Faculty Bibliography

BACKGROUND: Pneumosinus dilatans (PD) is a pathologic condition involving the hyperaeration of one or several of the paranasal sinuses that can lead to significant deformation of the overlying bone. Although the presenting complaint of patients with PD is most commonly aesthetic in nature, the condition has also been associated with intracranial tumors and several other serious conditions. MATERIALS AND METHODS: A meta-analysis of all available clinical publications on the subject of PD was conducted. Patients were categorized on the basis of their sinus involvement. Associated conditions were also identified and categorized. The resulting data were used to further characterize the condition and describe previously unreported associations between PD and other conditions. RESULTS: To date, a total of 123 cases of PD have been reported. The frontal sinus was the most commonly involved (63%), followed by the sphenoid sinus (24%), maxillary sinus (20%), and ethmoid sinus (19%). Of patients with symptomatic PD of the frontal sinus, 25% had intracranial pathology (meningioma or arachnoid cyst or orbital tumor). Patients with sphenoid PD had an 83% chance of having associated diagnosis of visual loss, meningioma, or arachnoid cyst, whereas patients with ethmoid PD had 83% chance of having associated diagnosis of exophthalmos, vision loss, or arachnoid cyst. CONCLUSIONS: Although the presenting complaint of patients with PD is most commonly aesthetic in nature, a significant percentage may have an associated diagnosis. Health care providers must be able to recognize the condition and carry out the appropriate clinical evaluation to avoid missing an associated diagnosis.

The Morel-Lavallee lesion is a closed, internal degloving injury that results when a strong, shearing force is applied parallel to the plane of injury, as is common in vehicular trauma. It is an underdiagnosed entity that is often missed during the initial trauma workup as symptoms can be subtle. There are few reports of lesions occurring below the knee. Most cases affect the proximal thigh and trochanter, as these tend to be dependent areas in high velocity trauma. To the best of our knowledge, this is the first literature report of bilateral lower extremity Morel-Lavallee lesions.

Successful repair of craniofacial and periodontal tissue defects ideally involves a combined therapy that includes inflammation modulation, control of soft tissue infiltration, and bone regeneration. In this study, an anti-inflammatory polymer, salicylic acid-based poly(anhydride-ester) (SAPAE) and a three-dimensional osteoconductive ceramic scaffold were evaluated as a combined guided bone regeneration (GBR) system for concurrent control of inflammation, soft tissue ingrowth, and bone repair in a rabbit cranial defect model. At time periods of 1, 3, and 8 weeks, five groups were compared: (1) scaffolds with a solid ceramic cap (as a GBR structure); (2) scaffolds with no cap; (3) scaffolds with a poly(lactide-glycolide) cap; (4) scaffolds with a slow release SAPAE polymer cap; and (5) scaffolds with a fast release SAPAE polymer cap. Cellular infiltration and bone formation in these scaffolds were evaluated to assess inflammation and bone repair capacity of the test groups. The SAPAE polymers suppressed inflammation and displayed no deleterious effect on bone formation. Additional work is warranted to optimize the anti-inflammatory action of the SAPAE, GBR suppression of soft tissue infiltration, and stimulation of bone formation in the scaffolds and create a composite device for successful repair of craniofacial and periodontal tissue defects. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 655-664, 2014.

BACKGROUND: Robin sequence (RS) is defined as a triad of retrognathia, glossoptosis, and airway obstruction. Although several studies have reported on the efficacy of mandibular distraction, the risks associated with this operation remain unclear. An outcomes analysis focusing on complications is reported here. METHODS: A 7-year retrospective review of all patients with RS treated with mandibular distraction was performed. Recorded variables included associated medical comorbidities, improvement in apnea/hypopnea index, need for tracheostomy, repeat distraction, and complications. Complications associated with mandibular distraction were categorized as major, moderate, or minor. They included surgical site infection (SSI), device failure, temporomandibular joint ankylosis, facial nerve injury, hypertrophic scarring, self-extubation premature ossification, and fibrous nonunion. RESULTS: Fifty patients were identified. Four patients (8%) required tracheostomy following distraction, and 3 required repeat distraction. There were 0% major, 12% moderate, and 18% minor complications. Moderate complications were device failure (2%), SSI requiring return to the operating room (2%), and SSI requiring intravenous antibiotics (8%). Minor complications were SSI managed with oral antibiotics (12%), self-extubation (4%), and transient facial nerve palsy (2%). The most common complication was SSI (22%), of which 90.9% were successfully treated by antibiotics alone. There was a 0% rate of temporomandibular joint ankylosis. CONCLUSIONS: Mandibular distraction is a safe and effective treatment option for infants with RS and severe airway obstruction. The most common complication is infection; the majority of cases are successfully treated with antibiotics alone.

BACKGROUND: Cancer pain severely limits function and significantly reduces quality of life. Subtypes of sensory neurons involved in cancer pain and proliferation are not clear. METHODS: We produced a cancer model by inoculating human oral squamous cell carcinoma (SCC) cells into the hind paw of athymic mice. We quantified mechanical and thermal nociception using the paw withdrawal assays. Neurotoxins isolectin B4-saporin (IB4-SAP), or capsaicin was injected intrathecally to selectively ablate IB4(+) neurons or TRPV1(+) neurons, respectively. JNJ-17203212, a TRPV1 antagonist, was also injected intrathecally. TRPV1 protein expression in the spinal cord was quantified with western blot. Paw volume was measured by a plethysmometer and was used as an index for tumor size. Ki-67 immunostaining in mouse paw sections was performed to evaluate cancer proliferation in situ. RESULTS: We showed that mice with SCC exhibited both mechanical and thermal hypersensitivity. Selective ablation of IB4(+) neurons by IB4-SAP decreased mechanical allodynia in mice with SCC. Selective ablation of TRPV1(+) neurons by intrathecal capsaicin injection, or TRPV1 antagonism by JNJ-17203212 in the IB4-SAP treated mice completely reversed SCC-induced thermal hyperalgesia, without affecting mechanical allodynia. Furthermore, TRPV1 protein expression was increased in the spinal cord of SCC mice compared to normal mice. Neither removal of IB4(+) or TRPV1(+) neurons affected SCC proliferation. CONCLUSIONS: We show in a mouse model that IB4(+) neurons play an important role in cancer-induced mechanical allodynia, while TRPV1 mediates cancer-induced thermal hyperalgesia. Characterization of the sensory fiber subtypes responsible for cancer pain could lead to the development of targeted therapeutics.

The human body is covered with several million sweat glands. These tiny coiled tubular skin appendages produce the sweat that is our primary source of cooling and hydration of the skin. Numerous studies have been published on their morphology and physiology. Until recently, however, little was known about how glandular skin maintains homeostasis and repairs itself after tissue injury. Here, we provide a brief overview of sweat gland biology, including newly identified reservoirs of stem cells in glandular skin and their activation in response to different types of injuries. Finally, we discuss how the genetics and biology of glandular skin has advanced our knowledge of human disorders associated with altered sweat gland activity.