 Several additional theories had been proposed regarding the origin of lateral periodontal cysts, including the possibility that the lesions may arise as a result of pulpal infection manifesting itself in a lateral position or chronic periodontal disease activating the rests of Malassez.Lateral periodontal cysts are asymptomatic and are usually exposed in patients routine radiography.The onset of lateral periodontal cyst are insidious and subtle, with a yearly growth rate of 0.7 mm.