Koohyar Karimi

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.

Antibiotics in head and neck surgery in the setting of malnutrition, tracheotomy, and diabetes.

The objectives of this study are to compare short vs. long antibiotic prophylaxis in the setting of malnutrition, diabetes, and tracheotomy.

Evolving Attractive Faces Using Morphing Technology and a Genetic Algorithm: A New Approach to Determining Ideal Facial Aesthetics†

Objectives: The objectives of this study were to: 1) determine if a genetic algorithm in combination with morphing software can be used to evolve more attractive faces; and 2) evaluate whether this approach can be used as a tool to define or identify the attributes of the ideal attractive face.

Nasal Tip Projection and Facial Attractiveness

Six nasal tip projection (NTP) ratios from Goode, Simons, Baum, Powell, and Crumley guide clinical and academic practice on quantifying NTP, but none have been empirically correlated with facial attractiveness. This studys objectives were to determine: 1) if there is a correlation between these ratios and facial attractiveness; and 2) which of the six ratios has the greatest linkage to overall facial attractiveness.

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.

The Virtual Focus Group: A Modern Methodology for Facial Attractiveness Rating

Background: Traditional focus groups have been essential to facial aesthetics research. Although they are currently the criterion standard in acquiring facial attractiveness ratings, they retain many shortcomings. This studys objectives were twofold: to determine whether attractiveness scores obtained from a social network site correlate with those from the traditional focus group method; and to evaluate whether this methodology could be a superior tool in evaluating facial attractiveness. Methods: Forty facial portraits were rated for attractiveness scores using three different subject recruitment methods: traditional live focus groups (n = 123 raters), Internet-based rating (n = 857 raters), and a novel method using a combination of focus groups and a social network site (i.e., Facebook) (n = 1775 raters). Each facial image was scored on a 10-point Likert scale. Regression analysis compared each approach to the traditional method. Results: The methods varied in terms of data accrual time, rater demographics/ages, researchers accessibility, necessity for subject incentives, researcher labor, and rater effort/accuracy. A strong correlation (0.922) existed between the online social network-based rating and focus group method. A minimum of 992 raters achieved stabilization of the attractiveness scores using social network–based rating. Conclusions: This study shows significant advantages to using a social network site–based method over both Internet-based rating and traditional focus groups for evaluating facial attractiveness. The main benefits include exponential increase in raters, minimized researcher time/labor, rater scores comparable to those of the focus group method, nonnecessity of rater monetary incentives, and selectable demographics/ages of raters. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, II.

A web-based method for rating facial attractiveness†‡§

To determine if facial attractiveness scores from a novel Internet‐based facial attractiveness rating method correlate with those from the traditional focus group rating method, and whether this method can be an alternative for rating and evaluating facial attractiveness.

A Quantitative Approach to Determining the Ideal Female Lip Aesthetic and Its Effect on Facial Attractiveness

Importance Aesthetic proportions of the lips and their effect on facial attractiveness are poorly defined. Established guidelines would aid practitioners in achieving optimal aesthetic outcomes during cosmetic augmentation. Objective To assess the most attractive lip dimensions of white women based on attractiveness ranking of surface area, ratio of upper to lower lip, and dimensions of the lip surface area relative to the lower third of the face. Design, Setting, and Participants In phase 1 of this study, synthetic morph frontal digital images of the faces of 20 white women ages 18 to 25 years old were used to generate 5 varied lip surface areas for each face. These 100 faces were cardinally ranked by attractiveness through our developed conventional and internet-based focus groups by 150 participants. A summed ranking score of each face was plotted to quantify the most attractive surface area. In phase 2 of the study, 4 variants for each face were created with 15 of the most attractive images manipulating upper to lower lip ratios while maintaining the most attractive surface area from phase 1. A total of 60 faces were created, and each ratio was ranked by attractiveness by 428 participants (internet-based focus groups). In phase 3, the surface area from the most attractive faces was used to determine the total lip surface area relative to the lower facial third. Data were collected from March 1 to November 31, 2010, and analyzed from June 1 to October 31, 2016. Main Outcomes and Measures Most attractive lip surface area, ratio of upper to lower lip, and dimension of the lips relative to the lower facial third. Results In phase 1, all 100 faces were cardinally ranked by 150 individuals (internet-based focus groups [n = 130] and raters from conventional focus groups [conventional raters] [n = 20]). In phase 2, all 60 faces were cardinally ranked by 428 participants (internet-based focus groups [n = 408] and conventional raters [n = 20]). The surface area that corresponded to the range of 2.0 to 2.5 × 104 pixels represented the highest summed rank, generating a pool of 14 images. This surface area was determined to be the most attractive and corresponded to a 53.5% increase in surface area from the original image. With the highest mean and highest proportions of most attractive rankings, the 1:2 ratio was deemed most attractive. Conversely, the ratio of 2:1 was deemed least attractive, having the lowest mean at 1.61 and the highest proportion of ranks within 1 with 310 votes (72.3%). Conclusions and Relevance Using a robust sample size, this study found that the most attractive lip surface area represents a 53.5% increase from baseline, an upper to lower lip ratio of 1:2, and a surface area equal to 9.6% of the lower third of the face. Lip dimensions and ratios derived in this study may provide guidelines in improving overall facial aesthetics and have clinical relevance to the field of facial plastic surgery. Level of Evidence NA.

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.

Morphometric facial analysis: a methodology to create lateral facial images

IntroductionCurrently, the majority of research in facial analysis using computational morphing methods focuses exclusively on analysis of frontal facial projections. Lateral facial morphing analysis has not been extensively investigated, and landmark features critical to specify registry points are unknown. This study aims to (1) determine the quantity of registry points (RP) required to create realistic lateral faces and (2) determine key facial registry point landmarks required to create synthetic lateral faces.Method36 synthetic lateral faces with a 50 to 250 RP were created to determine the ideal quantity of RP to create a realistic lateral image; ear, eyebrow, eye, nose, lips, hairline, facial outline, and overall outline were evaluated by an expert panel of seven evaluators using a 1 to 5 point Lickert scale rating system.ResultANOVA single-variable analyses revealed significant differences when comparing templates of 200 and 250 RP with 50 and 100 RP templates (p < 0.05). Furthermore, analysis of all key landmark areas of the face indicated significant differences between different registry points except for 200 and 250 registry point markers. Kruskal-Wallis statistical analysis revealed the landmarks varied significantly from 50 to 200 RP,but had no significance with 200 and 250 RP.ConclusionThe most ideal quantity of RP used for the creation of realistic lateral faces was in the range of 200 RP. Defined lateral facial registry point landmarks generated successful realistic faces.