Objective To systematically review the anatomy of the ossicular chain. Data Sources Google Scholar, PubMed, and otologic textbooks. Review Methods A systematic literature search was performed on January 26, 2015. Search terms used to discover articles consisted of combinations of 2 keywords. One keyword from both groups was used: [ ossicular, ossicle, malleus, incus, stapes] and [ morphology, morphometric, anatomy, variation, physiology], yielding more than 50,000 hits. Articles were then screened by title and abstract if they did not contain information relevant to human ossicular chain anatomy. In addition to this search, references of selected articles were studied as well as suggested relevant articles from publication databases. Standard otologic textbooks were screened using the search criteria. Results Thirty-three sources were selected for use in this review. From these studies, data on the composition, physiology, morphology, and morphometrics were acquired. In addition, any correlations or lack of correlations between features of the ossicular chain and other features of the ossicular chain or patient were noted, with bilateral symmetry between ossicles being the only important correlation reported. Conclusion There was significant variation in all dimensions of each ossicle between individuals, given that degree of variation, custom fitting, or custom manufacturing of prostheses for each patient could optimize prosthesis fit. From published data, an accurate 3-dimensional model of the malleus, incus, and stapes can be created, which can then be further modified for each patient's individual anatomy.

We have generated a model for custom 3-D synthesis of incudal prostheses. While current 3-D printing in biocompatible materials at the size required is limited, the technology is rapidly advancing, and 3-D printing of incudal replacements with polylactic acid (PLA) is of the correct size and shape.

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The most common oral cavity cancer is squamous cell carcinoma (SCC), of which perineural invasion (PNI) is a significant prognostic factor associated with decreased survival and an increased rate of locoregional recurrence. In the classical theory of PNI, cancer was believed to invade nerves directly through the path of least resistance in the perineural space; however, more recent evidence suggests that PNI requires reciprocal signaling interactions between tumor cells and nerve components, particularly Schwann cells. Specifically, head and neck SCC can express neurotrophins and neurotrophin receptors that may contribute to cancer migration towards nerves, PNI, and neuritogenesis towards cancer. Through reciprocal signaling, recent studies also suggest that Schwann cells may play an important role in promoting PNI by migrating toward cancer cells, intercalating, and dispersing cancer, and facilitating cancer migration toward nerves. The interactions of neurotrophins with their high affinity receptors is a new area of interest in the development of pharmaceutical therapies for many types of cancer. In this comprehensive review, we discuss diagnosis and treatment of oral cavity SCC, how PNI affects locoregional recurrence and survival, and the impact of adjuvant therapies on tumors with PNI. We also describe the molecular and cellular mechanisms associated with PNI, including the expression of neurotrophins and their receptors, and highlight potential targets for therapeutic intervention for PNI in oral SCC.

A 75-year-old woman presented with a 6-to 8-month history of new-onset headaches, dizziness, and difficulty concentrating to an outside otolaryngologist. Outside imaging was concerning for possible cholesteatoma of the left temporal bone, necessitating a left cortical mastoidectomy. Intraoperatively, a sinodural angle neoplastic process was encountered. Biopsies were taken, and the procedure was terminated. Permanent pathology revealed a benign hemangioma, prompting referral of the patient to our tertiary care center for further treatment.The patient continued to report headaches with additional complaints of left aural fullness and hearing loss. Audiometry revealed a right mild to moderate high-frequency sensorineural hearing loss and left-sided mild to moderate mixed hearing loss from 125 to 6,000 Hz with severe loss at 8,000 Hz, with an air-bone gap ranging from 20 to 30 dB in all frequencies. Bilateral word recognition scores were 100%. The case, including pertinent imaging and pathology, was reviewed at a multidisciplinary tumor board.High-resolution computed tomography (CT) of the temporal bone demonstrated a well-marginated, expansile lesion that measured about 12.3 Â 13.8 mm in the left mastoid bone (Fig. 1, A and B). The lesion was associated with an intact outer table with focal erosion of the sinodural plate and demonstrated a honeycomb pattern of radiating trabeculae.Magnetic resonance angiography showed an expansile, irregular, lobulated isointense T1 and a high T2 signal intensity mass lesion in the left mastoid that demonstrated heterogeneous contrast enhancement on postcontrast T1-weighted images (Fig. 2, A-E). Scattered low T1 signal intensity foci in the lesion were observed on both the precontrast and postcontrast images, which likely represent flow voids as seen on the axial gradient-echo sequence (Fig.