrepancy
→ Interincisal angle
🦷 THREE WAYS TO CORRECT DEEP BITE
1️⃣ INCISOR INTRUSION
↓
Intrude upper and/or lower incisors
Best when: Excessive incisor eruption contributes to deep bite
2️⃣ INCISOR LABIAL INCLINATION
↓
Pseudo-intrusion
Incisor proclination increases effective vertical clearance.
3️⃣ POSTERIOR EXTRUSION
↓
Posterior tooth eruption
↓
Possible clockwise mandibular rotation
↓
↑ Lower anterior facial height
↓
Open bite / reduce deep bite
⚠️ Clockwise rotation does not necessarily occur in every patient.
🔴 THE MOST IMPORTANT CLINICAL FINDING
Successfully corrected deep bite
More stable than expected
90% remained without vertical relapse
Relapse
Only 10.3% demonstrated recurrence to ≥50% incisor overlap.
And even in these cases:
The amount of relapse was small
Median increase = 6.7%
🚨 PARTIAL TREATMENT ≠ TRUE RELAPSE
This is the most clinically important message from the study.
True relapse
T1: Deep bite
↓
T2: Successfully corrected
↓
T3: Deep bite returns
Partial correction / noncompliance
T1: Deep bite
↓
T2: Still deep bite
↓
T3: Deep bite persists or worsens
Study finding
Deep bite at long-term follow-up was more likely due to PARTIAL CORRECTION than TRUE RELAPSE.
| Group | Deep bite at T3 |
|---|---|
| True relapse | 4 patients |
| Partial treatment | 7 patients |
⭐ Clinical takeaway
Finish the correction!
Incomplete leveling and incomplete establishment of anterior contact may be more problematic than relapse after successful correction.
🦷 CONTACT AT LONG-TERM FOLLOW-UP
Completely treated group
- Dental incisor contact: 88%
- No incisor contact: 12%
- Gingival contact: 0%
- Palatal impingement: 0%
Partial treatment group
- Dental incisor contact: 29%
- Gingival contact: 57%
- Palatal impingement: 14%
🚨 Clinical implication
Persistent deep bite + incomplete treatment
→ ↑ Gingival contact
→ ↑ Palatal impingement
→ ↑ Risk of traumatic contact
🔒 RETENTION PEARLS
In the relapse group:
- No patient had an upper fixed retainer at T3
- Only 2/4 had a lower fixed retainer
- Only 1/4 received removable retention
Possible clinical implication
Absence of retention may facilitate:
- Upper anterior spacing
- Loss of incisor contact
- Arch form changes
- Deepening of overbite
⚠️ However: The study was not large enough to prove retention as a relapse risk factor.
🧠 WHY WAS RELAPSE LOW?
Possible explanations:
1. Older age at debonding
Median age at T2 ≈ 17 years
↓ Less remaining growth
2. Long treatment duration
More periodontal remodeling may have occurred before debonding.
3. Retention
Majority received:
- Lower fixed retainer
- Temporary upper removable bite plate
4. Successful correction
Most patients achieved:
- Proper incisor contact
- Adequate leveling
❌ RISK FACTORS COULD NOT BE CONFIRMED
The study could not identify reliable predictors of deep bite relapse because:
- Relapse prevalence was low
- Relapse magnitude was small
- Only 4 relapse cases
- Sample size was limited
- Retention protocols were not standardized
Therefore:
No clinically reliable prediction model for individual deep bite relapse could be established.
🩺 CHAIR-SIDE CLINICAL CHECKLIST
Before debonding
☐ Deep bite fully corrected
☐ Curve of Spee adequately leveled
☐ Stable anterior incisor contact
☐ No gingival contact
☐ No palatal impingement
☐ Evaluate incisor inclination
☐ Assess interincisal angle
☐ Check arch form
☐ Check anterior spacing
☐ Evaluate sagittal relationship
☐ Plan long-term retention
After treatment
Monitor for:
🔍 Increased overbite
🔍 Loss of anterior contact
🔍 Upper anterior spacing
🔍 Lower anterior crowding
🔍 Loss of arch length
🔍 Sagittal relapse
🔍 Growth-related mandibular rotation
⭐ GOLD MEDAL EXAM TAKE-HOME
Danz et al. 2014
Long-term relapse of successfully treated moderate deep bite was relatively uncommon and small. Approximately 90% remained stable after a median 11.9-year follow-up, while 10.3% showed relapse, with a median increase in incisor overlap of only 6.7%. Importantly, persistent deep bite at long-term follow-up was more commonly associated with incomplete treatment than true relapse.
🔥 ONE-LINE MEMORY HOOK
“Correct it completely → Establish anterior contact → Retain it → Relapse is usually small.”
Dentowesome 