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.

Body donation trends in Yonsei University: a statistical analysis of donor records / 대한해부학회지

Body donation trends in Korea have changed significantly over the last 3 decades. Establishing a body donation system will promote donations to universities for academic purposes. Yonsei University College of Medicine started its own body donation system in 1992, including documenting donors’ records. However, there has been no reported attempt to analyze the trend of these records, which could provide noteworthy information that can be interpreted for medical advances. This study performed a statistical analysis of the donors’ records between 1992 and 2019 to analyze the sociological and anthropological changes. Donor personal information such as sex, age, religion, and place and cause of death were extracted from the Yonsei University College of Medicine database. Our statistical analysis revealed significant correlations between donors’ records and the changes in the number of geriatric hospitals, religious beliefs, number of donations, and donor age.

Body donation trends in Yonsei University: a statistical analysis of donor records / 대한해부학회지

Body donation trends in Korea have changed significantly over the last 3 decades. Establishing a body donation system will promote donations to universities for academic purposes. Yonsei University College of Medicine started its own body donation system in 1992, including documenting donors’ records. However, there has been no reported attempt to analyze the trend of these records, which could provide noteworthy information that can be interpreted for medical advances. This study performed a statistical analysis of the donors’ records between 1992 and 2019 to analyze the sociological and anthropological changes. Donor personal information such as sex, age, religion, and place and cause of death were extracted from the Yonsei University College of Medicine database. Our statistical analysis revealed significant correlations between donors’ records and the changes in the number of geriatric hospitals, religious beliefs, number of donations, and donor age.

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

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.

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

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.

Eight-week healing of grafted calvarial bone defects with hyperbaric oxygen therapy in rats

PURPOSE: The purpose of this study was to evaluate the synergistic effect of adjunctive hyperbaric oxygen (HBO) therapy on new bone formation and angiogenesis after 8 weeks of healing. METHODS: Sprague-Dawley rats (n=28) were split into 2 groups according to the application of adjunctive HBO therapy: a group that received HBO therapy (HBO group [n=14]) and another group that did not receive HBO therapy (NHBO group [n=14]). Each group was divided into 2 subgroups according to the type of bone graft material: a biphasic calcium phosphate (BCP) subgroup and an Escherichia coli-derived recombinant human bone morphogenetic protein-2-/epigallocatechin-3-gallate-coated BCP (mBCP) subgroup. Two identical circular defects with a 6-mm diameter were made in the right and left parietal bones of each rat. One defect was grafted with bone graft material (BCP or mBCP). The other defect was not grafted. The HBO group received 2 weeks of adjunctive HBO therapy (1 hour, 5 times a week). The rats were euthanized 8 weeks after surgery. The specimens were prepared for histologic analysis. RESULTS: New bone (%) was higher in the NHBO-mBCP group than in the NHBO-BCP and control groups (P<0.05). Blood vessel count (%) and vascular endothelial growth factor staining (%) were higher in the HBO-mBCP group than in the NHBO-mBCP group (P<0.05). CONCLUSIONS: HBO therapy did not have a positive influence on bone formation irrespective of the type of bone graft material applied after 8 weeks of healing. HBO therapy had a positive effect on angiogenic activity.

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.

Schematic of mean thickness distribution on the lateral aspect of the canine frontal sinus as an experimental model of sinus surgery / 대한해부학회지

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.

Does Retaining Ligament Exist in the Neck? / 체질인류학회지

The goal of this study was to determine the characteristics of the horizontal cervical wrinkle and to investigate histological feature, especially with respect to elastin and collagen fiber. Histologic sample were harvested from two fresh adult cadavers where the cervical wrinkle is in the neck. The tissue sections were stained with hematoxylin and eosin (HE) or Masson's Trichrome. In sections of neck skin, keratinization was observed in the epidermis, and many collagen fibers were observed in the dermis layer as in other skin. Specifically, a lot of short and curly elastic fiber were observed between the collagen fibers in the dermis. These elastic fibers were not stained with eosin and observed in gray. This long ligament-like structures were observed in the dermis. The ligament-like structures were stained with dark red by trichrome. These results indicate that these ligament-like structures are neither typical ligament nor typical smooth muscles. The results obtained from present study showed a ligamentous structure originating from the fascial layer (platysma muscle or investing layer). The results may help to understand the reasons about the formation of horizontal cervical wrinkle.

Four-week histologic evaluation of grafted calvarial defects with adjunctive hyperbaric oxygen therapy in rats

PURPOSE: The aim of this study was to characterize the healing in the grafted calvarial defects of rats after adjunctive hyperbaric oxygen therapy. METHODS: Twenty-eight male Sprague-Dawley rats (body weight, 250–300 g) were randomly divided into two treatment groups: with hyperbaric oxygen therapy (HBO; n=14) and without HBO (NHBO; n=14). Each group was further subdivided according to the bone substitute applied: biphasic calcium phosphate (BCP; n=7) and surface-modified BCP (mBCP; n=7). The mBCP comprised BCP coated with Escherichia-coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) and epigallocatechin-3-gallate (EGCG). Two symmetrical circular defects (6-mm diameter) were created in the right and left parietal bones of each animal. One defect was assigned as a control defect and received no bone substitute, while the other defect was filled with either BCP or mBCP. The animals were allowed to heal for 4 weeks, during which those in the HBO group underwent 5 sessions of HBO. At 4 weeks, the animals were sacrificed, and the defects were harvested for histologic and histomorphometric analysis. RESULTS: Well-maintained space was found in the grafted groups. Woven bone connected to and away from the defect margin was formed. More angiogenesis was found with HBO and EGCG/BMP-2 (P<0.05). None of the defects achieved complete defect closure. Increased new bone formation with HBO or EGCG/BMP-2 was evident in histologic evaluation, but it did not reach statistical significance in histometric analysis. A synergic effect between HBO and EGCG/BMP-2 was not found. CONCLUSIONS: Within the limitations of this study, the present findings indicate that adjunctive HBO and EGCG/BMP-2 could be beneficial for new bone formation in rat calvarial defects.

Phylogenic Oto-stomatognathic Connection of the Mammalian Jaw: A Novel Hypothesis for Tensor Tympani Muscle and TMD-related Otologic Symptoms / 체질인류학회지

Otologic complaints, including otalgia, tinnitus, vertigo, and hearing loss, are known to be related to temporomandibular disorders (TMDs). There have been several hypotheses regarding the clinical correlation between otologic complaints and TMDs, based on clinical phenomena with corresponding symptoms, the close neurological relationship between otic and masticatory structures, and anatomical features of the tympanic cavity and jaw joint. Function of the tensor tympani muscle seems to be crucial to understanding TMD-related otologic symptoms. The tensor tympani inserts into the handle of the malleus and it modulates sound transduction in situations of excessive noise. This muscle is innervated by the trigeminal nerve, like the masticatory muscles. Voluntary eardrum movement by pathological tensor tympani contraction results in various otologic symptoms. Thus, co-contraction of the tensor tympani with the masticatory muscle could be a possible cause of TMD-related otologic symptoms. The tensor tympani is rather unrelated to the acoustic reflex, in which the stapedius is strongly involved. The tensor tympani seem to be controlled by proprioceptive information from the trigeminal sensory nucleus. The peripheral innervation pattern of the tensor tympani and masticatory muscles is also supposed to be interconnected. The middle ear structure, including the malleus, incus, and tensor tympani, of mammals had been adapted for acoustic function and lacks the masticatory role seen in non-mammalian jawed vertebrates. The tensor tympani in non-mammals is one of the masticatory muscles and plays a role in the modulation of sound transduction and mastication. After the functional differentiation of the mammalian middle ear, the nervous connection of the tensor tympani with other masticatory apparatus still remains. Through this oto-stomatognathic vestige, the tensor tympani seems to contract unnecessarily in some pathological conditions of the TMD in which the masticatory muscles contract excessively. We hypothesized that the phylogenic relationship between the tensor tympani and masticatory apparatus is a significant and logical reason for TMD-related otologic complaints.

Anatomical and Functional Consideration of the Trigemino-Facial Nervous Communication and Facial Expresssion Muscles / 체질인류학회지

The aim of the study is to examine the distribution and communications of the trigeminal nerve (TN) and facial nerve (FN) and considerate their relationship with the anatomy and function of the facial expression muscles (FEMs) by means of the literature study. The TN emerged on the face via various structures of the skull, and received sensation of the skin and muscles on the face. The FN supplied the motor components to the FEMs, as ramifying five branches after running through the stylohyoid foramen. The TN and FN constituted "nervous communication between heterogeneous cranial nerves" on the ocular (supraorbital nerve and temporal branch), zygomatic (zygomatic nerve and temporal/zygomatic branch), infraorbital (infraorbital nerve and zygomatic branch), retromandibular (auriculotemporal nerve and FN trunk), buccal (buccal nerve and buccal/zygomatic branch) and mental areas (mental nerve and buccal/marginal mandibular branch). The exquisite movement of the FEM which was controlled by the facial motor nucleus would be referred by the proprioception from the TN. The motor components from the FN could be delivered to the FEM via the TN as recruiting the heterogeneous nervous communications. The sensation from the FN also could be conveyed to the TN via the communication.

Topography of Superficial Arteries on the Face / 체질인류학회지

The facial artery (FA) and superficial temporal artery (STA) from the external carotid artery and the supraorbital, supra- and infratrochlear arteries from the internal carotid artery are the superficial arteries distributing to the face. It was broadly known that the FA winds on the antegonial notch, ascends superomedially and finally reaches to the medial canthus area as forming the angular artery (AA). However many previous studies reported that the AA was only observed in 4~68% in their studies. The superior labial artery (SLA) from the FA issues the superficial and deep septal artery proceeding superiorly toward the nasal septum. It was reported that the nasal branches were ramified from the FA, after the bifurcation of the SLA in most Korean cadavers, and it seems that the lateral nasal and dorsal nasal arteries are crucial vasculature of the external nose. The branches of the ophthalmic artery distribute the glabellar and forehead, and they form anastomoses each other or are communicated to the AA. The topography of the superficial arteries of face is very important in the reconstructive surgery and non-invasive treatment such as the botulinum neurotoxin type A or dermal filler injection.

Reliability of two different presurgical preparation methods for implant dentistry based on panoramic radiography and cone-beam computed tomography in cadavers

PURPOSE: Special care is necessary to avoid invading important anatomic structures during surgery when presurgical planning is made based on radiographs. However, none of these types of radiography represents a perfect modality. The purpose of this study was to determine the reliability of presurgical planning based on the use of two types of radiographic image (digital panoramic radiography [DPR] and cone-beam computed tomography [CBCT]) by beginner dentists to place implants, and to quantify differences in measurements between radiographic images and real specimens. METHODS: Ten fresh cadavers without posterior teeth were used, and twelve practitioners who had no experience of implant surgery performed implant surgery after 10 hours of basic instruction using conventional surgical guide based on CBCT or DPR. Two types of measurement error were evaluated: 1) the presurgical measurement error, defined as that between the presurgical and postsurgical measurements in each modality of radiographic analysis, and 2) the measurement error between postsurgical radiography and the real specimen. RESULTS: The mean presurgical measurement error was significantly smaller for CBCT than for DPR in the maxillary region, whereas it did not differ significantly between the two imaging modalities in the mandibular region. The mean measurement error between radiography and real specimens was significantly smaller for CBCT than for DPR in the maxillary region, but did not differ significantly in the mandibular region. CONCLUSIONS: Presurgical planning can be performed safely using DPR in the mandible; however, presurgical planning using CBCT is recommended in the maxilla when a structure in a buccolingual location needs to be evaluated because this imaging modality supplies buccolingual information that cannot be obtained from DPR.

Reliability of two different presurgical preparation methods for implant dentistry based on panoramic radiography and cone-beam computed tomography in cadavers

PURPOSE: Special care is necessary to avoid invading important anatomic structures during surgery when presurgical planning is made based on radiographs. However, none of these types of radiography represents a perfect modality. The purpose of this study was to determine the reliability of presurgical planning based on the use of two types of radiographic image (digital panoramic radiography [DPR] and cone-beam computed tomography [CBCT]) by beginner dentists to place implants, and to quantify differences in measurements between radiographic images and real specimens. METHODS: Ten fresh cadavers without posterior teeth were used, and twelve practitioners who had no experience of implant surgery performed implant surgery after 10 hours of basic instruction using conventional surgical guide based on CBCT or DPR. Two types of measurement error were evaluated: 1) the presurgical measurement error, defined as that between the presurgical and postsurgical measurements in each modality of radiographic analysis, and 2) the measurement error between postsurgical radiography and the real specimen. RESULTS: The mean presurgical measurement error was significantly smaller for CBCT than for DPR in the maxillary region, whereas it did not differ significantly between the two imaging modalities in the mandibular region. The mean measurement error between radiography and real specimens was significantly smaller for CBCT than for DPR in the maxillary region, but did not differ significantly in the mandibular region. CONCLUSIONS: Presurgical planning can be performed safely using DPR in the mandible; however, presurgical planning using CBCT is recommended in the maxilla when a structure in a buccolingual location needs to be evaluated because this imaging modality supplies buccolingual information that cannot be obtained from DPR.

Surface characteristics of a novel hydroxyapatite-coated dental implant

PURPOSE: This study evaluated the surface characteristics and bond strength produced using a novel technique for coating hydroxyapatite (HA) onto titanium implants. METHODS: HA was coated on the titanium implant surface using a super-high-speed (SHS) blasting method with highly purified HA. The coating was performed at a low temperature, unlike conventional HA coating methods. Coating thickness was measured. The novel HA-coated disc was fabricated. X-ray diffraction analysis was performed directly on the disc to evaluate crystallinity. Four novel HA-coated discs and four resorbable blast medium (RBM) discs were prepared. Their surface roughnesses and areas were measured. Five puretitanium, RBM-treated, and novel HA-coated discs were prepared. Contact angle was measured. Two-way analysis of variance and the post-hoc Scheffe's test were used to analyze differences between the groups, with those with a probability of P<0.05 considered to be statistically significant. To evaluate exfoliation of the coating layer, 7 sites on the mandibles from 7 mongrel dogs were used. Other sites were used for another research project. In total, seven novel HA-coated implants were placed 2 months after extraction of premolars according to the manufacturer's instructions. The dogs were sacrificed 8 weeks after implant surgery. Implants were removed using a ratchet driver. The surface of the retrieved implants was evaluated microscopically. RESULTS: A uniform HA coating layer was formed on the titanium implants with no deformation of the RBM titanium surface microtexture when an SHS blasting method was used. CONCLUSIONS: These HA-coated implants exhibited increased roughness, crystallinity, and wettability when compared with RBM implants.

Surface characteristics of a novel hydroxyapatite-coated dental implant

PURPOSE: This study evaluated the surface characteristics and bond strength produced using a novel technique for coating hydroxyapatite (HA) onto titanium implants. METHODS: HA was coated on the titanium implant surface using a super-high-speed (SHS) blasting method with highly purified HA. The coating was performed at a low temperature, unlike conventional HA coating methods. Coating thickness was measured. The novel HA-coated disc was fabricated. X-ray diffraction analysis was performed directly on the disc to evaluate crystallinity. Four novel HA-coated discs and four resorbable blast medium (RBM) discs were prepared. Their surface roughnesses and areas were measured. Five puretitanium, RBM-treated, and novel HA-coated discs were prepared. Contact angle was measured. Two-way analysis of variance and the post-hoc Scheffe's test were used to analyze differences between the groups, with those with a probability of P<0.05 considered to be statistically significant. To evaluate exfoliation of the coating layer, 7 sites on the mandibles from 7 mongrel dogs were used. Other sites were used for another research project. In total, seven novel HA-coated implants were placed 2 months after extraction of premolars according to the manufacturer's instructions. The dogs were sacrificed 8 weeks after implant surgery. Implants were removed using a ratchet driver. The surface of the retrieved implants was evaluated microscopically. RESULTS: A uniform HA coating layer was formed on the titanium implants with no deformation of the RBM titanium surface microtexture when an SHS blasting method was used. CONCLUSIONS: These HA-coated implants exhibited increased roughness, crystallinity, and wettability when compared with RBM implants.

Reply on "Reliability of two different presurgical preparation methods for implant dentistry based on panoramic radiography and cone-beam computed tomography in cadavers"

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Clinical and anatomical approach using Sihler's staining technique (whole mount nerve stain) / 대한해부학회지

Sihler's staining allows visualization of the nerve distribution within soft tissues without extensive dissection and does not require slide preparation, unlike traditional approaches. This technique can be applied to the mucosa, muscle, and organs that contain myelinated nerve fibers. In particular, Sihler's technique may be considered the best tool for observing nerve distribution within skeletal muscles. The intramuscular distribution pattern of nerves is difficult to observe through manual manipulation due to the gradual tapering of nerves toward the terminal end of muscles, so it should be accompanied by histological studies to establish the finer branches therein. This method provides useful information not only for anatomists but also for physiologists and clinicians. Advanced knowledge of the nerve distribution patterns will be useful for developing guidelines for clinicians who perform operations such as muscle resection, tendon transplantation, and botulinum toxin injection. Furthermore, it is a useful technique to develop neurosurgical techniques and perform electrophysiological experiments. In this review, Sihler's staining technique is described in detail, covering its history, staining protocol, advantages, disadvantages, and possible applications. The application of this technique for determining the arterial distribution pattern is also described additionally in this study.

Fabrication of Korean Skull Model / 체질인류학회지

Anatomy education using skull models has been widely performed for a long time and known that it is actually much convenient and economical. However, until now, most of skull models used in anatomy class are imported from the United State or Europe. Therefore, the models showed characteristics of Caucasian skulls, and had several differences from skulls of Koreans. Hence, we made a specific replica model of skull which have various Korean characteristics. We used Korean male skull (aged 50 years) without defect due to diseases or fractures. The silicon was poured over the skull in the cubic frame and hardened. We took out the skull from the silicon frame and poured the resin into the frame to duplicate the original skull. After defoamation and hardening the resin, the skull model was taken out of frame. And we modified defects which occurred during duplicated process and made detailed structures which unrevealed in real skull. After completion of the skull model, we measured ten items of anthropological characteristics of the Korean and American skull models and compared 9 categories of index. As a result, there were significant differences in length-breadth index, length-height index, frontozygomatic index, nasal index between the Korean and American skull models; As aforementioned, the skull model, compared to Caucasian skull models, had numerous distinctive Korean skull features and this model can be used for anatomy education in South Korea.