So, we’ve all sat through those ortho lectures where the professor keeps throwing around terms like “external root resorption” and “tooth-borne versus bone-borne expanders,” and honestly, at first, it feels like way too much. But here’s the simple breakdown of what’s actually happening.
Rapid Maxillary Expansion (RME) is used to fix transverse maxillary deficiency. The problem? The forces aren’t exactly gentle—they’re around 0.9 to 4.5 kg—and sometimes your roots pay the price. That’s where ERR (External Root Resorption) comes in.
Now, there are two main types of expanders:
Tooth-borne (Hyrax type): All the force is on the teeth.
Bone-borne (MARPE type): Screws in the palate take the load instead.
Now, how do we actually see ERR? That’s where CBCT comes in. It’s almost as accurate as micro-CT (which is super precise but can only be used on extracted teeth). Studies using CBCT showed that first molars (M1) and first premolars (P1) lose root volume after expansion, and even second premolars (P2) — the ones not holding the appliance — can get affected too. Forces spread everywhere!
Here’s the important point: most studies only looked at ERR right after expansion. But remember, cementum can repair itself a bit over time. So if you only check right away, you might overestimate the “permanent” damage. That’s why this study looked at ERR after 6 months of retention — to see what happens once the dust settles.
Here’s what the research shows:
Tooth-borne RME → more ERR. First molars lose the most root volume (around 17 mm³), followed by premolars. Even second premolars, which aren’t directly attached, still show resorption.
Bone-borne RME → less ERR. Molars only lose about 3 mm³. There’s still some resorption, but it’s way less compared to tooth-borne.
📊 Findings (6-month post-retention, CBCT-based)
Tooth
ERR Volume Loss (mm³)
TB Group
BB Group
M1 (1st molar)
Highest
17.03
3.11
P1 (1st premolar)
Moderate
6.42
1.04
P2 (2nd premolar)
Least
5.26
1.24
All teeth showed ERR (anchored + unanchored).
M1 palatal root most affected in length shortening.
ERR localized to apical, bucco-apical & bucco-medial areas.
Greater in TB vs. BB, but differences clinically questionable.
Mechanism of ERR: The buccal forces from the RME appliance compress the periodontal ligament, leading to tissue hyalinization. ERR occurs during the subsequent removal of this necrotic tissue on the compressed (buccal) side of the root. The root apex is also a sensitive area due to high force concentration and denser bone.
⚠️ Clinical Insights
ERR occurs in both abutment and non-abutment teeth.
Amount of root shortening (~0.3 mm) unlikely to affect longevity.
Bone-borne expanders ↓ ERR risk but do not eliminate it.
Cementum repair may occur post-retention.
📖 Citation
Leonardi R, Ronsivalle V, Barbato E, Lagravère M, Flores-Mir C, Lo Giudice A. External root resorption and rapid maxillary expansion: TB vs BB comparison at post-retention. Progress in Orthodontics. 2022; 23:45.
✅ Skeletally mature patients with narrow arch ✅ Bilateral posterior crossbite ✅ Nasal airway obstruction ✅ Non-surgical alternative to SARPE ✅ Need for posterior/superior nasal cavity expansion
Contraindications
❌ Poor posterior palatal bone quality ❌ Active periodontal disease ❌ Palatal bone <4 mm ❌ Poor compliance ❌ Medical contraindications to minor surgery
APPLIANCE COMPONENTS of MARPE
Jackscrew: Positioned between maxillary first molars
Microimplants: Four implants (1.5-1.8mm Ø, 11mm length)
Engagement: Bicortical (palatal + nasal cortex)
Framework: Rigid design for parallel expansion
PLACEMENT PROTOCOL of MARPE
Pre-op CBCT for bone thickness
Site: T-zone (distal to 3rd rugae, 2nd premolar region)
Align force vectors toward zygomatic buttress (center of resistance)
Tight adaptation to palatal vault
Ensure bicortical penetration
👉 Viva Q:Why is MARPE positioned anterior to the soft palate (T-zone)? ✔️ To direct forces through the palatal vault toward the zygomatic buttress, optimizing skeletal expansion and reducing tipping.
The MSE was specifically designed to apply expansion force more posteriorly against the zygomatic buttress bones and pterygopalatine sutures, and more superiorly against the midpalatal suture and superiorly positioned perimaxillary suture
VIVA: Why is MARPE positioned anterior to the soft palate
The MARPE appliance is sited anterior to the soft palate—in the T-zone at the level of the second premolars—so that its miniscrews deliver force vectors through the palatal vault directly toward the zygomatic buttress, optimizing skeletal expansion and minimizing dental tipping. With expansion, a lateral force is applied directly to the midplatal suture medial to the zygomatic buttress. This force distribution promotes more even expansion anteroposteriorly
Biomechanical Rationale: The zygomatic buttress is the center of resistance of the maxillary complex during transverse expansion. Positioning MARPE miniscrews in the T-zone aligns the force vector with this buttress, shortening the moment arm to skeletal resistance points and producing more parallel, translational movement of the maxillary halves rather than rotational tipping of the alveolar processes or teeth.
T-Zone Landmark:
Defined by Poorsattar-Bejeh Mir et al. as the area distal to the third rugae, corresponding clinically to the second premolar region in the anterior palate.
This zone offers maximal palatal bone thickness with minimal soft tissue height, ensuring bicortical engagement and implant stability.
Viva Question: How does having a fulcrum near the frontozygomatic sutures influence hemi-midface movement during maxillary expansion with an MSE?
The amount of lateral rotation seen with an MSE is associated with the archial movement of the hemi-midface, with a fulcrum near the frontozygomatic sutures
With a high‑lateral fulcrum at the frontozygomatic region, the hemi‑midface opens like a fan around that pivot, producing outward archial rotation of the zygomatico‑maxillary block and relatively parallel separation of the maxillary halves
Viva Question: Explain how dual cortical support of microimplants reduces internal strain at the implant neck.
One‐line Answer “Engaging both palatal and nasal cortical plates at the implant neck and apex distributes load across two dense bony layers, minimizing microimplant neck bending and internal strain.”
Biomechanical Explanation
When a microimplant is bicortically engaged, its neck is stabilized by the thin palatal cortical plate while its apex is anchored in the thicker nasal (or floor) cortical plate. Under lateral expansion forces, this dual‐plane engagement creates a load path through two rigid cortices rather than a single bone interface. Consequently, bending moments and shear stresses at the implant neck are significantly reduced, decreasing risk of neck‐plate microfracture and implant loosening.
Maxillary constriction is a common problem we face in orthodontics. In younger patients, rapid palatal expansion (RPE) works beautifully because the midpalatal suture is still immature and repairs predictably. But in adults, things get tricky. Conventional RPE is often insufficient, and that’s where miniscrew-assisted rapid palatal expansion (MARPE)comes in.
A recent study by Naveda et al. (2022) looked into how the midpalatal suture actually repairs in adults after MARPE. And the findings are important for how we plan retention and manage expectations in this age group.
🦴 Midpalatal Suture Repair (16 months post-MARPE)
Incomplete repair common in adults
Bone density ↓ (vs. pre-expansion):
Anterior: –34%
Median: –77%
Posterior: –52%
Anterior region always repaired (100%)
Middle third = weakest (57% unrepaired)
>50% repair in 81% of patients
📊 Repair Scoring (0–3 scale)
Score
Description
Frequency
0
No repair
0%
1
<50% repair
19%
2
>50% repair
38%
3
Complete repair
43%
🔑 Clinical Takeaways
✔ Expect slower & incomplete repair in adults ✔ Anterior + posterior heal better (vascular supply) ✔ Middle third caution → miniscrew zone, less vascularity ✔ Always reinforce retention
🔒 Retention Protocol
Maintain expander in situ: 12 months
After removal → place 0.8 mm stainless steel TPA
Monitor with CBCT + visual scoring
Inform patients: repair ≠ full ossification even after 16 months
“Dentistry is saturated,” they said. “Pick MBBS,” they said. But Dr. Khushal Makhija? He looked at that mountain called Dentistry and thought—why not climb Everest instead? 🏔️✨
Armed with a NEET rank most would trade for, he still chose the drill over the stethoscope. And thank God he did—because his idea of success isn’t just fillings and crowns, it’s making sure no patient ever leaves the chair unsatisfied.
And here’s the kicker: in a world where most see limits, he sees opportunity. While others sigh at saturation, he smirks—because that’s just fewer people to compete with on his way to the top two percent.
Trust me, this is one interview you don’t want to skip. If you’ve ever wondered “Is dentistry really worth it?”—here’s your answer, served with grit, wit, and a little sparkle.
👉 Read the full interview in Dentowesome Monsoon 2025 | Issue No. 3 —
Anterior open bite has always been one of the most challenging malocclusions to treat. Patients often present with esthetic concerns, speech difficulties, and compromised function. While orthognathic surgery is a definitive option for severe skeletal open bites, not all patients are candidates—or willing—for surgery. Fortunately, nonsurgical strategies can offer promising results when case selection is appropriate.
🔍 Understanding the Problem
Open bite malocclusion can be dental or skeletal in origin:
Dental open bite: ▸ Normal craniofacial pattern ▸ Proclined incisors, under-erupted anterior teeth ▸ Often linked to habits like thumb/finger sucking
Skeletal open bite: ▸ Long face syndrome, ↑ mandibular plane angle, retrognathic mandible ▸ Greater vertical growth pattern ▸ More difficult to manage without surgery
Key Diagnostic Tools
UAFH : LAFH ratio (<0.65 → poor prognosis for orthodontics)
Extractions & retraction (first premolars) → “drawbridge effect” closes the bite by uprighting incisors.
Best suited for patients with: ✅ Proclined incisors ✅ Minimal gingival display ✅ ≤2–3 mm incisor show at rest
B. Skeletal Open Bite (Nonsurgical Options)
Skeletal open bite is much harder to correct nonsurgically than dental open bite. The central challenge lies in controlling vertical dimension—particularly by preventing or reducing molar eruption.
Posterior extractions preferred if needed (e.g., caries, premature contact, etc.)
👉 Clinical insight: For every 1 mm molar intrusion, you can achieve about 3 mm anterior bite closure through mandibular counterclockwise rotation.
Method
Key Points
High-pull headgear, lingual arches, bite blocks
Prevent molar eruption; maintain curve of Spee.
Implants / Miniplates
Posterior intrusion (3–5 mm possible); counterclockwise mandibular rotation.
Multiloop Edgewise Archwire (MEAW) Multilooped .016 × .022 SS wires + heavy anterior elastics
Molar intrusion + incisor extrusion; alters occlusal plane; mainly dentoalveolar effects. Not ideal in patients with already excessive dentoalveolar height.
Passive Posterior Biteblocks extend 3–4 mm beyond rest position
Inhibit molar eruption; Restrict buccal dentoalveolar eruption → allow mandibular autorotation forward, hence more effective in growing patients; can be spring-loaded or magnetic (more effective; ~3 mm improvement vs 1.3 mm for spring type)
Functional Appliances – Open bite is worsened by faulty orofacial muscle posture.
FR-4 (Frankel regulator): Alters dentoalveolar eruption, retracts incisors. Some evidence of forward mandibular rotation.
Bionator/Activator: Restricts maxillary molar eruption, mild decrease in facial height (~1.3 mm). Used mainly in Class II with mild anterior open bite, not severe skeletal cases.
Active Vertical Corrector (AVC) – using samarium cobalt magnets embedded in acrylic.
Magnetic molar intrusion; worn 12–24 hrs; ~3 mm bite closure avg, bulky (7 mm interocclusal opening needed)
Vertical Pull Chincup
Useful for patients with excessive vertical dimension and backward mandibular rotation tendencies. ↓ mandibular plane angle, restricts molar extrusion; compliance dependent.
Glossectomy
Only in true macroglossia cases. If tongue is normal in size but thrusting, it often adapts after bite closure → surgery not needed. If tongue is truly enlarged relative to oral cavity → partial glossectomy may improve stability.
🔄 The Retention Challenge
One of the biggest hurdles in open bite management is long-term stability.
Studies show relapse rates of 35–43%.
Relapse is often due to dentoalveolar rebound rather than skeletal relapse.
Retention strategies:
Long-term/fixed retainers
Retainers with occlusal coverage to limit molar eruption
🎤 “So here’s the thing — most people pick a career because their parents told them to, or because they panicked after Class 12. But Dr. Akansha Kashyap? Nope. She picked dentistry like it was a love affair between science and art — and guess what? She got the gold medal to prove it. 🏅✨
She’s the kind of dentist who can fix your smile in the morning and sell you a handmade art piece in the evening. Honestly, if she wasn’t drilling cavities, she’d probably be designing album covers. 🎨🦷
In this interview, she spills about: 💡 How to juggle academics without losing your mind (or your hobbies) 🌟 Why mentors + creativity = survival kit in dentistry 🖊️ And a piece of advice so good, you’ll want to embroider it on your scrubs.
So… why are you still here? Go read the full interview — it’s like fluoride for your brain. 🧠💎
Anterior open bite is one of the trickiest malocclusions we deal with in orthodontics. It’s not just about teeth — skeletal, dental, functional, and even habitual factors play a role.
🔹 Traditional Approaches
For decades, open bites in adults were often corrected by:
Extruding anterior teeth orthodontically (which works dentoalveolarly but doesn’t do much for facial esthetics in skeletal cases).
Orthognathic surgery (Le Fort I osteotomy, sometimes two-jaw surgery) to reposition the maxilla.
These surgical approaches improve facial esthetics but come with a catch — relapse.
Denison et al. found a 21% relapse at 1-year post-surgery.
Proffit et al. reported 7–12% overbite reduction within 3 years after Le Fort I surgery.
🔹 The Game Changer: Skeletal Anchorage
With the introduction of absolute anchorage (miniscrews, miniplates), things got exciting. Now, orthodontists could correct open bites without surgery, by intruding the posterior teeth and letting the mandible autorotate upward and forward.
Kuroda et al.: Skeletal anchorage makes open-bite treatment simpler than surgery.
Sugawara et al.: Used miniplates to intrude mandibular molars; reported ~30% relapse after 1 year.
Lee & Park: Miniscrew intrusion of maxillary molars → only 10.4% relapse in molars and 18.1% relapse in overbite at 1 year.
🛠️ How Was Intrusion Done?
Two different miniscrew protocols were used:
1️⃣ Buccal + Palatal Screws
Screws placed between roots of 2nd premolar–1st molar and 1st–2nd molar.
Intrusive force applied with elastomeric chains after 1–2 weeks.
2️⃣ Buccal Screws Only
Screws placed on buccal side at the same sites.
Rigid transpalatal arch (TPA) added to prevent buccal tipping.
Interpretation: It’s not just teeth—it’s also muscles & soft tissue adaptation trying to return to “old balance.”
🔹 Role of Retention & Soft Tissue
Tongue posture, perioral muscles, and habits play a huge role.
Myofunctional therapy after treatment improves stability.
Standard retainers (lingual + circumferential) aren’t enough for intruded molars — because intrusion is inherently less stable than tipping or mesiodistal movement.
Authors suggest an “active retainer”: clear retainer with buccal buttons that can be hooked to miniscrews with elastics to hold molars in place.
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