Faculty Bibliography

Mandibular distraction osteogenesis lengthens not only the affected skeleton but also the associated muscles of mastication. The purpose of this study was to determine medial pterygoid volume before and after distraction by using computed tomography. Using computed tomographic scans, the volume of the medial pterygoid muscle was determined before and after mandibular distraction in six pediatric patients. In four unilateral distraction patients (average age, 65 months), the average increase of the medial pterygoid muscle on the distracted side of the mandible was 29 percent, and on the contralateral nondistracted side, 10 percent. The average increase in medial pterygoid muscle volume in two bilateral distraction patients (each aged 8 months) was 75 percent. Results of this study demonstrate that distraction osteogenesis of the human mandible not only lengthens deficient bone, but it also increases the volume of the attached musculature

The incidence and character of neurological deficits following resection of glial neoplasms localized to the Heschl gyrus are currently unknown. In this series, the authors report the clinical presentation, management, and postoperative course of three patients with right hemisphere Heschl gyrus gliomas, one of whom developed difficulty with music production and comprehension postoperatively. Resection of right hemisphere Heschl gyms gliomas can result in deficits involving music comprehension. Preliminary evidence suggests that when these deficits occur, they may be transient in nature

We conducted a retrospective chart review of treatment outcomes in 17 adults who had been selected to undergo concomitant chemotherapy and radiation (chemo/XRT) for late-stage oropharyngeal cancers. All patients had been treated at the West Los Angeles VA Medical Center between March 1, 1998, and Sept. 30, 2000. Nine patients had a primary tumor at the base of the tongue, five had a primary tumor in the tonsillar area, and three had a tumor that affected both sites. Of this group, 15 patients completed one to three cycles of chemo/XRT, and the remaining two died during therapy. At the most recent follow-up, 9 of the 17 patients (52.9%) were documented to still be alive; seven patients had earlier died as a result of their primary tumor or a distant metastasis, and one patient had been lost to follow-up after completing treatment. At study's end, the duration of post-treatment survival ranged from 2 to 36 months (mean: 12.5). Based on the results of our small series, we conclude that chemo/XRT is a valid alternative to surgery with postoperative radiation and to radiation alone. Chemo/XRT yields acceptable rates of local control and allows for organ preservation with tolerable side effects.

Recent studies have suggested that regionally differentiated dura mater regulates murine cranial suture fate by providing growth factors to the osteoblasts in the overlying suture complex. To determine if regionally differentiated dura mater is capable of effecting changes in osteoblast gene expression, an in vitro coculture system was established in which osteoblast-enriched cell cultures derived from neonatal rat calvaria were grown in serum-free media in the presence of dural cells derived from posterior frontal (PF) or sagittal (SAG) dural tissues, recapitulating the in situ relation between the underlying dura mater and the osteoblasts in the overlying cranial suture. In this study, the changes in osteoblast gene expression induced by signaling from regional dura mater were examined by analyzing total cellular RNA isolated from osteoblasts cocultured with PF or SAG dural cells. The expression of extracellular matrix molecules (alkaline phosphatase, bone sialoprotein, osteopontin, and osteocalcin) and the transcription factor Msx2 was assessed. Consistent with previous data, the findings demonstrate that osteoblasts cocultured with dural cells undergo changes in gene expression indicative of a more differentiated osteoblast. Additionally, the data suggest that regionally differentiated dura mater isolated from the PF suture enhances the expression of osteogenic genes to a greater extent than SAG suture-derived dural cells. These data support an osteoinductive role for suture-derived dural cells in vitro that may have implications for suture biology in vivo

The purpose of the study was to determine the feasibility of preserving ovarian function after heterotopic transplantation by means of microvascular anastomosis of the transplanted vascular pedicles to a set of preselected vessels. Six groups of 10 Sprague-Dawley inbred rats were used in this study. Group I underwent bilateral ovariectomy operation and served as the ovariectomy control. Group II underwent bilateral ovariectomy followed by heterotopic isogenic ovarian implantation. Group III underwent bilateral ovariectomy and isogenic heterotopic ovarian transplantation by means of microvascular anastomosis. Group IV served as the laparotomy sham-operated control. Group V served as the ovarian donor for group II. Group VI served as the donor of the ovarian-kidney vascular pedicle complex for group III. Postoperative ovarian estradiol levels were measured, and histological characteristics were elucidated in groups I, II, III, and IV. The results demonstrated that the estradiol level of the transplantation group was comparable to that of the sham operation group and was significantly higher than that of the implantation group. Histologically normal ovarian architecture was observed in the sham group (IV) and also in the transplantation group (III). Altered architecture was observed in the implantation group (II). These findings indicate that extraabdominal heterotopic ovarian transplantation with microvascular anastomosis led to normal ovarian hormonal function and was effective in preserving oocyte production capacity.

During skull development, the cranial connective tissue framework undergoes intramembranous ossification to form skull bones (calvaria). As the calvarial bones advance to envelop the brain, fibrous sutures form between the calvarial plates. Expansion of the brain is coupled with calvarial growth through a series of tissue interactions within the cranial suture complex. Craniosynostosis, or premature cranial suture fusion, results in an abnormal skull shape, blindness and mental retardation. Recent studies have demonstrated that gain-of-function mutations in fibroblast growth factor receptors (fgfr) are associated with syndromic forms of craniosynostosis. Noggin, an antagonist of bone morphogenetic proteins (BMPs), is required for embryonic neural tube, somites and skeleton patterning. Here we show that noggin is expressed postnatally in the suture mesenchyme of patent, but not fusing, cranial sutures, and that noggin expression is suppressed by FGF2 and syndromic fgfr signalling. Since noggin misexpression prevents cranial suture fusion in vitro and in vivo, we suggest that syndromic fgfr-mediated craniosynostoses may be the result of inappropriate downregulation of noggin expression

This article is a logical extension of previous articles written on the topic of aesthetic chin surgery. In it, the authors expand on previously published surgical techniques and provide specific updates to increase success in some unusual situations. They review the indications for and uses of reduced-height implants, discuss the validity of centralized chin incisions in both reconstruction and revisions, show the diversity of mentalis muscle anatomy and chin pad variations, reveal the importance of the lip-to-labiomental crease inclination in cases of macrogenia, note a key update on reefing the mentalis muscle to a higher position for permanent sulcus position, discuss the issues of lower lip position and lower incisor show, and expound on the horizontal smile/chin ptosis phenomenon