~Precision in action: Retrieving a fractured implant abutment screw to restore implant function and stability
Dental implants have revolutionized the way we replace missing teeth. With proper planning and execution, they offer excellent long-term success. However, like any mechanical system, implants can occasionally face complications. One situation clinicians may encounter is- loosening or fracture of an implant abutment screw. Although it may initially seem alarming, a fractured abutment screw does not necessarily mean the implant has failed. In many cases, the screw fragment can be retrieved safely with the right technique and instruments.
Why Do Abutment Screws Loosen or Fracture?
Implant abutment screws are designed to withstand significant functional forces. Factors which may lead to loosening or eventual fracture:
1)Inadequate torque during placement 2)Occlusal overload 3)Poor implant–abutment fit 4)Parafunctional habits such as bruxism 5)Repeated screw loosening causing metal fatigue
Over time, these factors can weaken the screw and lead to fracture within the implant.
How Do You Recognize the Problem?
Patients may report that their implant crown feels loose or unstable while chewing. Sometimes they may simply notice a slight movement in the prosthesis. Clinically, you might observe:
1)Mobility of the implant crown 2)Difficulty tightening the prosthesis 3)Occlusal discomfort 4)Radiographic evidence of a separated screw fragment
Once confirmed, the next step is careful retrieval of the remaining screw fragment.
Armamentarium Needed:
Having the right instruments makes the procedure much easier. Commonly used tools include: 1)Implant screw retrieval kit 2)Ultrasonic scaler with fine tips 3)Dental explorer or probe 4)Round or carbide bur 5)High-speed handpiece 6)Magnification (loupes or microscope) 7)Micro forceps or endodontic files
Step-by-Step Method for Screw Retrieval:
1. Careful Assessment Begin with a thorough clinical and radiographic evaluation to determine the position of the fractured screw fragment. 2. Remove the Prosthesis The crown or prosthetic component should be removed to allow clear access to the implant platform. 3. Visualize the Screw Fragment Good lighting and magnification are extremely helpful at this stage. Clear visualization helps prevent damage to the implant threads. 4. Attempt Gentle Counter-Clockwise Rotation Often, fractured screws lose their preload and are not tightly engaged. Using a sharp explorer, ultrasonic tip, or a fine endodontic file, gently attempt to rotate the fragment in a counter-clockwise direction. 5. Use a Retrieval Kit If the fragment does not move easily, a manufacturer-specific screw retrieval kit can be used. These kits contain specially designed instruments that engage the broken screw and help remove it safely. 6. Create a Small Slot (If Necessary) In some cases, a tiny slot can be prepared on the surface of the screw using a small bur. This allows a flat driver to engage the fragment and unscrew it. 7. Ultrasonic Assistance Ultrasonic vibration may help loosen the fragment by disrupting the mechanical binding between the screw and implant. 8. Inspect the Implant Once the screw fragment is removed, the internal implant threads should be carefully examined and cleaned to ensure there is no debris or damage. 9. Place a New Screw A new abutment screw should be inserted and tightened according to the manufacturer’s recommended torque value. 10. Reinstall the Prosthesis Finally, the prosthesis can be repositioned and secured after confirming the stability of the new screw.
The clinical case which is illustrated in this blog post ,the abutment screw fracture happened inrt 46.Implant placement was done inrt 46 47 around 3 years ago and individual implant crowns (FP1) were placed .The patient reported with Dislodged implant crown inrt 46 .Radigraphic examination shows abutment screw fractured and lodged within the implant fixture.
Treatment planning included careful retrieval of abutment screw after mid crestal incision and flap elevation followed by retrieval using engaging the visible screw tip with artery forcep with firm press and anticlockwise rotation to disengage the screw from the fixture.This was followed by placing of healing abutment inrt 46 and suturing and follow up after 1 week for suture removal.
Practical Tips for Clinicians:
-Always work under magnification and proper illumination -Apply minimal force to protect the implant threads -Use manufacturer-specific retrieval kits when available -Take your time—patience often makes the difference
Preventing Future Screw Complications:
Prevention is always better than repair. The following steps can help reduce the risk of screw loosening or fracture: 1)Following correct torque protocols 2)Designing proper occlusion 3)Applying principles of implant-protected occlusion 4)Scheduling regular follow-ups for maintenance
Final Thoughts~
A fractured implant abutment screw can feel like a frustrating complication, but in most cases it is manageable with careful technique and the right instruments. With proper diagnosis and a systematic retrieval approach, the implant itself can often be preserved, allowing the prosthesis to continue functioning successfully for years.
Picture this: a young dental student staring at a microscope, trying to figure out why her physiology textbook looks more like a foreign language manual than a path to making people smile. Enter Dr. Anukrati Srivastava—the woman who took that confusion, added a sprinkle of stubbornness, a dash of curiosity, and bam!—turned it into a dental career that makes patients beam and teachers proud. With an All India Rank of 97, a master’s degree, and an obsession with magnification and illumination, she’s not just treating teeth; she’s rewriting the rulebook on what it means to be a dentist who actually cares.
Think of her as the stand-up comedian of dentistry—only instead of punchlines, she delivers precision, patience, and those little “aha!” moments that make you go, “Wow, I never knew dental school could be like this.”
1) Can you share how your path in the dental profession began and the key milestones that shaped it?
My journey in dentistry began with a bit of resistance. During the first year, I wasn’t particularly interested, as the subjects like physiology and biochemistry seemed far removed from clinical dentistry. It didn’t feel relevant to what I wanted to do—treat patients and create smiles.
Everything changed in the third year when I joined a private clinic to experience dentistry beyond textbooks. That hands-on exposure taught me that dentistry is not just about treating teeth—it’s about patience, communication, and understanding the financial and emotional aspects of patient care.
A major milestone during my internship was preparing for the pre-PG exam. I began studying not just to pass, but to truly understand subjects and connect concepts. With guidance from exceptional teachers across India, patience, and consistent effort, I achieved AIR 97 and completed my master’s—a challenging journey that brought immense satisfaction.
Another pivotal moment came when I committed to performing all my cases under proper isolation, using magnification and illumination. I believe every dental student should use at least 3.5X magnification. Without it, you miss details that are crucial for becoming a better dentist.
2) What inspires you to stay passionate and committed to dentistry, even during challenging times?
I was fortunate to complete my bachelor’s and master’s at a prestigious institution—Govt. Dental College, Jaipur—with faculty who truly inspired me. Watching teachers work, understanding their thought process, and seeing their dedication to patients—not for money but for the joy of delivering excellent care—motivated me to push myself. Their example has been my anchor during challenging times, reminding me to always give my best.
3) Who is your role model in the dental field, and how has this person influenced your approach to patient care, academics, or professional growth?
While I’ve learned from many, I must mention Dr. Lalit Likhiyani and Dr. Manoj Aggarwal. They taught me to strive to be a better person every day and to deliver dentistry better than I did yesterday. During my student life, I often thought, “What would they say if they saw this?”—a question that drove me to excellence.
Academically, they never gave me straight answers. Instead, they asked more questions, encouraging me to explore literature, dig into articles, and develop reasoning. This approach instilled in me a love for learning and a habit of critical thinking.
4) Could you discuss the strategies you use to manage academic responsibilities alongside your personal interests or hobbies?
Balancing academics, clinical responsibilities, and personal life has been challenging. I realized early on the importance of prioritizing personal life. Some rules I follow include:
No work calls after 7 PM.
Weekly days off with my husband, who is also an orthodontist, with no appointments.
Allocating time for House of Endodontics in my calendar.
Maintaining an afternoon nap that I never compromise.
I also make time for painting, gardening with a cup of coffee, and long drives—simple joys that help me recharge. Sticking to a routine has been key to maintaining balance.
5) What advice would you give to current dental students and aspiring dentists?
Yes, dentistry is challenging. Yes, it requires patience and perseverance. Yes, you will be self-critical about your cases. But the satisfaction of growing, learning, and creating beautiful smiles makes it all worthwhile. Stay curious, embrace mentorship, and never stop improving.
Conclusion:
So, what’s the takeaway from Dr. Anukrati Srivastava’s story? Simple. Dentistry is tough, exams are tougher, and yes, sometimes your coffee might get cold while you’re deep in a case. But passion, perseverance, and a touch of sass can turn all that chaos into something magical.
She’s living proof that you can love what you do, learn endlessly, and still have time to sip your coffee, paint a masterpiece, or take a Sunday drive. If dental students remember one thing from her journey, let it be this: don’t just aim to fix teeth—aim to shine brighter than the overhead lamp in your operatory. And maybe, just maybe, make it look effortless while you’re at it.
Every orthodontic student reaches a moment in clinic where a 9-year-old with Class II malocclusion is sitting in the chair—and the faculty asks:
“So… headgear or functional appliance?”
The confusion is understandable. One appliance pulls the maxilla back, the other pushes the mandible forward. But do they actually produce different outcomes?
Evidence says something interesting: 👉 They reach the same destination—using different roads.
Let’s break this down logically.
The Clinical Question
Are headgears and functional appliances equally effective in correcting Class II malocclusions in children before comprehensive treatment?
Short answer
✅ Yes. Both appliances produce similar overall Class II correction, especially in terms of ANB reduction and overjet correction.
Evidence at a Glance
5 prospective randomized clinical trials
Children aged 7–10 years
Phase I treatment only (no fixed appliances)
Compared headgear vs functional appliances vs controls
📚 Databases used: PubMed & Cochrane Library
Study
N
Age
Duration
Appliances
Key Design
Jakobsson (1990)
57
8.5 yr
18 mo
Cervical headgear vs Andresen activator vs control
Random, all Class II
Tulloch (1998)
166
9.4 yr
15 mo
Straight-pull headgear vs mod. Bionator vs control
Headgears and functional appliances are equally effective in early Class II correction in children. The difference lies not in how much correction occurs, but in how that correction is achieved—headgear acts mainly on the maxilla, while functional appliances rely largely on dentoalveolar changes and mandibular positioning.
Class III malocclusion is diagnostically easy to spot and frustratingly hard to treat. Parents see a negative overjet and come in early, but what you actually inherit is a complex mix of maxillary retrusion, mandibular excess, dentoalveolar compensation, and growth uncertainty. Functional Regulator‑3 (FR‑3) is one of the classic early‑treatment tools aimed at modifying growth in Class III children, introduced by Rolf Frankel in 1970 and designed to work not directly on teeth, but on the perioral and buccal soft tissues.
Levin, McNamara and co‑workers published a landmark retrospective controlled study in 2008 that, for the first time, followed an FR‑3 group and matched untreated Class III controls from pre‑puberty all the way past the pubertal spurt (about 9 years total). All FR‑3 patients were treated personally by Rolf Frankel, had good compliance, and wore the same appliance first full‑time (about 2.5 years), then part‑time (about 3 years) using his original protocol. For you as a student, that makes this study a practical “gold standard” for what FR‑3 can really do when the technique and compliance are not the problem
First, a Mental Reset: What FR-3 Is NOT
Before we discuss effects, let’s clear misconceptions:
❌ FR-3 does not stop mandibular growth ❌ FR-3 does not pull the maxilla forward like a facemask ❌ FR-3 does not “fix” all Class III cases
👉 FR-3 is not a force-delivery appliance 👉 It is a functional environment modifier
That distinction changes everything.
🔹 Components and Their Purpose
Component
Primary Function
Clinical Logic
Buccal shields
Remove cheek pressure
Allows transverse & sagittal maxillary development
Lip pads
Reduce upper lip pressure
Facilitates forward maxillary displacement
Lower labial wire
Controls mandibular incisors
Prevents excessive lingual tipping
Lingual support
Influences tongue posture
Improves oral seal & functional balance
One of the biggest mistakes students make with functional appliances is assuming that all changes seen during treatment are permanent. FR-3 is a perfect example of why time-segmented thinking (T1–T2 vs T2–T3) matters.
TIME POINTS (Keep these fixed in your head)
Time Point
Meaning
T1
Start of FR-3 treatment
T2
End of full-time wear (~2.5 years)
T3
Long-term follow-up after puberty (≈9 years from T1)
PART 1: Short-Term Effects (T1 → T2)
What changes while the child wears FR-3 full-time
Between T1 and T2, FR-3 patients were compared with untreated Class III controls. This comparison is crucial—because growth alone can fool you.
1. Maxilla: Real Growth + Modest Forward Positioning
📌 Key Finding
The maxilla does not just “look better”—it actually grows more.
When you begin the leveling and aligning stage in fixed orthodontic treatment, one challenge always lurks around the corner—upper anterior teeth love to tip forward. This is especially true with preadjusted edgewise appliances because of the built-in tip in the brackets.
To solve this, McLaughlin and Bennett introduced something brilliantly simple: the laceback ligature. The idea was elegant—use a figure-eight stainless-steel ligature from the molar to the canine to prevent incisor flaring and apply light distalizing forces on the canine.
But the clinical question is: 👉 Are laceback ligatures actually effective? 👉 And how do they compare to something stronger, like NiTi closed coil springs?
A controlled clinical study by Melih Sueri and Tamer Turk (Angle Orthodontist, 2006) provides the answers—and some surprises.
1. PURPOSE OF LACEBACK LIGATURES
Prevent forward tipping of upper anterior teeth during leveling.
Apply a light, interrupted distalizing force on canines.
Provide controlled movement with minimal anchorage loss.
2. FORCE APPLICATION
Laceback Ligature
Material: 0.010″ stainless steel ligature wire
From first molar → canine
Re-tighten at every visit
Force type: interrupted / light
NiTi Closed Coil Spring
Material: Superelastic NiTi
Force: 150 g
From first molar → canine
Reactivate monthly
Force type: continuous
3. CLINICAL EFFECTS
Canine Movement
Parameter
Laceback
NiTi Coil Spring
Distal movement
~1.67 mm
~4.07 mm
Distal tipping
4.5°
11.6°
Rotation
2.7° distobuccal
7.8° distopalatal
Movement rate
0.66 mm/month
1.61 mm/month
🔎 Interpretation:
Lacebacks = Slower but more controlled movement
NiTi coil springs = Faster, less controlled, more tipping & rotation
4. MOLAR MOVEMENT (Anchorage Loss)
Parameter
Laceback
NiTi Coil Spring
Mesial movement
0.70 mm
1.93 mm
Mesial tipping
3.9°
3.1°
🔎 Interpretation:
Lacebacks cause significantly less anchorage loss.
5. INCISOR EFFECTS
Upper incisors show retroclination and posterior movement with both methods due to overall anterior segment retraction forces.
WHEN TO USE WHAT?
✔ Use Laceback Ligatures When:
You want maximum anchorage control
You’re in the leveling & aligning stage
Controlling canine tipping/rotation is critical
Light, intermittent forces are preferred
✔ Use NiTi Closed Coil Springs When:
You need faster canine retraction
Anchorage can be reinforced or is less critical
Canine tipping is acceptable or planned
Final Thoughts
This study beautifully highlights a truth every orthodontist must embrace: Success isn’t just about moving teeth—it’s about controlling how they move.
Lacebacks may look old-school, but they offer unmatched finesse during the initial phase of treatment. NiTi coils, on the other hand, are powerful tools when used at the right time.
Mastering when to use each one is a hallmark of an excellent clinician.
Class III malocclusion is one of those topics that every orthodontic student eventually dreads—complex etiology, unpredictable growth, and tough treatment calls, especially in adults.
But what if we told you that there is a systematic way to simplify treatment planning?
A classic study by Stellzig-Eisenhauer et al. gives us a powerful, evidence-based roadmap. This blog breaks it down into easy, clinic-ready points.
🔍 Why Class III in Adults Is So Challenging
Growth is almost complete → no skeletal correction with ortho alone.
Many patients show combined skeletal + dentoalveolar features.
Borderline cases make it hard to decide between:
✔️ camouflage orthodontics (non-surgical)
✔️ orthognathic surgery with orthodontics
The BIG Q: How do we objectively decide?
HIGH-YIELD CEPH PARAMETERS
A. Primary Predictor
Wits Appraisal (MOST RELIABLE)
−1 to −5 mm → Often orthodontic (camouflage)
< −7 mm → Borderline
≤ −10 mm → Usually surgical
B. Other Key Predictors (Discriminant Model)
Variable
Trend
Interpretation
S–N Length
↓ shorter
Increased likelihood of surgery
M/M Ratio (Maxilla/Mandible)
↓ low
Mandibular excess or maxillary deficiency → surgery
Lower Gonial Angle
↑ large
Vertical growth pattern → challenging to camouflage
3️⃣ NON-SURGICAL (ORTHODONTIC) CANDIDATES
Likely treatable with camouflage if: ✔ Wits > −6 mm ✔ Acceptable facial esthetics ✔ Mild–moderate skeletal discrepancy ✔ Good incisor inclinations possible (no excessive decomp needed) ✔ No significant vertical maxillary deficiency ✔ Patient prefers non-surgical path
Common Strategies:
Class III elastics
Lower incisor retraction (limits apply)
Upper expansion/advancement via dentoalveolar mechanics
Mini-screws for camouflage anchorage
4️⃣ SURGICAL CANDIDATES
Recommend ortho + orthognathic surgery when: ✔ Wits ≤ −8 to −10 mm ✔ Severe skeletal discrepancy (maxillary deficiency / mandibular prognathism) ✔ Large M/M discrepancy ✔ High lower gonial angle (vertical growers) ✔ Soft-tissue profile compromised ✔ Decompensation needed beyond safe limits ✔ Patient wants ideal esthetics & occlusion
Typical Surgical Options:
Le Fort I Maxillary Advancement
BSSO Mandibular Setback
Bimaxillary Surgery (common)
5️⃣ BORDERLINE CASE CHECKLIST
Use these for “grey-zone” decisions:
☐ Dual bite? (Check CR vs CO)
☐ Incisor decompensation possible without harming periodontium?
☐ How much soft tissue improvement expected?
☐ Stability concerns? (high angle, open bite tendency)
ORTHO ONLY = Mild skeletal discrepancy + Acceptable esthetics + Wits > −6 mm SURGERY = Severe skeletal Class III + Esthetic disharmony + Wits < −10 mm BORDERLINE = Depends on soft tissue, decomp needs, patient expectations
Every smile has a story, and so does every dentist who crafts them. In this exclusive conversation, we sit down with Dr. Anchal Shah, Prosthodontist at Dr. Shah’s Smile Studio, to learn about her inspiring journey—from a childhood fascination with chocolates to rebuilding lives through maxillofacial prosthetics.
1) Can you share how your path in the dental profession began and the key milestones that shaped it?
✨ Childhood: It’s funny how a simple love for chocolates led me toward a world I never imagined—dentistry. What began as curiosity slowly transformed into passion.
✨ BDS Days: The first two years were honestly tough. I often felt lost, wondering why I was spending hours working on baseplates or burning my fingers. But once clinics began, everything changed. I discovered joy in the smallest things—making dentures, performing extractions, or the adrenaline rush of placing my first suture.
✨ The Big Leap: I always dreamt of specializing in Prosthodontics. My first NEET MDS attempt didn’t work out, but I refused to give up. Taking a drop year was challenging, but it became one of the best decisions of my life. The effort paid off with AIR 66and admission to my dream college.
✨ Shaping My Purpose: Training under legends in Maxillofacial Prosthodontics gave me a mission bigger than myself—helping oral cancer survivors regain not just their smile, but their confidence and dignity.
✨ Where I Am Today: At Dr. Shah’s Smile Studio, I blend skill with compassion. My approach is holistic—every smile matters, every pain deserves care, and every patient’s story reminds me why I chose this path.
2) What inspires you to stay passionate and committed to dentistry, even during challenging times?
Dentistry, like life, isn’t always smooth. Some days are tough—when cases get complicated, outcomes don’t go as planned, or the weight of responsibility feels overwhelming.
On those days, I remind myself of two things:
🌱 How far I’ve come: From a confused BDS student burning my fingers on a baseplate to securing AIR 66 and finding my calling in Prosthodontics—every struggle has shaped me.
💡 Why I started: It was never just about teeth. It’s always been about people—their pain, their confidence, and their smiles. Watching a patient smile again after years is the kind of reward that keeps me going.
Every difficult moment becomes lighter when I remind myself of this: 👉 I didn’t come this far to give up. I came this far to make a difference
3) Who is your role model in the dental field and how has this person influenced your approach to patient care, academics, or professional growth?
I owe so much to my mentors.
• Dr. Rupal Shah, my postgraduate guide and Head of Department, taught me how much can be achieved with so little in hand. Her resourcefulness and patient-centered care continue to inspire my daily practice.
• Dr. P. C. Jacob, my mentor in oral cancer rehabilitation, showed me the power of perseverance and empathy in dealing with some of the most complex and emotionally demanding cases.
Their teachings shaped my outlook—not just as a clinician, but as a human being who believes in healing beyond treatment.
4) Could you discuss the strategies you use to manage academic responsibilities alongside your personal interests or hobbies?
Dentistry can easily consume your entire day, but I’ve learned that balance is key. Keeping my small passions alive keeps me grounded.
For me, it’s listening to podcasts, tuning into music, or watching a good movie. Podcasts give me new perspectives, music uplifts my mood instantly, and movies help me pause and reset.
Even 20–30 minutes a day can make a difference. You don’t need hours for hobbies—just intention. These little joys refill my energy, empathy, and creativity, helping me return to dentistry with a refreshed mind.
Because while dentistry defines my work, my hobbies remind me who I am.
5) What advice would you give to current dental students and aspiring dentists?
Don’t rush to have it all figured out. It’s completely normal to feel lost in the beginning—to question your path, or to wonder why you’re spending endless hours perfecting a baseplate or bending wires.
Trust the process. Those small, repetitive tasks are building your foundation—your patience, precision, and perseverance.
Stay consistent. Stay curious. And don’t fear setbacks. One exam, one failure, or one tough day doesn’t define your journey—your persistence does.
Most importantly, never forget why you started. Dentistry is not just about teeth—it’s about people, their confidence, and their smiles.
For decades, orthodontists have feared the words “open bite relapse.” We’ve all seen those post-surgical cases where the overbite slowly flattens out again, leaving both the clinician and the patient frustrated.
But recent evidence tells a more optimistic story. We looked at three landmark studies that prove surgical open bite correction can, in fact, stay stable long-term — if planned and executed correctly.
Let’s break it down 👇
🧠 Why Does Open Bite Relapse Happen?
Open bites often involve vertical skeletal discrepancies, soft-tissue imbalances, and habit-related influences (like tongue thrust or mouth breathing). Even after successful closure, relapse can creep in because of:
Posterior mandibular rotation post-surgery
Muscle and condylar adaptation
Incomplete control of incisor inclination
Prolonged vertical elastics or residual tongue posture
Understanding these helps us choose treatment options that offer the best long-term stability.
🔍 What Does the Evidence Show?
🔹 1. Bimaxillary Surgery: Fischer et al., 2000 (EJO)
This study followed 58 patients who underwent Le Fort I osteotomy + Bilateral Sagittal Split Osteotomy (BSSO) to correct open bite and mandibular retrognathism.
🩺 Findings after 2 years:
The maxilla stayed stable.
The mandible rotated back by only 1.4°, showing mild skeletal relapse.
17 patients developed a small open bite again, mostly due to incisor proclination, not jaw rotation.
The most stable results occurred in patients who had no post-op MMF (maxillomandibular fixation) — early mobilization helped muscles adapt better.
💡 Take-home: Rigid fixation + early mobilization = better stability.
🔹 2. Mandibular-Only Surgery: Fontes et al., 2012 (AJODO)
This study challenged the belief that we must operate on the maxilla for every open bite case. It followed 31 patients treated with BSSO and closing mandibular rotation only (no maxillary impaction).
📊 Results after 4.5 years:
Initial open bite: –2.6 mm
Surgical correction: +3.7° closing rotation of mandible
Long-term: 90% maintained positive overlap!
Even though about 60% of the rotation was lost, only 3 patients relapsed to zero overbite.
💡 Take-home: For mild-to-moderate skeletal open bites, mandibular-only surgery can be predictably stable and avoids unwanted soft-tissue changes (like widened nasal base or flattened upper lip).
3️⃣ Surgical vs. Nonsurgical Approaches – What’s More Stable?
Greenlee et al., 2011 — The Meta-Analysis That Ties It Together
This systematic review pooled data from 21 studies on open bite correction — both surgical and nonsurgical.
📈 The big picture:
Surgical treatments: ~82% stability (positive overbite ≥ 1 year post-op)
Nonsurgical treatments: ~75% stability
Average relapse in overbite: < 0.5 mm over 3–4 years
💡 Take-home: Both surgical and orthodontic approaches can be stable when case selection, fixation, and retention are well managed.
⚙️ Clinical Insights for Students
Focus Area
Key Point for Practice
Case selection
Choose surgical correction for true skeletal AOB with steep mandibular plane angles.
Avoid proclination of upper/lower incisors post-surgery.
MMF duration
Short or no MMF enhances functional recovery and stability.
Post-op care
Encourage physiotherapy and early functional movement.
Retention
Prolonged retention and habit control are essential to prevent vertical relapse.
Parameter
Pretreatment
Post-Surgery
Long-term Follow-up
Change/Relapse
Mean open bite (BSSO)
–2.6 mm
+1.4 mm
+1.0 mm
0.4 mm relapse
Mandibular rotation
+3.7° closing
–2.2° reopening (4.5 yrs)
60% rotation loss
Clinically stable outcome
Bimaxillary (Fischer et al.)
–0.9 mm
+2.2 mm
+0.8 mm
~1.4° mandibular reopening
Pooled (Meta-analysis)
–2.8 mm
+11.6 mm
+10.3 mm
82% maintained positive OB
References:
Fischer K, von Konow L, Brattström V. Eur J Orthod. 2000;22:711–718.
Fontes AM, et al. Am J Orthod Dentofacial Orthop. 2012;142:792–800.
Greenlee GM, et al. Am J Orthod Dentofacial Orthop. 2011;139:154–169.
🦷 Clinical-Oriented MCQs: Anterior Open Bite Stability After Surgery
1.
A 25-year-old female underwent bimaxillary surgery (Le Fort I impaction and BSSO) for anterior open bite. Two years later, her cephalometric evaluation shows a 1.4° posterior rotation of the mandible. What is the most likely reason for this relapse?
A. Condylar sag during fixation B. Maxillary relapse C. Incisor proclination and dentoalveolar compensation D. Nasal soft-tissue tension
✅ Answer: C. Incisor proclination and dentoalveolar compensation 🩺 Explanation: Fischer et al. (2000) reported that the mild relapse seen in 17/58 patients was primarily due to dental changes (incisor proclination), not skeletal instability.
2.
Which fixation method is most strongly associated with long-term stability in open bite surgery?
A. Wire osteosynthesis B. Rigid internal fixation using plates and monocortical screws C. Intermaxillary fixation for 8 weeks D. External pin fixation
✅ Answer: B. Rigid internal fixation using plates and monocortical screws 🩺 Explanation: Rigid fixation provides superior skeletal stability and minimizes posterior mandibular rotation. (Fischer et al., 2000; Fontes et al., 2012)
3.
In Fontes et al. (2012), which surgical technique was assessed for its long-term stability in anterior open bite correction?
A. Le Fort I impaction of the maxilla B. Bimaxillary osteotomy C. Bilateral sagittal split osteotomy (BSSO) with closing rotation of the mandible D. Segmental maxillary osteotomy
✅ Answer: C. Bilateral sagittal split osteotomy with closing rotation of the mandible 🩺 Explanation: The study specifically evaluated BSSO with rigid internal fixation and found 90% of patients maintained a positive overbite 4.5 years post-treatment.
4.
What was the long-term success rate (positive overbite ≥1 year post-op) for surgical open bite treatment according to Greenlee et al. (2011)?
A. 60% B. 70% C. 82% D. 90%
✅ Answer: C. 82% 🩺 Explanation: The meta-analysis reported an 82% success rate for surgical interventions and 75% for nonsurgical treatment in maintaining positive overbite.
5.
During open bite correction, which factor most increases the risk of relapse due to soft tissue and muscular tension?
A. Steep mandibular plane angle B. Reduced condylar height C. Excessive mandibular closing rotation (>4°) D. Small gonial angle
✅ Answer: C. Excessive mandibular closing rotation (>4°) 🩺 Explanation: Over-rotation increases muscular stretch and pterygoid tension, contributing to relapse (Fontes et al., 2012).
6.
Which postoperative protocol demonstrated the most favorable stability outcomes in bimaxillary surgery cases?
A. 8-week maxillomandibular fixation B. 1–3 weeks of MMF C. No MMF with early mobilization D. Rigid fixation followed by elastic traction
✅ Answer: C. No MMF with early mobilization 🩺 Explanation: Fischer et al. (2000) found the most stable overbite in patients without MMF, suggesting early mobilization promotes muscle adaptation and healing.
7.
In mandibular-only surgery for open bite, approximately what percentage of surgical closing rotation is typically lost long-term?
A. 10% B. 30% C. 60% D. 80%
✅ Answer: C. 60% 🩺 Explanation: Fontes et al. (2012) reported that about 60% of the mandibular closing rotation achieved at surgery was lost, yet functional overlap was maintained.
8.
Which cephalometric parameter was significantly correlated with open bite relapse post-surgery?
A. ANB angle B. SN–ML angle (mandibular plane angle) C. U1–L1 interincisal angle D. SNA angle
✅ Answer: B. SN–ML angle 🩺 Explanation: Increased mandibular plane angles are associated with vertical skeletal patterns that predispose to relapse (Fischer et al., 2000).
9.
Why might mandibular-only BSSO be preferred over maxillary impaction surgery in some open bite cases?
A. It allows greater anterior movement of the maxilla B. It produces fewer unfavorable nasal and upper lip changes C. It reduces operation time by half D. It eliminates the need for orthodontic finishing
✅ Answer: B. It produces fewer unfavorable nasal and upper lip changes 🩺 Explanation: Fontes et al. (2012) noted mandibular-only correction avoids side effects like nasal widening, upper lip thinning, and excessive gingival display.
10.
Which of the following best summarizes the long-term evidence on open bite surgical stability?
A. Relapse is inevitable due to vertical muscle pull. B. Only bimaxillary surgery yields stable results. C. Both surgical and nonsurgical approaches show >75% long-term stability. D. Stability depends only on orthodontic retention.
✅ Answer: C. Both surgical and nonsurgical approaches show >75% long-term stability. 🩺 Explanation: Greenlee et al. (2011) meta-analysis found 82% stability for surgical and 75% for nonsurgical corrections at ≥1-year follow-up.
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