The lateral periodontal cyst: aetiology, clinical significance and diagnosis

The lateral periodontal cyst (LPC) is a relatively uncommon but widely recognized odontogenic cyst of developmental origin. It is found mostly in adults and has no sex predilection. LPC is usually discovered during routine radiographic examination, is located mainly between the roots of vital mandibular canines and premolars, and seldom causes pain or other clinical symptoms. The defect appears on radiographs as a round or teardrop-shaped, well circumscribed radiolucency. Due to its location it can easily be misdiagnosed as a lesion of endodontic origin. In this paper, two cases of lateral periodontal cysts are presented. In the first case, the patient (woman, 62 years old) complained of an asymptomatic gingival swelling in the region between the right maxillary canine and premolar. The radiographic examination revealed a well circumscribed radiolucency with a radiopaque margin between the roots of the canine and premolar. The adjacent teeth had vital pulp. Surgical enucleation of the lesion was performed and the histological examination revealed that the lesion was a "lateral periodontal cyst of developmental origin". In the second case, the patient (women, 44 years old) complained of a swelling in the area of tooth 32. During radiographic examination a well circumscribed radiolucency between the roots of the lateral incisor and the canine was discovered. Surgical enucleation of the lesion was performed and the histological examination revealed that the lesion was a "lateral periodontal cyst of developmental origin".