Orthodontic Treatment Combined with Temporary Anchorage Device for Cases of Class II with Progressive Condylar Resorption
Progressive condylar resorption (PCR) is sometimes observed in Class II patients with mandiblar retrusion. Although orthognathic surgery is usually recommended for Class II dentofacial deformity with receding mandible, surgical mandibular advancement might be the contraindicated method for Class II patients with PCR. Mandibular advancement and rapid change of mandibular position may result in further condylar resoption. Recently, temporary anchorage device (TAD) has been developed in the orthodontic field. The major applications for TAD in the orthodontic treatment are intrusion and distal movement of the upper molars. For this reason, treatment with TAD has become a new strategy for certain Class II cases. To correct Class II with PCR, we have applied this method for controlling the maxillary molars and gradual change of mandibular position. In this presentation, we introduced two cases of Class II with PCR. The first case was skeletal Class II open bite with Class III molar relationship, because of the congenital absence of lower lateral incisors. The mandibular condylar erosions were recognized on the CT. The upper first premolars were extracted and plate type TADs were placed bilaterally at the base of the zygomatic arch for intruding the upper molars. The second case was also Class II and had condylar erosion. The occlusion was unstable with RCP ICP difference and Class II molar relation was more severe at RCP. Four premolars were extracted and TADs were placed for distal movement of the upper molars. At the completion of the treatment, ideal occlusion was given on both cases. Even two years after the treatment, the stable occlusion has been maintained. In conclusion, the orthodontic treatment with TAD is one of the potent devices to provide the suitable occlusion for the patient with PCR.