Background: Radical cysts are the most common inflammatory odontogenic cystic lesions that can be treated by Marsupialization, especially if the cyst is large and has vital structures. There are a few things to consider when treating a growing patient with an odontogenic cyst. Marsupialization has more benefits for the growing patient than enucleation to overcome treatment morbidity, such as damage to vital structures, bone loss, jaw growth disorders and pathological fractures. Purpose: This article reports on the success of marsupialization of odontogenic cysts "that have been associated with very decaying deciduous molars" to reduce treatment morbidity and to discuss enucleation in young patients. Materials and Methods: A healthy 9 patients with average age of 8 years old with unilateral radicular mandibular cysts. Marsupialization was done before the end of cyst enucleation incorporating a multipurpose space maintainer. Results: Periodic contraction of the cysts was observed in all patient cystic site. The position of the cyst wall was placed superficially and an enucleation was performed. The treatment result was satisfactory with low morbidity. Conclusion: Marsupialization with a versatile space maintainer for the odontogenic periapical cyst in growing patients has more advantages than enucleation in reducing treatment morbidity.