Implants, spaces and a lost tooth

Correct answer: B. Steep, or exaggerated

• A. A flat curve is associated with an open bite tendency, the opposite pattern.
• B. Correct. Class II division 2 features retroclined maxillary central incisors and a deep overbite, and the deep bite is accompanied by an exaggerated curve of Spee as the mandibular posterior teeth overerupt. Levelling that curve is a defined objective of orthodontic treatment and requires arch length that must be accounted for in planning.
• C. A reversed curve of Spee is found in some skeletal Class III and open bite presentations, and is also created deliberately by a reverse curve archwire used to level a deep bite.
• D. The curve of Spee is closely tied to the vertical relationship, so it is very much affected here.

Correct answer: D. Hypodontia

• A. Hyperdontia is the presence of supernumerary teeth, which is the opposite condition.
• B. Oligodontia is the absence of six or more teeth excluding third molars, and it is frequently syndromic.
• C. Anodontia is the complete absence of all teeth and is very rare, associated with severe ectodermal dysplasia.
• D. Correct. Hypodontia is the absence of one to five teeth excluding third molars. It is the most common dental developmental anomaly, most often affecting third molars, then mandibular second premolars and maxillary lateral incisors.

Correct answer: D. A compound odontoma

• A. A complex odontoma is a disorganised, irregular mass of the same tissues without recognisable tooth forms, and it favours the posterior mandible.
• B. An ameloblastic fibro-odontoma combines the soft tissue elements of an ameloblastic fibroma with calcified odontoma-like material.
• C. A cementoblastoma is a radiopaque mass fused to the root of a vital tooth, usually the mandibular first molar, and is characteristically painful.
• D. Correct. A compound odontoma consists of multiple small tooth-like denticles with all four dental tissues arranged in normal relationship. It occurs most often in the anterior maxilla and typically presents as a failure of eruption of a permanent tooth. Treatment is conservative excision with an excellent prognosis.

Correct answer: C. The need for an artefact-free specimen if histopathology is required

• A. Speed is a convenience, not a clinical justification for compromising a specimen.
• B. Patient preference is respected in genuinely equivalent options, but the diagnostic requirement takes priority.
• C. Correct. Where a diagnosis has not been established, thermal modalities such as electrosurgery and lasers coagulate the specimen margins and can render the histology uninterpretable. If the tissue must be examined, use a cold blade, or take an incisional biopsy first and only then use a thermal device for definitive removal.
• D. Cost matters to the practice but does not determine what is right for a given lesion.

Note: The recall recorded a choice between electrosurgery and an erbium laser with the author unsure. The examinable principle is that whichever is chosen, the histological requirement comes first, and electrosurgery is additionally contraindicated in patients with a cardiac pacemaker.