LAUSR

I wish to draw your attention to an unusual presentation of an odontogenic cyst in a 4-year-old boy. The patient was referred to the oral and maxillofacial department by his general practitioner following a 4-month history of chronic bilateral labial swelling. The mother gave a history of trauma at 2 years of age when the patient had knocked his face when learning to walk. On examination there was bilateral hard bony swelling of the maxilla from the upper right lateral incisor to the upper left lateral incisor causing fullness to the upper lip. There were no signs of acute infection, caries or discolouration of teeth. However, the upper central incisors were mobile. Fibrous dysplasia, ameloblastoma and odontogenic cysts were included in the list of differential diagnoses. Following the initial appointment, the patient underwent a computerised tomography scan and incisional biopsy under a general anaesthetic to aid diagnosis and treatment planning. The computerised tomography scan revealed two well-defined unilocular radiolucencies associated with the roots of the first maxillary incisors with no aggressive bony features (Fig. 1). The specimen showed a cyst lined by non-keratinising squamous epithelium with underlying active chronic inflammation and fibrosis. A diagnosis of radicular cysts was later confirmed by enucleation of the cysts with histology. Radicular cysts are inflammatory in origin and occur commonly after pulp necrosis of a carious or traumatised tooth. Radicular cysts are often asymptomatic unless there is an infection or the cyst has become large enough to cause a swelling. In some cases, these cysts are initially identified by dental radiography. Radicular cysts are the most common type of cyst affecting the jaws; however, reports of radicular cysts affecting the deciduous dentition are extremely rare. It has been estimated that less than 3.3% of radicular cysts are associated with deciduous teeth. Patients following a history of trauma should be encouraged to visit a general dental practitioner for regular follow-up. Clinicians should be aware that radicular cysts do occur in paediatric patients and early detection and referral may avoid extensive surgery.