Application of an augmented reality tool for maxillary positioning in orthognathic surgery – A feasibility study

BACKGROUND: An augmented reality tool for computer assisted surgery named X-Scope allows visual tracking of real anatomical structures in superposition with volume rendered CT or MRI scans and thus can be used for navigated translocation of bony segments. METHODS: In a feasibility study X-Scope was used in orthognathic surgery to control the translocation of the maxilla after Le Fort I osteotomy within a bimaxillary procedure. The situation achieved was compared with the pre-operative situation by means of cephalometric analysis on lateral and frontal cephalograms. RESULTS: The technique was successfully utilized in 5 patients. Maxillary positioning using X-Scope was accomplished accurately within a range of 1mm. The tool was used in all cases in addition to the usual intra-operative splints. A stand-alone application without conventional control does not yet seem reasonable. CONCLUSION: Augmented reality tools like X-Scope may be helpful for controlling maxillary translocation in orthognathic surgery. The application to other interventions in cranio-maxillofacial surgery such as Le Fort III osteotomy, fronto-orbital advancement, and cranial vault reshaping or repair may also be considered.     

Tungiasis in New York

A 33-year-old African woman was evaluated for tender nodules on her feet. Accompanied by her four children, she had recently immigrated from Somalia. Before her immigration, she resided in a Kenyan refugee camp for approximately 1 year, where she walked barefoot in sand and dirt. The patient stated that she and her four children, as well as many people living in the same compound, had similar, tender lesions on their feet. Her children were "treated" by their grandmother, who removed the contents of their lesions with a safety pin.
On physical examination the patient had numerous tender, isolated, and clustered hyperkeratotic, crusted papules, measuring 4–6 mm, on the plantar and periungual surfaces. Several lesions were ulcerated (Figs 1 and 2). The hyperkeratotic masses were debrided with a surgical blade. An intact, white, coiled structure was curetted from each papule, leaving numerous empty crater-like lesions (Fig. 3), which were identified on histologic sections as Tunga penetrans. Microscopic examination of unstained specimens showed branching, thin, translucent tubular structures with numerous eggs. Ring-shaped cross-sections of the organism's respiratory and digestive tracts were seen on hematoxylin and eosin stain (Fig. 4).
The patient received a 10-day course of dicloxacillin and topical bacitracin ointment. All lesions were healed within 1 week of therapy.     

Studies on Propafenone-type Modulators of Multidrug-Resistance IV: Synthesis and Pharmacological Activity of 5-Hydroxy and 5-Benzyloxy Derivatives

A series of 5-hydroxy and 5-benzyloxy analogs of the antiarrhythmic and multidrug resistance (MDR) modulating drug propafenone was synthesized and the MDR-modulating activity of the compounds was evaluated using a daunomycin efflux assay system. The key step of the synthesis is the selective reduction of the double bond in 1 without cleavage of the benzyl group thus leading to the phenol 3 . Alkylation with epichlorohydrine followed by nucleophilic epoxide ring opening gave the benzylated target compounds 5a–d . Subsequent cleavage of the benzyl group gave the 5-hydroxy analogs 6a–d . Structure activity relationship studies showed, that the 5-hydroxy derivates 6a–d fit the log P/log potency correlation line previously established for a series of propafenone analogs. In contrast, all four 5-benzyloxy analogs 5a–d showed almost identical EC₅₀ values, independent of their log P value.     

Identification and treatment of scurvy: a case report.

Scurvy is a nondiscriminatory disease process resulting from a nutritional deficiency of ascorbic acid (vitamin C). The severe vitamin deficiency produces a breakdown in the cellular structure of the body. This case report describes a middle-age woman with a history of edema, bruising of the lower extremities, anemia, and severe periodontal disease. Her presentation and medical history are classic for the signs of scurvy. Scurvy is now only uncommonly seen in developed countries, but there are still vulnerable populations whose nutritional status can lead to scurvy. The aim of this report is to help the clinician identify and treat scurvy, a disease that was once feared for its high mortality but is now easily treatable, even in cases that have progressed to multiple organ dysfunction and failure.