ISSN:1049-2275    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

&NA;Personal computer (PC)‐based computing is now ubiquitous in common consumer applications. Although PCs have equaled or surpassed engineering workstations in basic computing power and economy, there is still strong workstation dependency for imaging applications. This article demonstrates that a complete system, based on a Pentium PC (Intel Corporation, Santa Clara, CA) and readily available and inexpensive software, can be built very economically for effective execution of most of the commonly used three‐dimensional imaging operations. For the craniofacial application, the Pentium system offers a twofold speed advantage over a Sparc 20 system using similar three‐dimensional processing software. The Pentium system allows interactive fuzzy volume rendering, and manipulation and analysis of complex hard and soft‐tissue structures.

ISSN:1049-2275    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

&NA;Numerous reports on the complications of craniofacial surgery have been published in the western world. However, relatively little such information concerning Oriental populations has been documented. We therefore set out to provide a retrospective analysis of all the complications of craniofacial surgery encountered during the 10‐year period of 1986 to 1995 at Seoul National University Children's Hospital, the only children's hospital in Korea. Forty‐nine children underwent 57 consecutive craniofacial procedures at our institution during 1986 to 1995. A retrospective chart analysis of the frequency and types of complications was performed. Mantel‐Haenszel chi‐square tests were then calculated for several factors, including age at surgery, duration of surgery, intraoperative losses of hemoglobin and hematocrit, total amount of blood transfusion, and the number of complications according to year, diagnosis, and operative procedure to find any significant correlation with the incidence of complications. Mortality was 1.8%. The major complication rate was 7.0% and included cases of visual loss and persistent cerebrospinal fluid leak. Analysis revealed the presence of several trends, including an increased incidence of complications with increased patient age at surgery, duration of surgery, and intraoperative loss of hematocrit. The number of complications was also noted to increase in cases with complex craniofacial synostosis syndromes (Crouzon's, Apert's Antley‐Bixler, etc.) and tumors of the orbit and cranium. Finally, complications were noted to decrease in recent years, most likely due to the increased experience of our craniofacial team. Nevertheless, statistical analysis revealed that the incidence of complications correlatedsignificantlyonly with increased duration of surgery (p< 0.05). The results of our study indicate that although craniofacial surgery in the Orient carries an inherent risk for significant complications, the risk can be minimized and the rate of mortality and major complications kept to an acceptable level by a careful and experienced craniofacial team. Groups at most risk for complications are those with a long duration of surgery.

ISSN:1049-2275    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

&NA;Blindness can result from traumatic optic neuropathy following facial trauma and can complicate the management of concomitant facial fractures. Traumatic optic neuropathy can cause a substantial delay in the repair of facial fractures, leading to compromised surgical results. It can also result in postoperative visual loss following facial fracture repair. We present four cases of traumatic optic neuropathy that compromised the treatment of facial fractures. The management of facial fractures in patients with traumatic optic neuropathy must proceed cautiously. Delayed primary repair of midface fractures by postponing surgery for 10 to 14 days may be of benefit in avoiding further deterioration of vision. In addition, megadose corticosteroids and/or optic nerve decompression is useful in the management of these patients.

ISSN:1049-2275    

出版商:OVID    

年代:1997

数据来源: OVID

ISSN:1049-2275    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

&NA;The purpose of this investigation was to determine whether a constant direct current stimulation applied at the coronal suture would alter sutural morphology and selected cephalometric parameters of the cranial vault and cranial base. In each of six rabbit litters (N = 36), animals were randomly assigned to control, sham, and experimental groups. At 21 days of age, the sham and experimental groups had thin titanium wire cathodes surgically positioned between the fascial layers of the scalp overlying the coronal suture. On this same day and on day 70, all animals had standardized lateral and dorsoventral cephalograms taken and also received lead acetate vital stain injections. The following results were demonstrated: (1) a significantly greater flexure in the cranial base angle (P< 0.01) for the experimental group at day 70; (2) no statistically significant differences for percentage changes (day 70/day 21) in cranial vault length or cranial vault width among the control, sham, and experimental groups (P< 0.05); (3) alterations in sutural morphology at day 70 for the experimental group, including lengthened collagenous fibers, abundant cartilage in the suture, and a twofold increase in the bony modeling of the ectocranial surface. This study concludes that, although the exact mechanisms of action for direct current stimulation remain unknown, this manipulation can indeed alter some parameters of the cranial skeleton and suture morphology.

ISSN:1049-2275    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

&NA;This study was designed to evaluate hydroxyapatite paste (BoneSource; Leibinger Corp., Dallas, TX) as an alloplastic implant for supraorbital and malar augmentation. Ten male Sprague‐Dawley rats had cylindrical onlay implants made of the hydroxyapatite cement placed above their left orbits on the supraorbital rim. Size‐ matched Medpor implants were placed similarly on the right side. To test the utility of this new material in the midface, hydroxyapatite paste and Medpor implants were also placed in the right malar regions of a different set of rats. The implants were left in situ for 6 months and examined for evidence of bone ingrowth, infection, migration, resorption, and detrimental effects on the surrounding tissue. All hydroxyapatite cement implants provided excellent soft tissue projection and demonstrated steadfast adherence to the adjacent bone. The surface of the hydroxyapatite implant in contact with the native bone demonstrated evidence of native bony ingrowth into approximately 12% of the implant. There was no evidence of implant migration or gross infection. There was no bony resorption below the hydroxyapatite paste, but four of the Medpor implants showed evidence of this in the underlying bone. Only one negative aspect to the use of hydroxyapatite cement paste as an onlay implant was identified. Two of the supraorbital and one of the malar hydroxyapatite implants had approximately 20 to 25% volume loss during the experimental period (P= 0.05). Overall, the vast majority of the implants retained their original form. We concluded that hydroxyapatite paste may possibly be used to effectively augment bone in the supraorbital and malar regions. Its biocompatibility, excellent bony adherence, and tendency to be replaced by natural bone may make it suitable for the aesthetic patient. The possible resorptive aspects of the material need to be evaluated further.

ISSN:1049-2275    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

&NA;Craniosynostosis is often associated with restrictive cranial vault deformities, diminished intracranial volume, and intracranial hypertension. Advances in imaging techniques have provided a method of intracranial volume analysis that has demonstrated a more complicated relationship between craniofacial abnormalities and elevated intracranial pressures. Studies have confirmed a decrease in intracranial volume in the presence of craniosynostosis, but this association is not found in every patient. We report an unusual case of elevated intracranial pressure in a patient with the clinical stigmata of Crouzon's syndrome but with patent cranial vault sutures.

ISSN:1049-2275    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

&NA;Scintigraphic methods used in intraoral and extraoral implantology allow the evaluation of bone metabolism in the peri‐implant zones, providing anatomic images and functional dynamics information on the osteointegration process. Twenty‐five patients who underwent implantation operations for the application of intra‐ and extraoral prostheses were studied using technetium 99 m single photon emission computed tomographic (SPECT) procedures to evaluate osteointegration dynamics at 3 weeks, and 3, 6, 12, and 24 months. The study demonstrates that radiation emission peaks 3 weeks after surgery with the maximal bone remodeling activity and 6 months after surgery after the functional loading of the implants only in intraoral fixtures. High uptake past the eighth month after surgery has never been detected and must be considered abnormal. SPECT offers the possibility of obtaining a three‐dimensional reconstruction of the photon emission of selected structures. The use of these nuclear medicine methods in addition to traditional‐type radiological procedures introduces new possibilities, although still in the clinical experimentation phase, for early diagnosis and inserted implant prognosis.

ISSN:1049-2275    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

&NA;Two patients with recurrent parotid gland carcinoma required subtotal petrosectomy and infratemporal fossa type C approach. To achieve en bloc resection, the ascending mandibular ramus and the entire temporomandibular joint, including the adjacent temporal bone, were removed. An original technique for immediate reconstruction of the infratemporal region, including the glenoid fossa and the ramus of the mandible, is described. Rigid fixation, as well as good functional and aesthetic results, was achieved with autologous calvarial bone and full‐thickness rib grafts, allowing the patients to mobilize their jaw very rapidly.

ISSN:1049-2275    

出版商:OVID    

年代:1997

数据来源: OVID