Oral Surgery
The most-tested oral surgery topics on the OSCE all hinge on numbers — implant clearances in millimetres, OAC sizes, bone density classes. Memorize the numbers and most procedure-choice questions answer themselves.
Surgical Procedures
Ten procedures the exam asks you to name from a description or photograph.
| Procedure | What it is | Indication |
|---|---|---|
| Operculectomy | Removal of the operculum overlying a partially erupted tooth | Recurrent pericoronitis with normally erupting tooth |
| Coronectomy | Crown amputation, leaving roots in place | Mandibular 3rd molar with high IAN injury risk on radiograph |
| Hemisection | Mandibular molar split into two halves; one removed | Severe perio loss / fracture / endo failure on one root |
| Marsupialization | Cyst opened and sutured to mucosa, allowing decompression | Large cysts (esp. dentigerous) where enucleation risks vital structures |
| Enucleation | Complete removal of cyst with intact lining | Most cysts — gold standard if size/location permits |
| I & D | Incision and drainage of fluctuant abscess | Localized fluctuant swelling, esp. with airway risk |
| Surgical Debridement | Removal of necrotic / infected tissue surgically | Necrotizing fasciitis, MRONJ, osteomyelitis |
| Surgical Exposure | Flap raised to expose unerupted tooth crown | Impacted tooth requiring orthodontic traction (esp. canine) |
| Repositioning | Surgical reposition of luxated/intruded tooth | Lateral luxation, severe intrusion |
| Resection | Removal of part of jaw with margins | Aggressive cysts (OKC), benign tumours, malignancy |
Extraction Difficulty Factors
Twelve features that increase extraction difficulty. Multiple usually compound.
| Factor | Why it matters |
|---|---|
| Conical / fused roots | Less retentive, easier — but root tip risk |
| Multiple divergent roots | Cannot extract in one piece — section |
| Curved / dilacerated roots | Risk of fracture during luxation |
| Long roots | More retentive, harder to luxate |
| Hypercementosis | Bulbous root, cannot pass through socket |
| Ankylosis | No PDL — bone removal required |
| Dense bone | Type I or II bone, less expansion |
| Bone pathology (osteoradionecrosis, MRONJ) | Defer extraction; conservative care |
| Crown destruction (extensive caries) | No purchase point for forceps |
| Endo-treated tooth | Brittle — fractures during luxation |
| Proximity to vital structures | IAN, sinus, lingual nerve, mental foramen |
| Limited access (trismus, microstomia) | Surgical / operating-room consideration |
Post-Op Complications
Seven complications. Most ask for management, not just diagnosis.
| Complication | Recognition | Management |
|---|---|---|
| Alveolar Osteitis (Dry Socket) | 3-5 days post-extraction · severe throbbing · empty socket · halitosis | Irrigate · medicated dressing (eugenol/iodoform) · NSAIDs · re-pack q24-48h until comfort |
| Hemorrhage | Continued bleeding > 24h post-op | Local pressure 20 min · oxidized cellulose · gelfoam · suture · electrocautery if persistent |
| Infection | Days 2-5 · ↑ pain · swelling · purulence · ± systemic signs | Drain · culture · antibiotic (amoxicillin first line) |
| Nerve Injury | Paresthesia / dysesthesia · IAN, lingual, mental | Most resolve 6-12 mo · refer to OMFS for severe / persistent |
| Tuberosity Fracture | Audible crack during max 3rd molar extraction | 3 scenarios — see below |
| Oro-Antral Communication (OAC) | Air through socket · positive Valsalva · sinus communication | Size-dependent — see below |
| Displaced Root / Tooth | Root displaced into sinus or IAN canal | Refer to OMFS · surgical retrieval |
Tuberosity fracture — three scenarios
Tuberosity attached to extracted tooth
Tooth + bone come out together. Smooth bone edges, primary closure.
Tuberosity loose but tooth not fully removed
Splint tooth, abort extraction, allow 6 weeks for tuberosity to heal, then surgical extraction.
Tuberosity loose with completed extraction
Stabilize tuberosity to adjacent teeth, suture mucosa, allow healing.
OAC Management — Size Decides Everything
Three brackets, three protocols.
Small
Mgmt: No surgical closure required.
Sinus precautions × 2 weeks: no nose blowing, no straws, sneeze with mouth open, no smoking.
Antibiotic (amoxicillin) + decongestant (pseudoephedrine).
Moderate
Mgmt: Figure-8 suture over socket to support clot.
Same sinus precautions × 2 wk.
Antibiotic + decongestant.
Large
Mgmt: Surgical flap closure (buccal advancement or palatal rotation).
Same sinus precautions × 2 wk.
Antibiotic + decongestant. OMFS referral if symptomatic / chronic fistula.
Implant Placement Minimums
Six clearance numbers. The exam expects exact values.
Implant clearance distances
Compromising factors
| Factor | Impact |
|---|---|
| Uncontrolled diabetes (HbA1c > 8) | ↑ failure · poor osseointegration |
| Active periodontitis | ↑ peri-implantitis risk · treat first |
| Smoking (≥ 10/day) | ↑ failure · ↑ peri-implantitis |
| Bisphosphonates (especially IV) | MRONJ risk · individual assessment |
| Radiation to jaws (> 50 Gy) | Osteoradionecrosis risk |
| Bruxism / heavy occlusion | Mechanical overload · night guard |
| Insufficient bone | Augmentation required (sinus lift, GBR, ridge split) |
| Poor oral hygiene | Treat / educate before placement |
| Age < 16 (girls), < 18 (boys) | Skeletal growth incomplete |
Bone Density Types
Misch I-IV. Most success in II-III; extremes give problems on opposite ends.
Anterior Mandible
Dense cortical, no trabecular. Slow healing from poor blood supply. Risk of overheating during osteotomy.
Posterior Mandible
Thick cortical + dense trabecular. Best for implants. Excellent primary stability.
Anterior Maxilla
Thin cortical + coarse trabecular. Good for implants but lower primary stability.
Posterior Maxilla
Very thin cortical + sparse trabecular. Worst primary stability. Often requires sinus lift / longer healing.