What do you do when a lateral incisor is missing from birth (congenitally)?
You’ve got three main options:
| Option | Description | Pros | Cons |
|---|---|---|---|
| 🦷 Space Closure | Canine takes the lateral’s place | No prosthetic needed | Canine isn’t a perfect aesthetic match |
| 🧱 Resin-Bonded Bridge | A minimally invasive bridge | Saves adjacent teeth | 53% survival in 10.5 yrs, may fall off |
| 🛠️ Implant | Place a single-tooth implant | Long-term, tooth-friendly | Timing is tricky, needs bone support |
To find out: When is the best time to start orthodontic space opening if the goal is to place a single-tooth implant later?
- 14 Caucasian teenagers (9 girls 👧, 5 boys 👦)
- 26 missing lateral incisors
- All treated at University Hospital Carl Gustav Carus, Dresden (That’s in Germany 🇩🇪, folks!)
Timeline Translation:
| Time Point | Age (Mean ± SD) | What’s Happening |
|---|---|---|
| T1 | 13.02 ± 1.49 yrs | Start of ortho treatment 👩⚕️ |
| T2 | 15.55 ± 1.38 yrs | End of ortho treatment 🎉 |
| T3 | 18.67 ± 2.83 yrs | Implant placement time 🔩🦷 |
| Time | Bone Deficiency (mm²) | Significance vs T1 |
|---|---|---|
| T1 | 0.26 ± 0.69 | – |
| T2 | 1.92 ± 1.54 | ✅ P = .044 |
| T3 | 3.77 ± 3.07 | ✅ P = .028 |
👀 Observation: The longer you wait, the more bone disappears. So don’t dilly-dally with space opening if you’re planning an implant!
| Group | T1 Deficiency | T2 Deficiency | T3 Deficiency |
|---|---|---|---|
| Early Starters ⏰ | 0.44 mm² | 2.05 mm² | 2.61 mm² ✅ |
| Late Starters 😴 | 0.00 mm² | 1.78 mm² | 4.93 mm² ❌ |
🏆 Winner: Early treatment group – less bone loss at implant time!
Ortho mechanics led to incisor proclination during space opening. Let’s break it down:
| Time | Inclination Angle (°) | Change |
|---|---|---|
| Start (T1) | 22.1° ± 6.9 | – |
| End (T2) | 31.5° ± 7.2 | +9.4° |
⚠️ Why it matters: The implant angle needs to match the natural inclination of the incisors. Planning is 🔑!
- Ideal implant size: 3.75 mm shaft, 4 mm collar (But minis like 3.0 mm are also used!)
- Safe distance: At least 1 mm between implant and neighboring roots.
- Required bone support: 6 mm × 12 mm = 72 mm² implant surface.
- Gingival trick: Lateral incisor gingival margin is 1 mm higher than central incisor—so the implant must be placed 1 mm below the central’s margin.
🧠 Pro Tip: Use cephs and stone casts to assess inclination and bone volume before diving in!
Once a tooth is missing (especially in the front upper jaw), the bone and soft tissue in that area start shrinking—kind of like a deflated balloon 🎈.
Researchers noticed something wild 😳:
| 🕒 Time Point | % Ridge Deficiency |
|---|---|
| T1 (Start of ortho treatment) | 0.4% |
| T2 (End of ortho) | 2.7% |
| T3 (Time of implant) | 5.2% |
👉 14x increase from T1 to T3! Yikes!
But wait…
The late treatment group had less bone loss at T2.
But then they lost more bone by T3 compared to the early group. 🤔
Translation: It’s not just about when you start ortho—it’s about how the bone behaves later, and spoiler alert: it’s moody.
There’s a strong genetic component to how much ridge loss happens—some people lose more, some less.
- Growth factors (hello, biology!) 📈
- Differences in how people’s bones respond after treatment
- Timing of canine eruption and extraction of baby teeth
If you remove the primary lateral, the canine erupts into that space.
But if you remove the primary canine too early → 🥴 buccolingual resorption (bye bye, bone).
👉 Pro Tip:
Only extract the baby canine just before you move the permanent one distally.This way, the root stretches the PDL and…
💥 Builds Bone Like a Boss 💪