Hyun-Do Park

Location of the mandibular canal and the topography of its neurovascular structures.

The major complication in dental implant surgery is loss of sensation due to damage to the inferior alveolar nerve resulting from poor characterization of the location of the mandibular canal and the traveling course of the inferior alveolar nerve, artery, and vein therein. The purposes of this study were to determine the buccolingual location of the mandibular canal and to verify the topography of the inferior alveolar nerve, artery, and vein therein by three-dimensional reconstruction of these structures. Sixty-two mandible sides were used for this study. The buccolingual location of the mandibular canal was classified into 3 types: type 1 (70%), where the canal follows the lingual cortical plate at the mandibular ramus and body; type 2 (15%), where the canal follows the middle of the ramus behind the second molar and the lingual plate passing through the second and first molars; and type 3 (15%), where the canal follows the middle or the lingual one third of the mandible from the ramus to the body. Three-dimensional reconstruction of the mandibular canal revealed that the inferior alveolar vessel traveled above the inferior alveolar nerve in 8 cases (80%), with the inferior alveolar artery being lingual to the inferior alveolar vein, and in 2 cases (20%) where the inferior alveolar vessel was buccal to the nerve.

A study on the activity classification using a triaxial accelerometer

This paper describes a design of an algorithm for analyzing human activity using a body-fixed triaxial accelerometer on the back. In the first step, we distinguish static and dynamic activity period using AC signal analysis. Then five static activities were classified by applying the threshold in DC signal corresponding to the static activity period. Also, after taking AC signal and negative peak signal in the dynamic activity period, the four dynamic activities were classified by adaptive threshold method. To evaluate the performance of the proposed algorithm, the measured signals obtained from 12 subjects were applied to the proposed algorithm and the results were compared with the simultaneously measured video data. As a result, the activity classification rate of 95.1% on average was obtained. Overall results show that the proposed classification algorithm has a possibility to be used to analyze the static and dynamic physical activity.

An anatomic assessment on perforators of the lateral circumflex femoral artery for anterolateral thigh flap

The anterolateral thigh flap was originally described in 1984 as a septocutaneous flap based on the descending branch of the lateral femoral circumflex artery (LCFA). This flap has many advantages for head and neck reconstruction. However, it is not widely used as a result of the broad range of anatomic variation of the cutaneous perforators and because dissection of these perforators is tedious when they are small. The purposes of this study are to classify the vascular anatomy of the LCFA and to assess the suitability of the anterolateral thigh flap for head and neck reconstruction in Koreans. From 38 thigh dissections of Korean cadavers, the LCFA commonly arose from the deep femoral artery and divided into ascending, transverse, and descending branches. In five cases, the LCFA arose directly from the femoral artery. The cutaneous perforators were present in 37 cases except one and the septocutaneous perforators were found in 17 of the 38 cases. Of the 160 perforators, 28 (17.5%) were the septocutaneous perforators and 132 (82.5%) were the musculocutaneous perforators. The average number of cutaneous perforators for the anterolateral thigh flap was 4.2 (range, 0-8), and these perforators were concentrated in the middle third of the anterolateral thigh. The septocutaneous perforators were located more proximally than the musculocutaneous perforators. The average length of the vascular pedicle derived from the descending branch or the transverse branch was 83.3 mm (range, 53.4-124.3 mm). The results of this study suggest that the vascular anatomy of the anterolateral thigh flap was reliable and well suited for head and neck reconstruction in Koreans.

Effects of Fraction Obtained From Korean Corni Fructus Extracts Causing Anti-Proliferation and p53-Dependent Apoptosis in A549 Lung Cancer Cells

Corni Fructus has traditionally been used as herbal medicine for the treatment of tuberculosis, asthma, hepatitis, and chronic nephritis in Korea, Japan, and China. This research was carried out to evaluate the proliferative-inhibitory effect of CF extracts against cancer cells and to identify the new pro-substance from medicinal plants. Among these herbal extracts extracted from KCF (Korean Corni Fructus), JCF (Japanese Corni Fructus) and CCF (Chinese Corni Fructus), KCF extracts strongly induced anti-proliferation of cancer cells in a dose-dependent manner compared with other extracts. Moreover, after treatment with CM/F3 (fraction 3 obtained from KCF extracts) for 24 h, A549 cells were evaluated by several indicators such as cell viability, LDH release, DNA fragmentation, nuclear condensation, and apoptotic proteins in vitro. CM/F3 showed the tumor-selective growth inhibitory activity in a dose- and time-dependent manner in A549 cells. Consistently, CM/F3 effectively induced the activation of bax, cytochrome-c, caspase-3, -8, -9, p53, and p21 causing apoptosis, and caused the suppression of Cdk2, pRb, and E2F1 related to cell arrest in A549 cells. These results demonstrate that CM/F3 caused not only anti-proliferation but also cell death involving cell arrest through interaction between apoptotic proteins and the upregulation of p53 in A549 cells.

The discomallear ligament and the anterior ligament of malleus: An anatomic study in human adults and fetuses

According to some reports, movement of the malleus, resulting from anterior hypertension on the discomallear ligament (DML), could produce aural symptoms related with damage to middle ear structures. The aim of this study was to examine the topographic relationship of the DML and the anterior ligament of malleus (ALM). Four fetuses and 16 adult hemi-sectioned heads were used to determine the anatomic-clinical relevance of DML and ALM in temporomandibular disorder. In fetal specimens, the DML was distinctly interposed between the malleus and the disc of the temporomandibular joint (TMJ), and the ALM had a structure apparently composed of the superior and inferior lamellae, running anteriorly in continuation with the sphenomandibular ligament (SML) through the future petrotympanic fissure (PTF). In all adult specimens, the DML was inserted into the malleus, and it expanded broadly toward the disc and capsular region of the TMJ in a triangular shape and inserted into the disc and capsule of the TMJ. The two-lamellae structure of the ALM was not distinguishable in adult specimens. The overstretched ALM resulted in movement of the malleus in five cases, but similar tension applied to the DML did not cause any movement of the malleus. This result provides an indication of the clinical significance of the ALM, a ligamentous structure continuous with the SML. It is apparent that the ALM has the potential to cause aural symptoms as a result of damage to the middle ear structure.

Extra- and intramuscular nerve distribution patterns of the muscles of the ventral compartment of the forearm.

Won S-Y, Hur M-S, Rha D-W, Park H-D, Hu K-S, Fontaine C, Kim H-J: Extra- and intramuscular nerve distribution patterns of the muscles of the ventral compartment of the forearm. Objective:This study describes the extra- and intramuscular nerve branching of muscles of the ventral compartment of forearm, thereby providing critical information on determining the points for botulinum toxin injections that would be effective at reducing muscular spasticity. Design:Twenty-three Korean and French cadavers were dissected and subjected to Modified Sihlers staining to investigate nerve entry points and intramuscular nerve arborization patterns. Nerve entry point and abundant arborizing area of each muscle were analyzed on 20 segments with reference to transverse lines obtained by dividing the forearm into ten equal divisions and a vertical line bisecting the medial and lateral halves of the forearm. Results:The nerve entry points of the first and second layers of forearm muscles were located at medial levels 3 and 2, respectively. The entry points of the median and ulnar nerves innervating the flexor digitorum profundus (third layer) were located at medial levels 4 and 3, respectively. The intramuscular regions of abundant arborization in each muscle were located one level distal to the nerve entry point. Conclusions:This study has yielded a map of nerve entry and abundant arborization of motor nerves innervating each muscle of the ventral compartment of the forearm.

Topographic and histologic characteristics of the sural nerve for use in nerve grafting.

The sural nerve (SN) is a sensory nerve supplying the skin of the lateral and posterior parts of the inferior third of the calf and the lateral side of the foot and is easy to harvest because of its location posterior and superior to the tip of the lateral malleolus. Seventy-one lower limbs from 42 Korean cadavers were dissected to describe the joining type and level of perforated the fascia of the SN. The segments of sural nerve were stained and measured. The communication and joining patterns of the SN formed by the medial sural cutaneous nerve and the communicating branch of the lateral sural cutaneous nerve could be divided into five types. The region where the medial sural cutaneous nerve and the communicating branch of the lateral sural cutaneous nerve join together was observed in 52 cases with this found in the lower two fifths of the calf in 28 (53.8%) of the specimens. The mean number of fascicles was 8.1 (range, 2-12) at the lower calf and 5.8 (range, 1-11) at the middle calf before where the medial sural cutaneous nerve and the communicating branch of the lateral sural cutaneous nerve joined. The mean total areas of the fascicles were 0.55 mm2 and 0.43 mm2 in the lower and middle calf, respectively. This study demonstrates that the anatomy of the SN affects its harvesting for use in nerve grafts with the reported results providing a useful reference for SN grafting procedures.

Classification of Heartbeats based on Linear Discriminant Analysis and Artificial Neural Network

In this paper, we proposed a heartbeat classification algorithm based on linear discriminant analysis and artificial neural network. For the input of classifier, we extracted 275 input features from the first derivative signal of ECG signal and RR interval information and it was reduced to be 6 by LDA. To evaluate the performance of the proposed algorithm, we compared the result of the proposed algorithm with that of fuzzy inference system classifier. MIT-BIH Arrhythmia database were used as test and learning data. The performance of the proposed algorithm was 97.49% for sensitivity, 97.91% for specificity and 96.36% for accuracy. For the extraction of features, the first derivative signal of ECG is used only so that the real-time implementation of this algorithm was possible. And, on account of the reduction of feature dimensionality, the time cost for learning and testing can be expected