This guide supports candidates preparing for the Canadian National Dental Specialty Examination (NDSE) in Oral and Maxillofacial Surgery. Its 60 selected concepts connect assessment findings with diagnostic interpretations, treatment planning and safety decisions. Use the examples to distinguish similar clinical situations, then consult the references for the broader specialty knowledge and procedural detail.
Medical assessment and medication safety
1. Bleeding risk includes the patient's history
For dental patients taking anticoagulants or antiplatelet drugs, SDCEP advises assessing bleeding history and systemic conditions alongside the planned procedure, because kidney, liver and bone marrow disease can modify coagulation or platelet function.
Worked example: A patient taking clopidogrel reports that a previous tooth extraction caused prolonged bleeding needing hospital review, and she also has chronic kidney disease. Her assessment therefore considers both that bleeding history and the kidney disease, rather than relying on the medication name alone.
Mistake to avoid: Relying only on the named antithrombotic while ignoring the patient's reported previous abnormal bleeding episodes.
Source: [11]
2. Resolve uncertain medication information before treatment
SDCEP advises that when medication or medical-condition details are unclear, the prescribing clinician, who may be a haematologist or cardiologist, should be consulted before dental treatment to clarify bleeding risk and inform planning; uncertainty alone does not authorize interruption.
Worked example: A patient mentions that his cardiologist recently adjusted a blood-thinning regimen but cannot name the drugs involved. Before planning an invasive surgical extraction, the dentist contacts the prescribing cardiologist to clarify the regimen and bleeding risk, without altering any medication.
Mistake to avoid: Guessing the unclear regimen or giving a generic instruction to stop tablets without prescriber input.
Source: [11]
3. Time-limited antithrombotic therapy can affect scheduling
SDCEP advises that, where possible, non-urgent invasive dental procedures be delayed until a prescribed time-limited anticoagulant or antiplatelet course has ended; urgent needs require individual assessment, and any interruption requires appropriate medical liaison.
Worked example: A patient requests elective gum surgery during the final week of a three-month anticoagulant course prescribed after a venous thrombosis. Because the care is non-urgent and deferral is clinically reasonable, the dentist schedules the procedure after the prescribed course finishes, leaving the medication schedule untouched.
Mistake to avoid: Interpreting deferral advice as approval to end the patient's medication course early.
Source: [11]
4. Persistent dry mouth requires a cause-based assessment
NIDCR states that persistent xerostomia is not a normal part of aging and raises caries and oral fungal-infection risk; assessment includes reviewing the medical history and medications, since possible causes include medicines, systemic disease, cancer treatment and nerve damage.
Worked example: An older patient develops persistent dry mouth several weeks after starting a new blood-pressure medicine, and tooth decay risk concerns the dentist. The dentist reviews the medication list and medical history to identify a possible cause instead of attributing the symptom to the patient's age.
Mistake to avoid: Offering only symptom relief while overlooking a potentially modifiable cause of persistent dryness.
Source: [17]
5. Acetaminophen in combination products still counts
Medication reconciliation must capture every acetaminophen-containing preparation, because an acetaminophen–opioid combination tablet delivers acetaminophen alongside the opioid, and total daily acetaminophen exposure should not exceed 4,000 mg.
Worked example: A patient awaiting extraction review reports taking two separate 500 mg acetaminophen tablets plus a prescribed hydrocodone–acetaminophen combination product; both preparations must be included when totaling her daily acetaminophen exposure.
Mistake to avoid: Counting only tablets labelled primarily as acetaminophen while ignoring the acetaminophen inside an opioid combination pill.
Source: [13]
Sedation assessment, monitoring and recovery
6. Sedation depth is independent of administration route
Sedation depth is classified by the patient's clinical state, not by oral, inhaled or intravenous administration; moderate or deeper sedation can occur via any route, and reflex withdrawal from pain is not a purposeful response.
Worked example: After an oral sedative, a patient responds to a painful stimulus with reflex withdrawal only; the oral route does not establish moderate sedation, since depth depends on clinical state rather than administration route.
Mistake to avoid: Using the oral route or a reflex withdrawal movement as proof of the intended sedation depth.
Source: [24]
7. Airway assessment extends beyond the mouth opening
A sedation airway assessment considers previous anesthesia or sedation problems, stridor, snoring or sleep apnea, neck and head findings, oral anatomy, and jaw abnormalities such as micrognathia, retrognathia, trismus or significant malocclusion.
Worked example: A patient has mouth opening greater than 3 cm but reports sleep apnea and shows limited neck extension; both findings remain relevant to sedation airway planning despite acceptable mouth opening.
Mistake to avoid: Declaring an airway uncomplicated based on mouth opening alone while ignoring sleep apnea history.
Source: [24]
8. Capnography supplements oxygenation monitoring
The 2018 multisociety moderate procedural sedation guideline recommends continual monitoring of ventilatory function with capnography to supplement standard monitoring by observation and pulse oximetry, adding a ventilatory modality beyond oxygen saturation.
Worked example: A sedation monitoring plan for an oral surgery patient lists visual observation and pulse oximetry but omits capnography; it lacks the ventilatory monitoring modality the 2018 guideline recommends alongside those standards.
Mistake to avoid: Treating oxygen saturation monitoring as the entire recommended respiratory monitoring plan for moderate sedation.
Source: [24]
9. Pediatric sedation requires rescue capability
Under the AAP/AAPD pediatric sedation guidance reaffirmed in 2025, practitioners must be able to rescue a child from a deeper sedation level than intended, using practical rescue training and age- and size-appropriate equipment for cardiopulmonary support.
Worked example: A dental team plans moderate sedation for a seven-year-old needing molar extractions. Their preparation must include the skills and equipment to rescue from deep sedation, not only techniques suited to the intended moderate level.
Mistake to avoid: Assuming careful drug selection alone removes the need to prepare for deeper sedation.
Source: [23]
10. Elective fasting intervals depend on the intake
The 2018 ASA fasting table, for healthy patients undergoing elective procedures, assigns a two-hour minimum to clear liquids and a six-hour minimum to a light meal, while fried, fatty, or meat-containing meals may require eight hours or more; fasting does not guarantee complete gastric emptying.
Worked example: A healthy adult drinks water at 07:00 before a 09:30 elective procedure, giving 2.5 hours and exceeding the clear-liquid minimum. This calculation alone does not establish overall anesthetic suitability.
Mistake to avoid: Applying the clear-liquid interval to milk or a meal, or to emergencies.
Source: [24]
11. Reversal does not end the monitoring requirement
After pharmacologic reversal, patients must be observed and monitored long enough to ensure sedation and cardiorespiratory depression do not recur once the antagonist dissipates; reversal should not be an intended, routine component of any sedation regimen.
Worked example: A patient becomes more alert after receiving an antagonist during recovery. Continued monitoring is still required, because the apparent improvement may not persist once the antagonist's effect wanes.
Mistake to avoid: Equating an immediate response to reversal with readiness for discharge.
Source: [24]
12. Recovery decisions depend on residual risk
After moderate sedation, monitor the patient in an appropriately staffed and equipped area until consciousness approaches baseline and increased cardiorespiratory risk has resolved, with oxygenation monitored continuously until hypoxemia risk has passed.
Worked example: Extraction treatment is complete, but the patient remains markedly drowsy compared with baseline. Supervised recovery must continue in an appropriately staffed and equipped area rather than discharge occurring because the procedure ended.
Mistake to avoid: Using a fixed appointment duration as the sole discharge criterion.
Source: [24]
Temporomandibular assessment and management
13. Muscle and joint disorders require different descriptions
TMD encompasses a group of musculoskeletal conditions affecting the muscles of mastication, the temporomandibular joint and associated structures. Confirmatory examination findings support attributing the presentation as myogenous, arthrogenous, or combined, and a person may have several conditions at the same time.
Worked example: Examination of an adult patient supports both masticatory-muscle tenderness and painful joint findings, so the record describes combined myogenous and arthrogenous involvement rather than one category.
Mistake to avoid: Recording 'TMJ' as the patient's diagnosis instead of naming the specific myogenous or arthrogenous condition.
14. Painless clicking is different from painful dysfunction
Clicking or popping sounds in the TMJs without pain are common, are considered normal, and do not require treatment. Symptoms such as pain, limited movement or locking of the jaw change the clinical assessment and may signal a TMD.
Worked example: A patient reports long-standing joint clicking with comfortable, unrestricted opening and closing and no pain; the sound alone gives no reason to recommend any treatment.
Mistake to avoid: Recommending intervention solely to eliminate a painless joint noise that needs no treatment.
Source: [19]
15. A TMD screening result is not a diagnosis
The 3Q/TMD tool is a screening instrument that helps clinicians but cannot diagnose. A positive screen supports further clinical assessment, during which symptoms are evaluated and competing conditions ruled out before any TMD diagnosis is made.
Worked example: An adult screens positive on 3Q/TMD but has not undergone a facial-pain assessment; the result prompts thorough evaluation rather than a definitive TMD label.
Mistake to avoid: Converting a positive screening score directly into a specific TMD subtype diagnosis.
16. Supported self-management is individualized care
Initial supported self-management for painful adult TMD begins with an individualized plan developed in collaboration with the diagnosed person, targeting that patient's specific habits and symptoms rather than applying a standard instruction sheet without discussion.
Worked example: An adult identifies habitual daytime clenching as her main problem; the collaboratively agreed plan targets that habit and schedules review of its effect on her symptoms.
Mistake to avoid: Handing every patient identical self-management goals regardless of their assessed symptoms and habits.
17. Permanent bite alteration lacks a reliable TMD rationale
Current evidence does not support a strong causal link between malocclusion and TMD, and irreversible occlusal treatments proposed specifically to manage TMD lack sufficient evidence of benefit; separate restorative or orthodontic indications require their own assessment.
Worked example: A clinician proposes crowns and selective grinding solely to cure a patient's jaw pain attributed to a minor bite discrepancy. The evidence does not justify promising that TMD benefit from irreversible occlusal treatment.
Mistake to avoid: Treating the mere presence of malocclusion as proof that permanently altering the bite will resolve TMD.
Source: [19]
18. TMD surgery depends on the disorder being treated
The adult guideline identifies severe arthrogenous TMD and disc displacement without reduction with specific case features as possible surgical situations, but surgery is adjunctive to supported self-management and conservative care, never a sole or first-line option, and shows no demonstrated benefit for myogenous TMD.
Worked example: A patient's persistent pain is attributed to the masticatory muscles, with no surgical joint indication identified. Persistence despite conservative care alone does not establish a rationale for considering temporomandibular joint surgery.
Mistake to avoid: Assuming that unsuccessful conservative care automatically makes every TMD presentation suitable for joint surgery.
Source: [10]
Implant timing, site development and imaging
19. Placement timing describes healing after extraction
The ITI consensus defines immediate placement as placement in the socket on extraction day, early placement after soft-tissue healing (4–8 weeks) or partial bone healing (12–16 weeks), and late placement after complete bone healing beyond six months. These definitions describe timing, not clinical suitability.
Worked example: An implant is placed six weeks after extraction, once soft-tissue healing has occurred. Under the ITI consensus definitions, this timing falls within the early-placement category, not the immediate-placement category.
Mistake to avoid: Calling any implant placement before complete socket healing immediate, regardless of the defined healing intervals.
Source: [8]
20. Immediate restoration and immediate loading differ by occlusion
Within one week of implant placement, the ITI consensus calls a prosthesis in occlusion with the opposing arch immediate loading, while a prosthesis deliberately held out of opposing-arch occlusion is immediate restoration. Placement timing and loading timing remain separate classifications.
Worked example: A provisional prosthesis is connected on day three after placement but is deliberately kept out of occlusion with the opposing arch. This meets the ITI definition of immediate restoration rather than immediate loading.
Mistake to avoid: Describing every promptly connected provisional prosthesis as immediate loading without checking its opposing-arch occlusal contact.
Source: [8]
21. Plan a fallback before extracting the tooth
The ITI consensus recommends deciding both the implant placement and loading protocol before extraction and preparing alternative treatments in case intraoperative criteria, such as adequate primary stability, cannot be met.
Worked example: A clinician plans immediate implant placement for a first premolar, but intraoperatively the insertion torque shows inadequate primary stability, so the previously consented staged alternative is followed instead of forcing the planned protocol.
Mistake to avoid: Obtaining consent only for the preferred implant pathway.
Source: [8]
22. Immediate placement with immediate loading needs multiple conditions
The ITI type 1A protocol requires patient-centred advantages and clinicians with high skill and experience. Concurrent conditions include intact socket walls, facial bone wall at least 1 mm thick, thick soft tissue, no acute site infection, apical and lingual bone for primary stability, insertion torque of 25–40 Ncm and/or ISQ above 70, an occlusal scheme protecting the provisional restoration during function, and patient compliance.
Worked example: A compliant patient has documented aesthetic advantages, intact socket walls, facial bone 1.5 mm thick, thick soft tissue, no acute infection, adequate apical and lingual bone for primary stability, insertion torque of 30 Ncm and a provisional restoration protected during function. With a highly skilled, experienced clinician, the case meets the listed type 1A conditions; success is not guaranteed.
Mistake to avoid: Treating one favourable torque or ISQ result as sufficient eligibility.
Source: [8]
23. Early placement does not justify routine early loading
The cited ITI consensus states conventional loading is well documented and recommended with early implant placement, while immediate and early loading combined with early placement lack sufficient documentation for routine recommendation.
Worked example: An implant is placed 6 weeks after extraction once soft tissue has healed. The consensus-supported routine pairing is conventional loading, meaning no prosthesis connection for more than 2 months after implant placement rather than an early-loaded prosthesis.
Mistake to avoid: Assuming placement and loading must share the same timing label.
Source: [8]
24. Ridge augmentation staging follows position and stability
For horizontal ridge augmentation in the anterior maxilla, the ITI consensus indicates simultaneous implant placement when soft tissue conditions are adequate and correct positioning with primary stability is achievable; large defects precluding these favour a staged approach.
Worked example: A wide anterior maxillary defect leaves insufficient bone for proper three-dimensional implant positioning and no achievable primary stability, so the cited guidance supports staged horizontal augmentation before implant placement rather than simultaneous placement.
Mistake to avoid: Selecting simultaneous placement solely to reduce the number of appointments.
Source: [9]
25. Implant imaging depends on the treatment phase
The AAOMR's 2012 advisory assigns imaging by phase: panoramic radiography for initial evaluation, cross-sectional imaging orthogonal to the site for preoperative assessment, and periapical radiography for routine postoperative review, while advising against periodic CBCT for clinically asymptomatic implants.
Worked example: A patient returns for routine review of a clinically asymptomatic implant with no signs or symptoms. Under this advisory, intraoral periapical radiography is appropriate rather than automatic periodic CBCT.
Mistake to avoid: Ordering CBCT for every implant visit regardless of the treatment phase or symptoms.
Source: [22]
Dentoalveolar and preprosthetic decisions
26. Extraction extent changes the bleeding-risk category
SDCEP places simple extraction of one to three teeth with restricted wound size in the lower bleeding-risk category, while complex extractions, adjacent extractions creating a large wound, or more than three extractions at once fall in the higher-risk category, judged individually.
Worked example: For an antithrombotic patient, two adjacent molars are extracted and the combined socket is expected to form a large wound, so individual judgement places the session in the higher-risk category despite only two teeth.
Mistake to avoid: Classifying an extraction session's bleeding risk from tooth count alone, ignoring wound size and invasiveness.
Source: [11]
27. Confirm local haemostasis before discharge
For patients taking anticoagulants or antiplatelet drugs, haemostasis should be achieved with local measures before discharge from care; packing and suturing may stabilise the clot and wound margins unless likely to cause further trauma, with serious consideration given to individual patient factors.
Worked example: A patient on an anticoagulant has persistent socket oozing after extraction. The practitioner uses packing and a suture to achieve local haemostasis before discharge, having confirmed the necessary skills and equipment are available.
Mistake to avoid: Discharging a bleeding antithrombotic patient with home instructions instead of achieving local haemostasis first.
Source: [11]
28. Extraction pain treatment begins with nonopioid options
The ADA's 2024 guideline recommends nonopioid analgesics as first-line therapy after surgical extraction, and nonopioid analgesics only, recommending against opioids, after simple extraction; both recommendations are conditional with low certainty and apply to patients aged 12 years and older.
Worked example: An adult without relevant contraindications requests an opioid after a simple extraction. The guideline-supported approach is nonopioid pain management, such as an NSAID alone or combined with acetaminophen, rather than an opioid prescription.
Mistake to avoid: Prescribing an opioid routinely after a simple extraction instead of recommending nonopioid analgesics only.
Source: [13]
29. Corticosteroid advice for pain has a defined boundary
The ADA's 2024 extraction-pain guideline conditionally suggests against adding oral, submucosal, or intramuscular corticosteroids to standard analgesia after surgical extraction, with very low certainty; intravenous corticosteroids and inflammatory complications such as trismus, swelling, or infection fall outside its scope.
Worked example: A surgeon considers adding an oral corticosteroid purely to reduce postoperative pain after surgical third molar extraction; the guideline suggests against that addition, while remaining silent on intravenous use and inflammatory complications.
Mistake to avoid: Treating this pain recommendation as a blanket prohibition on corticosteroids for swelling, trismus, or infection.
Source: [13]
30. Residual ridge assessment includes shape as well as volume
AAOMR's 2012 implant-imaging advisory holds that residual ridge assessment covers vertical height, horizontal width, edentulous saddle length, and the orientation and topography of the alveolar-basal complex; excessive or irregular vertical bone may require alveoloplasty, judged individually against prosthetic and surgical plans.
Worked example: An anterior maxillary ridge shows ample height and width, yet a labial cortical concavity could compromise implant alignment with the planned restoration, so abundant volume alone does not establish that the site needs no preparation.
Mistake to avoid: Assuming generous bone volume guarantees favourable ridge geometry without assessing orientation and residual contour.
Source: [22]
Cleft and craniofacial care
31. Craniofacial care is longitudinal and interdisciplinary
ACPA states that craniofacial care is best delivered by an interdisciplinary team with longitudinal follow-up and documentation, evaluating outcomes for growth, function, appearance, and psychosocial well-being; complex diagnostic and surgical procedures require appropriate facilities and experienced providers.
Worked example: A child's repaired cleft looks satisfactory, yet team follow-up still evaluates speech, occlusion, growth, and psychosocial well-being longitudinally rather than closing the case on postoperative appearance alone.
Mistake to avoid: Declaring a craniofacial outcome successful based solely on how the surgical repair looks.
Source: [6]
32. Velopharyngeal surgery requires speech-based assessment
ACPA recommends that secondary palatal or velopharyngeal surgery follow evaluation, including imaging and/or endoscopy, of the velopharyngeal mechanism during speech, with speech-language pathology input before and after; surgery does not correct compensatory articulations, and planning must consider airway obstruction.
Worked example: A patient with velopharyngeal dysfunction uses glottal stops; endoscopic evaluation during speech precedes surgery, and the compensatory articulation pattern may still require postoperative speech therapy despite structural correction.
Mistake to avoid: Promising families that anatomical correction alone will automatically normalize every compensatory speech error.
Source: [6]
33. Alveolar cleft graft timing follows dental development
Timing of alveolar cleft bone grafting is determined by the stage of dental development, with input from the treating orthodontist, and is commonly performed before eruption of the permanent maxillary teeth in the cleft region. Late presentation does not preclude grafting after permanent-tooth eruption; need and timing depend on the cleft and previous treatment.
Worked example: Two nine-year-olds present with clefts at different eruption stages near the cleft site; each graft is planned from dental development and orthodontic advice, not an identical birthday-based schedule.
Mistake to avoid: Scheduling every cleft graft by chronological age alone while ignoring dental development and orthodontic input.
Source: [6]
34. Definitive nasal surgery follows skeletal planning
In cleft and craniofacial care, definitive septorhinoplasty should await skeletal maturity, and when orthognathic surgery is indicated it is usually undertaken afterwards, because jaw surgery can change the nose. This concerns definitive septorhinoplasty, not every earlier nasal intervention.
Worked example: A skeletally mature adult with a cleft needs both maxillary advancement and definitive septorhinoplasty; the plan sequences jaw surgery first, then nasal reconstruction, anticipating nasal changes from jaw surgery.
Mistake to avoid: Completing definitive septorhinoplasty before planned orthognathic surgery, ignoring how jaw movement reshapes the nose.
Source: [6]
35. Earlier craniofacial jaw surgery has functional exceptions
Midface and mandibular surgery is generally delayed until physical maturation is completed, but serious concerns about a compromised airway, jaw function, speech, or psychosocial adjustment can justify earlier surgery. When performed early, patients and families should receive counselling that additional procedures may be needed and may be more complicated.
Worked example: A growing patient with a craniofacial syndrome has severe maxillary hypoplasia causing serious airway compromise; the team considers earlier midface surgery while counselling the family that later procedures may be needed.
Mistake to avoid: Telling families that early jaw correction removes any possibility of further corrective procedures later.
Source: [6]
Salivary pathology and diagnostic decisions
36. Meal-related swelling suggests salivary obstruction
Pain and swelling of a salivary gland that worsen at mealtime support an obstructive differential including calculi and ductal strictures, which produce sialectasis; the symptom pattern alone does not confirm a stone, and other inflammatory or neoplastic causes remain possible.
Worked example: A patient reports recurrent right submandibular swelling and pain during meals; the clinician includes both sialolithiasis and ductal stricture in the obstructive differential and investigates before naming a stone.
Mistake to avoid: Diagnosing a submandibular stone purely from mealtime swelling without imaging or excluding other causes.
Source: [14]
37. Sialadenosis differs from inflammatory sialadenitis
Sialadenosis is described as chronic, bilateral, diffuse, painless, noninflammatory and nonneoplastic gland enlargement, often associated with metabolic or medical conditions. This descriptive pattern supports including it in a differential diagnosis rather than excluding all other causes of bilateral swelling.
Worked example: A patient with a metabolic disorder presents with chronic, bilateral, diffuse, painless parotid enlargement and no inflammatory findings, so sialadenosis belongs in the differential diagnosis.
Mistake to avoid: Calling every enlarged salivary gland an acute infection.
Source: [14]
38. Sjögren's features extend beyond dry mouth
Salivary gland swelling with xerostomia and dry eyes, sometimes with another connective tissue disease, supports assessment for Sjögren's disease. Diagnosis involves laboratory autoantibody testing and minor salivary gland biopsy, and primary Sjögren's carries increased lymphoma risk.
Worked example: A patient reports dry eyes, dry mouth and intermittent gland enlargement; autoimmune assessment with serology and biopsy consideration is appropriate rather than assuming isolated local duct obstruction.
Mistake to avoid: Treating all gland enlargement in known Sjögren's as automatically benign.
Source: [14]
39. A painless salivary mass can still be malignant
Most parotid tumors, both benign and malignant, present as asymptomatic masses, so absence of pain does not exclude malignancy. Neurological signs such as numbness or weakness from nerve involvement typically indicate malignancy, and persistent facial pain is highly suggestive of it.
Worked example: A patient has a painless parotid mass with new facial weakness; the neurological finding increases malignant concern despite the comfortable presentation, prompting appropriate diagnostic workup rather than reassurance.
Mistake to avoid: Using painless presentation to reassure that a salivary mass is benign.
Source: [16]
40. An infiltrative margin supports salivary malignancy
In salivary tumour pathology, demonstrating an infiltrative margin is the key guiding principle for establishing malignancy. Histological grading informs treatment approach but is not an independent indicator of clinical course and must be interpreted alongside clinical stage by qualified pathologists.
Worked example: A salivary tumour report identifies an infiltrative margin, supporting malignancy; prognostic interpretation still requires clinical stage and other tumour features, since grade alone does not determine the clinical course.
Mistake to avoid: Treating histological grade as a complete substitute for staging.
Source: [16]
41. Acute sialadenitis changes sialendoscopy suitability
The Iowa protocol names acute sialadenitis as the contraindication to sialendoscopy but immediately qualifies it as nonabsolute. Inflammation makes ductal dilation and endoscopy more difficult and increases the chance of ductal trauma, potentially fostering spread of infection into the head and neck soft tissues.
Worked example: A patient scheduled for sialendoscopy of an obstructed submandibular duct develops an acute inflammatory sialadenitis episode beforehand. Because inflammation makes ductal dilation harder and raises ductal trauma and infection-spread risk, the team reassesses whether proceeding remains appropriate.
Mistake to avoid: Recording acute sialadenitis as an absolute bar, or treating the inflammatory episode as procedurally irrelevant.
Source: [15]
Orthognathic diagnosis and planning
42. Orthognathic planning starts with a combined diagnosis
AO planning guidance states that precise diagnosis underpins proper planning and integrates clinical examination, cephalometry and standardized photography. Additional three-dimensional imaging, including CT, reformatted CT, 3D photography and 3D models, may be indicated for complex asymmetric cases.
Worked example: A candidate for jaw surgery undergoes clinical examination, cephalometric analysis and standardized photographs. Because marked asymmetry is not adequately characterized on this two-dimensional assessment, the team considers three-dimensional imaging to define the deformity before formulating the problem list.
Mistake to avoid: Selecting an osteotomy from one isolated cephalometric measurement instead of the combined diagnostic workup.
Source: [18]
43. Profile and frontal examinations answer different questions
In AO's clinical examination framework, profile evaluation emphasizes anteroposterior maxillary and mandibular position plus lip support and competence. Frontal evaluation instead assesses facial midline, symmetry, lower lip and chin muscle activity, and tooth-to-lip relationship; both views together inform the combined assessment.
Worked example: A patient's profile appears balanced, with reasonable anteroposterior jaw positions and lip support. The frontal view, however, reveals a facial midline deviation with asymmetry. The acceptable profile does not resolve this finding, so both examinations must be documented together.
Mistake to avoid: Judging overall facial balance from a profile photograph alone and skipping the frontal assessment.
Source: [18]
44. Preserve baseline models when simulating surgery
In AO's conventional model workflow, two sets of mounted models are used: one is kept to analyze and document the preoperative situation, while the second undergoes mock surgery into a planned position agreed upon by both surgeon and orthodontist.
Worked example: A conventional planning team mounts two model sets, then performs mock surgery on one after the surgeon and orthodontist agree the planned occlusal position. The untouched baseline set remains available to compare the simulated correction against the original occlusion.
Mistake to avoid: Cutting the only baseline model, or simulating a final position without the orthodontist's agreement.
Source: [18]
45. Intermediate and final splints have different roles
In AO's splint-based two-jaw workflow, two acrylic splints are fabricated: the intermediate splint positions the first osteotomized jaw against the stable jaw, while the final splint establishes the occlusal relationship after the second jaw has been osteotomized.
Worked example: A surgical plan sequences a Le Fort I osteotomy followed by a BSSO. The splint designated for use after the maxillary osteotomy serves an intermediate role, not the final two-jaw occlusal relationship.
Mistake to avoid: Treating the intermediate and final splints as interchangeable during two-jaw orthognathic surgery.
Source: [18]
46. Soft-tissue prediction is not a one-to-one translation
AO notes that when bone is moved, the overlying soft tissues follow, but not in a 1:1 ratio; virtual profile predictions therefore help discuss possible outcomes and alternatives with the patient rather than guarantee an exact appearance.
Worked example: A plan advances a skeletal segment 5 mm. The surgeon describes the simulated profile as showing a possible outcome, not an exact 5 mm change at the overlying soft-tissue landmark.
Mistake to avoid: Presenting a simulated postoperative profile image to the patient as a guaranteed result.
Source: [18]
Fibula flap reconstruction foundations
47. Fibula reconstruction can support later dental rehabilitation
The osteocutaneous fibula flap has been used extensively for oromandibular reconstruction and provides ample bone stock for osseointegrated implants, so future implant rehabilitation is a relevant consideration during flap planning, though individual suitability still requires assessment.
Worked example: A patient with a lateral mandibular defect after tumor resection needs bony reconstruction. The team selects a fibula flap partly because its bone stock may later support implant-retained dental rehabilitation.
Mistake to avoid: Assuming that restoring mandibular continuity with a fibula flap alone completes the patient's dental rehabilitation.
Source: [7]
48. Donor vascular anatomy can rule out fibula selection
Flap-specific contraindications include lower-extremity peripheral vascular disease, significant atherosclerotic disease on color flow Doppler or angiography, and anomalous vasculature—especially a hypoplastic anterior tibial artery leaving foot perfusion dependent on the peroneal artery—so both legs require careful donor evaluation.
Worked example: Preoperative color flow Doppler of both legs shows the proposed donor foot's circulation depends primarily on the peroneal artery via a perforating branch; the team rules out harvesting that fibula.
Mistake to avoid: Selecting the donor leg solely for convenience or bone length without vascular assessment of both legs.
Source: [7]
49. Soft-tissue geometry can change flap choice
The fibula skin paddle is usually elliptical, oriented parallel to the bone, and cannot be rotated significantly. A relative contraindication is needing a large skin paddle positioned independently of the bone; the scapula may then be more appropriate.
Worked example: A mandibular defect suits fibula reconstruction, but the soft-tissue deficit needs a large paddle positioned independently of the bone. The surgeon reassesses flap choice, considering the scapula as a relative alternative rather than an absolute requirement.
Mistake to avoid: Selecting a flap based only on the bony defect while ignoring the soft-tissue deficit's geometry.
Source: [7]
50. Bone and skin rely on different perforator pathways
The harvested fibula flap's primary blood supply comes from periosteal perforators travelling circumferentially around the fibula. The skin paddle is dependable only if care is taken to preserve its fasciocutaneous perforators, so the two components have distinct perfusion requirements.
Worked example: During reconstructive assessment, the bone segment's periosteal perfusion appears preserved, but the skin paddle's fasciocutaneous perforators must be assessed separately, since intact bone perfusion alone does not confirm skin-paddle viability.
Mistake to avoid: Assuming bone and skin components of the fibula flap have interchangeable perfusion requirements during assessment.
Source: [7]
51. Donor morbidity includes nerve and ankle consequences
The common peroneal nerve crosses the proximal fibula, and injury to its branches may cause foot drop. The lower 7 to 8 cm of the fibula and its fibrous attachments support the ankle mortise and should not be disrupted.
Worked example: A patient develops new foot drop after fibula-flap harvest. This is compatible with a peroneal-nerve complication and requires clinical evaluation, while counselling should also have covered the distal fibula's role in ankle support.
Mistake to avoid: Describing fibula donation as having no potential effect on lower-limb function or ankle stability.
Source: [7]
Trauma priorities and fracture complications
52. Airway protection remains the first trauma priority
Establishing and maintaining a patent airway is always the highest priority through all phases of pre-hospital and hospital care, including oxygenation and ventilation. Emergency management may arise at any time, so an initially satisfactory airway does not end surveillance.
Worked example: While planning facial fracture fixation, a patient develops airway compromise from swelling. Airway assessment and protection by appropriately trained personnel take priority over continuing fixation planning, since compromise can arise at any time.
Mistake to avoid: Assuming an airway stable on arrival will remain stable throughout all later phases of care.
Source: [5]
53. An unaccounted-for tooth is an airway concern
After facial trauma, every tooth, implant, or denture must be accounted for. When dentition integrity is uncertain or an object's location is unknown, AO recommends radiographic examination of the neck, chest, and abdomen rather than assuming external loss.
Worked example: A patient arrives from an assault with a broken molar that was never recovered at the scene. The team orders neck, chest, and abdominal imaging to locate the tooth instead of presuming it was spat out.
Mistake to avoid: Documenting the missing tooth as externally lost without arranging imaging for internal displacement.
Source: [5]
54. Postoperative swelling can change airway requirements
Mucosal, lingual, and pharyngeal swelling can narrow the airway after facial injury or surgery. Increasing swelling, maxillomandibular fixation, and impaired consciousness all influence how airway protection is planned, and reassessment continues until edema and consciousness improve.
Worked example: After midface repair, a patient's facial swelling worsens overnight while consciousness remains impaired. The team reassesses airway protection rather than treating the completed operation as evidence that the airway risk has resolved.
Mistake to avoid: Judging airway readiness only by how well the skeletal repair looks on imaging.
Source: [5]
55. Facial bleeding threatens the airway and aspiration safety
Traumatic facial bleeding can obstruct the airway directly or fill the stomach, raising the risk of vomiting and aspiration. Patients with an altered level of consciousness carry an increased aspiration risk, so bleeding demands diagnostic and prioritization attention.
Worked example: An obtunded trauma patient has ongoing nasal and pharyngeal bleeding. The trauma team's assessment addresses aspiration and airway compromise together with blood loss, rather than focusing only on volume replacement.
Mistake to avoid: Treating swallowed blood purely as a gastrointestinal problem and overlooking its aspiration threat.
Source: [5]
56. Subtle neck findings can signal laryngeal trauma
Laryngeal trauma is often overlooked after severe facial trauma, particularly blunt midneck injury. Pain, swelling, ecchymosis, or subcutaneous emphysema over the laryngeal area should raise suspicion, because these findings are frequently subtle beside more obvious facial injuries.
Worked example: A patient with prominent midface fractures also shows neck bruising and palpable subcutaneous air. The assessment includes possible laryngeal injury despite the facial injuries dominating the clinical picture and the patient's complaint.
Mistake to avoid: Allowing dramatic facial injuries to distract attention from a quiet but significant neck injury.
Source: [5]
57. MMF requires preparation for an airway emergency
Maxillomandibular fixation can complicate airway management: vomiting or a low Glasgow coma score may cause further airway problems or inadequate ventilation, so the treating team must be prepared for emergency release of the fixation if airway problems arise.
Worked example: A postoperative patient in maxillomandibular fixation begins vomiting and shows deteriorating airway protection. The team's emergency plan must address releasing the fixation as part of airway management, not treat it as separate from respiration.
Mistake to avoid: Applying maxillomandibular fixation without first establishing a workable airway-emergency release plan.
Source: [5]
58. Contamination and established fracture infection are distinct
Mandibular fractures in the dentate area communicate with the oral cavity and are therefore considered open and contaminated. Clinically relevant infection shows swelling, pain, fever, redness, and pus, and in acute infection radiographic signs can be absent.
Worked example: A dentate-region mandibular fracture shows pus and inflammatory clinical findings, but imaging reveals no clear radiographic infection changes. The negative early imaging does not exclude an acute infection at the fracture site.
Mistake to avoid: Diagnosing infection from openness alone, or excluding acute infection because early imaging appears negative.
Source: [20]
59. Instability can perpetuate an infected fracture
Instability produces and maintains the infectious process in mandibular fractures, and antibiotic therapy alone does not eliminate the infection while the fracture remains unstable. AO describes rigid load-bearing bridging with a reconstruction plate and debridement for these cases.
Worked example: An infected mandibular fracture stays mobile despite a course of antimicrobial treatment. Reassessment must address mechanical stabilization and the local infected bone problem rather than continuing antibiotics alone.
Mistake to avoid: Repeating antibiotic courses while disregarding the persistent mechanical instability of the fracture fragments.
Source: [20]
60. Postoperative malocclusion needs an anatomical explanation
In aftercare of infected mandibular fractures, the surgeon must determine malocclusion's etiology using appropriate imaging. Malocclusion from surgical edema or muscle splinting may benefit from training elastics, but elastics cannot correct a bony fixation problem.
Worked example: During aftercare of an infected mandibular fracture, new malocclusion accompanies imaging-confirmed hardware displacement. This bony problem requires surgical reassessment and revision rather than any attempt at correction with training elastics.
Mistake to avoid: Treating every postoperative bite discrepancy as transient edema or muscle splinting without imaging.
Source: [20]
References
- 2027 NDSE Protocol: Oral and Maxillofacial Surgery blueprint, pages 25–26
- Official NDSE FAQs: NDSE versus Fellowship Examination
- Official 2027 NDSE specialty examination dates
- AO Surgery Reference: Basic Techniques for Mandibular Fractures—MMF, locking plates and lag screws
- AO Surgery Reference: Airway Considerations in Maxillofacial Trauma
- ACPA: Parameters of Care for Evaluation and Treatment of Individuals with Cleft Lip/Palate and Other Craniofacial Differences, 2024
- University of Iowa: Osteocutaneous Fibula Free Flap—indications, donor assessment, harvest and postoperative care
- ITI Consensus: Implant Placement and Loading Protocols
- ITI Consensus: Horizontal Ridge Augmentation in the Anterior Maxilla—grafting and staged versus simultaneous placement
- NHS England GIRFT/RCS: Management of Painful Temporomandibular Disorder in Adults, version 1.1, August 2025
- SDCEP: Management of Dental Patients Taking Anticoagulants or Antiplatelet Drugs, second edition
- RCDSO: Use of Sedation and General Anesthesia in Dental Practice—Ontario standard on assessment, monitoring, rescue and discharge
- ADA: Evidence-Based Chairside Guide for Pharmacologic Management of Acute Pain after Tooth Extraction, 2024
- University of Iowa: salivary swelling, differential and management
- University of Iowa: sialendoscopy indications and contraindications
- NCI Salivary Gland Cancer Treatment PDQ, health professional version
- NIDCR Dry Mouth
- AO Surgery Reference: orthognathic surgery planning
- NIDCR Temporomandibular Disorders
- AO Surgery Reference: infected mandibular fractures and bone loss
- FDA Dermal Fillers: indications, contraindications and serious risks
- AAOMR Dental implant radiology selection position statement (2012; scope dated)
- AAP/AAPD pediatric sedation monitoring and management, reaffirmed 2025; pediatric scope only
- ASA/AAOMS/ADA moderate procedural sedation guideline 2018, original society paper hosted by ASPHO