Edward C. Wu

Needle-Electrode-Based Electromechanical Reshaping of Rabbit Septal Cartilage: A Systematic Evaluation

Electromechanical reshaping (EMR) provides a means of producing shape change in the cartilage by initiating oxidation-reduction reactions in mechanically deformed specimens. This paper evaluates the effect of voltage and application time on specimen shape change using needle electrodes. Rabbit septal cartilage specimens (20 mm × 8 mm × 1 mm, n = 200) were bent 90° in a precision-machined plastic jig. Optimal electrode placement and the range of applied voltages were estimated using numerical modeling of the initial electric field within the cartilage sample. A geometric configuration of three platinum needle electrodes 2 mm apart from each other and inserted 6 mm from the bend axis on opposite ends was selected. One row of electrodes served as the anode and the other as the cathode. Constant voltage was applied at 1, 2, 4, 6, and 8 V for 1, 2, and 4 min, followed by rehydration in phosphate buffered saline. Samples were then removed from the jig and bend angle was measured. In accordance with previous studies, bend angle increased with increasing voltage and application time. Below a voltage threshold of 4 V, 4 min, no clinically significant reshaping was observed. The maximum bend angle obtained was 35.7 ± 1.7° at 8 V, 4 min.

Anthropometric and aesthetic analysis of the Indian American woman's face☆

BACKGROUND This is the first study defining the facial anthropometric and aesthetic measurements in Indian American women (IAW). METHODS This is a prospective cohort study involving evaluation of facial photographs. Frontal, lateral and basal photographs were taken of IAW (n=102), and 30 anthropometric measurements were determined. Proportions were compared with published North American white women (NAWW) norms. Judges (n=6) evaluated the photographs for aesthetics using a visual analogue scale. Attractive IAW (top 15%) were compared with average IAW (remaining 85%) and average NAWW. All completed a facial self-esteem survey. RESULTS There were significant differences between IAW and NAWW in 25 of 30 facial measurements. Six measurements correlated with aesthetic scores: intercanthal distance, mouth width, nasolabial angle, midface height 2, ear length and nasal height. Attractive IAW had nine measurements approximating NAWW features, 15 measurements similar to average IAW values and two measurements distinct from both average IAW and average NAWW. Attractive IAW had higher facial self-esteem scores than average IAW. CONCLUSIONS Facial measurements in IAW are much different from NAWW, and these results will assist in preoperative planning. Several features are correlated with attractiveness in IAW: larger and wider-set eyes, a smaller midface, a smaller nose with greater tip rotation, smaller ears and a larger mouth. Attractive IAW display many measurements typical of average IAW and several measurements that reflect average NAWW values. These results contribute to concepts of transcultural aesthetics--for a minority ethnic group, facial beauty appears to be an assimilation of deep-rooted ethnic features with prevailing cultural traits and aesthetic standards.

Optical coherence tomography of cholesteatoma.

Objectives: To image cholesteatoma using optical coherence tomography (OCT) and correlate the results with clinical findings and conventional observations obtained using binocular microscopy and histology. OCT is a high-resolution optical imaging modality that generates cross-sectional images of turbid media, such as tissue with resolution approaching that of light microscopy. OCT relies on intrinsic differences in tissue optical properties for image contrast. Study Design: In vivo prospective clinical study. Setting: University Medical Center. Patients: Patients with cholesteatoma undergoing otologic surgery. Intervention: Using a commercial OCT imaging system, we obtained cross-sectional images (resolution, ∼10 &mgr;m; depth penetration, ∼1 mm) of cholesteatomas. Main Outcome Measures: Images are obtained by raster scanning a single mode fiber across the interior of the probe. The imaging probe is sterilized and inserted into the middle ear or mastoid under microscopic guidance, and still images of the middle ear or mastoid mucosa and cholesteatoma when present were obtained. Results: OCT images of cholesteatomas demonstrate differences in signal intensity, which are distinct from those of normal or inflamed middle ear/mastoid mucosa. Identification of keratin in cholesteatoma, even if very thin, distinguished it from inflamed mucosa. Conclusion: This is the first study that systematically used OCT to image cholesteatoma during otologic surgery. Cholesteatomas can be distinguished from normal or inflamed adjacent mucosa.

Systematic review and meta-analysis of total intravenous anesthesia and endoscopic sinus surgery.

Total intravenous anesthesia (TIVA) has been shown in some studies to impact visual field, blood loss, and cardiovascular parameters during endoscopic sinus surgery when compared to inhalational anesthesia (IA). These variables are critical in endoscopic sinus surgery. A systematic review and meta‐analysis was undertaken to discern the impact of TIVA vs IA in endoscopic sinus surgery.

Personality types of otolaryngology resident applicants as described by the Myers-Briggs Type Indicator.

Objective. To assess the personality types of applicants to a single otolaryngology residency program using the Myers-Briggs Type Indicator. The personality types were compared with those of the general population and with physicians in other medical specialties. Study Design. Cross-sectional survey. Setting. University hospital. Subjects and Methods. A personality survey was emailed to 327 resident physician applicants over 2 consecutive years (2008-2009). Analysis was accomplished by calculating prevalence estimates. Results. Of the 327 anonymous surveys, 137 were completed (response rate = 42%). The Introverted/Sensing/Thinking/ Judging personality type was the most prevalent (14.6%), representing 13% of the general population. Prospective applicants displayed mostly Extroverted (E; 58%), Sensing (S; 54%), Thinking (T; 62%), and Judging (J; 61%) personality traits. Of the 16 personality types, statistically significant differences were found between otolaryngology resident applicants and the general population only for the Extroverted/Sensing/Thinking/ Perceiving (P = .002) personality type after correcting for multiple comparisons. The Intuitive (N; 46%) and Feeling (F; 38%) types correlated closely with the reported personality types of those individuals in non–primary care specialties, 47% and 28%, respectively. Extroverted (E) and Thinking (T) individuals appeared to prefer surgical specialties, which occurred in 58% and 62% of the applicants, respectively. There were no significant differences between male and female applicants. Conclusion. This study examines the personality types of medical students applying to an otolaryngology residency. The results support a highly structured, data-driven teaching preference among applicants. These results may allow for a better understanding of the personalities of medical students who are interested in otolaryngology.

Lasers and Optical Technologies in Facial Plastic Surgery

Lasers and optical technologies play a significant role in aesthetic and reconstructive surgery. The unique ability of optical technologies to target specific structures and layers in tissues to effect chemical, mechanical, or thermal changes makes them a powerful tool in cutaneous rejuvenation, hair removal, fat removal, and treatment of vascular lesions such as port-wine stains, among many other procedures. With the development of adjunct techniques such as epidermal cooling, lasers and optical technologies have become more versatile and safe. The constant improvement of existing applications and the emergence of novel applications such as photodynamic therapy, nanoparticles, spectroscopy, and noninvasive imaging continue to revolutionize aesthetic medicine by offering a minimally invasive alternative to traditional surgery. In the future, therapies will be based on individualized, maximum, safe radiant exposure to deliver optimal dosimetry. Lasers and optical technologies are headed toward safer, easier, more quantifiable, and more individualized therapy.

A novel method to determine standardized anatomic dimensions of the osseous external auditory canal.

Objective To introduce a novel method for measuring the dimensions of the osseous external auditory canal (OEAC) on computed tomographic images of the temporal bone. Study Design Radiology case series. Setting Tertiary care medical center. Patients A retrospective review of high-resolution computed tomographic images of the temporal bones of 69 patients (120 ears) between the ages of 5 and 85 years (mean, 29.1 yr) was performed. Main Outcome Measures Using a novel method to measure dimensions of the OEAC in the parasagittal planes, 6 defined dimensions as well as length and shape of the OEAC were studied at the annulus, midcanal, and the border of the bony cartilaginous junction. Results There was no statistically significant difference in OEAC dimensions between the male and female subjects or patients with and without a history of chronic otitis media within similar age groups. The length of the OEAC was significantly different between age groups of 5 to 12 and older than 13 years. The 6 defined dimensions were statistically different between the age groups of 5 to 8 years and older. These dimensions were not statistically different between the age groups of 9 to 12, 13 to 18, and older than 18 years. The most prevalent shape of the OEAC was conical (64%). Conclusion Standardized anatomic dimensions of the OEAC provide important measurements for design of novel in-the-canal hearing aids and specialized earplugs and assist in defining average sizes for canalplasty procedures.

Electromechanical reshaping of rabbit septal cartilage: a six needle electrode geometric configuration

Electromechanical reshaping (EMR) of cartilage is a novel technique that has significant potential for use in facial reconstructive surgery. EMR achieves permanent shape change by initiating electrochemical redox reactions in the vicinity of stress concentrations, thereby altering mechanical properties of tissue matrix. This study reports the use of a six electrode needle-based geometric configuration to reshape cartilage. Rectangular samples (24 x 12 x 1 mm) of rabbit nasal septal cartilages were bent at a right angle in a precision-machined reshaping jig. Two parallel arrays of three platinum needle electrodes were each inserted into cartilage along the bend at 3 mm from the bend line. One array served as an anode and the other as cathode. Constant voltage at 1, 2, 4, 6, and 8 volts was applied to the arrays for 2 minutes. The specimens were then removed from the jig and rehydrated for 15 minutes in phosphate buffered saline. Following rehydration, bend angles and thicknesses were measured. Bend angle increased with increasing voltage and application time. No statistically significant bending was observed below 6 volts for 2 minutes application time. Maximum bend angle of 33 ± 8 degrees or reshaping degree of 33% was observed at 8 volts applied for 2 minutes. Current flow was small (< 0.1 A) for each case. Sample thickness was 0.9 ± 0.2 mm. ANOVA analysis showed that cartilage thickness had no significant impact on the extent of reshaping at given voltage and application time. The six needle electrode geometric configuration conforms to the voltage- and time-dependent trends predicted by previous EMR studies. In the future, the reshaping properties of other geometric configurations will be explored.

The effect of topical anesthetic hydration on the depth of thermal injury from the plasma skin regeneration device

The plasma skin regeneration (PSR) device delivers thermal energy to the skin by converting nitrogen gas to plasma. Prior to treatment, hydration of the skin is recommended as it is thought to limit the zone of thermal damage. However, there is limited data on optimal hydration time. This pilot study aims to determine the effect of topical anesthetic application time on the depth of thermal injury from a PSR device using histology.

Bilateral juvenile nasopharyngeal angiofibroma: Report of a case

Juvenile nasopharyngeal angiofibroma (JNA) is the most common benign neoplasm of the nasopharynx. Almost always unilateral on diagnosis, JNAs are locally invasive and may extend across the midline, giving a false bilateral appearance; as such, true bilateral JNA is exceedingly rare. We present a recent case of true bilateral JNA.