The value of cone beam computed tomography in the management of dentigerous cysts – a review and case report

Radiography is important in the diagnosis and management of most oral and dental pathology, and is often invaluable for lesions of the jaw whose precise location and nature may be difficult to appreciate clinically. For most of the early 20th century, plain film dental radiography was the mainstay, before the introduction in the latter part of the century of tomographic techniques. It wasn't until around the turn of this century, however, that cone beam computed tomography (CBCT) became commercially available within dentistry, and its use has been increasing over the last decade particularly.¹

When localizing a lesion clinically, cortical expansion may give an indication of whether it lies nearer the buccal or palatal cortical plate, and plain film radiography is useful in imaging small lesions, often using parallax techniques. Plain film radiography is cheap and accessible and exposes the patient to a comparably lower dose than other modalities such as CT. However, there may be difficulty in fully appreciating spatial relationships where lesions are complex. CBCT can provide high resolution three dimensional imaging at a much lower dose than conventional multi-detector CT, however, the radiation dose received is significantly greater than conventional radiography. The effective dose received from a single intra-oral radiograph may be less than 1.5 microSieverts (μSv) when adequate dose reduction techniques are used, compared to between 2.7–24.3 μSv for a dental panoramic radiograph. Doses for CBCT investigations are between 11–674 μSv for small to medium field dento-alveolar views, and 30–1073 μSv for large field craniofacial views.² The reported ranges in dosimetry are largely due to differences in CBCT equipment.