Iran Dental Specialty Board - Orthodontics common mistakes
Iran Dental Specialty Board - Orthodontics · Understand the traps and how to avoid them.
Selecting a cephalometric analysis and then reporting only SNA, SNB, and ANB as the complete diagnostic summary, without interpreting the vertical pattern (SN-MP, FMA, LFH), dental inclinations, or soft-tissue profile, so the diagnosis collapses into a single sagittal number.
AnB is the most memorised value and the easiest to recall under time pressure, so candidates anchor on it and stop. They never practised building a full problem list from a tracing, so they do not notice that a Class II skeletal pattern with a high mandibular plane angle implies a completely different mechanics plan than one with a low angle.
What to do instead
Adopt a fixed reading order for every tracing: sagittal (SNA, SNB, ANB, Wits), vertical (SN-MP, FMA, Y-axis, LFH ratio), dental (U1-SN, IMPA, interincisal angle), and soft tissue (upper/lower lip to E-line, nasolabial angle). Write one sentence of interpretation per category before writing the diagnosis. Practise 20 tracings where you must produce a five-item problem list, not just numbers.
Planning anchorage and force levels without estimating the required tooth movement in millimetres and the anchorage ratio it demands, then being surprised when molars tip or spaces reopen.
Candidates memorise appliance names (transpalatal arch, Nance, mini-screw) as a checklist rather than as answers to a quantitative question. Biomechanics is studied as physics formulas disconnected from the clinical decision of maximum versus moderate anchorage.
What to do instead
For every case, first write the millimetre requirement per arch (e.g., 6 mm space closure), then classify anchorage need as maximum/moderate/minimum, then choose the appliance that satisfies that ratio. Learn the M/F ratio thresholds and be able to state which teeth will move and in which direction for each force system you propose.
Treating a mixed-dentition patient with a full fixed appliance plan immediately, instead of first deciding whether the problem is skeletal, functional, or dental and whether growth modification or interceptive therapy is indicated now, later, or not at all.
Candidates equate 'orthodontics' with brackets and assume earlier is always better. They do not screen for functional shifts, habits, airway, and eruption sequence, and they cannot articulate the timing window for each interceptive measure.
What to do instead
Before any appliance decision, classify the problem and state the growth status (CVMS or cervical stage, or at minimum prepubertal/pubertal/postpubertal). Then justify timing: which intervention is effective only in this window (e.g., maxillary expansion before palatal suture interdigitation, functional appliance at peak pubertal growth) and which should be deferred. Include a 'what I am watching and when I will re-evaluate' line in every growing-patient plan.
Presenting a retention plan as 'upper and lower Hawley, review in six months' without specifying the retention regime, duration, or how relapse risk was assessed from the pre-treatment record.
Retention is taught last and often skimmed, so candidates default to a generic appliance. They do not connect initial crowding, expansion, rotational corrections, and periodontal status to relapse risk, and they forget that the retention question in a board case is about reasoning, not appliance naming.
What to do instead
For each case, state the relapse risk factors (initial irregularity index, amount of expansion, rotated teeth, lower incisor position relative to symphysis, tongue posture, periodontal attachment), then choose fixed versus removable versus combined retention with a stated wear protocol and review schedule. Be ready to justify why a bonded retainer is preferred in one case and a vacuum-formed retainer in another.
Ignoring periodontal and restorative constraints until after the orthodontic plan is written, then proposing intrusion or tipping across teeth with reduced attachment or across space needed for an implant.
Candidates compartmentalise specialties and treat the perio-restorative interface as a separate rotation. They do not routinely ask about attachment loss, crown-root ratio, bone level, existing restorations, or the restorative space plan before choosing mechanics.
What to do instead
Add a mandatory 'restorative and periodontal audit' step to every treatment plan: probing depths and attachment level on at-risk teeth, crown-root ratio, presence of implants or planned implants, and the required mesiodistal and occlusal space. Then specify mechanics that respect those limits (e.g., avoid uncontrolled tipping of a periodontally compromised incisor; coordinate space closure with the implant site plan).
Answering TMD questions by asserting that orthodontic treatment causes or cures TMD, or by recommending irreversible occlusal therapy for a patient with a disc displacement.
This is a persistent myth in training and in patient expectation, and candidates answer from anecdote rather than from the evidence base. They also confuse the orthodontist's role (screening, conservative management, referral) with definitive temporomandibular joint management.
What to do instead
Learn the evidence-based position: malocclusion and orthodontic treatment are not established causes of TMD, and orthodontics is not a treatment for TMD. For any TMD item, structure the answer as screening (history, pain, function, imaging if indicated), reversible conservative care, and clear referral thresholds. Never choose irreversible occlusal adjustment as a first-line answer.
When an item presents a clinical scenario, choosing the answer that is true in general rather than the answer that is best for the specific patient described, and missing the qualifier in the stem.
Candidates under time pressure skim the stem and pattern-match to a familiar fact. Many board items deliberately include a distinguishing detail (age, growth status, missing tooth, medical history, patient priority) that reverses the correct choice.
What to do instead
Read the last line of the stem first to identify the exact question, then read the stem and underline the discriminating detail. Before selecting, ask: 'What in this stem makes the general answer wrong here?' Practise with items where two options are both factually true and only one fits the scenario.
Confusing statistical significance with clinical importance, and misreporting study design, when answering evidence-based practice and research methods items (e.g., calling a retrospective case series a cohort study, or treating a p-value as a measure of effect size).
Research methods are studied as isolated definitions rather than as a hierarchy of evidence applied to an orthodontic paper. Candidates do not routinely read the abstract's design, sample, and effect size together.
What to do instead
For every paper-based item, identify four things in order: design, sample and selection, effect size with confidence interval, and applicability to the patient. Learn the levels of evidence and the biases characteristic of orthodontic research (selection bias in retrospective samples, measurement error in cephalometrics, attrition in long-term retention studies). Treat p-values as separate from magnitude.
Writing a treatment plan without documenting the alternatives, the risks, and the patient's informed consent, or accepting a plan the patient cannot comply with (e.g., removable appliance in a non-compliant adolescent) without discussing it.
Candidates treat ethics and communication as a soft topic and focus only on the technical plan. They also omit the no-treatment and compromise options, which is where most real ethical and medicolegal exposure lies.
What to do instead
Use a standard consent structure for each case: diagnosis, options including no treatment, recommended option with rationale, material risks (root resorption, decalcification, relapse, gingival recession), and the compliance-dependent nature of the plan. Explicitly record the patient's goals and the agreed compromise when the ideal plan is not accepted.
Choosing a material or appliance by brand familiarity rather than by its mechanical properties, and misstating properties such as the force-deflection behaviour of NiTi versus stainless steel, or the bond strength and moisture sensitivity of different adhesives.
Materials are learned as product lists. Candidates do not connect alloy composition and cross-section to the load-deflection curve, so they cannot predict which wire delivers light continuous force over a wide activation range.
What to do instead
For each wire and adhesive, be able to state the property that drives the clinical choice: modulus, springback, range, formability, friction, moisture tolerance, and bond strength. Practise matching clinical situations (severe crowding, space closure, torque expression in a rectangular slot) to the material property required, and justify the choice in one sentence.