This study aimed to clarify the relationship between the joint and ligament structures of the sub... more This study aimed to clarify the relationship between the joint and ligament structures of the subtalar joint and degeneration of the subtalar articular facet. We examined 50 feet from 25 Japanese cadavers. The number of articular facets, joint congruence, and intersecting angle were measured for the joint structure of the subtalar joint, and the footprint areas of the ligament attachments of the cervical ligament, interosseous talocalcaneal ligament (ITCL), and anterior capsular ligament were measured for the ligament structure. Also, subtalar joint facets were classified into Degeneration (+) and (-) groups according to degeneration of the talus and calcaneus. No significant relationship was identified between the joint structure of the subtalar joint and degeneration of the subtalar articular facet. In contrast, footprint area of the ITCL was significantly higher in the Degeneration (+) group than in the Degeneration (-) group for the subtalar joint facet. These results suggest th...
The purpose of this study was to clarify the attachment types of the tibialis anterior tendon (TA... more The purpose of this study was to clarify the attachment types of the tibialis anterior tendon (TAT) in Japanese fixed cadavers and to determine the attachment site area in three dimensions. We examined 100 feet from 50 Japanese cadavers. The TAT was classified according to differences in the number of fiber bundles as: Type I, with one fiber bundle; Type II, with two fiber bundles; and Type III, with three fiber bundles. The attachment site area of the TAT was measured using a three-dimensional scanner. Cases were Type II in 95% and Type III in 5%, with no cases of Type I identified. In Type II, mean attachment site areas were 85.2 ± 18.2 mm2 for the medial cuneiform bone (MCB) and 72.4 ± 19.0 mm2 for the first metatarsal bone (1MB), showing a significantly larger area for MCB than for 1MB. These findings suggest the possibility of ethnic differences in TAT attachment types and suggest that TAT attachments in Japanese individuals are highly likely to be Type II, with rare cases of T...
International Journal of Environmental Research and Public Health
Background: The purpose of this study was not only to examine the attachment site but also to qua... more Background: The purpose of this study was not only to examine the attachment site but also to quantify the effect of the tibialis posterior tendon (TPT) on each attachment site by examining the surface area of the attachment region. Methods: We examined 100 feet from 50 Japanese cadavers. The TPT attachment to the navicular bone (NB), medial cuneiform bone (MCB), and lateral cuneiform bone (LCB) were set as the main attachment sites (Type I). The attachment seen in Type I with the addition of one additional site of attachment was defined as Type II. Furthermore, surface area was measured using a three-dimensional scanner. Results: Attachment to the NB, MCB, and LCB was present in all specimens. The TPT attachment to the NB, MCB, and LCB comprised 75.1% of total attachment surface area. The ratio of the NB, MCB, and LCB in each type was about 90% in Types II and III, and 70–80% in Types IV–VII. Conclusion: The quantitative results demonstrated the NB, MCB, and LCB to be the main site...
The aims of this study were to compare crown dimensions of mandibular first molars (M1) and secon... more The aims of this study were to compare crown dimensions of mandibular first molars (M1) and second molars (M2) between Mongolians (belonging to the Khalkha-Mogol grouping) and Caucasians (Northern European ancestry) and to attempt to explain any observed differences in phylogenetic and ontogenetic terms. Materials in this study comprised dental casts of 48 Mongolian female subjects with a mean age of 20.5 years and 50 Caucasian female subjects with a mean age of 21.5 years. For M1, the buccolingual diameters of both mesial and distal crown components in Mongolians were significantly larger than in Caucasians. For M2, the mesiodistal and buccolingual diameters of the (1990) observed this dental pattern in populations of Northern China, Mongolia, and Southern Siberia. Even though frequencies of occurrence and degrees of expression of nonmetric morphological crown features have been described in many Asian populations, including Mongolians (Scott and Turner, 1998; Turner, 1990; Manabe ...
The aim of this study was to elucidate the morphological characteristics of the lateral Lisfranc ... more The aim of this study was to elucidate the morphological characteristics of the lateral Lisfranc ligament in a large sample. This investigation examined 100 legs from 50 cadavers. Each of the lower limbs was dissected to identify the plantar aspect of the transverse metatarsal arch, and morphological characteristics of the lateral plantar ligament were assessed, including the length, width, and thickness of the fiber bundles. The majority of plantar ligaments originated from the base of M5 and the plantar aspect of the lateral cuneiform (LC). The lateral plantar ligament could be classified into three types: Type I, a band‐like fiber bundle originating from the base of M5 to the LC (41%); Type II, originating from the base of M5 and the plantar aspect of LC and mostly connected the blending the fiber bundles of the tibialis posterior (TP) and long plantar ligament (LPL) (21%); and Type III, with no ligaments originating from the base of M5 and plantar aspect of the LC (38%). The morphological characteristics of Type I lateral plantar ligament were as follows: length, 31.8 ± 3.7 mm; width, 2.3 ± 1.0 mm; and thickness, 0.2 ± 0.3 mm. The morphology of the lateral plantar ligament showed variation, originating from the base of M5 and the plantar aspect of LC most commonly, but this was not the case in 38% of limbs. The findings suggest that the lateral plantar ligament might play a role in the transverse tarsal arch, indicating a cooperative mechanism with the TP and LPL.
Scandinavian Journal of Medicine & Science in Sports, 2017
In this study, detailed investigations of the shape of the inferior patellar pole, the site of th... more In this study, detailed investigations of the shape of the inferior patellar pole, the site of the patellar tendon attachment, and the length and course of the patellar tendon were performed with the aim of examining the anatomical factors involved in the developmental mechanism of patellar tendinitis. The investigation examined 100 legs from 50 cadavers. The inferior patellar pole was classified into three types: Pointed, Intermediate, and Blunt. The attachment Accepted Article This article is protected by copyright. All rights reserved. of the patellar tendon to the inferior patellar pole was classified into two types: an anterior and a posterior. The length of the patellar tendon was measured from the tibial tuberosity to the inferior patellar pole. The Pointed Type was seen in 57% of legs, the Intermediate Type in 21%, and the Blunt Type in 22%. Twenty-one legs were the Pointed Type, as well as the Anterior Type. The patellar tendon was significantly shorter with the Posterior Type than with the Anterior Type. The Blunt Type also had a significantly shorter patellar tendon than the Pointed Type. In legs that were both the Pointed Type and the Anterior Type, the inferior patellar pole and the proximal posterior surface of the patellar tendon impinged during knee flexion due to the posterior tilt of the patella, suggesting the possibility that this may induce damage. With the Posterior Type and Blunt Type, on the other hand, the possibility of strong tensile stress on the tendon fibres of the posterior facet of the inferior patellar pole was suggested.
Background The aim of this study was to clarify the differences in morphological features between... more Background The aim of this study was to clarify the differences in morphological features between the long plantar ligament (LPL) and the short plantar ligament (SPL). Methods This investigation examined 50 legs from 25 Japanese cadavers. The LPL and SPL of each leg were classified into one of three types based on the shape and number of fiber bundles. Then, fiber bundle length, fiber bundle width, and fiber bundle thickness were measured. Results The LPL was rectangular in shape (Type I) in 12%, hourglass shape (Type II) in 62%, and triangular in shape (Type III) in 26%. The SPL was a single fiber bundle (Type I-a) in 26%, a surface fiber bundle and a deep fiber bundle (Type I-b) in 60%, and a surface fiber bundle (medial and lateral) and a deep fiber bundle (Type II) in 14%. Regarding the morphological characteristics, there were no significant differences among the types in the LPL, but there were differences between types and between surface and deep fiber bundles in the SPL. Co...
BACKGROUND The knowledge of nerves and vessels in the maxillofacial region, particularly the anat... more BACKGROUND The knowledge of nerves and vessels in the maxillofacial region, particularly the anatomical structures in the maxilla, mandible, tongue muscles, and salivary glands, is essential for dental surgeons. In addition, the structures in the mandibular canal, palate, and maxillary sinus should be understood well. HIGHLIGHT The arteries and nerves in the maxillofacial region were observed in this study. Some variations in the origin of the inferior alveolar artery were found. Notably, the variations in the origin of the inferior alveolar artery from that of the external carotid artery and a double origin of the inferior alveolar artery were observed. Thus, the maxillary artery may originate from the external carotid and stapedial arteries. The following points are important. (1)The greater palatine artery is always located deeper than the greater palatine nerve. (2)The posterior superior alveolar artery often runs through the compact bone of the maxilla. Using CT scans, the canal of the artery can be observed. (3)Variations in origins of the inferior alveolar artery have been observed. The origin of the inferior alveolar nerve may differ depending on the course of the maxillary artery. CONCLUSIONS Dental practitioners should, therefore, have a comprehensive knowledge of the anatomy of the maxillofacial region and its variations. Without this knowledge, they should not operate on patients.
BACKGROUND The aim of this study was to clarify the morphology of the mylohyoid branch of the inf... more BACKGROUND The aim of this study was to clarify the morphology of the mylohyoid branch of the inferior alveolar artery and the main blood supply to the mylohyoid muscle. METHODS The maxillary artery (MA) and inferior alveolar artery (IAA) within the infratemporal fossa, the facial and submental arteries within the submandibular triangle, and the nerve to the mylohyoid muscle and related artery were dissected in twelve sides from embalmed cadaveric heads. The main blood supply to the extraoral (inferior) surface of the mylohyoid muscle was recorded. RESULTS The mylohyoid branch of the inferior alveolar artery was an anastomosis of the descending branch of either the inferior alveolar or maxillary artery and the ascending branch of either the submental or facial artery. The anastomosis was classified into four types according to the origins of the arteries. The main blood supply to the extraoral surface of the mylohyoid muscle was the submental artery. CONCLUSIONS The results of this study indicate that the mylohyoid branch of the IAA in human adults is an anastomosis of branches of the maxillary and facial arteries.
The tongues of two Pacific white-sided dolphins were examined by light and scanning electron micr... more The tongues of two Pacific white-sided dolphins were examined by light and scanning electron microscopy. Each tongue was triangular shaped with about 15 cm in length and 6.5 cm in width. The surface of the tongue appeared relatively smooth and no lingual papillae were observed. Parakeratinization was observed in the stratum corneum epidermidis. The tongue was formed of V shape with 6 to 8 grooves on the dorsal surface posterior of the tongue. The taste buds were observed on the papillae in the grooves. By removing the epithelium, it was revealed that the conical connective tissue cores were densely distributed. The morphological characters of the tongue of the Pacific white-sided dolphin were similar to those of the Striped dolphin and Bottlenose dolphin.
BACKGROUND Evaluating segmental variations in the lumbar plexus is crucial for neurological diagn... more BACKGROUND Evaluating segmental variations in the lumbar plexus is crucial for neurological diagnosis. In the present study, we examined the relationship between the segmental composition of the lumbar plexus and length of the 12th rib. PROCEDURES To evaluate segmental variations in the lumbar plexus, the furcal nerve (Nf) which forms the boundary between the lumbar and sacral plexus, was used as an index of plexus arrangement. MAIN FINDINGS Segmental variations in the Nf were classified into four groups on the basis of whether the Nf originated from the ventral rami of L3 and L4 (Nf L3 + L4 group), L4 (Nf L4 group), L4 and L5 (Nf L4 + L5 group), or L5 (Nf L5 group). The Nf L3 + L4 group was associated with short 12th rib, and groups Nf L4 + L5 and Nf L5 were associated with long 12th rib. These findings suggest that the segmental variations in the lumbar plexus are related to the length of the 12th rib. CONCLUSIONS Therefore, the segmental variations in the lumbar plexus can be evaluated non-invasively and easily by measuring the length of the 12th rib. This may contribute to the diagnosis and treatment of various lumbar radiculopathies.
The purpose of this study was to determine the long axes of molars with multiple roots through or... more The purpose of this study was to determine the long axes of molars with multiple roots through ordinary least squares regression (LSR) and to compare them with the axes defined by principal component analysis (PCA). Three-dimensional radiological images of 20 dry skulls were obtained by cone-beam computed tomography (CBCT). Data from maxillary and mandibular first molars were extracted from the CBCT DICOM data with a three-dimensional image visualization system. The obtained data were reconstructed, converted to STL files, and three-dimensional coordinate values were extracted. The long axes were estimated by an algorithm to synchronize the LSR line with the horizontal axis which was translated to the vertical axis. The axes of the molars defined by LSR were compared with the axes of the molars defined by PCA. The coordinate point number of each molar was 5400–5800. The algorithm for determining the tooth axes in this study consisted of four stages containing three steps each. The d...
The course of the superior gluteal artery (SGA) as it passes through the lumbosacral plexus is va... more The course of the superior gluteal artery (SGA) as it passes through the lumbosacral plexus is variable. The variations of the arterial course in relation to the lumbosacral plexus have focused on statistical analysis, and it is limited arterial diversity. In this study, we investigated the positional relation between the SGA and the furcal nerve (FN): guide to segmentation of the lumbosacral plexus, arising from the L4, ie, the contribution to the femoral nerve, obturator nerve, and lumbosacral trunk. We could classify the pathway of the SGA into three types based on its positional relation to the FN. The SGA courses under the ramus from which the FN originates (Type A), under the ramus one segment below the origin of the FN (Type B), or between the obturator nerve and the lumbosacral trunk (Type C). The SGA pathway in Types A and B showed a cranial or caudal shift along with cranial or caudal deviation of the FN. In summary, the variation in the SGA pathway was correlated with cranial or caudal shift of the FN. Our findings indicate that variations of the SGA pathway are associated not only with arterial transformation, but also with diversity of the lumbosacral plexus.
To clarify the role of the primate tongue as a means to better understand the evolution of oral f... more To clarify the role of the primate tongue as a means to better understand the evolution of oral function among primatesan example of adaptation within the restricted phylogenetic group-we review the morphological knowledge of the tongues of extant primates in relation to phylogenetic classification. Prosimians tongues are more effective than those of Haplorhini for taking up food with the tongue alone, because they are capable of fine movement when outside the oral cavity. However, the role of the tongue in food uptake has diminished when juxtaposed with progress in hand manipulation of food and tools in Haplorhini, especially with the manipulation of tools by Homininae. This change in the tongue from prosimians to Homininae can be regarded as degeneration in food uptake by the tongue, although the functional role of the tongue within the oral cavity has not diminished. The distribution pattern and form of lingual papillae, except foliate papillae, are very similar among all reported primates species. Although foliate papillae are generally well developed in Haplorhini, most prosimian species have no foliate papillae, or a different type of papillae that substitute for foliate papillae. There are three vallate papillae in prosimian species and the New-World macaques, Platyrrhini. These papillae exhibit an inverted V-shape and are more numerous in Old World macaques, Catarrhini. These differences seem to be the result of phylogenetic origin.
This study aimed to clarify the relationship between the joint and ligament structures of the sub... more This study aimed to clarify the relationship between the joint and ligament structures of the subtalar joint and degeneration of the subtalar articular facet. We examined 50 feet from 25 Japanese cadavers. The number of articular facets, joint congruence, and intersecting angle were measured for the joint structure of the subtalar joint, and the footprint areas of the ligament attachments of the cervical ligament, interosseous talocalcaneal ligament (ITCL), and anterior capsular ligament were measured for the ligament structure. Also, subtalar joint facets were classified into Degeneration (+) and (-) groups according to degeneration of the talus and calcaneus. No significant relationship was identified between the joint structure of the subtalar joint and degeneration of the subtalar articular facet. In contrast, footprint area of the ITCL was significantly higher in the Degeneration (+) group than in the Degeneration (-) group for the subtalar joint facet. These results suggest th...
The purpose of this study was to clarify the attachment types of the tibialis anterior tendon (TA... more The purpose of this study was to clarify the attachment types of the tibialis anterior tendon (TAT) in Japanese fixed cadavers and to determine the attachment site area in three dimensions. We examined 100 feet from 50 Japanese cadavers. The TAT was classified according to differences in the number of fiber bundles as: Type I, with one fiber bundle; Type II, with two fiber bundles; and Type III, with three fiber bundles. The attachment site area of the TAT was measured using a three-dimensional scanner. Cases were Type II in 95% and Type III in 5%, with no cases of Type I identified. In Type II, mean attachment site areas were 85.2 ± 18.2 mm2 for the medial cuneiform bone (MCB) and 72.4 ± 19.0 mm2 for the first metatarsal bone (1MB), showing a significantly larger area for MCB than for 1MB. These findings suggest the possibility of ethnic differences in TAT attachment types and suggest that TAT attachments in Japanese individuals are highly likely to be Type II, with rare cases of T...
International Journal of Environmental Research and Public Health
Background: The purpose of this study was not only to examine the attachment site but also to qua... more Background: The purpose of this study was not only to examine the attachment site but also to quantify the effect of the tibialis posterior tendon (TPT) on each attachment site by examining the surface area of the attachment region. Methods: We examined 100 feet from 50 Japanese cadavers. The TPT attachment to the navicular bone (NB), medial cuneiform bone (MCB), and lateral cuneiform bone (LCB) were set as the main attachment sites (Type I). The attachment seen in Type I with the addition of one additional site of attachment was defined as Type II. Furthermore, surface area was measured using a three-dimensional scanner. Results: Attachment to the NB, MCB, and LCB was present in all specimens. The TPT attachment to the NB, MCB, and LCB comprised 75.1% of total attachment surface area. The ratio of the NB, MCB, and LCB in each type was about 90% in Types II and III, and 70–80% in Types IV–VII. Conclusion: The quantitative results demonstrated the NB, MCB, and LCB to be the main site...
The aims of this study were to compare crown dimensions of mandibular first molars (M1) and secon... more The aims of this study were to compare crown dimensions of mandibular first molars (M1) and second molars (M2) between Mongolians (belonging to the Khalkha-Mogol grouping) and Caucasians (Northern European ancestry) and to attempt to explain any observed differences in phylogenetic and ontogenetic terms. Materials in this study comprised dental casts of 48 Mongolian female subjects with a mean age of 20.5 years and 50 Caucasian female subjects with a mean age of 21.5 years. For M1, the buccolingual diameters of both mesial and distal crown components in Mongolians were significantly larger than in Caucasians. For M2, the mesiodistal and buccolingual diameters of the (1990) observed this dental pattern in populations of Northern China, Mongolia, and Southern Siberia. Even though frequencies of occurrence and degrees of expression of nonmetric morphological crown features have been described in many Asian populations, including Mongolians (Scott and Turner, 1998; Turner, 1990; Manabe ...
The aim of this study was to elucidate the morphological characteristics of the lateral Lisfranc ... more The aim of this study was to elucidate the morphological characteristics of the lateral Lisfranc ligament in a large sample. This investigation examined 100 legs from 50 cadavers. Each of the lower limbs was dissected to identify the plantar aspect of the transverse metatarsal arch, and morphological characteristics of the lateral plantar ligament were assessed, including the length, width, and thickness of the fiber bundles. The majority of plantar ligaments originated from the base of M5 and the plantar aspect of the lateral cuneiform (LC). The lateral plantar ligament could be classified into three types: Type I, a band‐like fiber bundle originating from the base of M5 to the LC (41%); Type II, originating from the base of M5 and the plantar aspect of LC and mostly connected the blending the fiber bundles of the tibialis posterior (TP) and long plantar ligament (LPL) (21%); and Type III, with no ligaments originating from the base of M5 and plantar aspect of the LC (38%). The morphological characteristics of Type I lateral plantar ligament were as follows: length, 31.8 ± 3.7 mm; width, 2.3 ± 1.0 mm; and thickness, 0.2 ± 0.3 mm. The morphology of the lateral plantar ligament showed variation, originating from the base of M5 and the plantar aspect of LC most commonly, but this was not the case in 38% of limbs. The findings suggest that the lateral plantar ligament might play a role in the transverse tarsal arch, indicating a cooperative mechanism with the TP and LPL.
Scandinavian Journal of Medicine & Science in Sports, 2017
In this study, detailed investigations of the shape of the inferior patellar pole, the site of th... more In this study, detailed investigations of the shape of the inferior patellar pole, the site of the patellar tendon attachment, and the length and course of the patellar tendon were performed with the aim of examining the anatomical factors involved in the developmental mechanism of patellar tendinitis. The investigation examined 100 legs from 50 cadavers. The inferior patellar pole was classified into three types: Pointed, Intermediate, and Blunt. The attachment Accepted Article This article is protected by copyright. All rights reserved. of the patellar tendon to the inferior patellar pole was classified into two types: an anterior and a posterior. The length of the patellar tendon was measured from the tibial tuberosity to the inferior patellar pole. The Pointed Type was seen in 57% of legs, the Intermediate Type in 21%, and the Blunt Type in 22%. Twenty-one legs were the Pointed Type, as well as the Anterior Type. The patellar tendon was significantly shorter with the Posterior Type than with the Anterior Type. The Blunt Type also had a significantly shorter patellar tendon than the Pointed Type. In legs that were both the Pointed Type and the Anterior Type, the inferior patellar pole and the proximal posterior surface of the patellar tendon impinged during knee flexion due to the posterior tilt of the patella, suggesting the possibility that this may induce damage. With the Posterior Type and Blunt Type, on the other hand, the possibility of strong tensile stress on the tendon fibres of the posterior facet of the inferior patellar pole was suggested.
Background The aim of this study was to clarify the differences in morphological features between... more Background The aim of this study was to clarify the differences in morphological features between the long plantar ligament (LPL) and the short plantar ligament (SPL). Methods This investigation examined 50 legs from 25 Japanese cadavers. The LPL and SPL of each leg were classified into one of three types based on the shape and number of fiber bundles. Then, fiber bundle length, fiber bundle width, and fiber bundle thickness were measured. Results The LPL was rectangular in shape (Type I) in 12%, hourglass shape (Type II) in 62%, and triangular in shape (Type III) in 26%. The SPL was a single fiber bundle (Type I-a) in 26%, a surface fiber bundle and a deep fiber bundle (Type I-b) in 60%, and a surface fiber bundle (medial and lateral) and a deep fiber bundle (Type II) in 14%. Regarding the morphological characteristics, there were no significant differences among the types in the LPL, but there were differences between types and between surface and deep fiber bundles in the SPL. Co...
BACKGROUND The knowledge of nerves and vessels in the maxillofacial region, particularly the anat... more BACKGROUND The knowledge of nerves and vessels in the maxillofacial region, particularly the anatomical structures in the maxilla, mandible, tongue muscles, and salivary glands, is essential for dental surgeons. In addition, the structures in the mandibular canal, palate, and maxillary sinus should be understood well. HIGHLIGHT The arteries and nerves in the maxillofacial region were observed in this study. Some variations in the origin of the inferior alveolar artery were found. Notably, the variations in the origin of the inferior alveolar artery from that of the external carotid artery and a double origin of the inferior alveolar artery were observed. Thus, the maxillary artery may originate from the external carotid and stapedial arteries. The following points are important. (1)The greater palatine artery is always located deeper than the greater palatine nerve. (2)The posterior superior alveolar artery often runs through the compact bone of the maxilla. Using CT scans, the canal of the artery can be observed. (3)Variations in origins of the inferior alveolar artery have been observed. The origin of the inferior alveolar nerve may differ depending on the course of the maxillary artery. CONCLUSIONS Dental practitioners should, therefore, have a comprehensive knowledge of the anatomy of the maxillofacial region and its variations. Without this knowledge, they should not operate on patients.
BACKGROUND The aim of this study was to clarify the morphology of the mylohyoid branch of the inf... more BACKGROUND The aim of this study was to clarify the morphology of the mylohyoid branch of the inferior alveolar artery and the main blood supply to the mylohyoid muscle. METHODS The maxillary artery (MA) and inferior alveolar artery (IAA) within the infratemporal fossa, the facial and submental arteries within the submandibular triangle, and the nerve to the mylohyoid muscle and related artery were dissected in twelve sides from embalmed cadaveric heads. The main blood supply to the extraoral (inferior) surface of the mylohyoid muscle was recorded. RESULTS The mylohyoid branch of the inferior alveolar artery was an anastomosis of the descending branch of either the inferior alveolar or maxillary artery and the ascending branch of either the submental or facial artery. The anastomosis was classified into four types according to the origins of the arteries. The main blood supply to the extraoral surface of the mylohyoid muscle was the submental artery. CONCLUSIONS The results of this study indicate that the mylohyoid branch of the IAA in human adults is an anastomosis of branches of the maxillary and facial arteries.
The tongues of two Pacific white-sided dolphins were examined by light and scanning electron micr... more The tongues of two Pacific white-sided dolphins were examined by light and scanning electron microscopy. Each tongue was triangular shaped with about 15 cm in length and 6.5 cm in width. The surface of the tongue appeared relatively smooth and no lingual papillae were observed. Parakeratinization was observed in the stratum corneum epidermidis. The tongue was formed of V shape with 6 to 8 grooves on the dorsal surface posterior of the tongue. The taste buds were observed on the papillae in the grooves. By removing the epithelium, it was revealed that the conical connective tissue cores were densely distributed. The morphological characters of the tongue of the Pacific white-sided dolphin were similar to those of the Striped dolphin and Bottlenose dolphin.
BACKGROUND Evaluating segmental variations in the lumbar plexus is crucial for neurological diagn... more BACKGROUND Evaluating segmental variations in the lumbar plexus is crucial for neurological diagnosis. In the present study, we examined the relationship between the segmental composition of the lumbar plexus and length of the 12th rib. PROCEDURES To evaluate segmental variations in the lumbar plexus, the furcal nerve (Nf) which forms the boundary between the lumbar and sacral plexus, was used as an index of plexus arrangement. MAIN FINDINGS Segmental variations in the Nf were classified into four groups on the basis of whether the Nf originated from the ventral rami of L3 and L4 (Nf L3 + L4 group), L4 (Nf L4 group), L4 and L5 (Nf L4 + L5 group), or L5 (Nf L5 group). The Nf L3 + L4 group was associated with short 12th rib, and groups Nf L4 + L5 and Nf L5 were associated with long 12th rib. These findings suggest that the segmental variations in the lumbar plexus are related to the length of the 12th rib. CONCLUSIONS Therefore, the segmental variations in the lumbar plexus can be evaluated non-invasively and easily by measuring the length of the 12th rib. This may contribute to the diagnosis and treatment of various lumbar radiculopathies.
The purpose of this study was to determine the long axes of molars with multiple roots through or... more The purpose of this study was to determine the long axes of molars with multiple roots through ordinary least squares regression (LSR) and to compare them with the axes defined by principal component analysis (PCA). Three-dimensional radiological images of 20 dry skulls were obtained by cone-beam computed tomography (CBCT). Data from maxillary and mandibular first molars were extracted from the CBCT DICOM data with a three-dimensional image visualization system. The obtained data were reconstructed, converted to STL files, and three-dimensional coordinate values were extracted. The long axes were estimated by an algorithm to synchronize the LSR line with the horizontal axis which was translated to the vertical axis. The axes of the molars defined by LSR were compared with the axes of the molars defined by PCA. The coordinate point number of each molar was 5400–5800. The algorithm for determining the tooth axes in this study consisted of four stages containing three steps each. The d...
The course of the superior gluteal artery (SGA) as it passes through the lumbosacral plexus is va... more The course of the superior gluteal artery (SGA) as it passes through the lumbosacral plexus is variable. The variations of the arterial course in relation to the lumbosacral plexus have focused on statistical analysis, and it is limited arterial diversity. In this study, we investigated the positional relation between the SGA and the furcal nerve (FN): guide to segmentation of the lumbosacral plexus, arising from the L4, ie, the contribution to the femoral nerve, obturator nerve, and lumbosacral trunk. We could classify the pathway of the SGA into three types based on its positional relation to the FN. The SGA courses under the ramus from which the FN originates (Type A), under the ramus one segment below the origin of the FN (Type B), or between the obturator nerve and the lumbosacral trunk (Type C). The SGA pathway in Types A and B showed a cranial or caudal shift along with cranial or caudal deviation of the FN. In summary, the variation in the SGA pathway was correlated with cranial or caudal shift of the FN. Our findings indicate that variations of the SGA pathway are associated not only with arterial transformation, but also with diversity of the lumbosacral plexus.
To clarify the role of the primate tongue as a means to better understand the evolution of oral f... more To clarify the role of the primate tongue as a means to better understand the evolution of oral function among primatesan example of adaptation within the restricted phylogenetic group-we review the morphological knowledge of the tongues of extant primates in relation to phylogenetic classification. Prosimians tongues are more effective than those of Haplorhini for taking up food with the tongue alone, because they are capable of fine movement when outside the oral cavity. However, the role of the tongue in food uptake has diminished when juxtaposed with progress in hand manipulation of food and tools in Haplorhini, especially with the manipulation of tools by Homininae. This change in the tongue from prosimians to Homininae can be regarded as degeneration in food uptake by the tongue, although the functional role of the tongue within the oral cavity has not diminished. The distribution pattern and form of lingual papillae, except foliate papillae, are very similar among all reported primates species. Although foliate papillae are generally well developed in Haplorhini, most prosimian species have no foliate papillae, or a different type of papillae that substitute for foliate papillae. There are three vallate papillae in prosimian species and the New-World macaques, Platyrrhini. These papillae exhibit an inverted V-shape and are more numerous in Old World macaques, Catarrhini. These differences seem to be the result of phylogenetic origin.
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Papers by Ikuo Kageyama