Most orthodontic patients, unlike those having implants or endodontic treatment, are children who are particularly vulnerable to ionising radiation. In orthodontics, cone-beam computed tomography (CBCT) has both hazards and benefits. Ionizing radiation, the existence of artefacts, higher costs, limited accessibility, and the need for additional training are the main hazards and limits. This imaging modality, however, has several recognised indications in orthodontics, including the assessment of impacted and ectopic teeth, the assessment of pharyngeal airway, the assessment of mini-implant sites, the evaluation of craniofacial abnormalities, the evaluation of sinus anatomy or pathology, the evaluation of root resorption, the evaluation of the cortical bone plate, and the planning and evaluation of orthognathic surgery. For certain patients, CBCT should be considered for clinical orthodontics. The use of CBCT requires careful consideration and strong clinical judgement. The important themes and topics in the literature about application of CBCT in orthodontics are summarised in this review.