Faculty Bibliography

Learning Objectives: After studying this article, the participant should be able to: 1. Describe the alternatives for auricular reconstruction. 2. Discuss the pros and cons of autogenous reconstruction of total or subtotal auricular defects. 3. Enumerate the indications for prosthetic reconstruction of total or subtotal auricular defects. 4. Understand the complexity of and the expertise required for prosthetic reconstruction of auricular defects.The indications for autogenous auricular reconstruction versus prosthetic reconstruction with osseointegrated implant-retained prostheses were outlined in Plastic and Reconstructive Surgery in 1994 by Wilkes et al. of Canada, but because of the relatively recent Food and Drug Administration approval (1995) of extraoral osseointegrated implants, these indications had not been examined by a surgical unit in the United States. The purpose of this article is to present an evolving algorithm based on an experience with 98 patients who underwent auricular reconstruction over a 10-year period. From this experience, the authors conclude that autogenous reconstruction is the procedure of choice in the majority of pediatric patients with microtia. Prosthetic reconstruction of the auricle is considered in such pediatric patients with congenital deformities for the following three relative indications: (1) failed autogenous reconstruction, (2) severe soft-tissue/skeletal hypoplasia, and/or (3) a low or unfavorable hairline. A fourth, and in our opinion the ideal, indication for prosthetic ear reconstruction is the acquired total or subtotal auricular defect, most often traumatic or ablative in origin, which is usually encountered in adults. Although prosthetic reconstruction requires surgical techniques that are less demanding than autogenous reconstruction, construction of the prosthesis is a time-consuming task requiring experience and expertise. Although autogenous reconstruction presents a technical challenge to the surgeon, it is the prosthetic reconstruction that requires lifelong attention and may be associated with late complications. This article reports the first American series of auricular reconstruction containing both autogenous and prosthetic methods by a single surgical team

Lower eyelid malpositions and ocular damage occur with inadequate reconstructions of facial defects that encroach on the periocular region. Reconstructive principles and techniques are presented that are essential in the prevention of ectropion in these situations. Eyelid and periocular anatomy is reviewed. The use of canthalplasties, canalicular reconstruction, and ancillary techniques for facial flaps are presented

The purpose of this study was to examine the effect of Lactosorb absorbable plates on bone healing across cranial bone defects in the rabbit skull. Two 10-mm diameter parietal skull defects were created in each of 20 rabbits, with one defect being placed on either side of the sagittal suture. In 10 rabbits, an absorbable plate was placed across both the inner and outer cortices of the left defect, and in the other 10 rabbits, an absorbable plate was placed across the outer cortex only of the left defect. The right defect always served as the control side, with no plate being placed across it. Rabbits were killed an average of 25 weeks postoperatively. Areas of reossification in the experimental and control defects of each rabbit were then measured, examined histologically, and compared. Growth across defects spanned by one plate was also compared with growth across defects spanned by two plates. Histologic and statistical analyses revealed no significant differences in reossification between the control and experimental defects in each animal and between the defects spanned by one versus two plates. This study suggests that these copolymer absorbable plates neither inhibit nor facilitate reossification across 10-mm diameter rabbit cranial defects

Bannayan-Zonana syndrome (BZS) is a genetic disorder with autosomal dominant inheritance characterized by macrocephaly and multiple hamartomas of mesodermal origin. Here we present a patient with BZS manifested by many of the classic features, as well as a high-flow upper extremity arteriovenous malformation (AVM). Although this rare syndrome was initially described in 1971, to our knowledge, this is the first report showing an association of AVM with BZS and the first report of this syndrome in the radiologic literature

Transverse mandibular distraction osteogenesis involves moving the osteotomized segments of the mandible in either a varus or valgus direction. This maneuver allows for widening of the bigonial distance or for a lateral shift of an asymmetric mandibular midline. During this process, a significant amount of torque is placed on the mandibular condyles, because they act as the pivot point for the mandibular translation. Although standard linear distraction osteogenesis induces transient, reversible changes in the temporomandibular joint, it is not known what effect the varus and valgus stresses of transverse distraction have on the temporomandibular joint. We therefore designed a study to document the temporomandibular joint changes following various degrees of transverse distraction.Bilateral transverse mandibular distraction was performed on 10 adult, female mongrel dogs using an external, multiplanar mandibular distraction device. The distraction protocol was as follows: (1) complete osteotomy at the angle of the mandible, (2) 5-day latency period, (3) distraction rate of 1 mm/day, (4) rhythm of one turn per day, (5) linear activation 16 to 30 mm bilaterally, and (6) 8-week consolidation period. A variety of varus and valgus distraction vectors were applied to the mandible only after 10 mm of initial linear distraction had been achieved. Posteroanterior and lateral cephalograms were performed throughout the entire process. Pre-distraction and post-consolidation computed tomographic scans were also performed. Changes in mandibular conformation, axis of rotation, temporomandibular joint structure, and glenoid fossa changes were directly assessed by evaluating the postmortem craniofacial skeleton. The findings were compared with those of normal, age-matched mongrel dog skulls.Significant remodeling changes were observed in the temporomandibular joints of all animals involved in the study. The mandibular condyles demonstrated varying degrees of flattening and erosion at all contact points with the craniofacial skeleton. In some cases, the condyle became part of the distraction regenerate process and was hypertrophied in all dimensions. The condyles were frequently displaced out of the glenoid fossa, particularly on the side in the direction of varus distraction. When the latter occurred, a new fossa was created on the undersurface of the zygomatic arch. Varying degrees of mandibular rotation in the sagittal plane were also observed, which led to abnormal torquing of the condyles in the coronal plane, depending on whether the axis of rotation occurred primarily around the condyle or around the distraction regenerate zone.In conclusion, transverse mandibular distraction is an effective means of producing a varus or valgus shift in the gonion relative to the midsagittal plane. However, unlike linear or angular mandibular distraction, transverse distraction has a multitude of nontransient effects on the temporomandibular joint. Therefore it must be emphasized that in clinical practice, transverse distraction should be used cautiously. One must also be aware that such a maneuver in distraction can have negative effects on the temporomandibular joint

The transforming growth factor beta (TGF-beta) superfamily encompasses a number of important growth factors including several TGF-beta isoforms, the bone morphogenetic proteins, activins, inhibins, and growth and differentiation factors. TGF-beta 1, -beta 2, and -beta 3 are three closely related isoforms that are widely expressed during skeletal morphogenesis and bone repair. Numerous studies suggest that each isoform has unique in vivo functions; however, the effects of these TGF-beta isoforms on osteoblast gene expression and maturation have never been directly compared. In the current study, we treated undifferentiated neonatal rat calvaria osteoblast-enriched cell cultures with 2.5 ng/ml of each TGF-beta isoform and analyzed gene expression at 0, 3, 6, and 24 hours. We demonstrated unique isoform-specific regulation of endogenous TGF-beta 1 and type I collagen mRNA transcription. To assess the effects of extended TGF-beta treatment on osteoblast maturation, we differentiated osteoblast cultures in the presence of 2.5 ng/ml of each TGF-beta isoform. Analysis of collagen I, alkaline phosphatase, and osteocalcin demonstrated that each TGF-beta isoform uniquely suppressed the transcription of these osteoblast differentiation markers. Interestingly, TGF-beta isoform treatment increased osteopontin expression in primary osteoblasts after 4 and 10 days of differentiation. To our knowledge, these data provide the first direct comparison of the effects of the TGF-beta isoforms on osteoblast gene expression in vitro. Furthermore, these data suggest that TGF-beta isoforms may exert their unique in vivo effects by differentially regulating osteoblast cytokine secretion, extracellular matrix production, and the rate of cellular maturation