Ja-Young Yoo

Quantitative Analysis of the Cochlea using Three-Dimensional Reconstruction based on Microcomputed Tomographic Images

The aim of this study was to provide data on various dimensions of the normal cochlea using three‐dimensional reconstruction based on high‐resolution micro‐CT images. The petrous parts of 39 temporal bones were scanned by micro‐computed tomography (CT) with a slice thickness of 35 μm. The micro‐CT images were used in reconstructing three‐dimensional volumes of the bony labyrinth using computer software. The volumes were used to measure 12 dimensions of the cochlea, and statistical analysis was carried out. The dimensions of cochleae varied widely between different specimens. The mean height and length of the cochlea were 3.8 and 9.7 mm, respectively. The angle between the basal and middle turns was slightly larger in males than in females, while none of the other 11 dimensions differed significantly between males and females. The cochlear accessory canals were observed in about half of the cases (51.3%). Correlation analysis among measured items revealed positive correlations among several of the measured dimensions. The present study could investigate the detailed anatomy of the normal cochlea using high‐resolution imaging technologies. The results of the present study could be helpful for the precise diagnosis of congenital cochlear malformations and for producing optimized cochlear implants. Anat Rec, 296:1083–1088, 2013.

A morphometric study of the semicircular canals using micro-CT images in three-dimensional reconstruction.

It is generally accepted that the three semicircular canals are set at right angles to each other and the lateral semicircular canal is smaller than the anterior and posterior semicircular canals. Precise knowledge of the size and spatial relationships of the semicircular canals is vital, and so the 40 petrous parts of the temporal bones were scanned by micro‐CT at a slice thickness of 35 µm. The micro‐CT images were used in reconstructing three‐dimensional models of the bony labyrinth using computer software. Various dimensions of the semicircular canals were measured using the software, and statistical analysis was performed. The anterior semicircular canal was slightly wider than the posterior semicircular canal, and their heights were similar. The radius of curvature of the lateral semicircular canal was 20% smaller than those of the anterior and posterior semicircular canals. The angles between the three canals were not exactly 90 degrees: they were 92.1, 84.4, and 86.2 degrees between the anterior and posterior, anterior and lateral, and posterior and lateral semicircular canals, respectively. We obtained high‐resolution images of the semicircular canals using three‐dimensional reconstruction software, and these were used to precisely measure the angles between the semicircular canals and the area of the distorted circle formed by each semicircular canal. Anat Rec, 296:834–839, 2013.

Microanatomy of the infraorbital canal and its connecting canals in the maxilla using 3-D reconstruction of microcomputed tomographic images.

Abstract The current study investigated the anatomy of the infraorbital canal (IOC) and its related small canals in the maxilla. Twenty-eight hemimaxillae from human cadavers were studied. The samples were scanned using microcomputed tomography, and then images were three-dimensionally reconstructed using computer software. The branch point of the canal into the anterior superior alveolar nerve from the IOC occurred at about one third along the length of the IOC in the anterior direction. Just over half of the cases had 1 canal. The branch arose either laterally (21/28) or inferiorly (7/28) from the IOC. There was a canal located at the inferior lateral border of the piriform aperture in all cases. The distribution of the canals in the maxilla is represented indirectly by the course and distribution of the nerve and blood vessels therein. This distribution could explain various phenomena encountered in the clinical field.

Topographic anatomy of the masseter muscle focusing on the tendinous digitation.

The masseter muscle has superficial tendons that interdigitate like a saw (tendinous digitations), but a detailed description of these tendons is lacking in anatomic textbooks and atlases. The aim of the present study was to elucidate the topographic anatomy of the masseter muscle, focusing on its tendinous digitation. Sixty‐five adult faces (113 sides) were dissected. Five parameters, including the lengths, widths, and thickness of the muscle, were measured. The number and morphology of tendinous digitations were also investigated. The length and width of the masseter muscle were longer and wider in male specimens than in female specimens. The number of masseter muscle tendinous digitations was predominantly two in males and three in females. The length of the tendinous digitations tended to be about three‐quarters of that of the muscle. The second tendinous digitation was the longest in male specimens, while the first tendinous digitation was the longest in females. Based on our results, the external morphology of the masseter muscle does not match that described in anatomical atlases and textbooks. These findings may be helpful as a basic reference and in the treatment of masseter muscle hypertrophy and masseter tenomyositis. Clin. Anat. 25:889–892, 2012.

Topographic relationships between the transverse facial artery, branches of the facial nerve, and the parotid duct in the lateral midface in a Korean population.

BackgroundThe aims of the present study were to clarify the topographic relationships between various structures in the lateral midface and to provide important anatomical information pertinent to face lifting or treatment of damage to the midface structure. MethodsThirty-two fixed cadavers were dissected (23 males and 9 females; mean age, 66.8 years) and 55 sides of midface were used. The transverse facial artery (TFA), zygomatic branch (Zb) and buccal branch (Bb) of the facial nerve, and the parotid duct (PD) were identified. The structures of the lateral midface were measured relative to the zygion and tragion. The vertical average distances from the zygion to each structure increased in the following order: ZB of the facial nerve, TFA, first Bb of the facial nerve, and PD. The horizontal average distance from the tragion to the point of emergence from anterior border of the parotid gland was also measured. ResultsThe TFA was the closest and the third Bb of the facial nerve was the farthest away. The angles between the horizontal line and ZB of the facial nerve, TFA, PD, and first Bb of the facial nerve were +10.4, −2.3, −18.5, and −27.1 degrees, respectively. ConclusionsThese results may be used to establish the precise locations and the courses of the important midface structures, and represent valuable data that may help to prevent complications during surgery for face lifting and reconstruction of the facial nerve and PD.

Centralization or decentralization of facial structures in Korean young adults.

AbstractIt is well known that facial beauty is dictated by facial type, and harmony between the eyes, nose, and mouth. Furthermore, facial impression is judged according to the overall facial contour and the relationship between the facial structures. The aims of the present study were to determine the optimal criteria for the assessment of gathering or separation of the facial structures and to define standardized ratios for centralization or decentralization of the facial structures.Four different lengths were measured, and 2 indexes were calculated from standardized photographs of 551 volunteers. Centralization and decentralization were assessed using the width index (interpupillary distance / facial width) and height index (eyes-mouth distance / facial height). The mean ranges of the width index and height index were 42.0 to 45.0 and 36.0 to 39.0, respectively. The width index did not differ with sex, but males had more decentralized faces, and females had more centralized faces, vertically. The incidence rate of decentralized faces among the men was 30.3%, and that of centralized faces among the women was 25.2%.The mean ranges in width and height indexes have been determined in a Korean population. Faces with width and height index scores under and over the median ranges are determined to be “centralized” and “decentralized,” respectively.

Assessment of Normal Eyeball Protrusion Using Computed Tomographic Imaging and Three-Dimensional Reconstruction in Korean Adults.

ABSTRACT Purpose: The aim of the present study was to assess normal eyeball protrusion from the orbital rim using two- and three-dimensional images and demonstrate the better suitability of CT images for assessment of exophthalmos. Methods: The facial computed tomographic (CT) images of Korean adults were acquired in sagittal and transverse views. The CT images were used in reconstructing three-dimensional volume of faces using computer software. The protrusion distances from orbital rims and the diameters of eyeballs were measured in the two views of the CT image and three-dimensional volume of the face. Relative exophthalmometry was calculated by the difference in protrusion distance between the right and left sides. Results: The eyeball protrusion was 4.9 and 12.5 mm in sagittal and transverse views, respectively. The protrusion distances were 2.9 mm in the three-dimensional volume of face. There were no significant differences between right and left sides in the degree of protrusion, and the difference was within 2 mm in more than 90% of the subjects. Conclusions: The results of the present study will provide reliable criteria for precise diagnosis and postoperative monitoring using CT imaging of diseases such as thyroid-associated ophthalmopathy and orbital tumors.

A mechanism of rat vibrissal movement based on actual morphology of the intrinsic muscle using three-dimensional reconstruction.

The vibrissal capsular muscle (VCM) of the rat is known to differ from the arrector pili muscle. The purpose of the present study was to characterize the rat VCM morphologically using three-dimensional reconstruction. The rat snout skin was fixed, processed with routine histological methods, sectioned serially at a thickness of 10 µm, and then stained with Masson’s trichrome. The sectioned images were reconstructed three-dimensionally using ‘Reconstruct’ software. The findings confirmed that the VCM is a skeletal muscle attached to the vibrissal follicle such that the latter is rooted within the former. The VCM encircles the follicle almost entirely, from base to apex, and hooks around the follicle caudally. Each one of these capsular muscles is connected to two adjacent follicles in the same row. They overlap each other in the lower part, as the rostral follicular muscle that surrounds the caudal follicle. The present findings suggest that the vibrissae are able to move more freely (under voluntary control) than other general arrector pili muscles, in line with their sensory function.

Anatomical characteristics of the nasal cartilages for successful rhinoplasty in Koreans.

BackgroundsThe aims of the present study were to determine the exact level of separation of the upper lateral cartilage from the septal cartilage, and to classify the patterns of connection between the upper lateral cartilage and the lower lateral cartilage. MethodsWe dissected and photographed 60 sides of noses; 18 specimens were sectioned and stained with Masson’s trichrome. ResultsThe mean length of the connection between the upper lateral cartilage and septal cartilage was 16.1 mm. The mean level for separation of the upper lateral cartilage was 7.5 mm from the nasal bone. The pattern of connection between the upper lateral cartilage and lower lateral cartilage could be classified into five types: disconnection, end-to-end, overlap, scroll, and reverse scroll. ConclusionsThe results of the present study will be helpful for surgical procedures such as nasal hump reduction and nasal cartilage work and also provide information for the anthropometric study of the nose.