Anatomical variations of the stylopharyngeus and superior constrictors in relation to their function

The aims of this study were to clarify the topography and variations stylopharyngeus (STP) and superior constrictor (SC) muscles, and to examine what role they play in the pharyngeal movement. Forty-four specimens (22 right and 22 left sides) from embalmed Korean adult cadavers (13 males, 9 females; age range, 46-89 years; mean age, 69.2 years) were used in this study. The accessory bundle of STP and petropharyngeus was found in 18.2% (8/44) and 25.0% (11/44) of cases, respectively. A variation of the STP, in which it ran transversely and merged with the SC muscle, was found in 2.3% (1/44) of cases while a variation of the SC muscle, in which it ran longitudinally and merged with the contralateral constrictors, was found in 11.4% (5/44). The variant muscle bundles play their own role in pharyngeal movement according to their morphology. These results provide information that will help a comprehensive understanding of the effects of pharyngeal muscles on movement.ope

Anatomical Study for Measurement of Ligature Marks at the Scene of Hanging Death

The hanging death is the most frequently used method by suicide attempters. In particular, the ligature marks on the victim’s neck in hanging deaths are important evidence of asphyxia due to compression of the neck (strangulation). Moreover, it can be an important piece of evidence that can differentiate the manner of death (suicide, homicide, and homicide disguised as a suicide). Therefore, the analysis and interpretation of ligature marks should ensure consistency and reliability as evidence in criminal investigations. However, in the past, when police officers demonstrating the patterns of ligature mark in cases of compressed neck, the standards and principles were not sufficient to make a valid decision in terms of anatomical measurement points, measurement methods, and measurement tools. Consequently, not only various errors may unconsciously occur in the meticulous examination of the ligature marks, but also as evidence, consistency and reliability may not be guaranteed. The aim of this study is to propose the new measurement method of ligature marks in case of death by hanging. A total of 18 cases in 2018 were analyzed (excluding 10 cases due to decomposition of the body) among 28 hanging deaths occurred in north area in Seoul. The classification and analysis of suicide by hanging were conducted in order to diagnose ligature mark of hanging, using the traditional (A) and new (G) measurement methods. The new measurement method was measured the four items (G1~G3) based on labrale inferius, otobasion inferius, and external occipital protuberance. When comparing the average difference between the new and traditional measurement methods, G1- A1 was observed as 3.9 cm, G2L-A2L as 0.6 cm, and G2R-A2R as 0.6 cm. Investigation of the first death scene as well as the medicolegal death investigation of the deceased are of utmost importance in resolving the criminal case. In the case of hanging death, the new measurement method for diagnosing ligature mark in the field of investigation can yield the same results without any differences between individuals. Also, this method can provide consistency and reliability as evidence during crime scene investigation.ope

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The dog frontal sinus may represent an alternative model dental implant research; its topographical resemblance to the maxillary sinus renders it a potentially favorable experimental environment. The aim of this study was thus to elucidate the anatomical configuration of the canine frontal sinus and histological characteristics, and to determine whether it could be a new canine experimental model for dental implant research. Twenty-four sides of canine frontal bones were harvested. The distance from the nasion to the emerging point of the lateral aspect of the canine frontal sinus was measured with the aid of Lucion software. The thicknesses of the canine frontal sinus wall were measured, and the two specimens stained with hematoxylin and eosin. The mean distance from the nasion to the emerging point of the lateral aspect of the canine frontal sinus was 16.0 mm. The mean thicknesses of the canine frontal bone at 3, 6, 9, 12, and 15 mm lateral to the midsagittal plane were 2.3, 2.7, 3.2, 3.8, and 3.7 mm, respectively. The canine frontal sinus was lined with pseudostratified ciliated columnar epithelium. These data suggest that the canine frontal sinus is a suitable alternative to the canine maxillary sinus as a model for studying various sinus augmentation protocols.ope

Murder of a Korean Police Officer with a Homemade Firearm

In the Republic of Korea, only permit holders are allowed to use firearms. We present a previously unreported case of a police officer who was killed by a homemade firearm. The criminal, an ex-convict who had committed serious crimes in the past, faced economic and social difficulties since his release from prison. Because the criminal felt anger and hatred towards the police officers who had investigated his past violent crimes, he made homemade firearms with the intention of killing the police officers. The victim was immediately dispatched to the scene, after receiving an emergency call. The police officer was shot in the left scapula, from a distance of approximately 5 m, with a matchlock gun that was fired by inserting stainless-steel balls and gunpowder into the barrels and igniting the wick. Multiple barrels were fastened to the wooden stock, which allowed multiple bullets to be fired simultaneously.ope

Adjunctive hyperbaric oxygen therapy for irradiated rat calvarial defects

Purpose: The aim of this study was to conduct a histologic evaluation of irradiated calvarial defects in rats 4 weeks after applying fibroblast growth factor-2 (FGF-2) with hyaluronan or biphasic calcium phosphate (BCP) block in the presence or absence of adjunctive hyperbaric oxygen (HBO) therapy. Methods: Twenty rats were divided into HBO and non-HBO (NHBO) groups, each of which was divided into FGF-2 and BCP-block subgroups according to the grafted material. Localized radiation with a single 12-Gy dose was applied to the calvaria of rats to simulate radiotherapy. Four weeks after applying this radiation, 2 symmetrical circular defects with a diameter of 6 mm were created in the parietal bones of each animal. The right-side defect was filled with the materials mentioned above and the left-side defect was not filled (as a control). All defects were covered with a resorbable barrier membrane. During 4 weeks of healing, 1 hour of HBO therapy was applied to the rats in the HBO groups 5 times a week. The rats were then killed, and the calvarial specimens were harvested for radiographic and histologic analyses. Results: New bone formation was greatest in the FGF-2 subgroup, and improvement was not found in the BCP subgroup. HBO seemed to have a minimal effect on new bone formation. There was tendency for more angiogenesis in the HBO groups than the NHBO groups, but the group with HBO and FGF-2 did not show significantly better outcomes than the HBO-only group or the NHBO group with FGF-2. Conclusions: HBO exerted beneficial effects on angiogenesis in calvarial defects of irradiated rats over a 4-week healing period, but it appeared to have minimal effects on bone regeneration. FGF-2 seemed to enhance new bone formation and angiogenesis, but its efficacy appeared to be reduced when HBO was applied.ope

Anatomic Description of the Infraorbital Soft Tissues by Three-dimensional Scanning System

Purpose: For minimally invasive procedures, three-dimensional (3D) anatomical knowledge of the structures of the face is essential. This study aimed to describe the thickness of the skin and subcutaneous tissue and depths of the facial muscles located in the infraorbital region using a 3D scanner to provide critical clinical anatomical guidelines for improving minimally invasive cosmetic procedures. Materials and Methods: The 3D scanning images of 38 Korean cadavers (22 males and 16 females; age range: 51~94 years at the time of death) were analyzed. Eight facial landmarks (P1~P8) were marked on the cadaveric faces. The images were scanned in three steps-undissected face, hemiface after skinning, and revealing the facial muscles. Student's t-test was used to identify significant differences. Result: The skin and subcutaneous tissue tended to become thicker from the upper to lower and medial to lateral aspects, and the muscles followed the same pattern as that of the most superficial located muscle and the deepest located muscles. No significant sex-related differences were found in the skin at any landmark. However, the muscles tended to be deeper in the female participants. Conclusion: The study data can serve as a basis for creating or enhancing clinical anatomy-based guidelines or improving procedures in the infraorbital region.ope

Improvement of accessibility to dental care due to expansion of national health insurance coverage for scaling in South Korea

Since 2013, adults aged over 20 can receive national health insurance scaling once a year in South Korea. In this study, we analyzed the usage status of national health insurance care service for periodontal disease in 2010-2018 by using Healthcare big data of the Health Insurance Review and Assessment Service. The increase rate of the dental care users was very high at 7.8 and 11.2% in 2013 and 2014, respectively. These are higher than the increase rate of all medical institution users, which is between -1.7 and 3.7%. In 2017, the rate of dental use was 44.4%, which has increased more than 10% compared to 2012. Percent receiver of national health insurance scaling was 19.5% in 2017. The 20s had the highest rate of 23.2%. The rate decreased with age. Based on these results, it can be evaluated that the expansion of national health insurance coverage for scaling improves accessibility to dental care. A more long-term assessment of the effect of periodic dental examination and scaling on reducing the prevalence of periodontal disease is needed. National health insurance coverage should be extended to oral hygiene education and supportive periodontal therapy in order to prevent periodontal disease.ope

삼차원 재구성된 CT 영상을 통한 한국인의 하악관 주행 양상

Purpose : The location of the mandibular canal is must be determined before performing implant surgery and other procedures. This study was undertaken to identify the running patterns of mandibular canals in the Korean population using a 3- dimensional reconstructed computed tomographic(CT) image. Materials and methods : CT images of 30 patients were included in the investigation. The vertical and bucco-lingual positions of the mandibular canals were identified under each premolar and molar, and the location of the mental foramen and the anterior extension of the anterior loop were measured using 3-D CT reconstruction software. The vertical position of the canal and mental foramen were measured from the CEJ of the tooth to the upper border of the structure. Results : The mean lengths between the cement-enamel junction of the tooth and the canal were 19.94, 19.07, 17.82, and 15.75mm under the first and second premolars and the first and second molars. Most of the canals were located at the lingual aspect under the molars, and at the buccal aspect under the 1st premolar. The average vertical location of the mental foramen was 15.37mm from the CEJ, and had an average diameter of 2.32mm. The mean length of the anterior loop was found to be 4.23mm. Conclusion : In most subjects, the vertical position of the mandibular canal was closer to the molars than the premolars. The running pattern of the mandibular canal from the molar region to the premolar region tended to be from the lingual to the buccal aspect of the mandible. The mental foramen was located superior to the canal, and the anterior loop extended anteriorly in various lengthsope

Effective Locations for Injecting Botulinum Toxin into the Mentalis Muscle; Cadaveric and Ultrasonographic Study

The mentalis muscle is now considered key structures when performing procedures for rejuvenating the lower face. The aim of this study was to determine the anatomical morphology and location of the mentalis muscle and thereby provide anatomical information for facilitating clinical procedures designed to rejuvenate the lower face. Forty-four adult hemifaces from five Thai cadavers and 21 Korean cadavers were dissected to identify the locations of the mentalis muscle. Sixty-six hemifaces from 33 healthy young Korean subjects were included in an ultrasonographic study. The depth of the mentalis muscle below the skin surface, the thickness of the mentalis muscle, and the distance from the bone to the mentalis muscle were measured at the two points that were 5 mm lateral to the most-prominent point of the chin. The mentalis muscle was classified into two types based to its shape: in type A (86.4%, 38 of the 44 cases) it was dome shaped in three dimensions, while in type B (13.6%, 6 of the 44 cases) it was flat. The mentalis muscle was present mostly at the area 5-10 mm from the midsagittal line and 20-30 mm from a horizontal line connecting the mouth corners. The mentalis muscle was present between depths of 6.7 to 10.7 mm below the skin. This new information about the location of the mentalis muscle may help when identifying the most effective and safe botulinum toxin injection points and depths during esthetic procedures for weakened facial rhytides on the lower face.ope

Anatomical Injection Guidelines for Glabellar Frown Lines Based on Ultrasonographic Evaluation

When botulinum neurotoxin (BoNT) is injected to treat glabellar frown lines, the corrugator supercilia muscle (CSM) and procerus muscles are the main targets. Although there have been many studies on the treatment of glabellar frown lines, no study has confirmed the dynamic movement under ultrasonography (US). This study examined and evaluated dynamic muscle movements under US, thereby providing more effective BoNT injection guidelines for glabellar frowning. Glabellar frowning was categorized as either Type A or B. Type A is the general frowning pattern in which vertical wrinkles are made by contracting the CSM and procerus muscles (81%, n = 13). On US images, the procerus muscle thickens and the bilateral CSMs contract. Type B is an upward frowning pattern demonstrating upward elevation of vertical wrinkles due to hyperactive contraction of the frontalis muscle during frowning (19%, n = 3). On US images, the hypoechoic frontalis muscle thickens, forming horizontal forehead lines. After BoNT injection into the CSM and frontalis muscle but not the procerus muscle, Type B patterns showed improvements in the vertical crease and horizontal forehead line. Both types showed improvement in glabellar frown lines after conventional injection, but the horizontal forehead line did not improve in Type B. Type B wrinkles improved after additional injections into the frontalis muscle. This study provided novel anatomical findings related to the injection of glabellar frown lines with BoNT. Preliminary analysis and optimized procedures using US will enable more effective and safer injections.ope