An Angle Class I malocclusion with a paradental cyst

According to the WHO, a paradental cyst is classified as an odontogenic inflammatory lesion, showing a relative frequency of 0.9–4.7% in the world population. There are no identifiable reports of orthodontic treatment of patients who also present with a paradental cyst. The presenting patient was a Japanese female, aged 16 years and 10 months. The chief complaint was crowding and protrusion of the incisors. The magnitude of the overjet was +4.0 mm, overbite was +3.8 mm, and the intermolar relationship was Angle Class I. Pretreatment computed tomography identified a radiolucency extending from the root furcation to the apex of the mandibular left first molar, which was diagnosed as a paradental cyst. Orthodontic treatment was performed using lingual multi-bracket appliances and miniscrews following the extraction of the affected mandibular first molar, mandibular right first premolar and both maxillary first premolars. The paradental cyst was enucleated, and occlusal cusp-fossa relationships were maintained with complete space closure. This case is the first report of orthodontic treatment in association with the management of a paradental cys.