Da-Yae Choi

The anatomical origin and course of the angular artery regarding its clinical implications.

BACKGROUND The purposes of this study were to determine the morphological features and conceptualize the anatomical definition of the angular artery (AA) as an aid to practical operations in the clinical field. MATERIALS AND METHODS Thirty-one hemifaces from 17 Korean cadavers and 26 hemifaces from 13 Thai cadavers were dissected. RESULTS The topography of the AA was classified into 4 types according to its course: Type I (persistent pattern), in which the AA traverses the lateral side of the nose (11%); Type II (detouring pattern), in which the AA traverses the cheek and tear trough area (18%); Type III (alternative pattern), in which the AA traverses the medial canthal area through a branch of the ophthalmic artery (22.8%); and Type IV (latent pattern), in which the AA is absent (26.3%). CONCLUSION The findings of this study will contribute toward improved outcomes for cosmetic surgery involving the injection of facial filler by enhancing the understanding of AA anatomy.

The risorius muscle: anatomic considerations with reference to botulinum neurotoxin injection for masseteric hypertrophy.

BACKGROUND The botulinum neurotoxin Type A (BTX) injection into the masseter muscle often causes a change in the facial expression. There is as yet no precise anatomic evidence to support this etiologic factor of constrained facial expressions. OBJECTIVE The aim of this study was to clarify the location and boundaries of the risorius muscle and its topographical relationship with the surrounding structures. MATERIALS AND METHODS This study involved the dissection of 48 hemifaces. The locations of origin and insertion points of the risorius muscle were measured, and the masseter muscle was divided into 6 equally sized rectangular areas. RESULTS Cases where the masseter muscle was covered by the risorius muscle were classified into the following 4 types: in Type A, Area III was partially covered by the risorius (17.8%); in Type B, Area VI was partially covered (20.0%); in Type C, Areas III and VI were partially covered (53.3%); and in Type D, Areas II, III, and VI were covered (6.7%). CONCLUSION These findings suggest that the medial part of the masseter muscle represents a hazard zone into which the injection of BTX may affect the risorius muscle, potentially resulting in iatrogenic unnatural facial expressions.

Topography of the lingual foramen using micro-computed tomography for improving safety during implant placement of anterior mandibular region.

AbstractThe aim of this study was to determine the location and size of the lingual foramina and the course of their canals using micro–computed tomography. Twenty Korean mandibles were scanned using a micro–computed tomography system and reconstructed three-dimensionally to enable observation of the lingual foramina and their canals.Four mandibles (20%) had a single foramen at the lingual side of the mandibular midline, 8 mandibles (40%) had 2 foramina, and 5 mandibles (25%) had 3 foramina. Three mandibles (15%) had 4 small foramina with short canals. The foramina were classified as either superior lingual foramina or inferior lingual foramina according to their vertical location relative to the mental spine. The diameters of superior lingual foramina and inferior lingual foramina were 0.75 ± 0.36 and 0.73 ± 0.38 mm (mean ± SD), respectively. The distances from the inferior border of the mandible to superior lingual foramina and inferior lingual foramina were 12.58 ± 2.49 and 6.43 ± 3.08 mm, respectively. Ten canals (21%) traveled upward to the labial side, 24 canals (51%) downward, and 13 canals (28%) parallel to it. Ten mandibles (50%) had lateral foramina.With regard to implant surgery of the anterior mandibular region, the most hazardous zones for lingual foramina are 0 to 2 mm from the midline, the upper 3 to 17 mm from the inferior border of the mandible, and the anterior 0 to 7 mm from the lingual side. Careful preoperative planning taking into account the anatomical location of these foramina might help to avoid complications due to damage to the foramina, their canals, and their contents.

Topography of the submental artery that should be considered in bleeding during dentoalveolar surgery.

Abstract The purpose of the present study was to provide precise data regarding the branching pattern of the submental artery, which should be considered in occasions of bleeding during various dentoalveolar surgical procedures of the mandible, such as implant surgeries, tori removal, and iatrogenic injuries. Twenty-six embalmed adult hemifaces from Korean cadavers were used in this study. The vertical distance, horizontal distance, and diameter of the submental artery were measured from the site of the first premolar to the third molar. In cases where there was penetration of the mylohyoid muscle by the main branches of the submental artery, the same items were measured at that point. The vertical distance between the submental artery and the inferior border of the mandible decreased toward the premolar, whereas the horizontal distance from the lingual plate of the mandible increased gradually as it traveled in the anterior direction. The diameter of the artery narrowed slightly toward the premolar. The main branches of the submental artery perforated the mylohyoid muscle in 14 (54%) of the 26 specimens. As a result of this study, the submental artery is located higher from the inferior border and closer to the lingual plate of the mandible in the region of the molar than that of the premolar. Therefore, clinicians should be more careful of bleeding when performing surgery in the molar region compared with the premolar region. Where the mylohyoid muscle is perforated by the main branches of the submental artery, its point of insertion can be observed in diverse locations.

Intramuscular communicating branches in the flexor digitorum profundus: dissection and Sihler's staining.

PurposeThis study was designed to clarify the anatomy of the intramuscular communicating branch (ICb) between the median and ulnar nerves in the flexor digitorum profundus (FDP), and morphologically demonstrate the location of connection.MethodsTwenty Korean cadavers were dissected and a further 8 were subjected to modified Sihler’s staining to investigate the pattern of innervation of the ICb and the location of its communicating points in muscle.ResultsThe median and ulnar nerves divided into small branches before entering FDP muscle. Of these small branches, one or two met inside the muscle. This communicating pattern could be classified into three types: type I, communicating branches in both the proximal and distal regions; type II, at least one communicating branch in the proximal region; type III, at least one communicating branch in the distal region. Of 20 dissected specimens, no case of type I was observed, but 3 cases of type II and 15 cases of type III were found. No ICbs at all were found in two of the dissected specimens. In eight stained specimens, one was classified as type I, two as type II, and five as type III. The proximal communicating branches were located at 34.1% from the interepicondylar line, inside the third muscle bundle. The distal communicating branches were located at 66.0% from the interepicondylar line, between third and fourth muscle bundles.ConclusionsThese findings could provide critical anatomical information regarding the nerve distribution of FDP focused on the ICbs.

Topography of the arteries supplying the masseter muscle: Using dissection and Sihler's method.

Various surgical procedures require surgeons to have detailed knowledge of the course of blood vessels in the masseter muscle, such as masseter muscle flap formation, mandibular angle resection, parotidectomy, and mandibular ramus osteotomy. Without this knowledge serious complications can occur, endangering the lives of patients. Occasionally, during routine dissections we sometimes encounter an additional branch. The purpose of this study was to provide a comprehensive detailed anatomic description of the blood supply of the masseter muscle. This will provide critical information for various surgical procedures. Twenty‐five Korean cadavers were dissected and subjected to modified Sihlers method to reveal the branching patterns of the arteries surrounding the masseter muscle, and its intramuscular blood supply. The masseter can be supplied by seven branches from the external carotid artery. Among these, the masseteric branch from the deep temporal artery has not been described previously. This previously undescribed branch enters the medial surface of the masseter, turning medially around the anterior border of the ramus immediately after the branching point of the deep temporal artery. The branch originating from the transverse facial artery was the largest, and the branches originating from the external carotid artery and deep temporal artery were the smallest. Examination of intramuscular patterns revealed that the branches of the transverse facial artery were the most widely distributed. When considering arterial diameters and distribution areas, the branches of the transverse facial artery can be considered the main components of the seven branches supplying the masseter muscle. Clin. Anat. 25:308–313, 2012.

Three-dimensional courses of zygomaticofacial and zygomaticotemporal canals using micro-computed tomography in Korean.

Abstract The zygomatic nerve (ZN), which originates from the maxillary nerve at the pterygopalatine fossa, enters the orbit through the inferior orbital fissure. Within the lateral region of the orbit, the ZN divides into the zygomaticofacial (ZF) and zygomaticotemporal (ZT) nerves. The ZF and ZT nerves then pass on to the face and temporal region through the zygomaticoorbital foramen and enter their own bony canals within the zygomatic bone. However, multiple zygomaticofacial and zygomaticotemporal canals (ZFCs and ZTCs, respectively) can be observed, and their detailed intrabony courses are unknown. The aim of this study was clarify the three-dimensional intrabony courses and running patterns of the ZFCs and ZTCs, both to obtain a detailed anatomical description and for clinical purposes. Fourteen sides of the zygomatic bones were scanned as two-dimensional images using a micro-computed tomography (CT), with 32-&mgr;m slice thickness. Intrabony structures of each canals were three-dimensionally reconstructed and analyzed using Mimics computer software (Version 10.01; Materialise, Leuven, Belgium). We found that some ZTC was originated from ZFC. In 71.4% of the specimens, the ZTC(s) divided from the intrabony canal along the course of the ZFC(s). In other cases, 28.6% of ZTCs were opened through each corresponding ZT foramen. Zygomaticofacial canal originates from zygomaticoorbital foramen, divided into some of ZTCs, and is finally opened as ZF foramen. This new anatomical description of the intrabony structures of the ZFC(s) and ZTC(s) within the zygomatic bone by micro-CT technology provided helpful information to surgeons performing clinical procedures such as Le Fort osteotomy and reconstructive surgeries in the midface region.