A 45-year-old female sought orthognathic treatment at Okayama University hospital. Her main complaint was occlusal imperfection and mandibular protrusion. She had a mandibular protrusion, a concave facial profile and facial asymmetry (Fig. 1). Intraoral examination revealed a Class III malocclusion with an excessive negative overbite (-1 mm) and overjet (-4 mm). Representative initial cephalometric values were as follows (Table 1): SNA, 78.5 ; SNB, 78.5 ; ANB, 0.0 ; Mp-FH, 40.5 ; Gonial angle, 136.0 ; U1-SN, 102.5 ; L1-Mp, 84.0 ; IIA, 127.0 , Occ P, 25.5 ; N-Me, 142.5 mm, N/NF, 61.0 mm; Me/NF, 81.5 mm; Go-Me, 78.0 mm; Ar-Go, 51.0 mm; Ar-Me, 121.0 mm, U6/NF, 26.9 mm; U1/NF, 34.1 mm, L6/Mp, 36.5 mm; and L1/Mp, 46.5 mm. The patient was diagnosed as having an Angle Class III malocclusion with a skeletal Class III jaw base relationship and skeletal open bite.
After pre-surgical orthodontic treatment, orthognathic surgery was planned in 2012, but in April of that year the patient first underwent a medical examination at Okayama University hospital under suspicion of cancer in the left breast. She was diagnosed with breast cancer (stage 1), and left breast-conserving surgery and sentinel lymph node biopsy were performed in May 2012 (Estrogen receptor >50%, progesterone receptor >50%, HER2 negative, surgical margin positive, sentinel lymph node metastasis positive). Postoperative chemotherapy (docetaxel 75 mg/m2 + cycloheximide 600 mg/m2 x 4) was performed from June to August, then radiotherapy (total 60 Gy) was performed from September to November. As the breast cancer surgeon provided confirmation of a good prognosis and the patient still wanted to undergo orthognathic surgery, we went ahead and scheduled the bimaxillary osteotomy. In November, a maxillary segmental Le Fort I osteotomy (mx1 impaction, 2 mm; mx6 expansion, 5 mm; mx6 advancement, right 6 mm, left 4 mm; mx1 segmental area, bone augmentation) and mandibular bilateral intraoral vertical ramus osteotomy (IVRO, right M6, 6 mm and left M6, 4 mm, setback) was performed. Fig. 2 shows a panoramic X-ray view after the segmental Le Fort I osteotomy and IVRO. During the jawbone-healing period, administration of tamoxifen began 6 weeks after the orthognathic surgery. Occlusal stabilization was obtained followed by the completion of the postsurgical orthodontic treatment 10 months after the surgery. Fig. 3 shows the extraoral and intraoral views at debonding 10 months after orthognathic surgery. The cephalometric evaluation showed a skeletal Class I jaw relationship (Table 1). In order to examine the stability of the position of the anterior-posterior position of the bimaxillary after the osteotomy, we compared the lateral cephalograms at 3 months and 10 months (debonding) by superimposition. From the post-operative bimaxillary stability shown in Fig. 4, it appeared that regeneration of the normal jawbone had occurred. It was also confirmed that the bone joining was performed normally even at the maxillary posterior part and the overlapping part of bone of the mandible IVRO (Fig. 5, arrows).
Four years after surgery, the stability of the occlusion has been maintained and there has been no recurrence of breast cancer.