Diagnosis and Treatment Planning
Framing the problem
Sound diagnosis begins with the chief complaint in the patient's own words, then moves through problem-oriented records: history, clinical exam, study casts, intraoral and extraoral photographs, panoramic and cephalometric radiographs, and when indicated CBCT. The candidate must be fluent in the components of a problem list - skeletal, dental, soft tissue, functional, periodontal, and psychosocial - and must be able to sequence treatment goals against growth status, cooperation, and caries risk.
Key concepts
Master the three planes of space and how they interact: sagittal (Class I/II/III), vertical (deep bite, open bite, hyperdivergent versus hypodivergent), and transverse (crossbite, constriction). Know the cephalometric norms and, more importantly, their limitations: norms are population averages, so a value outside one standard deviation is not automatically a problem. Understand the difference between a discrepancy that is dental (camouflage possible) and one that is skeletal (may need growth modification or surgery).
Traps
Questions love to present a patient with a normal occlusion but a facial asymmetry, or a Class II that is really a mandibular deficiency rather than maxillary excess. Another classic trap: choosing extraction therapy without considering the vertical dimension - extraction mechanics can deepen the bite and worsen a hyperdivergent pattern. Also watch for questions that ignore the patient's motivation or the parent's goals.
Worked example
A 12-year-old with a 6 mm overjet, Class II molar relationship, normal vertical pattern, and a mandible that is retrognathic on cephalometrics. Rule of thumb: if the discrepancy is primarily skeletal and growth remains, consider functional appliance or headgear timing; if dental, consider camouflage. Always state the goal, the mechanism, and the expected response.