Faculty Bibliography

Encased in lacunae, osteocytes receive nutrition and biomechanical signals through the lacunocanalicular system. We have developed a novel flow-perfusion bioreactor designed to support lacunocanalicular fluid flow. We hypothesize that ex vivo fluid flow can maintain endochondral bone viability and, ultimately, serve as a novel model to study bone biology in vitro. Sprague-Dawley rat femurs were harvested, stripped of soft tissue, loaded into a custom-designed bioreactor and perfused with osteogenic culture medium. After 14 days of flow-perfusion or static culture, the bones were harvested, fixed, decalcified, embedded, sectioned and stained with haematoxylin and eosin. Fresh long bone samples were similarly processed for comparison. Osteocyte viability and function were also evaluated, using thiazolyl blue tetrazolium bromide (MTT), fluorospectrophotometric DNA quantification, alkaline phosphatase (ALP) colorimetric assay and fluorochrome labelling of mineralizing surfaces. All samples remained free of infection throughout the study period. After 14 days of flow perfusion, histological analysis showed normal-appearing bony architecture, with 72% of lacunae being osteocyte-filled compared with 93% in freshly harvested samples and only 36% in static samples. MTT staining and assay confirmed osteocyte viability in the flow-perfusion samples as well as in fresh samples. DNA quantification demonstrated DNA to be preserved in flow-perfused samples when compared with freshly harvested samples. ALP activity in flow-perfusion explants was upregulated compared with fresh and static samples. Fluorochrome-labelled mineralizing surfaces were seen throughout the explanted flow-perfused samples. This is the first demonstration that flow perfusion provides adequate chemotransportation to explanted murine endochondal bones

BACKGROUND: Reconstruction of the maxilla with the fibula free flap is a popular and well-described technique. The ideal intraoral lining would be mucosa, which is moist, thin, and non-hair-bearing. Prelamination of the fibula with buccal mucosa replaces like tissue with like tissue, obviates the need for a skin paddle, and facilitates placement of osseointegrated implants in a single stage. For central maxillary defects, the authors have shifted from using an osteocutaneous to a prelaminated free fibula flap. In this article, the authors report their experience using the prelaminated osteomucosal fibula for maxillary reconstruction. METHODS: From 2003 to 2011, 24 patients underwent reconstruction of a central maxillary defect using a free fibula flap. The first 10 patients had osteoseptocutaneous flaps, and the other 14 patients had prelaminated flaps. Data collected included patient age, cause of defect, type and number of operations, complications at both the donor and recipient sites, and placement of osseointegrated implants. RESULTS: The majority of patients in the series (n = 21) had central maxillary defects caused by loss of the premaxilla during early repair of bilateral cleft lip-cleft palate. There was one flap failure in the nonprelaminated flap group and one in the prelaminated group. Repeated debulking to thin the skin paddle was required in all of the patients with osteocutaneous flaps. CONCLUSIONS: Prelamination delivers like tissue to the recipient site, obviates the need for debulking, and may reduce donor-site wound problems. To the authors' knowledge, this is the largest series of prelaminated fibulas for maxillary reconstruction in the literature. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

The pediatric dentist plays a crucial role in the treatment and management of infants born with cleft deformities of the lip, alveolus, and palate. At New York University Langone Medical Center in New York City, 70% of infants with cleft lip/cleft palate (CLCP) are detected on prenatal ultrasound analysis. Thus, the role of the pediatric dentist can start as early as prenatal counseling. Nasoalveolar molding (NAM) is delivered during the first 3 to 5 months of life. During this stage of treatment, the pediatric dentist establishes the foundation of the "cleft dental" home and initiates the first stage of anticipatory guidance. Consequently, parents are educated and motivated to initiate oral hygiene care upon eruption of the first primary teeth. The purpose of this paper was to describe the role of the pediatric dentist in performing nasoalveolar molding and also describe its indications, appliance design, fabrication, biomechanics, complications, and patient management.

OBJECTIVE:We report on the case of an 11-year-old girl with atypical neurothekeoma of the left lateral alar rim that was excised and ultimately closed primarily after an unsuccessful attempt at reconstruction with a full-thickness auricular composite graft. METHODS:In this case report, we present a description of the case and a review of the literature. RESULTS:The patient underwent successful excision of neurothekeoma and subsequent auricular cartilage graft reconstruction. Reconstruction failed to adequately heal at several months postoperatively and the defect was closed primarily. CONCLUSIONS:Rapidly growing nodules of the nose can have a broad differential and requires pathological diagnosis via early biopsy. This is important because the surgical approach varies depending on the lesion and its potential for metastasis and local growth.

ABSTRACT: Henry Kawamoto Jr and I go back a long way. Our friendship began at the Columbia-Presbyterian Medical Center. I had just returned from my service obligation after interrupting my general surgery residency. I heard that a new resident from California had been admitted to our class, and, of course, it was Henry.

Targeted therapy to prevent the progression from acute to chronic pain in cancer patients remains elusive. We developed three novel cancer models in mice that together recapitulate the anatomical, temporal, and functional characteristics of acute and chronic head and neck cancer pain in humans. Using pharmacologic and genetic approaches in these novel cancer models, we identified the interaction between protease-activated receptor 2 (PAR2) and serine proteases to be of central importance. We show that serine proteases such as trypsin induce acute cancer pain in a PAR2-dependent manner. Chronic cancer pain is associated with elevated serine proteases in the cancer microenvironment and PAR2 upregulation in peripheral nerves. Serine protease inhibition greatly reduces the severity of persistent cancer pain in wild-type mice, but most strikingly, the development of chronic cancer pain is prevented in PAR2-deficient mice. Our results demonstrate a direct role for PAR2 in acute cancer pain and suggest that PAR2 upregulation may favor the development and maintenance of chronic cancer pain. Targeting the PAR2-serine protease interaction is a promising approach to the treatment of acute cancer pain and prevention of chronic cancer pain.

Posterior tongue defects present a unique reconstructive challenge. The various reconstructive options available for treating the defect created by a posterior hemiglossectomy frequently result in a distorted tongue and functional impairment. This paper describes a novel sliding anterior hemitongue flap to allow reconstruction of moderate resection defects (i.e. for T1-T2 tongue squamous cell carcinomas) of the posterior tongue. By mobilizing the anterior tongue, near normal mobility and tongue length are maintained. This surgical technique may be performed alone intraorally or in combination with a neck dissection.