Characteristics of bone formation following marsupialization of jaw cysts

Objectives: To assess bone regeneration following marsupialization of jaw cysts. Methods: CT with multiplanar reconstruction (MPR) was performed on 23 patients with cysts of the jaws pre-operatively and 3-4 months after marsupialization. The two images were compared for the three-dimensional outline of the cyst, the distance between the cyst and adjacent structures (vital teeth, maxillary sinus, nasal cavity and mandibular canal) and the integrity of the cortex and mandibular canal. The characteristics of the new bone formation were also determined. Results: The outline of the cyst was changed and partially reduced. The distance between cyst wall and adjacent structures was increased. There was remodelling of the cortex and mandibular canal. The new bone formed in the periphery of the cyst showed either a ground glass appearance or radial bone spicules. Conclusion: CT with MPR is useful for evaluation of morphological changes and bone formation following marsupialization of jaw cysts. CT with MPR is the technique of choice for the maxilla and the entire body of the mandible and coronal CT for cysts in mandibular angle and ascending ramus. Cysts can be enucleated safely as early as 3 months after marsupialization.