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 |
📚 STUDY GOAL:
To find out: When is the best time to start orthodontic space opening if the goal is to place a single-tooth implant later?
👥 THE PATIENT CREW:
- 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!)
🦴 THE BONE CHRONICLES: T1 ➡️ T2 ➡️ T3
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 🔩🦷 |
📉 Bone Loss Over Time (Yikes!):
| 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!
🕰️ EARLY vs. LATE TREATMENT – Who Wins?
| 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!
📐 Incisor Inclination Drama
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 🔑!
🧪 IMPLANT PLACEMENT: A MINI MANUAL
- 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!
📉 Alveolar Ridge Loss: When Bone Gets Ghosted
Here’s the tea ☕:
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.
🧬 Blame It on Your Genes
There’s a strong genetic component to how much ridge loss happens—some people lose more, some less.
🔬 Why the variability?
- Growth factors (hello, biology!) 📈
- Differences in how people’s bones respond after treatment
- Timing of canine eruption and extraction of baby teeth
🐶 Canines to the Rescue
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 💪
📏 Kokich vs. This Study: A Bone-Off!
| Study | What they found |
|---|---|
| Kokich (20 pts) | Less than 1% bone loss up to 4 years later 😇 |
| This study | Up to 5.2% loss at implant time 😱 |
Why the difference?
This study measured surface area (6–12 mm region), not just distances. Also, they only looked at maxillary cases, not mandibular or premolars. Apples vs. oranges… or molars vs. incisors 🧐🍊
📣 Final Orthodontic Pro Tips 🎓
🎯 1. Late is great (sometimes)
- Starting treatment later (around age 16.5) = less time for ridge to disappear before implant.
- But don’t be too late or you’ll miss the growth train 🛤️
📐 2. Watch those incisor angles!
- Mean incisor proclination at T2 = 31.5° 😮
- Standard = 22.1° → so 9.4° extra
- Over-proclination = thin bone = implant trouble (think 👻 bone and 😬 visible crown margins)
📏 3. Don’t ignore root spacing!
- Just because crowns look good doesn’t mean roots are happy 😬
- Use wire bending or bracket repositioning to create that root party room 🎉🦷🦷🦷
🧠 Growth Matters: Don’t Jump the Implant Gun!
Since implants don’t move (hello, ankylosis 😑), don’t place them before facial growth is done.
📸 Take a ceph → wait 6 months → take another
If Nasion to Menton doesn’t change = 💡 Growth done!
🧠 TL;DR for Ortho Ninjas 🥷
| Takeaway | Why It Matters |
|---|---|
| Ridge loss is real! | And it gets worse with time ⏳ |
| Canine movement = bone creation | But only if timed right 🕒 |
| Late treatment can be helpful | Less waiting time till implant 🚀 |
| Incisor proclination can hurt you | Implant survival needs a strong cervical bone base 🧱 |
| Roots matter too! | Not just crown position 😅 |
So remember ortho fam:
You’re not just aligning teeth—you’re sculpting bone for the future 💀➡️🦷✨
Now go forth and move those canines smartly! 💃🕺
SPOTIFY EPISODE LINK: https://spotifycreators-web.app.link/e/PzKwJAxmfTb
Dentowesome 