Section A: Diagnosis, Treatment Planning, and Prognosis
What Section A is really testing
Section A asks whether you can move from data to a defensible plan. Candidates must be fluent in the diagnostic sequence: chief complaint and history, extraoral and intraoral examination, periodontal and occlusal assessment, mounted casts, and appropriate imaging. Know the difference between a provisional diagnosis, a definitive diagnosis, and a prognosis, and be able to classify prognosis (good, fair, poor, questionable, hopeless) using factors such as attachment loss, mobility, furcation involvement, crown-to-root ratio, and endodontic status.
Concepts to own
- Risk assessment as distinct from disease status: past periodontitis, smoking, diabetes control, caries risk, parafunction, and compliance all change the plan even when the mouth looks stable today.
- Tooth-level vs. arch-level vs. patient-level decisions. A restorable tooth can still be the wrong tooth to retain if it compromises the arch.
- Diagnostic wax-up and mounted casts to test occlusal scheme, space, and whether the proposed plan is physically possible.
- Sequence of care: disease control, then reassessment, then definitive restorative/prosthodontic care.
Traps
Questions love a single unfavorable finding presented as decisive. Mobility alone, a deep pocket alone, or a questionable radiograph rarely determines the plan; the answer is usually the option that completes diagnosis first or controls disease before prosthodontics. Watch for options that jump to extraction or to a complex reconstruction without a re-evaluation step. Also watch for "best" vs. "first" - these are different questions.
Rule of thumb
If an option commits to irreversible treatment before disease control and reassessment, it is almost never the best answer. When two options both seem reasonable, prefer the one that gathers more information or is more reversible.
Worked example: A patient presents with a mobile maxillary first molar, 7-mm pocket, and a failing MOD amalgam. The best next step is periodontal assessment and disease control with re-evaluation, not immediate crown lengthening and crown, and not automatic extraction.