Case report
A 19-year-old man who suffered from maxillofacial deformity and poor chewing was referred to the outpatient department in our center. He was subsequently admitted to the inpatient with a diagnosis of the skeletal Angle Ⅲ malocclusion combined with maxillary dentition defect. The general examination revealed that he had been healthy and well nourished and had experienced no systemic diseases. The detailed clinical examination was as follows: the maxillofacial region was basically symmetrical. 1/3 of the surface, the middle, and the bottom face was approximately 65mm, 65mm, 88mm, respective1y. The length of the upper lip was about 20mm. The orbital plane was basically parallel to the maxillary plane with a slight concave around the nose. From the lateral view, the middle of the face was concave and the nasolabial angle was about 120°. The position of the maxilla was retraction, the position of the mandible was protruding. The maxillary midline was basically centered and the mandibular midline was approximately 2 mm to the right. The reverse overjet of anterior teeth was about 7 mm and the bilateral first molars were the mesioclusion relationship. The congenital missing teeth included tooth 14、tooth 15、tooth 23 and tooth 24(Fig.1). The width of residual alveolar ridge in the absence of teeth was about 3-4 mm. The distance from tooth 14 to tooth 15, tooth 23 to tooth 24 was about 4 mm and 5 mm respectively(Fig.2a). The occlusal distance was normal and the results of cephalometric analysis were as follows: SNA=78°, SNB=83° and ANB=-5°(Fig.2b).
In our case, the treatment process consisted of three parts: preoperative orthodontic stage, orthognathic surgery stage and implant repair stage. Yantai Stomatological Hospital Review Board approved the clinical study and patient has been informed the surgical procedure and precaution, and signed the consent form. At the orthodontic treatment stage, we removed the tooth compensation, erected tooth 22, and moved tooth 25 to the tooth 24 position. Closed scattered spaces from tooth 13 to tooth 25 and concentrated missing spaces on tooth 15 and tooth 25. In the orthognathic operation stage, sagittal split osteotomy of bilateral mandibular ramus, anterior maxillary osteotomy and autogenous bone graft were performed under general anesthesia. The anterior maxillary incision was located in the tooth 15 and tooth 25 missing area. The anterior maxilla part moved forward about 2 mm and decreased about 2 mm and the distal bone mass of the mandible receded about 5 mm. In order to maintain the continuity, height and fullness of the bone, the removed mandibular bone was placed in the maxillary incision position(Fig.3). During the implant restoration phase, the postoperative orthodontics ended six months after orthognathic surgery. There was no obvious abnormality in the mucous membrane of the wound area, the bone tissue healed well, the alveolar ridge was edge-shaped in the bilateral edentulous region, and the mesiodistal width of the alveolar ridge was about 7 mm(Fig.4). Cone beam CT showed that the buccolingual bone width of tooth 15 was about 3 mm, the height of vertical bone was about 16 mm. The buccolingual bone width tooth 25 was about 3 mm, and the height of vertical bone was about 16mm(Fig. 5).
Bone augmentation operation was performed in the area of bone defect filled with Bio-oss bone powder, covered with Bio-gide membrane and fixed with titanium nail, the surface was covered with CGF and sutured tightly. One year after bone grafting alone, alveolar bone was found to be plump in the absence of teeth, occlusion space was obtainable, and mucous membrane was not abnormal. Cone beam CT showed that the buccolingual bone width of tooth 15 was about 7 mm, the height of vertical bone was about 14 mm. The buccolingual bone width tooth 25 was about 6 mm, and the height of vertical bone was about 16mm. Two straumann implants (4.1×10mm RN) were implanted in tooth 15 and tooth 25 and the postoperative x-ray showed the implant was in good position(Fig. 6). 7 months after implantation, Cobalt Chromium porcelain Crowns were used to repair tooth 15 and tooth 25(Fig. 7).
At revisit six months after completion of restoration, Bone tissue around implants healed well. variable values of cephalometric measurement before and after treatment were shown in the table 1.