Clinical Dynamic Study Of Jaw Cyst By Decompression

BACKGROUD:Oral and maxillofacial region is the high incidence area of jaw cyst,and The incidence rate of odontogenic jaw cysts is 0.125%.The most common odontogenic cysts are dentigerous cyst,apical cyst and keratocyst.At present,surgery is still the main method for the clinical treatment of odontogenic jaw cyst.The most commonly used surgical methods include fenestration decompression,curettage and curettage combined with guided bone regeneration.Considering the lesion range of cysts,fenestration decompression is often used for cysts with a diameter of more than 3.5 cm,which can not only reduce the damage of important anatomical structures and the occurrence of pathological fractures,but also preserve the patient’s jaw function and morphology.However,the shortcomings of fenestration decompression can not be ignored,such as long course of treatment,postoperative care,and the epithelial cells remaining in the capsule cavity may become residual tissue,resulting in tumor changes,increasing the invasion rate and recurrence rate.Therefore,it is necessary to analyze the contraction law of j aw cyst after fenestration decompression.PURPOSE:To observe the dynamic characteristics of odontogenic mandibular cyst after decompression,and analyze the treatment results.METHODS:Data of patients with odontogenic cyst of mandible confirmed in our hospital from June 2017 to June 2019 who underwent decompression were collected.There were 40 patients,including 21 males and 19 females.Pathological diagnosis included 6 cases of radicular cyst,21 cases of dentigerous cyst and 13 cases of keratocyst.According to the cone beam CT（CBCT）taken before and after operation using retrospective analysis.Three-dimensional reconstruction was conducted using E3D modeling software.The contraction direction of the cyst cavity,contraction speed of the cyst cavity and its relationship with age and time were analyed with spss 21.0 software.RESULTS:1.The cysts of the mandibular body mostly contracted with the largest diameter as the axis.After decompression,the cystic cavity contracted in an elliptical shape.2.The contraction rate of cystic cavity from small to large was as followed:odontogenic keratocysts,apical cyst,dentigerous cyst.3.The contraction speed was negatively correlated with time and age,and the contraction speed slowed down significantly after 12 months.CONCLIUSIONS:The effect of fenestration decompression in the treatment of mandibular odontogenic cysts is related to time,age and pathological type.It is recommended to deal with in a timely manner according to the characteristics of the cyst changes.