Applications of computer graphics in craniofacial surgery.

Three-dimensional surface images can be reconstructed from CT scans. These are particularly useful in the study and management of patients with congenital and acquired craniofacial deformities. The principles of 3-D reformation, the production of the surface images, and recent advances in modification of these images for specific clinical needs are presented.

Orbital lymphangioma.

In summary, we have presented a patient with an uncommon disorder, orbital lymphangioma, with an equally uncommon outcome, restoration of normal visual acuity and ocular motility following total surgical excision. High-resolution axial thin-slice CT scanning with paraxial re-formations was used for preoperative assessment and surgical planning in the case of this 5 1/2-year-old boy with probable lymphangioma of the orbit. The tumor became symptomatic following minor local trauma. Complete excision was possible without impairment of visual or extraocular motor function.

Internal fixation of malar fractures: an experimental biophysical study.

Open reduction and internal fixation of displaced zygoma fractures are necessary to avoid immediate and delayed facial disfigurement. Interosseous wires, Kirschner wires, and more recently, rigid metallic miniplates have been recommended for fixation of these and other midfacial fractures. However, the precise physical stability of the zygoma with respect to wire versus miniplate fixation methods and with respect to the number and location of miniplates applied is not known. Noncomminuted zygoma fractures were simulated by saw osteotomy in eight fresh human cadaver heads (16 zygoma "fractures"). Each zygoma was sequentially fixated with three miniplates, two miniplates, one miniplate, and three interosseous wires across the orbital rim and arch "fractures". Static and oscillating loads simulating maximal physiologic masticatory stresses were applied to the fixated zygoma along the lines of action of the masseter muscle by means of a tensometer. The stability and adequacy of each pattern of fixation were recorded. Double-miniplate fixation across the orbital rim of simulated noncomminuted zygoma "fractures" is sufficient to withstand static and oscillating loading similar to physiologic masticatory forces. Neither single-miniplate fixation nor triple-wire fixation are sufficient to stabilize the zygoma against similar forces.

Pediatric facial free flaps.

Facial soft tissue deficiency in children has components of both congenital and apparently acquired processes, such as craniofacial microsomia, facial clefts, and Romberg's hemifacial atrophy. Correction of these deficiencies has traditionally been delayed until completion of dentoskeletal reconstructions, facial growth, or the disease process. However, there is a trend toward ever earlier correction of these soft tissue deformities, as part of a general effort to minimize psychological trauma. Microvascular free flap augmentation seems to have replaced dermofat sandwich grafts and alloplastic materials as the method of choice for correction of soft tissue defects. The choices of donor site, recipient vessels, and the optimal age for reconstruction of pediatric facial defects are still undefined. In order to examine these variables a retrospective study of the microvascular free flaps that the authors have used was undertaken.

Cervical spine anomalies in the craniosynostosis syndromes.

Cervical spine radiographs of 34 patients with a variety of craniosynostosis syndromes were reviewed to determine the incidence and nature of skeletal anomalies and to evaluate the findings in terms of syndromal patterns. Intervertebral fusions occurred in 30 percent of Pfeiffer's, 38 percent of Crouzon's, and 71 percent of Apert's syndrome children. In Crouzon's and Pfeiffer's syndromes, isolated upper cervical fusions were most common; in Apert's syndrome, the fusions were more likely to be complex involving C5-C6. This syndromal variation, however, was not specific enough for diagnostic differentiation.

Calvarial erosion after scalp expansion.

A case is described of tissue expansion of the scalp with resultant erosion of the outer table and diploe of the calvaria. This resorption may have resulted from a prolonged period of expansion, excessive tension from inflation, and/or the nature or location of the defect. In cases of scalp expansion where the loose areolar space has become obliterated, periodic limited computed tomographic scanning may be useful to monitor the integrity of the skull. Postexpansion protective headgear may be indicated in selected patients.