Cone beam computed tomographic analyses of alveolar bone anatomy at the maxillary anterior region in Chinese adults

To provide an anatomical basis for clinical implant esthetics,we evaluated the morphology of the nasopalatine canal（NPC） and analyzed labial and interproximal bone anatomy at the maxillary anterior region.We sought to investigate the effect of maxillary protrusion and tooth labiolingual inclination on labial bone anatomy in Chinese adults.Three dimensional（3D） images were reconstructed using cone-beam computed tomography（CBCT） images from 80 Chinese subjects and by SimPlant 11.04.The dimensions of the NPC,the thickness and profile of the labial bone,the width and height of the interproximal bone,angle sella-nasion-subspinale（SNA） and angle upper central incisor-nasion,subspinale（U1-NA） were measured.The incisive foramen of the NPC was markedly wider than its nasal foramen.The dimension of its labial bone wall demonstrated an increasing width from the crestal to apical measurements.The labial bone at the maxillary anterior region was rather thin,especially at 3 mm below the cemento-enamel junction（CEJ） and the mid-root level;the profile of the labial bone was more curved at the central incisor,and the interproximal bone became wider and shorter posteriorly.There were significant relationships between maxillary protrusion and labial bone profile,tooth labiolingual inclination and labial bone thickness（P 〈 0.02）.To achieve optimal esthetic outcome of implant,bone augmentation is necessary at the maxillary anterior region.For immediate or early placement at the maxillary anterior region,the implant should be located palatally to reduce labial bone resorption and marginal recession;its apex should be angulated palatally to avoid labial perforation at the apical region.To protect the NPC,implants at the central incisor region should be placed away from NPC.     

Cone beam CT findings of retromolar canals in a Korean population

Purpose

The identification of the variation involving the mandibular canal is important during surgical procedures in the mandible. This study aims to investigate the incidence, course, width, and location of retromolar canals in a Korean population using cone beam CT.

Methods

The cross-sectional, sagittal, and three dimensional images from volumetric cone beam CT data of 446 patients were reconstructed using imaging analysis software for the presence of a retromolar canal. Retromolar canals were classified into three types according to the courses. The width and location (distance from the second molar) of retromolar canals were evaluated.

Results

A retromolar canal was observed in 8.5 % of patients (38/446). Most retromolar canals had vertically curved courses (Type 1, 66.7 %), followed by horizontally curved courses (Type 2, 20 %). Type 3 retromolar canals, which run independently from separate foramina in the mandibular ramus, were rare (13.3 %). The mean width of a retromolar canal was 1.13 mm (SD ± 0.38, 0.60–2.00), and the mean distance to the second molar was 14.08 mm (SD ± 3.85, 8.50–24.00).

Conclusions

The incidence of retromolar canals in the Korean population was lower than that reported in the investigated ethnic groups. In the presence of a retromolar canal, local anesthesia may be ineffective. The damage to a retromolar canal may be unavoidable during surgical procedures involving the mandible and may result in paresthesia, excessive bleeding, postoperative hematoma, or traumatic neuroma.     

The Quadratojugal of Eryops studied by computed tomography and the morphological variability of foramina and canals in the quadratojugal of basal tetrapods

With respect to its large size and abundance, Eryops is an important representative of Permo‐Carboniferous basal tetrapods and one of the best‐known large temnospondyl amphibians of this period. This taxon forms a significant component of the Early Permian tetrapod fauna of Texas and New Mexico and here we describe a new record of skull remains, the first one from Brushy Creek (30 km northeast of Seymour) in Texas (Petrolia Formation, Wichita Group; Lower Permian – lower Artinskian). Our material, found in 2015, consists of a left nasal, a jaw fragment (premaxilla or maxilla), left quadratojugal fragments, and a partial left mandible. We used computed tomography methods (micro‐CT) for imaging both internal and external structures, for the first time, for Eryops. The quadratojugal presented here is exceptional compared to all known basal tetrapods in having four different internal foramina. CT data show that these foramina are interconnected by canals within the bone. This indicates that the morphology of the foramina and the course of the canals in the quadratojugal of basal tetrapods are more variable than hitherto thought. Anat Rec, 299:1073–1079, 2016. © 2016 Wiley Periodicals, Inc.     

Clinical anatomy and surgical significance of the lingual foramina and their canals

The lingual foramina and canals can be categorized as median or lateral based on their relation to the midline of the mandible. Investigation of the mandibular lingual region is often done with gross anatomical dissections of cadavers, 2D panoramic radiographic imaging, CT, and cone beam CT (CBCT). While gross studies are the most reliable at qualifying canal contents and course, CBCT proved to be superior to other radiographic techniques for visualizing lingual foramina and canals. The submental and sublingual arteries, and their branches are found in the lingual vascular canals. There is tremendous variation between individuals in terms of the course of the lingual canals and their anastomosis with other vascular canals. Performing the dental implantation procedures in the anterior and posterior regions of the mandible can result in perforation of the lingual cortex, which could injure the arteries that lie within the lingual canal. If hemorrhage occurs, it could lead to life‐threatening upper airway obstruction. Pre‐surgical investigation to identify the diameter of the lingual foramina and canal as well as their distance from the alveolar process might be necessary to prevent hemorrhage for all patients. Clin. Anat. 30:194–204, 2017. © 2017 Wiley Periodicals, Inc.     

Cone beam computed tomography of plastinated hearts for instruction of radiological anatomy

Radiological anatomy education is an important aspect of the medical curriculum. The purpose of this study was to establish and demonstrate the use of plastinated anatomical specimens, specifically human hearts, for use in radiological anatomy education. Four human hearts were processed with routine plastination procedures at room temperature. Specimens were subjected to cone beam computed tomography and a graphics program (ER3D) was applied to generate 3D cardiac models. A comparison was conducted between plastinated hearts and their corresponding computer models based on a list of morphological cardiac features commonly studied in the gross anatomy laboratory. Results showed significant correspondence between plastinations and CBCT-generated 3D models (98 %; p < .01) for external structures and 100 % for internal cardiac features, while 85 % correspondence was achieved between plastinations and 2D CBCT slices. Complete correspondence (100 %) was achieved between key observations on the plastinations and internal radiological findings typically required of medical student. All pathologic features seen on the plastinated hearts were also visualized internally with the CBCT-generated models and 2D slices. These results suggest that CBCT-derived slices and models can be successfully generated from plastinated material and provide accurate representations for radiological anatomy education.     

Morphometric comparison of computed tomography to magnetic resonance imaging in the evaluation of the lumbar intervertebral foramina

The purpose of this study was to evaluate and compare the ability of computerized tomography (CT) and magnetic resonance imaging (MRI) as techniques to determine linear morphometric measurements of several parameters of the right and left lumbar intervertebral foramina (IVFs). Specifically, the greatest superior-to-inferior diameter and anterior-to-posterior diameter of the lumbar IVFs were measured in a cadaveric imaging phantom. The phantom was first measured directly with vernier calipers and then embedded in gelatin to simulate soft tissue. It was then scanned with two types of protocols each for CT and MRI. The scanned images were transferred directly from the imaging units to optical disks, which were then read using an optical disk drive. The measurements taken directly from the phantom were then taken from the scans using a Macintosh II computer interfaced with the optical disk drive. The results showed that both sagittally reformatted CT images and sagittal MRI images were clinically and statistically reliable and valid methods for linear evaluation of the IVF in the sagittal plane. However, measurements made from the MRI scans were found to be more accurate than those made from the CT scans. The results of this study should help increase understanding of the strengths and weaknesses of both imaging modalities in the sagittal evaluation of the lumbar IVFs. The results may also help with the future evaluation of the IVF in the condition known as nerve root canal stenosis. This study also indicates that a normal morphometric database from the MRI scans of normal human subjects should be developed. © 1994 Wiley-Liss, Inc.     

A study of the nutrient foramina in human long bones

Summary The present study analyzed the location and number of the diaphysial nutrient foramina in six long bones of adult human skeletons of unknown age and sex from a statistical view point. The diaphysial nutrient foramina in the humerus, are located at between 50 and 65 % of the total length; in the radius and ulna, at between 25 and 50 %; in the femur, at between 25 and 58 %; in the tibia, at between 30 and 40 %; and in the fibula at between 35 and 67 %, i.e. the middle third of the bone. Also studied were the anatomical position and number of the diaphysial nutrient foramina in each bone.

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Etude des trous nourriciers des os longs humains

Résumé Ce travail est une étude statistique du siège et du nombre des trous nourriciers de la diaphyse des six os longs de sujets adultes d'âge et de sexe non connus. Le niveau du trou nourricier de la diaphyse humérale se situe entre 50 et 65 % de la longueur totale de l'os; au niveau du radius et de l'ulna, il est entre 25 et 50 %; au niveau du fémur, entre 25 et 58 %; au niveau du tibia entre 30 et 40 % et au niveau de la fibula entre 35 et 67 %, c'est-à-dire au tiers moyen de l'os. La situation anatomique exacte et le nombre de trous nourriciers a été également Précisé pour chaque os.

     

3D-CTA检查确诊前循环动脉瘤与显微手术治疗

目的 通过手术对照,探讨急诊三维CT血管造影(3D-CTA)在前循环动脉瘤的临床应用及其价值,同时为了检验3D-CTA检查的诊断符合情况.方法 59例自发性蛛网膜下腔出血(SAH)患者,其中男性31例,女性28例;年龄35～70岁,平均年龄51岁.对普通CT高度怀疑为动脉瘤性SAH患者行急诊Philips 256i C...     

The intraorbital arrangement of the anterior and posterior ethmoidal foramina

This study, instigated by surgical observations, and mainly carried out on the dry bone, attempts to analyse both the depth and variability of the anterior and posterior ethmoidal foramina through which pass the ethmoidal aa. The surgical implications of this study relate not only to ligation of the ethmoidal aa. in certain cases of epistaxis, their embolisation and the endonasal microsurgery of the ethmoid, but also to the surgery of the anterior cranial fossa. The study is based on 200 anatomic observations.

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De la disposition endo-orbitaire des ostiums ethmoïdaux antérieur et postérieur

Résumé Ce travail, suscité par des observations chirurgicales, et essentiellement réalisé sur os sec, tente d'analyser à la fois la profondeur et la variabilité des foramina ethmoïdaux antérieur et postérieur par où passent les artères ethmoïdales. Les implications chirurgicales de cette étude concernent les ligatures des artères ethmoïdales lors de certaines épistaxis, leur embolisation et la microchirurgie endonasale de l'ethmoïde mais aussi la chirurgie de la fosse crânienne antérieure. Le travail réunit 200 observations anatomiques.

     

A study of the nutrient foramina of lower limb long bones

Summary In this study a total of 269 adult lower limb long bones were examined to determine the number and location of the nutrient foramina in the shafts of bones. The mean of foraminal index was 48.82 for femur, 33.17 for tibia, and 47.82 for fibula. The number of foramina noted were: two on the linea aspera in the middle third of the femur, one on the posterior surface of the upper third of the tibia, and one on the posterior surface of the middle third of the fibula.

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Etude des foramens nourriciers des os longs du membre inférieur

Résumé Les foramens nourriciers de 269 os longs de membres inférieurs d'adultes ont été étudiés afin d'en préciser le nombre et le siège. L'index foraminal moyen était de 48,82 pour le fémur, 33,17 pour le tibia, 47,82 pour la fibula. Sur le fémur, les foramens sont le plus souvent doubles, situés au tiers moyen de la ligne âpre. Sur le tibia, le foramen est le plus souvent au tiers supérieur de la face postérieure. Enfin sur la fibula, il se situe en général au tiers moyen de face postérieure.

     

High-resolution computed tomographic study of the retrotympanum

Summary The aim of this study was to define the imaging of the retrotympanum precisely by means of high-resolution CT. Based on 66 scans of petrous bones performed in 49 patients observed in an otologic department, several retrotympanic structures were studied: the pyramidal eminence, ponticulus, subiculum, chordal ridge, tympanic sinus of Proctor, sinus tympani and recess of the facial n. The variations in morphology and depth were noted as well as the relationship between the pyramid and the facial canal. In a second phase the same anatomic structures were studied in 24 temporal bones removed from embalmed cadavers and investigated with the same radiologic technique. Anatomic correlations were made for six temporal bones to confirm the general applicability of our radiologic hypotheses. In CT the pyramidal eminence was visualised in 100% of cases, the chordal ridge in 52%, the ponticulus in 63% and the subiculum in 57%. As regards the different recesses, the sinus tympani was visualised in 95% of cases, the posterior tympanic sinus of Proctor in 38%, the fossula of Grivot in 47% and the facial recess in 80%. The mean depth of the sinus tympani was 2.7 mm and that of the tympanic sinus of Proctor was 1.65 mm; the fossula of Grivot was assessed as 2.1 mm and the facial recess as 2.2 mm. A better knowledge of these sinuses and their variations will aid the surgeon, particularly in a posterior tympanotomy or a retro-facial approach.

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Étude tomodensitométrique en haute résolution du rétrotympanum — Confrontations anatomiques

Résumé Le but de ce travail était de définir avec précision en tomodensitométrie haute résolution l'imagerie du rétrotympanum. A partir de 66 TDMs des rochers réalisés chez 49 patients suivis en ORL, plusieurs structures du rétrotympanum ont été étudiées : éminence pyramidale, ponticulus, subiculum, crête cordale, sinus tympanique de proctor, sinus tympani et récessus du facial. Les variations morphologiques et de profondeur ont été notées ainsi que le rapport entre la pyramide et le canal facial. Dans un deuxième temps, à partir de 24 temporaux prélevés sur cadavres embaumés, explorés selon la même technique radiologique, les mêmes structures anatomiques ont été étudiées. Des corrélations anatomiques pour 6 temporaux ont été réalisées pour confirmer l'ensemble de nos hypothèse radiologiques. En tomodensitométrie la visibilité de l'éminence pyramidale était obtenue dans 100% des cas, celle de la crête cordale dans 52% des cas, du ponticulus dans 63% des cas et du subiculum dans 57% des cas. Pour ce qui est des différents récessus, le sinus tympani était visible dans 95% des cas, le sinus tympani de Proctor dans 38% des cas, la fossette de Grivot dans 47% des cas et le recessus du facial dans 80% des cas. La profondeur moyenne du sinus tympani était de 2.7 mm, le sinus tympani de Proctor mesurait 1.65 mm, la fossette de Grivot était évaluée à 2.1 mm et le récessus du facial à 2.2 mm. La meilleure connaissance de ces sinus et de leur variation aidera le chirurgien en particulier pour une tympanotomie postérieure ou un abord rétro-facial.

     

The demonstration of the number, course, and the location of nutrient artery canals of the femur by multidetector computed tomography

Purpose

The aim of this study was to evaluate the number, course, width and location of nutrient artery canals of the femur by using multidetector computed tomography (MDCT).

Methods

Sixty-six adult (35 right and 31 left) dry femurs were included in this study and scanned by MDCT. Nutrient artery canals were evaluated on the multi-planar reformatted and volume rendered images which were reproduced on the basis of axial images.

Results

The median value of nutrient artery canals was two (minimum 1 and maximum 6). We determined that there was a negative correlation between the number of nutrient canals and the canal diameters. The outer ostia of the nutrient artery canals were most frequently located at the middle third segment of femoral diaphysis (65%). While the vast majority of the canals were showing upward courses (95%), only a few canals were having transverse (3%) or downward (2%) courses. Most encountered location of outer ostia of the canals according to linea aspera was the medial lip of the linea aspera (44%). Various variations were demonstrated in the number, course, and location of nutrient artery canals using MDCT.

Conclusions

In conclusion, the knowledge of the topographic features of the nutrient artery canals may be useful in various clinical implications such as bone grafting or radiologic evaluation for the fracture lines.     

An assessment on spiral CT scan of the superior and inferior genial spinal foramina and canals

To characterise the superior as well as the inferior genial spinal foramen and their bony canal using a large CT data sample. The study included 555 mandibular spirals CT scans, taken from patients for pre-operative implant planning. Basic observation by three observers included the number of canals, their respective anatomical location and morphological variations. Furthermore, linear measurements were performed to describe the foramina and canal characteristics. On spiral CT scans, the superior and inferior genial spinal foramina were detected in 448 CT scans (81%). In 29% of the mandibular CTs, two or more midline canals were noted. 47% of the foramina were located in a position inferior to the genial spines; the others were located in a superior position. The mean (SD) lingual and buccal diameters of the canal structures were 0.73 (0.27) and 0.54 (0.29) mm, respectively with an average length of 3.94 (1.29) mm. The canal was located on average 7.40 (5.31) mm from the mandibular base at the lingual entrance and 7.96 (3.47) mm at the buccal canal end point. The average canal extended towards the buccal bone for an average 37% of the bone width. The results demonstrated the presence of both superior and inferior genial spinal foramina, with 29% of the individuals having double foramina. About 53% of the foramina was located superior to the genial spines. Considering its neurovascular content, these foramina should be carefully evaluated during pre-operative planning.     

Location, number and clinical significance of nutrient foramina in human long bones

Nutrient arteries, the main blood supply to long bones, are particularly important during the active growth period, as well as during the early phases of ossification. In the present study, 569 adult human long bones of the upper (101 humeri, 93 radii, 102 ulnae) and lower (100 femora, 100 tibiae, 73 fibulae) limbs were investigated to determine the number and location of their nutrient foramina. For each bone, a foraminal index was calculated giving the location of the nutrient foramen in relation to its proximal end. In the upper limb, foramina were located on the diaphysis 15-69% of the overall length of the humerus, 22-46% for the radius and 27-54% for the ulna. In the lower limb, foramina were located on the diaphysis 29-69% of the overall length of the femur, 27-63% for the tibia and 26-83% for the fibula. In addition, the number and the distribution of the foramina in relation to specific regions/surfaces of the diaphysis were identified. This study provides additional and important information on the location and number of nutrient foramina in the long bones of the upper and lower limbs in the Turkish Caucasian population.