Title: Our Method of Correcting Vertical Orbital Dystopia
Authors: Takeru Nomachi, MD, Keisuke Imai, MD, Akira Yamada, MD,
Takuya Fujimoto, MD, Miki Fujii, MD, and Shinnosuke Miyamoto, MD
Orbital osteotomies have been described by many plastic surgeons, but although orbital osteotomy-lowering mobilization has been described in photographs taken by McCarthy [1], the procedure has not been described in detail up to now. We report on our method of orbital osteotomy-mobilization for vertical orbital dystopia caused by plagiocephaly. In this procedure a bicoronal cranial incision and an inferior orbital marginal incision are made. A limited anterior or frontal craniotomy provides exposure of the anterior cranial fossa to allow osteotomies of the orbital roof. Supra and infra orbital nerves are identified and preserved, and then circumferential osteotomy is performed. In the case of partial osteotomy, it is not necessary to carry out a craniotomy, but a U-shape osteotomy is performed in the lower half of the orbit. A segment of bone is removed from the zygomaticomaxillary bone and the osteotomized orbital segment is translocated inferiorly. The osteotomized orbital segment is fixed with titanium plates (Fig.-1).
Fig.-1 outline of the Left, circumferential Right, partial osteotomy lines and the area of the zygomaticomaxillary bone resection (slash lines)
Case report
Case 1: A 16-year-old male had orbital dystopia caused by left plagiocephaly accompanied by Apert's syndrome. His right visual acuity was low, but he did not have diplopea. Cranioplasty and Le Fort III osteotomy were performed at another hospital. He came to our hospital with orbital dystopia as his chief complaint. Upon examination, his left medial canthus was found to be 6 mm higher than the right one. Consequently left orbital osteotomy was performed using the following method. The medial, inferior and lateral margin of the left orbit was osteotomized in a U-shaped mass. A 6mm wide segment of bone was removed from the zygomaticomaxillary bone and the osteotomized orbital segment was translocated inferiorly. Bone was grafted into the superior gap that was produced after lowering the left orbit. A natural contour was obtained (fig.-2).
Case 2: A 42-year-old female had orbital dystopia caused by right plagiocephaly. Her right visual acuity was low, but she did not have diplopea. When she was 39 years old, left orbital osteotomy was performed at aother hospital. On examination, her right canthus was found to be 4 mm higher than the left one and it was accompanied by hypertelorism. Craniotomy and orbital osteotomy were performed. The right circumferential orbit was osteotomized and the left superior and medial margin of the left orbit was osteotomized in an L-shape. The right osteotomized orbit was translocated 7 mm medially and 4mm inferiorly, while the left was moved 7 mm medially. The result obtained was satisfactory.
In conclusion, this method is useful to treat vertical orbital dystopia caused by plagiocephaly. The main advantage of this method is that supra and infra-orbital nerves are preserved.
Fig.-2 Orbital dystopia caused by left plagiocephaly corrected by lowering the left orbit. A, Preoperative and B, postoperative 3D-CT. C, Preoperative and D, postoperative views.
Reference
1. Joseph G. McCarthy, Glenn W. Jelks, Augustus J. Valauri, Donald Wood-Smith, Byron Smith: The Orbit and Zygoma, McCarthy J. G.: Plastic Surgery, Philadelphia, Saunders, 1990, 2, 1628-1631.