Cone Beam Computed Tomography (CBCT) has recently seen an expansion in use, however there are few robust, evidence-based guidelines to inform practitioners. This article reports the case of a large dentigerous cyst in the maxilla affecting the eruption of multiple teeth, considers the use of CBCT in the management of such lesions, and discusses guidelines on the use of CBCT in dentistry. Clinical relevance: As CBCT use increases it is important that practitioners understand the guidelines surrounding its use. Due to the prevalence of dentigerous cysts, it is likely that they will be encountered clinically, and it is important that clinicians referring patients with such lesions are familiar with the principles of managing them.