Faculty Bibliography

INTRODUCTION: Global health education is becoming more important for developing well-rounded physicians and may encourage students toward a career in primary care. Many medical schools, however, lack adequate and structured opportunities for students beginning the curriculum. METHODS: Second-year medical students initiated, designed, and facilitated a pass-fail international health elective, providing a curricular framework for preclinical medical students wishing to gain exposure to the clinical and cultural practices of a developing country. RESULTS: All course participants (N=30) completed a post-travel questionnaire within one week of sharing their experiences. Screening reflection essays for common themes that fulfill university core competencies yielded specific global health learning outcomes, including analysis of health care determinants. CONCLUSION: Medical students successfully implemented a sustainable global health curriculum for preclinical student peers. Financial constraints, language, and organizational burdens limit student participation. In future, long-term studies should analyze career impact and benefits to the host country.

OBJECTIVE: To systematically review outcomes of reinnervation techniques for the management of unilateral vocal fold paralysis (UVFP). DATA SOURCES: Medline and Cochrane databases for English-language studies published between 1966 and 2009 on the surgical management of UVFP. REVIEW METHODS: Studies were excluded if they reported on bilateral vocal fold paralysis, used nonhuman subjects, or did not assess clinical outcomes. Outcomes of interest were visual analysis, acoustic analysis, perceptual analysis, and electromyography. RESULTS: Of 686 initial studies, 14 studies encompassing 329 patients were eligible for analysis. All studies had a case-series design. Of reported patients, 60.2 percent were men, with mean age of 51 years (range, 12-79 years). The most common reinnervation technique was ansa cervicalis-to-recurrent laryngeal nerve (RLN), which was most commonly performed after thyroidectomy (43.5%). Other techniques with reportable outcomes included primary RLN anastomosis, ansa-to-RLN combined with cricothyroid muscle-nerve-muscle pedicle, ansa-to-thyroarytenoid neural implantation, ansa-to-thyroarytenoid neuromuscular pedicle, and hypoglossal-to-RLN. Median postsurgical follow-up was 12 months, and mean time to first signs of reinnervation was 4.5 months (SD 2.9 months). Visual analysis of glottic gap showed the greatest mean improvement with ansa-to-RLN, from 2.25 (SD 0.886) to 0.75 (SD 0.886) mm (P < 0.01). Acoustic analysis showed greatest improvement with neural implantation, with a change in mean phonation time from seven (SD 1.22) to 16 (SD 5.52) seconds (P < 0.01). Perceptual analysis and electromyography demonstrated improvement in all studies. CONCLUSION: Reinnervation is effective in the management of UVFP, although the specific method may be dictated by anatomical limitations. Prospective studies utilizing uniform and consistent outcome parameters are necessary.

A dermoid cyst is an ectodermally differentiated form of teratoma. Its occurrence in the parotid gland is very rare. Such a presentation must be properly evaluated in order to rule out malignancy. We describe the diagnostic evaluation and surgical management of a parotid dermoid cyst in an 18-year-old man. We also review the embryologic pathogenesis of the tumor and the usefulness of the physical examination, preoperative fine-needle aspiration cytology, magnetic resonance imaging, and computed tomography in evaluating the extent of the tumor, its histologic features, and its cystic characteristics. Finally, we discuss the role of surgical management in terms of preserving facial nerve integrity and preventing recurrence.

Sixty-four standardized continuing education courses were given for dentists throughout the ten public health districts of the USA to determine if certain behaviors regarding oral and pharyngeal cancer (OPC) control could be modified. Questionnaires were obtained at baseline and at 6 months along with matched control groups. One thousand eight hundred two general dentists participated at baseline and 988 at a 6-month questionnaire follow-up. Analysis of the data indicated that continuing education courses had a positive influence on participants' oral cancer attitudes, knowledge, and behavior that potentially could make a difference on prevention, early detection, and ultimately OPC control.

HYPOTHESIS: A new intraoral bone-conduction device has advantages over existing bone-conduction devices for reducing the auditory deficits associated with single-sided deafness (SSD). BACKGROUND: Existing bone-conduction devices effectively mitigate auditory deficits from single-sided deafness but have suboptimal microphone locations, limited frequency range, and/or require invasive surgery. A new device has been designed to improve microphone placement (in the ear canal of the deaf ear), provide a wider frequency range, and eliminate surgery by delivering bone-conduction signals to the teeth via a removable oral appliance. METHODS: Forces applied by the oral appliance were compared with forces typically experienced by the teeth from normal functions such as mastication or from other appliances. Tooth surface changes were measured on extracted teeth, and transducer temperature was measured under typical use conditions. Dynamic operating range, including gain, bandwidth, and maximum output limits, were determined from uncomfortable loudness levels and vibrotactile thresholds, and speech recognition scores were measured using normal-hearing subjects. Auditory performance in noise (Hearing in Noise Test) was measured in a limited sample of SSD subjects. Overall comfort, ease of insertion, and removal and visibility of the oral appliance in comparison with traditional hearing aids were measured using a rating scale. RESULTS: The oral appliance produces forces that are far below those experienced by the teeth from normal functions or conventional dental appliances. The bone-conduction signal level can be adjusted to prevent tactile perception yet provide sufficient gain and output at frequencies from 250 to 12,000 Hz. The device does not damage tooth surfaces nor produce heat, can be inserted and removed easily, and is as comfortable to wear as traditional hearing aids. The new microphone location has advantages for reducing the auditory deficits caused by SSD, including the potential to provide spatial cues introduced by reflections from the pinna, compared with microphone locations for existing devices. CONCLUSION: A new approach for SSD has been proposed that optimizes microphone location and delivers sound by bone conduction through a removable oral appliance. Measures in the laboratory using normal-hearing subjects indicate that the device provides useful gain and output for SSD patients, is comfortable, does not seem to have detrimental effects on oral function or oral health, and has several advantages over existing devices. Specifically, microphone placement is optimized for reducing the auditory deficit caused by SSD, frequency bandwidth is much greater, and the system does not require surgical placement. Auditory performance in a small sample of SSD subjects indicated a substantial advantage compared with not wearing the device. Future studies will involve performance measures on SSD patients wearing the device for longer periods.

Auditory thresholds with standardized clinical procedures are obtained over a much narrower frequency range by bone conduction than by air conduction. As a result, diagnostic information for both sensorineural and conductive-mechanism function is incomplete for high frequencies. A new magnetostrictive bone-conduction transducer that has the potential for improved output in the high-frequency range was evaluated in the laboratory and in a variety of subjects with normal hearing (N=11) or sensorineural hearing loss (N=9). Laboratory results indicated that harmonic distortion and acoustic radiation were both sufficiently low to allow accurate threshold measurements. Auditory thresholds obtained with this magnetostrictive bone-conduction transducer can be measured accurately under conventional clinical conditions for frequencies up to 16 kHz and levels up to 85 dB HL. These measures can be used to accurately characterize sensorineural hearing sensitivity for high frequencies and, when combined with standard air-conduction measures for high frequencies, to accurately characterize conductive-mechanism function for frequencies higher than possible with current diagnostic bone-conduction technology.

OBJECTIVE: A real-time MRI "movie" during natural sleep ("Sleep MRI") allows observation of dynamic airway obstructions in obstructive sleep apnea syndrome (OSAS) patients. The purpose of this article was to determine the reliability of assessing these obstructions. STUDY DESIGN: Cross-sectional diagnostic test evaluation. SETTING: Academic referral center. SUBJECTS AND METHODS: A total of 23 Sleep MRI sequences randomly selected from 20 consecutive OSAS patients were analyzed by two experienced sleep surgeons on two separate occasions separated by at least two weeks. Five dimensions were assessed: presence or absence of any obstruction, presence or absence of a retropalatal obstruction, presence or absence of a retroglossal obstruction, presence or absence of a swallow, and duration of an obstructive event. RESULTS: For all dimensions measured, intra-rater reliability coefficients ranged from a low of 0.95 to a high of 1.0 for each rater. Inter-rater reliability coefficients ranged from a low of 0.85 to a high of 1.0. On two separate evaluations separated by at least two weeks, rater 1 identified a retropalatal obstruction in 100 percent of sequences, whereas rater 2 did so in 91 percent and 96 percent of the sequences, respectively. Retroglossal obstruction was identified in 57 percent (rater 1) and 65 percent (rater 2) of sequences. CONCLUSION: Intra-rater and inter-rater reliability coefficients are very high for determination of presence or absence of any obstruction, presence or absence of a retropalatal obstruction, presence or absence of a retroglossal obstruction, presence or absence of a swallow, and duration of obstruction from Sleep MRI sequences in OSAS patients.

Preservation of fertility is important to adolescent and young adult (AYA) survivors of cancer. Many survivors will maintain their reproductive potential after the successful completion of treatment for cancer. However total-body irradiation, radiation to the gonads, and chemotherapy regimens containing high-dose alkylators can place women at risk for acute ovarian failure or premature menopause and men at risk for temporary or permanent azoospermia. The most effective and established means of preserving fertility in this population is embryo cryopreservation in women and sperm cryopreservation in men before the initiation of cancer-directed therapy. Cryopreservation of mature oocytes is also becoming more commonplace as methods of thawing become more sophisticated. The use of in vitro fertilization and intracytoplasmic sperm injection has added to the viability of sperm and oocyte cryopreservation. Cryopreservation and transplantation of gonadal tissue in both males and females remains experimental but continues to be evaluated. Hormonal suppression has not been shown to be effective in males but may have promise in females, although larger scale trials are needed to evaluate this. Providing information about risk of infertility and possible interventions to maintain reproductive potential are critical for the AYA population at the time of diagnosis. Given the competing demands of providing complicated and detailed information about cancer treatment, the evolving information related to fertility preservation, and the ethical issues involved, it may be preferable, where possible, to have a specialized team, rather than the primary oncologist, address these issues with AYA patients.