Missing medial tarsal artery replaced by the anterior medial malleolar artery.

The present case report describes an unusual variant of a missing medial tarsal artery (MTA) being replaced by the anterior medial malleolar artery (AMMA). The dorsalis pedis artery (DPA) did not give off any branches to the medial foot. The DPA coursed downward in the foot along with the superficial fibular nerve on the foot dorsum at the lateral side of the first metatarsal bone before entering the sole. In the medial malleolus, the AMMA arose from the anterior tibial artery and then ramified several branches, one of which descended to the medial talus. Thus, the possibility of a missing MTA being replaced by the AMMA should be considered by surgeons and radiologists when various surgeries are performed in the medial tarsal area.

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.

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.

Educational effect of 3D applications as a teaching aid for anatomical practice for dental hygiene students.

The purpose of this study is to find out effective methodology of anatomical curriculum by comparing the education effects and satisfaction using different teaching tools, plastic model and three-dimensional (3D) application. A survey was conducted on the satisfaction level, understanding, and the usefulness of the tools used in the lectures of the two dental hygiene students groups who used the 3D application and the plastic model respectively. The interest in anatomical structure of the 3D App group was 4.20, which was significantly higher than that of the plastic model group 3.60, and the usefulness of the content of anatomy education was 4.31 in the 3D App group, significantly higher than the plastic model group (P<0.05). It was found that the interest in anatomical structure of students increased by 0.347 when using 3D applications compared to the case without the use (P=0.012) and understanding in anatomical structure and class concentration increased by 0.191, respectively, but these results were marginally significant. We expect that this study serves as a reference for the development and supplementation of anatomy teaching and learning method.

Topography of the dorsal nasal artery and its clinical implications for augmentation of the dorsum of the nose.

BACKGROUND: Injections of filler into the nose for dorsum augmentation have a higher risk of complications due to the complicated blood supply and anastomotic channels in this area. OBJECTIVES: The aim of this study was to determine the anatomical features and location of the dorsal nasal artery (DNA), and to provide clinical anatomical information to reduce side effects and severe complications in the perinasal area. METHODS: Using the 31 cadaveric noses in Asians, dissections and histologic examinations were performed to identify the location and depth of the vascular structures including DNA. RESULTS: Dorsal nasal artery ran downward at 20.3 ± 3.5 mm from the intercanthal line and the communicating branch that connected the bilateral DNAs was located 8.5 ± 3.5 mm inferior to the intercanthal line. The DNA was located at 4.4 ± 3.2 mm, 4.6 ± 4.4 mm, and 5.2 ± 4.4 mm lateral to the midline of the nose on the intercanthal, quadrisected, and bisected lines, respectively. At the level of nasal bone, DNA was located superficial to the muscular layer and it runs inferolaterally on dorsum on nose. It was running more deeply and located beneath the fibromuscular layer at the cartilaginous portion of the dorsum of nose. CONCLUSIONS: Injection into deep fatty layer may reduce the risk of arterial injury and the consequent complications. However, in a hooked nose, the tip of the needle traveling along the deep layer approaches the superficial layer due to the convexity of the hump as it passes over it, which can increase the probability of damaging the DNA.

Accessory nerve distribution for aesthetic botulinum toxin injections into the upper trapezius muscle: anatomical study and clinical trial : Reproducible BoNT injection sites for upper trapezius.

PURPOSE: The descending part of the trapezius muscle is clinically associated with neck pain and aesthetic applications. The innervation of the trapezius muscle is not well described in the medical literature for clinicians. The aim of study was to analyze the perforating branch pattern of the accessory nerve in the descending part of the trapezius muscle with the aim of describing the most efficient and reproducible BoNT injection sites for aesthetic treatment of shoulder contouring. METHODS: Twenty-six specimens (five male and eight female) from embalmed Korean cadavers were used in this study. The trapezius muscle was dissected scrupulously and then reflected to enable examination of the locations of the perforating points. The thickness of trapezius muscle was measured in 13 volunteers using a diagnostic ultrasonography system. BoNT was injected into the trapezius muscle bilaterally. Injections were performed at 6 points separated by 2 cm. The muscle thicknesses were measured three times using ultrasonography: before the injection and at 4 and 12 weeks after the injection. RESULTS: The dense arborization of the perforating accessory nerve branches was confined mostly to section b (66.7%, 54/81) and section c (33.3%, 27/81). The mean muscle thickness at 4 and 12 weeks consistently decreased 0.68-0.63 cm  in conventional method and 0.65-0.61 cm in new method (NDM) respectively (right and left). CONCLUSION: To optimize the outcome of BoNT injection, we recommended injecting into six points separated by 2 cm in sections b and c of the upper trapezius muscle. It is significant that it is easier to apply to anyone than to apply unstructured techniques.

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.

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.

Anatomical considerations of the longitudinal pharyngeal muscles in relation to their function on the internal surface of pharynx.

The aim of this study was to clarify the topography of the longitudinal pharyngeal muscles and to relate the findings to pharyngeal muscular function. 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 palatopharyngeus muscle originated from the palatine aponeurosis and the median part of the soft palate on oral aspect; it ran downward and lateralward, respectively. The palatopharyngeus muscle, which held the levator veli palatini, was divided into two bundles, medial and lateral, according to the positional relationship with the levator veli palatini. The lateral bundle of the palatopharyngeus muscle was divided into two parts: longitudinal and transverse. The pharyngeal longitudinal muscles were classified into the following four types (I-IV) depending on the area of insertion: they were inserted into the palatine tonsil, epiglottis, arytenoid cartilage, piriform recess, thyroid cartilage, and pharyngeal wall. The transverse part of the palatopharyngeus muscle plays a role as a sphincter. Palatopharyngeus and levator veli palatini muscles help each other to function effectively in the soft palate. The present findings suggest that the pharyngeal muscles are involved not only in swallowing but also in respiration and phonation via their attachment to the laryngeal cartilage.

Clinical anatomic considerations of the zygomaticus minor muscle based on the morphology and insertion pattern.

BACKGROUND: The zygomaticus minor muscle (Zmi) is involved in the expression of many different facial emotions. However, the details of its insertion pattern and morphology are not well described. OBJECTIVE: The aim of this study was to clarify the morphology and insertion pattern of the Zmi, and to provide clinical anatomic information that will help elucidate its roles in animation. MATERIALS AND METHODS: Fifty-four embalmed adult hemifaces (18 men and 12 women; mean age, 67.4 years) from 30 cadavers were used in this study. The dissection was performed with the aid of a surgical microscope. RESULTS: This muscle could be classified into 3 types (A-C). Type A, in which the Zmi attached only to the upper lip, was observed in 63.0% of cases (34/54) and could be subdivided into 2 types: straight (A-1; 31.5%, 17 cases) and curved (A-2; 31.5%, 17 cases). Type B, in which the Zmi was attached to both the upper lip and the lateral alar region, occurred in 27.8% of cases (15/54). In Type C (9.2% of cases, 5/54), there was either no or only undeveloped Zmi fibers. CONCLUSION: The present finding of Zmi fibers being attached to the alar region in many cases (27.8%) suggests that this muscle is involved in elevation of both the nose ala and upper lip during various facial animations.

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

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-µm 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.

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

The 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.

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.

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.

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 Sihler's 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.

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

PURPOSE: This 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. METHODS: Twenty 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. RESULTS: The 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. CONCLUSIONS: These findings could provide critical anatomical information regarding the nerve distribution of FDP focused on the ICbs.