ISSN:1049-2275    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:1049-2275    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Craniofacial surgery is a multidisciplinary specialty that often uses the expertise of many specialists including surgeons, orthodontists, geneticists, and anthropologists. The clinical experience gained by their collaboration enables predictions to be made of the ultimate success of the reconstructive surgery. Various patterns among surgical outcomes are noted as greater experience is gained. These observations prompted the following questions: Is there a way to classify patients according to surgical results? What factors underlie a successful response to surgery? In a clinical setting, we are faced with a spectrum of presentations of craniofacial dysmorphology. We propose that the results of surgical correction may be based on the cause of the condition and not necessarily on the degree or character of the dysmorphology. Craniofacial dysmorphologies are often grouped under the termsdeformation, malformation, disruption, dysplasia, orsyndrome. Our hypothesis is that a categorization of craniofacial dysmorphology can be proposed on the basis of the response of the individual to surgery. We propose that such a classification reflects real differences in cause. A poor response to surgery reflects a condition that includes a growth disorder. Alternatively, cases that respond best to surgery are those in which the growth process is not affected. In the latter cases, a dysmorphic face is surgically transformed into an acceptable morphology, and normative growth vectors maintain or improve postoperative facial appearance. It is our belief that the physiological differences underlying our categorization scheme have to do with embryological timing of insults or specific components of the ontogenic process. The divergence in the response to surgery among patients relates directly to the role of the growth process in the various types of dysmorphologies.

ISSN:1049-2275    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Within the zygomatic arch, bilateral osteotomies were performed on 20 adult male New Zealand white rabbits. These were stabilized in an anatomical position with polyglyconate acid plates and screws. At 3,4,6,9, and 12 months, rabbits were killed and their zygomatic complexes removed en bloc. Specimens were serially sectioned for standard histological examination. Although no gross reactions were noted throughout the course of this investigation, histological reactions were brisk. At 3 months, particulate material was surrounded by a foreign body giant cell-type reaction. The quantity of foreign material appeared to decrease by 4 months, at which time the foreign body reaction was partially replaced by fibrous tissue. By 6 months, there was a thick periosteal scar at the osteotomy site with a few islands of persistent foreign material. These were primarily seen in small, irregular vesicular spaces surrounded by a large number of histiocytes with their characteristic foamy cytoplasm. Although this foreign body reaction had subsided by 12 months, small foci of chronic inflammation still persisted.

ISSN:1049-2275    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

This investigation compared the variation of the biomechanical properties of canine and porcine craniofacial bones in homotypical (same site in opposite sides of an animal) and heterotypical (same site in different animals) sites. Biomechanical analysis is a reliable method to assess bone healing, because fracture repair correlates closely with the changes in biomechanical properties. Paired bone fragments were harvested in nine dogs and nine minipigs from each side of the skull from three different sites—the frontal bone, the supraorbital rim, and the zygomatic arch—and submitted to torque to failure. Maximum torque, stiffness, and toughness were recorded and comparative analysis performed. A normal range of variation between paired craniofacial bones in two useful animal models is provided. The results showed that the variability between homotypic left and right sides was not significant, whereas the variability between heterotypic sites in separate animals was. Maximum torque was the most reliable of the three parameters considered, because the data fell over a much narrower range. We conclude that the use of the contralateral side is a valid control in experimental procedures that may alter the biomechanical properties of one side.

ISSN:1049-2275    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

On the basis of the clinical and experimental proof that intracranial translocation of osteosynthesis plates occurs in infants after fixation on frontal bone, we conducted an animal study on four adolescent Gottingen minipigs. Our aim was to study the effects on intracranial translocation of two different types of osteosynthesis plates by comparing the plate-bone interface on the intact frontal bone treated with a multiple-point contact plate versus a conventional smooth one, paying special emphasis to the periosteum. Within a few weeks of implantation, osseous regeneration products surrounded the plate. Total invagination of plates with initial intracranial translocation occurred 12 to 16 weeks postimplantation, regardless of plate design. In epiperiosteal fixation, intracranial translocation was delayed. The results revealed two mechanisms at play here: cranial growth-related passive intracranial translocation, which occurs regardless of plate design, and plate-dependent active intracranial translocation. In conclusion, we recommend that all metal osteosynthesis materials implanted in the infant cranium be removed as early as possible (within 3 months).

ISSN:1049-2275    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:1049-2275    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The migration or passive intracranial translocation of microplates and screws in the pediatric craniofacial patient has been reported. A retrospective review was undertaken to clarify the incidence of microplate translocation and identify potential clinical implications. Computed tomographic imaging demonstrated internalization of microfixation in 14 of 27 pediatric patients. Statistically significant factors for microplate translocation include longer plates (p< 0.05) and those placed in the temporal region (p< 0.001). Younger patients and those with syndromic craniofacial dysostosis also had a higher incidence of translocation. Specific complications relating to the translocation of microplates were not found in any patient. The direct effects of translocated microplates and screws on the underlying brain and dura remain unclear.

ISSN:1049-2275    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:1049-2275    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Osseous fixation techniques have been widely used to provide rigid stabilization in the craniofacial skeleton. Reported sequelae of its usage has been limited to palpation of the screw-plate system and radiological imaging artifacts. Over the past 3 years we have identified miniplates, microplates, and wire sutures on the inner cranial table of the growing child. The observation of “false” migration of these appliances has provided the impetus to review these patients in more detail. Twenty patients underwent secondary cranial remodeling within a two-year period; 7 of these patients were seen to have “false” migration. There were no untoward sequelae in removal of these appliances, and no adverse neurological symptoms were seen.

ISSN:1049-2275    

出版商:OVID    

年代:1995

数据来源: OVID