Standardized Extract of Centella asiatica Prevents Fear Memory Deficit in 3xTg-AD Mice

ECa 233 is a standardized extract of Centella asiatica (CA), an herb widely used in traditional Chinese and Ayurvedic medicine. Previous studies reported that ECa 233 enhanced memory retention and synaptic plasticity in the hippocampus of healthy rats. Because of this, we became curious whether ECa 233 has a therapeutic effect on the fear memory deficit in the triple transgenic Alzheimer's disease (3xTg-AD) model mice. Fear memory is a crucial emotional memory for survival that is found to be impaired in patients with early-onset Alzheimer's disease (AD). In this study, we orally administered ECa 233 (doses: 10, 30, and 100[Formula: see text]mg/kg) to 3xTg-AD mice, who were five months old, for 30 consecutive days. We found that ECa 233 prevented a cued fear memory deficit and enhanced hippocampal long-term potentiation (LTP) in 3xTg-AD mice. Subsequent proteomic and western blot analyses revealed increased expression levels of the molecules related to LTP induction and maintenance, including brain-derived neurotrophic factor (BDNF), tyrosine receptor kinase B (TrkB) and its network proteins, and extracellular signal-regulated kinase 1 and 2 (ERK1 and 2) in the hippocampi and amygdala of 3xTg-AD mice after ECa 233 pre-treatment. Our results indicate that ECa 233 is a promising potential herbal standardized extract that could be used in preventing the fear memory deficit and synaptic dysfunction before the early onset of AD.

Longus Colli and Vertebral Artery Guide Safety of Cervical Spine Surgery

Objective: To improve the safety of the anterior cervical vertebral surgical approach, MRI and CT have been used and the distances between the medial borders of the longus colli (LC) to expose the uncinated process (UP) have been reported. The anatomic parameters of the LC and vertebral artery (VA) were considered here in relation to the UP to minimize complications.Materials and Methods: Data were obtained from 60 Thai adult skeletons and 20 embalmed cadavers. Direct measurements of the dry cervical vertebrae were performed using digital Vernier calipers, while computer imaging analysis was used for the cadaveric measurements after capturing the images.Results: No significant difference was noted in the inter-UP distance between the dry and cadaveric cervical measurements. The average UP width was 6.7 ± 0.2 mm. The average distance from the tip of the UP to the VA was 2.6 ± 0.1 mm. The calculated distance from the LC to the UP which derived from the inter-UP distance and the distance between the LC increased from C2 to C7 with an average distance of 11.9 ± 0.3 mm.Conclusion: Within a distance of 11.9 ± 0.3 mm from the medial border of the LC, UP can be identified. Dissecting at a distance less than 10 mm posterior, 5–6 mm lateral and superior to the base of the UP can avoid VA injury and optimize the safety of the anterior cervical vertebral surgical approach.

Age and gender differences for the behavioral phenotypes of 3xTg alzheimer's disease mice

The triple transgenic Alzheimer's disease (3xTg-AD) strain is a common mouse model used for studying the pathology and mechanism of Alzheimer's disease (AD). The 3xTg-AD strain exhibits two hallmarks of AD, amyloid beta (Aβ) and neurofibrillary tangles. Several studies using different gender and age of 3xTg-AD mice to investigate their behavior phenotypes under the influence of various treatments have reported mixed results. Therefore, a comprehensive investigation on the optimal gender, age, and training paradigms used for behavioral studies of 3xTg-AD is necessary. In the present study, we investigated the behavioral phenotypes for the two genders of 3xTg-AD mice at 3, 6, 9, and 12 months old and compared the results with age-, gender-matched C57BL/6N control strain. All mice were subjected to tail flick, pinprick, open field, elevated plus maze, passive avoidance, and trace fear conditioning (TFC) tests to evaluate their sensory, locomotor, anxiety, and learning/memory functions. The results showed that TFC on male 3xTg-AD mice is optimal for studying the memory performance in AD. The sensory and locomotor functions of 3xTg-AD mice for two genders appear to be normal before 6 months, decline in fear memory afterwards. The differences between control and 3xTg-AD male mice in contextual and cued memory are robust, thus they are ideal for evaluating the effect of a treatment. Since it is costly and time consuming to obtain wildtype littermates as controls, C57BL/6N strain is suggested to be used as control mice because their baseline performance of sensorimotor functions are similar to that of 3xTg-AD mice.

Enhanced contextual fear memory in peroxiredoxin 6 knockout mice is associated with hyperactivation of MAPK signaling pathway

Fear dysregulation is one of the symptoms found in post-traumatic stress disorder (PTSD) patients. The functional abnormality of the hippocampus is known to be implicated in the development of such pathology. Peroxiredoxin 6 (PRDX6) belongs to the peroxiredoxin family. This antioxidant enzyme is expressed throughout the brain, including the hippocampus. Recent evidence reveals that PRDX6 plays an important role in redox regulation and the modulation of several signaling molecules involved in fear regulation. Thus, we hypothesized that PRDX6 plays a role in the regulation of fear memory. We subjected a systemic Prdx6 knockout (Prdx6-/-) mice to trace fear conditioning and observed enhanced fear response after training. Intraventricular injection of lentivirus-carried mouse Prdx6 into the 3rd ventricle reduced the enhanced fear response in these knockout mice. Proteomic analysis followed by validation of western blot analysis revealed that several proteins in the MAPK pathway, such as NTRK2, AKT, and phospho-ERK1/2, cPLA2 were significantly upregulated in the hippocampus of Prdx6-/- mice during the retrieval stage of contextual fear memory. The distribution of PRDX6 found in the astrocytes was also observed throughout the hippocampus. This study identifies PRDX6 as a participant in the regulation of fear response. It suggests that PRDX6 and related molecules may have important implications for understanding fear-dysregulation associated disorders like PTSD.

The 4-(Phenylsulfanyl) butan-2-one Improves Impaired Fear Memory Retrieval and Reduces Excessive Inflammatory Response in Triple Transgenic Alzheimer's Disease Mice

Alzheimer's disease (AD) is a neurodegenerative disease characterized by an excessive inflammatory response and impaired memory retrieval, including spatial memory, recognition memory, and emotional memory. Acquisition and retrieval of fear memory help one avoid dangers and natural threats. Thus, it is crucial for survival. AD patients with impaired retrieval of fear memory are vulnerable to dangerous conditions. Excessive expression of inflammatory markers is known to impede synaptic transmission and reduce the efficiency of memory retrieval. In wild-type mice, reducing inflammation response can improve fear memory retrieval; however, this effect of this approach is not yet investigated in 3xTg-AD model mice. To date, no satisfactory drug or treatment can attenuate the symptoms of AD despite numerous efforts. In the past few years, the direction of therapeutic drug development for AD has been shifted to natural compounds with anti-inflammatory effect. In the present study, we demonstrate that the compound 4-(phenylsulfanyl) butan-2-one (4-PSB-2) is effective in enhancing fear memory retrieval of wild-type and 3xTg-AD mice by reducing the expression of TNF-α, COX-2, and iNOS. We also found that 4-PSB-2 helps increase dendritic spine density, postsynaptic density protein-95 (PSD-95) expression, and long-term potentiation (LTP) in the hippocampus of 3xTg-AD mice. Our study indicates that 4-PSB-2 may be developed as a promising therapeutic compound for treating fear memory impairment of AD patients.

4-(Phenylsulfanyl) Butan-2-One Attenuates the Inflammatory Response Induced by Amyloid-β Oligomers in Retinal Pigment Epithelium Cells

Age-related macular degeneration (AMD) is a progressive eye disease that causes irreversible impairment of central vision, and effective treatment is not yet available. Extracellular accumulation of amyloid-beta (Aβ) in drusen that lie under the retinal pigment epithelium (RPE) has been reported as one of the early signs of AMD and was found in more than 60% of Alzheimer’s disease (AD) patients. Extracellular deposition of Aβ can induce the expression of inflammatory cytokines such as IL-1β, TNF-α, COX-2, and iNOS in RPE cells. Thus, finding a compound that can effectively reduce the inflammatory response may help the treatment of AMD. In this research, we investigated the anti-inflammatory effect of the coral-derived compound 4-(phenylsulfanyl) butan-2-one (4-PSB-2) on Aβ_1-42 oligomer (oAβ_1-42) added to the human adult retinal pigment epithelial cell line (ARPE-19). Our results demonstrated that 4-PSB-2 can decrease the elevated expressions of TNF-α, COX-2, and iNOS via NF-κB signaling in ARPE-19 cells treated with oAβ_1-42 without causing any cytotoxicity or notable side effects. This study suggests that 4-PSB-2 is a promising drug candidate for attenuation of AMD.

Germinated Brown Rice Attenuates Cell Death in Vascular Cognitive Impaired Mice and Glutamate-Induced Toxicity In HT22 Cells

Germinated brown rice (GBR) with unpolishing, soaking, and germinating processes can improve the texture, flavor, and nutritional value, including GABA and phenolic contents. The effect of GBR was first investigated in vascular cognitive impaired mice and glutamate-induced toxicity in HT22 cells with respect to standard pure GABA. Feeding mice with GBR for 5 weeks showed neuroprotection. In this study, the modified bilateral common carotid artery occlusion mice model was mild but a significant difference in cognitive impairment was still shown. Like pure GABA, GBR decreased cognitive deficits in memory behavioral tests and significantly attenuated hippocampal neuronal cell death at P < 0.001. Similarly to 0.125 μM of GABA, 100 μg/mL of GBR increased HT22 cell viability after glutamate toxicity. GBR affected less apoptotic cell death and less blocking by the GABA_A antangonist bicuculline in comparison to GABA. When the results are taken together, the underlying mechanism of GBR protection may mediate though the GABA_A receptor and its phenolic contents.

Behavioral and histopathological studies of cervical spinal cord contusion injury in rats caused by an adapted weight-drop device

Background

Models of spinal cord injury (SCI) caused by weight-drop devices to cause contusion have been used extensively, and transient behavioral deficits after thoracic injury have been demonstrated. The severity of the injury caused by the device should be mild enough to allow recovery.

Objective

To determine whether our adapted weight-drop device with a small tip can effectively induce mild hemicontusion at the level of the fifth cervical vertebra.

Methods

We divided 15 adult male Sprague Dawley rats into groups of 5 for the following treatments: sham (SH, laminectomy only), mild (MSCI) or severe SCI (SSCI). Behavioral tests and histopathology were used before (day 1) and after the treatment on days 3, 7, 14, 21, 28, and 35 to assess the injury.

Results

Rats with SSCI showed a significant somatosensory deficit on days 3 and 7 compared with rats in the SH group, recovering by day 14. In a horizontal-ladder test of skilled locomotion, rats with SSCI showed a significant increase in error scores and percentage of total rungs used, and a decrease in the percentage of correct paw placement compared with rats in the SH group. There was greater recovery to normal paw placement by rats with MSCI than by rats with SSCI. These behavioral deficits were consistent with histopathology using hematoxylin and eosin counterstained Luxol fast blue, indicating the degree of injury and lesion area.

Conclusions

Mild hemicontusion caused by the adapted device can be used to evaluate SCI and provides a model with which to test the efficacy of translational therapies for SCI.

Neural cell adhesion molecule (NCAM) and polysialic acid–NCAM expression in developing ICR mice

Background

Coexpression of polysialic acid (PSA)–neuronal cell adhesion molecule (NCAM) with immature neuronal markers is used to indicate the developmental state of neurons generated in the subgranular zone (SGZ) of adult hippocampus. PSA–NCAM is highly expressed throughout the embryonic and juvenile mammalian brain, but heavily downregulated in adult brain.

Objective

To visualize the expression profiles of NCAM/PSA–NCAM in the dentate SGZ of the hippocampus in developing ICR mice.

Methods

Cellular distribution, expression, and developmental changes of NCAM/PSA–NCAM were studied in ICR mice at embryonic age 17 days (E17); and similarly at postnatal ages P3, P5, and P7. The SGZ was studied using NCAM and PSA–NCAM immunoreactive staining with or without hematoxylin counterstaining. Western blotting was used to confirm protein expression levels.

Results

NCAM expression was localized to the surface of neurons and glia and was higher in postnatal mice than it was in embryonic mice. PSA–NCAM was found in cytoplasm and membrane of neural cells, more densely staining in the dentate SGZ at P7, but no staining found at E17. Western blotting of brain tissues also showed expression of both PSA–NCAM and NCAM increased significantly at P5 and P7 compared with expression at P3.

Conclusions

Progressive increase in NCAM expression occurs in the SGZ during embryogenic and postnatal development. PSA–NCAM was not expressed in embryonic ICR mice, but was increased after birth and highly localized in the SGZ at P7. This NCAM expression pattern in the developing brain indicating structural plasticity and neurogenesis may be useful for study of brain repair.

Anatomy of medial plantar superficial branch artery perforators: Facilitation of medial plantar superficial branch artery perforator (MPAP) flap harvesting and design for finger pulp reconstruction

BACKGROUND

Medial plantar artery perforator (MPAP) flap was proposed as proper option for finger pulp reconstruction. To provide the previously unavailable vessel information required for this small flap design, this study aimed to gather all necessary anatomy of MPA, MPAP, and their territories of blood supply to apply in clinical MPAP flap reconstruction minimizing perforator injury.

METHODS

Dissection of 30 Thai cadaveric feet for visualizing superficial branch of MPA and its perforators (MPAP) using acrylic dye cannulation were performed. Diameter, length, number of branches, course, distributing areas of these vessels, and also their areas of blood supply were recorded in relation to specified landmarks, eg, C-MTH line; medial calcaneal tuberosity to plantar side of the first metatarsal head and S point; emerging point of superficial branch of MPA from deep fasciae into subcutaneous layer.

RESULTS

Average diameter of MPA at its origin and total length are 1.63 ± 0.3 and 52.8 ± 16.1 mm, respectively. It provides 1-3 perforators, with an average size and length of 0.36 ± 0.11 and 23.2 ± 5.47 mm, respectively. Its distribution is mostly in the posteromedial quadrant within 50 and 30 mm from the midpoint of C-MTH line and the S point, respectively. The estimated perforator flap area is 2.5 cm × 1.5 cm and 4.5 cm × 2.5 cm for single and double perforators, respectively.

CONCLUSIONS

MPAP flap was proved as another ideal option for finger pulp reconstruction. Its limitation is small size of perforators but this can be overcome by using MPA for microsurgical anastomosis instead.

Postinjury administration of 17β-estradiol induces protection in the gray and white matter with associated functional recovery after cervical spinal cord injury in male rats

The majority of spinal cord injuries (SCIs) in the clinic occur at the lower cervical levels, resulting in both white and gray matter disruption. In contrast, most experimental models of SCI in rodents induce damage in the thoracic cord, resulting primarily in white matter disruption. To address this disparity, experimental cervical SCI models have been developed. Thus, we used a recently characterized model of cervical hemicontusion SCI in adult male rats to assess the potential therapeutic effect of post-SCI administration of 17β-estradiol. Rats received a hemicontusion at the level of the fifth cervical vertebra (C5) followed by administration of 17β-estradiol via a slow release pellet (0.5 or 5.0 mg/pellet) beginning at 30 minutes post-SCI. Behavioral evaluation of skilled and unskilled forelimb function and locomotor function were conducted for 7 weeks after SCI. Upon conclusion of the behavioral assessments, spinal cords were collected and histochemistry and stereology were conducted to evaluate the effect of treatment on the lesion characteristics. We found that post-SCI administration of 17β-estradiol decreased neuronal loss in the ventral horn, decreased reactive astrogliosis, decreased the immune response, and increased white mater sparing at the lesion epicenter. Additionally, post-SCI administration of 17β-estradiol improved skilled forelimb function and locomotor function. Taken together, these data suggest that post-SCI administration of 17β-estradiol protected both the gray and white matter in cervical SCI. Moreover, this treatment improved function on skilled motor tasks that involve both gray and white matter components, suggesting that this is likely a highly clinically relevant protective strategy.

Reversible short-term and delayed long-term cognitive impairment induced by chronic mild cerebral hypoperfusion in rats

Chronic cerebral hypoperfusion induced by aging in combination with vascular disorder potentially contributes to the development of vascular dementia. This study aimed to investigate the age-related changes in spatial performances in chronic mild cerebral hypoperfusion induced by permanent right common carotid artery occlusion (rCCAO) in rats. Four-month-old male Sprague-Dawley rats (n = 20) were randomly assigned into sham and rCCAO groups. Spatial performances of young adult rats (age 4-8 months) were evaluated repeatedly by the radial arm water maze at 6 days, and 1, 2 and 4 months after surgery. The spatial performance was re-assessed by the Morris water maze when the rats were 18 months old. The present results revealed that the rCCAO rats developed progressive deficit in spatial learning and memory, starting from day 6 and significant deficit was found at 2 months after rCCAO (p < 0.05). However, the spatial performance of the rCCAO rats was recovered at 4 months after surgery. Testing of the cognitive flexibility of the aged rCCAO rats (18 months old), indicated that the learning flexibility of the aged rCCAO rats was significantly impaired. This deficit was found in parallel with pronounced white matter damage in the corpus callosum and internal capsule and significant cell death in the dorsal hippocampus. Our results suggested that vascular risk insult in young adult rats resulted in spatial learning deficit which could be completely compensated later on. However, such previous vascular risk could be exacerbated by advancing age and subsequently lead to a deficit in cognitive flexibility with white matter damage and significant neuronal death in the dorsal hippocampus.

Occurrence of the foramen of Vesalius and its morphometry relevant to clinical consideration

All 377 dry skulls were examined for the occurrence and morphometry of the foramen of Vesalius (FV) both in the middle cranial fossa and at the extracranial view of the skull base. There were 25.9% and 10.9% of FV found at the extracranial view of the skull base and in the middle cranial fossa, respectively. Total patent FV were 16.1% (11.9% unilaterally and 4.2% bilaterally). Most FV were found in male and on the left side. Comparatively, FV at the extracranial view of the skull base had a larger maximum diameter. The distance between FV and the foramen ovale (FO) was as short as 2.05 ± 1.09 mm measured at the extracranial view of the skull base. In conclusion, although the existence of FV is inconstant, its occurrence could not be negligible. The proximity of FV to FO should remind neurosurgeons to be cautious when performing the surgical approach through FO.

Anatomical considerations of the Thai fibula used as a fibula osteocutaneous free flap in mandibular reconstruction and dental implant placement

OBJECTIVE

Although the fibula osteocutaneous free flap has many proven advantages in restoring mandibular defects, the dimension of available fibula is one of its limitations. The present study aimed to investigate the suitability of dimensions and the quality of harvested fibulae for mandibular reconstruction and dental implant placement in Thais.

MATERIAL AND METHOD

One hundred fourteen fibulae of 57 adult Thai cadavers were dissected. Total fibular length and the length of harvested fibula were measured. Dimensions of the fibula cross sections available for dental implant placement were recorded. Additionally, the cortical bone thickness and densities of cortical and spongy bones of 60 fibulae were assayed using cone beam computed tomography scan images.

RESULTS

Mean total fibular length and mean length of harvested fibulae were 34.2 +/- 2.3 cm and 18.2 +/- 2.3 cm, respectively. A dental implant length of 7 to 10 mm could be placed in the fibula. The mean cortical bone thickness was 2.2 +/- 0.6 mm. The mean densities of the cortical and spongy bones were 614.4 +/- 148.8 HU and -600.6 +/- 228.7 HU, respectively.

CONCLUSION

The present study suggests that, in Thais, a harvested fibula of 16 to 20 cm in length is sufficient to provide bone for reconstructing defected mandible and the dental implant placement is 7 to 10 mm in length. The mean cortical and spongy bone densities of fibula are less than that of the mandible in previous reports. The result supports the clinical experience using the fibula as donor site for the mandibular reconstruction and dental implant placement.

Characterization of a graded cervical hemicontusion spinal cord injury model in adult male rats

Most experimental models of spinal cord injury (SCI) in rodents induce damage in the thoracic cord and subsequently examine hindlimb function as an indicator of recovery. In these models, functional recovery is most attributable to white-matter preservation and is less influenced by grey-matter sparing. In contrast, most clinical cases of SCI occur at the lower cervical levels, a region in which both grey-matter and white-matter sparing contribute to functional motor recovery. Thus experimental cervical SCI models are beginning to be developed and used to assess protective and pharmacological interventions following SCI. The objective of this study was to characterize a model of graded cervical hemicontusion SCI with regard to several histological and behavioral outcome measures, including novel forelimb behavioral tasks. Using a commercially available rodent spinal cord impactor, adult male rats received hemicontusion SCI at vertebral level C5 at 100, 200, or 300 kdyn force, to produce mild, moderate, or severe injury severities. Tests of skilled and unskilled forelimb and locomotor function were employed to assess functional recovery, and spinal cord tissue was collected to assess lesion severity. Deficits in skilled and unskilled forelimb function and locomotion relating to injury severity were observed, as well as decreases in neuronal numbers, white-matter area, and white-matter gliosis. Significant correlations were observed between behavioral and histological data. Taken together, these data suggest that the forelimb functional and locomotor assessments employed here are sensitive enough to measure functional changes, and that this hemicontusion model can be used to evaluate potential protective and regenerative therapeutic strategies.

Anatomical consideration of pterion and its related references in Thai dry skulls for pterional surgical approach

OBJECTIVE

Pterion is a crucial surgical landmark for surgical approaches to the middle meningeal artery particular lesions, and tumors in the brain. The present study aimed to analyze the types of the pterion and its location related with nearby landmarks in dry skulls. In addition, variations of pterion in sex, age, and skull side were compared.

MATERIAL AND METHOD

Bilateral sides of 268 adult human Thai dry skulls were investigated Pterion types were classified as sphenoparietal, frontotemporal, epipteric, or stellate. To localize the pterion, linear distances were measured from the center of the pterion to neighboring landmarks.

RESULTS

The results showed the two most common types of the pterion, the sphenoparietal (81.2%), and the epiteric (17.4%). Externally, the pterion was commonly located 38.48 +/- 4.38 mm superior to the zygomatic arch and 31.12 +/- 4.89 mm posterior to the frontozygomatic suture. Internally, it was located 38.94 +/- 3.76 mm lateral to the optic canal and 11.70 +/- 4.83 mm from the sphenoid ridge. Sex influenced the occurrence of thepterion type, while sex, skull side, and age affected its location. Mean skull thickness at the pterion was 5.13 +/- 1.67 mm.

CONCLUSION

The pterion is predominantly sphenoparietal type and is typically located 39 mm superior to the zygomatic arch, 31 mm posterior to the frontozygomatic suture, 39 mm lateral to the optic canal and 12 mm from the sphenoid ridge. The data obtainedfrom the present study should be clinically useful for localizing the position of pterion.

17β-estradiol protects Schwann cells against H2O2-induced cytotoxicity and increases transplanted Schwann cell survival in a cervical hemicontusion spinal cord injury model

Schwann cell (SC) transplantation is a promising repair strategy after spinal cord injury (SCI); however, a large number of SCs do not survive following transplantation. Previous studies have shown that 17β-estradiol (E2) protects several cell types against cytotoxicity. Thus, this study evaluated the protective potential of E2 on SCs in vitro and investigated the effect of E2 on transplanted SC survival in a rat model of SCI. Primary SC cultures were found to robustly express estrogen receptors (ER) and incubation with E2 protected SCs against hydrogen peroxide-induced cell death. This protection was not inhibited by the ER antagonist ICI 182,780, suggesting that genomic signaling is not necessary for protection. In a subsequent experiment, cervical hemicontusion SCI was induced in male rats followed by sustained administration of E2 or placebo. Eight days after SCI, SCs were transplanted into the injury epicenter. E2 treatment significantly increased the number of surviving labeled transplanted SCs evaluated 7 days after transplantation. These data demonstrate that E2 protects SCs against oxidative stress and improves transplanted SC survival, which suggests that E2 administration may be an intervention of choice for enhancing survival of transplanted SCs after SCI.

The study of position of antilingula, midwaist of mandibular ramus and midpoint between coronoid process and gonion in relation to lingula of 92 Thai dried mandibles as potential surgical landmarks for vertical ramus osteotomy

This study aims to investigate positions of the antilingula (AL), the midwaist of the mandibular ramus (MW) and the midpoint between the coronoid process and the gonion (MCG) in relation to the lingula of dried mandibles. Bilateral rami of 92 Thai dried mandibles were studied. The AL, the MW, the MCG and the corresponding position of the tip of lingula (L) were marked on the external aspect of the mandibular ramus. The distances from the AL, the MW and the MCG to the L were measured in the anterior-posterior and the superior-inferior planes using computerized image analysis. The results showed the AL was discernible in 80.4% of lateral mandibular rami studied. The most of the AL was found anterior-superior to the L with a maximum distance of 5.9 mm anteriorly and 8.2 mm superiorly. The MW was frequently located anterior-inferior to the L with a maximum distance of 9.3 mm anteriorly and 9.9 mm inferiorly. The majority of the MCG was found anterior-superior to the L with a maximum distance of 9.6 mm anteriorly and 8.9 mm superiorly. A 5 mm radius from the L included 84.5% of the AL, 81.5% of the MW and 79.4% of the MCG. Medians (interquartiles) of distances from the AL, the MW and the MCG to the L were 3.4 (2.3-5.0) mm, 3.8 (2.5-5.3) mm and 4.1 (2.8-5.3) mm, respectively. In conclusion, the AL was identified in 80.4% of lateral mandibular rami studied. The AL and the MCG were commonly found anterior-superior to the lingula, whereas the MW was mostly observed anterior-inferior to the lingula. Therefore, a cut made more than a 5 mm posterior or superior to these landmarks would be in 79% of cases, within a statistically safe area avoiding encroaching upon the inferior alveolar neurovascular bundle passing immediately lateral to the lingula. Although the MW and the MCG might be alternative surgical guides when the AL is absent, their use alone as surgical landmarks is not recommended.

Anatomical considerations of the deep peroneal nerve for biopsy of the proximal fibula in Thais

The present research aims to study the anatomical relationship between the deep peroneal nerve and the neighboring structures in the proximal fibula of Thais, with special regard to define the boundaries of a "safe" area when performing a biopsy of the proximal fibula. The proximal parts of 118 legs of 59 formalin-embalmed adult cadavers (31 males, 28 females) were investigated. The distance from the apex of the fibular head to the point of origin of the deep peroneal nerve, the distance from the most lateral prominence of the fibular head to the anterior intermuscular septum, and the angle between the deep peroneal nerve and the fibula axis were measured. The results showed that the mean distances from the apex of the fibular head to the point of origin of the deep peroneal nerve was 28.4 +/- 4.8 mm and from the most lateral prominence of the fibular head to the anterior intermuscular septum was 14.9 +/- 2.0 mm. The mean angle between the deep peroneal nerve and the fibular axis was 28.1 degrees +/- 7.2 degrees . In conclusion, these findings suggest that a "safe" area for bone biopsy in the proximal fibula of Thais is palpable anterior to the fibular head and downward laterally, not lower than 28 mm or 8% of the fibular length and from the most lateral prominence transverse medially not further than 14 mm. The inferior boundary of this area is an oblique line of the deep peroneal nerve about 28 degrees from the fibular axis.

Dimensional guide to harvesting the radius for orofacial reconstruction

OBJECTIVE

To provide an accurate harvesting guide to maintain the maximum possible safe dimensions of the radius for orofacial reconstruction using the osteocutaneous radial forearm free flap.

MATERIAL AND METHOD

Two hundred radii of 100 adult formalin-embalmed cadavers (52 males, 48 females) were measured.

RESULTS

The mean minimum circumference of the radius measured between the pronator teres and brachioradialis insertions was 41.0 +/- 4.3 mm. At this point, the mean medio-lateral diameter was 13.4 +/- 1.6 mm. The mean of the maximum harvested length of the radius between the pronator teres and brachioradialis insertions was 81.3 +/- 10.4 mm. On the average, the maximum harvested length of the radius was 34.9% of its total length. The minimum medio-lateral diameter of the radius was consistently 1-5 mm less than 40% of its minimum circumference. There was no significant dimensional difference between sides but gender difference existed in all measurements (p < 0.001), except the maximum harvested length of the radius.

CONCLUSION

The present study may be helpful to guide reconstructive surgeons for safer harvesting of the radius using the osteocutaneous radial forearm free flap to repair orofacial defects.

The acromial morphology of Thais in relation to gender and age: study in scapular dried bone

OBJECTIVE

The objective of the present study was to determine the acromial shape and examine if there is a correlation between the acromial morphology and genders, ages and sides.

MATERIAL AND METHOD

The present examined 154 dried Thai scapulas (107 males and 47 females) with age range from 16 to 87years (mean = 49 + 17 years). The acromial morphology of each scapula was studied by the computerized image analysis of digitized photography through the supraspinatous outlet view, with the distance (M) measured from its anterior to posterior end, the height (H) of the resultant curve and the distance (N) from the anterior end to the point perpendicular to the height. The acromial types were defined as type I (flat), II (curved) and III (hooked) with the criteria that N is more than or equal to the 2/3, 1/3 and less than 1/3 of M, respectively.

RESULTS

The incidences of types I, II and III were 3.2%, 93.5% and 3.2%, respectively. It was found in both sexes, female (93.6%) and male (93.5%) and in both sides, left (96%) and right (91.1%). With respect to the age range, type II were found in 100% of subjects of less than 30 years, 4.5% in those between 30-60 years, were 4.5% (1), 93.2% (1), 2.3% (111). Those more than 60 years old were 2.3 %(1), 90.7% (11) and 7.0% (III). The spur formation on the anterior end of the acromion was found in 14.9% of scapulas, curved type mostly; and it was associated with hooked type in only one scapula.

CONCLUSION

There was no significant type difference between sex, side and age range (p > 0. 05). The spurs found are not related to acromial morphology and old age.

Supraorbital Notch/Foramen, Infraorbital Foramen and Mental Foramen in Thais: anthropometric measurements and surgical relevance

OBJECTIVE

To determine the morphology and the locations of the SupraOrbital Notch/Foramen (SON/F), InfraOrbital Foramen (IOF), and Mental Foramen (MF) relative to frequently encountered surgical landmarks.

MATERIAL AND METHOD

One hundred and six Thai adult skulls were investigated.

RESULTS

Mean horizontal widths of SON, SOF, IOF and MF were 4.31 +/- 1.61 mm, 2.81 +/- 0.62 mm, 3.35 +/- 0.62 mm and 2.80 +/- 0.70 mm, respectively. The SON/F was situated 25.14 +/- 4.29 mm lateral to the nasal midline, 26.57 +/- 3.92 mm medial to the temporal crest of the frontal bone and 3.15 +/- 1.29 mm superior to the supraorbital rim. The IOF was 28.43 +/- 2.29 mm lateral to the maxillary midline, 9.23 +/- 2.03 mm below the infraorbital rim and 2.15 +/- 1.67 mm medial to the zygomaticomaxillary suture. Mean vertical distances from the IOF to the SOF and to occlusal plane of the upper teeth were 44.95 +/- 2.96 mm and 42.52 +/- 3.89 mm, respectively. The IOF was frequently found in the same vertical line with the second upper premolar and its usual direction of opening pointed downward medially. The MF was a mean of 28.52 +/- 2.15 mm lateral to the symphysis menti and most commonly observed in line with the second lower premolar. Its usual direction of opening was in a posterosuperior direction.

CONCLUSION

The results of the present study may assist surgeons to localize important maxillofacial neurovascular bundles passing through these foramina in facilitating surgical, local anesthetic and other invasive procedures.

Mental foramen in Thais: an anatomical variation related to gender and side

Sixty-nine adult mandibles (45 male, 24 female) of Thai dry skulls were assessed to determine the size, the orientation and the location of the mental foramen (MF) related to gender and side. The results showed that the usual direction of exit of the MF was in a posterosuperior direction. The most common location of the MF was bilaterally symmetrical and located on the same vertical line with the long axis of the lower second premolar. The mean distances from the MF to the symphysis menti (A), to the posterior border of the mandibular ramus (P), to the lower border of the mandible (mb) and to the buccal cusp tip of the second premolar (cm) were 28.83, 68.85, 14.88 and 24.27 mm, respectively. The mean distances from the alveolar bone crest across the MF to the lower border of the mandible (ab) was 29.97 mm. The mean distance from the buccal cusp tip of the second premolar through the long axis of the clinical crown to the lower border of the mandible (cb) was 39.18 mm. No measurements varied according to the sides (P > 0.05). In contrast, gender differences were significant in all measurements with the longer distances in males (P < 0.05). The mean ratios of A/(A + P), mb/ab and cm/cb in all subjects were 0.30, 0.50 and 0.62, respectively. The values of the three ratios were nearly equal in males and females. Our results may assist surgeons to localize important maxillofacial neurovascular bundles passing through the MF in avoiding complication from local anesthetic, surgical and other invasive procedures.

Anatomy of greater palatine foramen and canal and pterygopalatine fossa in Thais: considerations for maxillary nerve block

This study aims to investigate the anatomy of the greater palatine foramen (GPF), greater palatine canal (GPC) and pterygopalatine fossa (PPF) with special reference to the blockage of the maxillary nerve. A correlation between the length of GPC and PPF and the heights of the orbit and the maxilla was also studied using simple linear regression analysis. The morphology of the GPF, GPC and PPF as well as heights of the orbit and the maxilla were assessed in 105 Thai skulls. The thickness of the mucosa over the GPF was also measured from the dissection of 55 cadavers. The results showed that most GPF appeared as an oval foramen located at the palatal aspect of the upper third molar. The GPF was 16.2+/-1.3 mm lateral to the median sagittal plane of the hard palate, 2.1+/-1.3 mm anterior to the posterior border of the hard palate and 5.1+/-1.3 mm from the greatest concavity of the distolateral margin of the hard palate. The mean length of GPC and PPF was 29.7+/-4.2 mm. The mean angles of the GPC in relation to the hard palate and the vertical plane were 57.9+/-5.8 degrees and 6.7+/-5.2 degrees , respectively. In attempting to insert a needle to reach the foramen rotundum through the GPF, 31.7% passed into the orbit while 8.7% passed into the brain. The mean thickness of the mucosa over GPF was 6.7+/-2.3 mm. Two models for estimating the depth of needle injection in maxillary nerve block have been developed as follows: Length of GPC and PPF=19.038+0.314 (orbital height) and length of GPC and PPF=21.204+0.187 (maxillary height). The calculated length combined with the mucosal thickness was the estimated depth of needle injection. In conclusion, our results concerning the GPF, GPC and PPF will provide the useful reference for clinicians to anesthetize the maxillary nerve with a greater degree of success.

Clinical anatomy of the posterior maxilla pertaining to Le Fort I osteotomy in Thais

This article studies the anatomy of the posterior maxilla pertaining to bone-cut design of Le Fort I osteotomy to avoid the injury to the descending palatine artery in Thais. Fifty-five skulls (38 males, 17 females) were assessed for the anatomical landmarks by a combination of direct inspection, computerized imaging, and computed tomography scan analysis. The results showed that 27.28% of the pterygomaxillary junction (PMJ) became synostosis. The mean heights of the PMJ, posterior maxilla, and maxillary tuberosity were 15.14 +/- 2.46 mm, 22.51 +/- 3.50 mm, and 7.45 +/- 2.76 mm, respectively. The mean length of the medial sinus wall measuring from the piriform rim to the descending palatine canal at the Le Fort I level was 34.40 +/- 2.96 mm. The mean widths of the posterior incision of Le Fort I osteotomy at the maxillary tuberosity and PMJ were 20.38 +/- 2.82 mm and 11.60 +/- 1.57 mm. The mean length of the posterior maxilla was 27.18 +/- 2.49 mm. Distances from the greater palatine foramen to the maxillary tuberosity incision and PMJ incision were 1.76 +/- 1.12 mm and 3.59 +/- 1.40 mm. The mean angle between the descending palatine canal and the hard palate was 57.33 +/- 4.54 degrees . There were no significant differences in any measurements between sides and genders, except the pterygoid process width and posterior maxilla length of males were longer than those of females (P < 0.05). This study could provide better understanding of the posterior maxillary anatomy that is important for the bone-cut design of Le Fort I osteotomy to avoid excessive intraoperative and postoperative hemorrhage including ischemia of the mobilized maxilla.

Anatomical study of the maxillary artery at the pterygomaxillary fissure in a Thai population: its relationship to maxillary osteotomy

BACKGROUND

The maxillary artery (MA) and its terminal branches are commonly damaged in the maxillary osteotomy, especially during separation of the pterygomaxillary junction (PMJ).

OBJECTIVE

To evaluate the positional relationship between the MA at the pterygomaxillary fissure (PMF) and the PMJ in Thais, as well as to measure the diameter of the MA as it enters the pterygopalatine fossa (PPF) and the heights of PMJ, maxillary tuberosity and posterior maxilla.

SUBJECTS AND METHOD

Both sides of 100 Thai adult cadavers (50 males and 50 females) were examined The mean age of the subjects was 64.5 +/- 12.8 years. With the lateral infratemporal approach, the branches from the third part of the MA, PMJ and posterolateral maxilla were dissected. Measurements taken included the following: First, the distance from the most inferior point of the PMJ to the most inferior position of the MA as it entered the PPF; second, the external diameter of the MA as it entered the PPF; third, vertical heights of the PMJ, maxillary tuberosity and posterior maxilla. Means, standard deviations and ranges were determined and statistical differences were calculated between sides and genders at p < 0. 05.

RESULTS

The MA entered the PPF at a mean distance of 23.5 +/- 2.5 mm above the most inferior point of the PMJ. The mean external diameter of the MA as it entered the PPF was 2.8 +/- 0.6 mm. The mean heights of the PMJ, maxillary tuberosity and posterior maxilla were 19.5 +/- 2.3 mm, 6.1 +/- 2.7 mm, and 25.6 +/- 3.3 mm, respectively. There were no differences with respect to side and gender, except that the distance from the most inferior point of the PMJ to the most inferior position of the MA as it entered the PPF was longer in males than in females (p < 0.05).

CONCLUSION

The mean location of the MA was 23.5 mm apart from the most inferior point of the PMJ, therefore, dysjunction of the PMJ using an osteotome with a 15-mm cutting edge may be conducted without damaging to the MA. When properly placed, the margin of safety from the superior cutting edge of the osteotome to the MA is approximately 8 mm in adults.