Orthodontic Treatment And Genetic Analysis In Patients With Cleidocranial Dysplasia Of A Family

Objective: To find more efficient method and identify the pathogenic genes and mutation types through the orthodontic treatment and genetic analysis for patients from one family with Cleidocranial dysplasia(CCD).Methods: A CCD family was diagnosed by a patient who visited our department with the chief complains of impacted teeth,and two of them were treated by a combined surgical and orthodontic management.The impacted incisors were pulled firstly,and then was the permanent canines and premolars.If possible,the retained deciduous teeth were used as anchorage for teeth traction and only were extracted when needed.Most of the supernumerary teeth were retained into mandibular except that of which might stop the permanent teeth eruption.All the surgical works were carried out under a local anesthesia condition.The next-generation sequencing and sanger test were performed on three patients with CCD clinical characteristics of this family.Results: The proband has been treated for three years and five months and another was one year and four months.Eight of the 23 impacted teeth have been pulled out so far.Two maxillary premolars erupted spontaneously.Two of the 10 supernumerary teeth were removed before the impacted teeth traction,and the remaining are no abnormalities.No lingual button bonding failure,infection and obvious gingival recession happened in this study.The intermaxillary anchorage combined with the primary teeth anchorage could provide sufficient help during teeth traction.Gene analysis demonstrated that three patients have a same insertion mutation(c.90＿91ins C;p.Ser31Leufs*130)in exon 3 of RUNX2 gene.Conclusions:1.Selectively retaining most of the supernumerary teeth in the mandibular,and achieving all the work in outpatient setting can well reduce surgical trauma,and shorten the course of treatment.2.Deciduous teeth working as anchorage is more efficient to tract the impacted permanent teeth than pre-extraction only.3.Some impacted teeth obtain the ability of spontaneous eruption again and the differences between the same RUNX2 gene mutation and various clinical phenotypes suggesting that the pathogenesis of CCD need further study.