Topographic Landmarks Research Articles

The human parahippocampal cortex subserves egocentric spatial learning during navigation in a virtual maze

Background Present evidence suggests that the hippocampus (HC) and the parahippocampal cortex (PHC) are involved in allocentric (world-centered) spatial memory. However, the putative role of the PHC in egocentric (body-centered) spatial learning has received only limited systematic investigation. Methods To examine the role of the PHC in egocentric learning, 19 healthy volunteers learned to find their way in a virtual maze during functional magnetic resonance imaging (fMRI). The virtual maze presented a first-person view, lacked any topographical landmarks and could be learned only using egocentric navigation strategies. Results During learning, increased medial temporal lobe activity was observed in the PHC bilaterally. Activity was also observed in cortical areas known to project to the PHC and proposed to contribute to egocentric spatial navigation and memory. Conclusions Our results point to a role of the PHC for the representation and storage of egocentric information. It seems possible that the PHC contributes to egocentric memory by its feedback projections to the posterior parietal cortex. Moreover, access to allocentric and egocentric streams of spatial information may enable the PHC to construct a global and comprehensive representation of spatial environments and to promote the construction of stable cognitive maps by translating between egocentric and allocentric frames of memory.

Tibialis Posterior Recession

The equinocavovarus deformity that results from tibialis posterior musculotendinous contracture poses a treatment challenge that has few reliable conservative or surgical remedies. In this techniques report, the author describes a tibialis posterior recession procedure that uses the sequential use of topographic anatomical landmarks, which can be useful in correcting contracture of the tibialis posterior musculotendinous unit.

Endoscopic Topographic and Anatomic Landmarks of Opticocarotid Region Structures, Perimesencephalic and Pontocerebellar Subarachnoid Cisterns in Surgery of Middle Fossa Arachnoid Cysts

Endoscopic Topographic and Anatomic Landmarks of Opticocarotid Region Structures, Perimesencephalic and Pontocerebellar Subarachnoid Cisterns in Surgery of Middle Fossa Arachnoid Cysts

Peroneus Longus Recession

Correction of the plantarflexed first ray as a result of peroneus longus musculotendinous contracture is commonly achieved through dorsiflexory osteotomy at the base of the first metatarsal or lengthening of the peroneus longus tendon at the lateral aspect of the hindfoot or fibular malleolus. In this techniques report, the author describes peroneus longus recession in the distal aspect of the lower leg based on topographic anatomical landmarks. This procedure can be used to correct soft tissue contracture of the peroneus longus musculotendinous unit.

Orbital Restoration Surgery in the Zygomaticotemporal and Zygomaticofacial Nerves and Important Anatomic Landmarks

A variety of etiologies may result in functional and aesthetic deficiencies requiring orbital reconstruction. Fractures of the zygomaticomaxillary complex in the acute stage are frequently accompanied by sensory disturbances of the zygomatic nerve (ZN). The purpose of the current study was to describe the anatomic and topographic landmarks of the ZN in 18 adult human cadavers regarding the localization and dimensions in the orbit. The zygomaticotemporal (ZTN) and zygomaticofacial nerves (ZFN) along the lateral wall of the orbit passed through the zygomaticotemporal and zygomaticofacial foramens, respectively. The angle between the ZTN and the ZFN within the orbit was approximately 42.21 degrees. The mean (SD) distance between the orbital opening of the ZTN and the meeting point of the ZTN was measured as 9.21 (5.18) mm. The mean (SD) distance between the orbital opening of the ZFN and the meeting point of the ZTN was calculated as 11.22 (4.25) mm. The mean (SD) distance between the orbital opening of the ZFN and the infraorbital margin of the orbit was 13.04. (3.21) mm. A detailed knowledge of the ZN's passage in the orbit is necessary for a surgeon while performing maxillofacial surgery. If these measurements are taken into account, there will be little surgical risk, and this will be helpful in identifying the extent of the operative field.

Age- and Gravity-Related Changes in Facial Morphology: 3-Dimensional Analysis of Facial Morphology in Mother-Daughter Pairs

There is increasing focus on the effects of gravity and age on facial appearance. Understanding these effects on facial morphology requires an accurate means of measuring surface topography. We present a preliminary study on the changes in facial topographic landmarks in a cohort of mothers and their daughters. The faces of mother-daughter pairs (N = 15, aged 13 to 61 years) were imaged by stereophotogrammetry in the upright and supine positions. Twenty anthropometric surface landmarks were placed, and the corresponding x, y, and z coordinates were generated with custom software. The relative excursion of each landmark from the upright to the supine position was calculated. Movement of up to 7.3 mm occurred in the horizontal (x) plane, 5.7 mm in the vertical (y) plane, and 7.6 mm in the dorsoventral (z) plane. Significant movement (P < .05) in the vertical plane occurred in the upper lip, lateral canthi, labial commissures, and gonia. There was no significant movement in the dorsoventral plane. Maximal movement occurred in the lower third of the face in both groups but was more marked in the mothers. Age- and gravity-related effects on the face can be accurately measured and documented with 3-dimensional imaging. This technique will allow comparison of rejuvenation techniques and a better understanding of the mechanisms of facial aging.

A Philosophy for Treating Complex Nasal Defects

Plastic and Reconstructive Surgery Defects of the Nose, Lip, and Cheek: Rebuilding the Composite Defect Frederick J. Menick, MD Background: The face can be divided into regions (units) with characteristic skin quality, border outline, and three-dimensional contour. A defect may lie entirely within a single major unit or encompass several adjacent units, creating unique problems for repair. Composite defects overlap two or more facial units. Nasal defects often extend into the adjacent lip and cheek. The simplest solution may appear to be [sic] to simply “fill the hole”—just replace the missing bulk. Poor contour, incorrect dimension, malposition, asymmetry, poor blending into adjacent normal tissues, and a patch-like repair often follow. Methods: The following principles of regional unit repair were applied to guide these complex reconstructions: (1) reconstruct units, not defects; (2) alter the wound in site, size, shape, and depth; (3) consider using separate grafts and flaps for each unit and subunit, if appropriate; (4) use “like” tissue for “like” tissue; (5) restore a stable platform; (6) build in stages; (7) use distant tissue for “invisible” needs and local skin for resurfacing; and (8) disregard old scars. Results: Clinical cases of increasing composite complexity were repaired with local, regional, and distant tissues. Excellent aesthetics and function were obtained. Conclusions: Careful visual analysis of the normal face and the defect can direct the choice, timing, and technique of facial repair. Regional unit principles provide a coordinated approach to the vision, planning, and fabrication of these difficult wounds. The entire repair should be intellectually planned, designed step by step, and laid out in a series of coordinated steps, with general principles applied to successfully repair composite defects of the nose, lip, and cheek. Plast Reconstr Surg. 2007;120(4):887-898.

The Paraspinal Splitting Approach: A Possible Approach to Perform Multiple Intercosto-Lumbar Neurotizations

Descriptive anatomy. OBJECTIVE.: To describe the anatomy associated with the extensive transmuscular paraspinal approach required to perform multiple intercosto-lumbar neurotizations. Neurotization of lumbar roots using lower intercostal nerves is a potential method of treating neurologic deficits after spinal cord injury. It appeared to us that the paraspinal splitting approach was potentially an optimal method to perform intercostal nerve harvesting, rerouting, and intercosto-lumbar neurotizations. Ninth, 10th, and 11th intercostal nerve harvesting and rerouting down to L2, L3, and L4 roots were performed on 50 cadavers. The descriptive anatomy and topographic landmarks are reported. The mean total length of intercostal nerve harvested was 17.96 (range, 10-27) cm for the 9th intercostal nerve, 17.14 cm (range, 10-20) for the 10th intercostal nerve and 15.94 cm (range, 10-25) for the 11th intercostal nerve. The length of harvested nerve was not correlated to the size of the trunk. The length of harvested nerve was sufficient to perform lumbar roots neurotizations in the 300 cases of nerve harvesting. Multiple lumbar roots neurotizations with lower intercostal nerves already have been proposed by other authors. In this strategy, the use of the spinal cord and intercostal nerves above the spinal cord lesion avoids the axonal regrowth required via the injured central nervous system. Rerouting intercostals nerves down to the lumbar roots at their exit from the intervertebral foraminae is less invasive that the same procedure performed down to the vertebral canal at the level of the cauda equina as we used in previous protocols. Our anatomic study confirms the advantage of the paraspinal sacrospinalis splitting approach in multiple intercosto-lumbar neurotizations. The approach is quick and easy and allows a good exposure of the nerve roots at the thoracic and lumbar levels. The L2, L3, and L4 roots could be satisfactorily neurotized with this procedure.

Proper Insertion Depth of Endotracheal Tubes in Adults by Topographic Landmarks Measurements

Survey of Anesthesiology: October 2007 - Volume 51 - Issue 5 - p 234-235 doi: 10.1097/SA.0b013e318149fae0

Experimental image-guided endoscopic pituitary surgery: A useful learning model

Objectives The purpose of this study, which combined image guidance and endocscopic pituitary surgery (EPS), was to test its practicability as a learning tool to acquire the necessary skills in an experimental setting. Methods Ten cadaver-heads were explored using a standard endoscopic transsphenoidal surgical technique combined with the InstaTrak 3500 (GE Medical Systems, Lawrence, MA, USA) image guidance system. The time taken for the experimental setup and the optic-radiologic correlations of topographic landmarks were recorded and photographed. Results The average time for setting up the system was 11.9 min ± 2.0, which included head fixation, headset positioning, registration, calibration and verification of the system. With the guidance of the navigation system, the ostium, sellar floor and adjacent structures encountered during EPS could be identified easily and were reflected on the 3D-CT images accurately. Conclusion The experimental model validated the practicability of image guidance combined with EPS. The non-invasive interactive computer-assisted CT-guided navigational system facilitated the surgical procedure by providing precise spatial relationship between instrument position and adjacent structures. This combination is a useful teaching and learning tool in the cadaver and in patients will be useful, particularly for complex cases and redo-surgery.

Endoscopic pituitary surgery with and without image guidance: an experimental comparison

Background The combination of image guidance and endoscopy is the newest trend in pituitary surgery. To assess the impact of image guidance on EPS, we measured and calculated the accuracy of the system and compared some critical surgical steps with and without image guidance under experimental conditions in terms of surgical time and precision. Methods Twenty cadaver heads were explored by standard endoscopic transsphenoidal surgical technique. Optic-radiologic correlations of topographic landmarks were photographed, and the system accuracy and actual visual accuracy were recorded. Some important anatomical parameters were measured in surgical field and on navigation system, and the differences were calculated and analyzed. Some critical surgical steps were recorded and compared between with and without image guidance. Results The system accuracy (root mean square), calculated by the computer automatically, showed a mean value of 0.28 ± 0.06 mm. In some cases, there was a small discrepancy between the visible position of the pointer and its counterpart on the navigation system; we coined this actual visual accuracy. The average value was 1.53 ± 0.49 mm. The maximum difference between the measurements from the navigation system and from their actual visual counterparts was less than 7%. With and without image guidance, in normal anatomical conditioning, there was no statistically significant difference between the duration of ostium sphenoidale exposure and sellar window creation; however, in anatomical variations, the surgical time was shown to be significantly shorter when navigation was used. Conclusion We have demonstrated in this experimental setting that the electromagnetic tracking image guidance possesses a high accuracy at millimetric level and therefore provides precise localization and orientation in EPS. With the assistance of neuronavigation system, it is advantageous not only in saving operating time, but also, more importantly, in enhancing the orientation, thus, rendering surgeries safer and more efficient. During the in vivo pituitary surgery, EPS with image guidance can provide accurate and reliable stereoinformation to achieve better results with lesser risks, particularly in complex cases or in reoperations, even in the hands of experienced surgeons.

Proper insertion depth of endotracheal tubes in adults by topographic landmarks measurements

To evaluate a new method of endotracheal tube (ETT) positioning relative to carina, based on external topographic landmarks. Prospective, randomized, crossover study. Operating room, university hospital. 200 American Society of Anesthesiologists (ASA) physical status I-II patients (100 women and 100 men) scheduled for elective surgery with general anesthesia. ETT insertion depth was topographically determined by adding the distance measured (in cm) from the right mouth corner to right mandibular angle to the distance measured from the right mandibular angle to a point situated on the center of a line running transversally through the middle of the sternal manubrium. This method was compared to the 21/23 cm insertion depth method. ETT position was assessed fiberoptically. The main end point was considered the percentage of ETT tips situated more than 25% higher or lower than a predetermined "best" tip position (4 cm above the carina). There were 58.5% ETT tips positioned too closely (<3 cm above the carina) to the carina with the control method and 24% with the study method (P=0.0001). No ETT tip was too high (>5 cm above the carina). The tip-carina distance was shorter in women (2.7+/-2.5 vs 3.6+/-2.2 cm in men P=0.0001) and in those aged more than 65 years (2.8+/-2.4 vs 3.4+/-2.4 cm with age less than 65 years; P=0.012) only with the 21/23 cm method. With our new ETT positioning method, there were fewer ETTs positioned outside the desired range of distance to carina. Our method may be especially valuable in women and in patients older than 65 years.

Role of intraoperative Iso-C based navigation in challenging spine trauma

Background:Pedicle screw fixation is the most preferred method of stabilizing unstable spinal fractures. Pedicle screw placement may be difficult in presence of fractured posterior elements, deformed spine, gross instability and spinal pathology. Challenging spine-fracture fixation is defined as the presence of one or more of the following: 1) obscured topographical landmarks as in ankylosing spondylitis, 2) fractures in occipitocervical or cervicothoracic regions and 3) preexisting altered spinal alignment. We report a series of pedicle screw insertion with guidance of navigation in difficult fixation problems..Materials and Methods:Fourteen patients [hangman's fracture (n=3), odontoid fracture (n=4), C1C2 fracture (n=1) and spinal fracture with coexistent ankylosing spondylitis (n=6)] underwent posterior stabilization. Intraoperatively after surgical exposure, images were acquired by Iso-C 3D C-arm and transferred to navigation system. Instrumentation was performed with navigational assistance. Postoperatively, placements of pedicle screws were evaluated with radiographs and CT scan.Results:Sixty-seven pedicle screws (cervical, n=33; thoracic, n=6; lumbar, n=26; sacral n=2) and 15 lateral mass screws were inserted with navigation guidance. The average time of image data acquisition by Iso-C 3D C-arm and its transfer to workstation was 4 minutes (range, 2-6 minutes). Postoperative CT scan revealed ideal placement of screws in 63 pedicles (94%), grade 1 cortical breaches (<2 mm) in 3 pedicles (4.5%) and grade 2 cortical breach (2-4 mm) in one pedicle (1.5%). There were no neurovascular complications. Deep infection was encountered in one case, which settled with debridement.Conclusions:Intraoperative Iso-C 3D C-arm based navigation is a useful adjunct while stabilizing challenging spinal trauma, rendering feasibility, accuracy and safety of pedicle screw placement even in difficult situations.

The Wiltse Paraspinal Approach to the Lumbar Spine Revisited

The paraspinal posterior approach to the lumbar spine initially was described for spinal fusion, particularly for treatment of lumbosacral spondylolisthesis. Despite the technical details described by Wiltse et al, the exact location of the sacrospinalis muscle that must be split remains unclear. We sought to clarify the anatomic description of the paraspinal posterior approach to the lumbar spine, and to provide topographic landmarks for facilitating this surgical approach. Fifty cadavers were dissected using an anatomic transmuscular paraspinal approach. The level of the natural cleavage plane between the multifidus and the longissimus parts of the sacrospinalis muscle was noted, and measurements were taken between this level and the midline at the level of the spinous process of L4. A natural cleavage plane between the multifidus and the longissimus parts of the sacrospinalis muscle was present in all specimens. There was a fibrous separation between the two muscular parts in 88 of 100 cases. The mean distance between the level of the cleavage plane and the midline was 4.04 cm (range, 2.4-7 cm). Small arteries and veins were present at the level of the cleavage plane in all specimens. These vascular landmarks make it easier to locate the muscular cleavage plane and reach the articular and transverse processes during the paraspinal approach.

The course of the greater occipital nerve in the suboccipital region: A proposal for setting landmarks for local anesthesia in patients with occipital neuralgia

The anatomical relationships of the greater occipital nerve (GON) to the semispinalis capitis muscle (SCM) and the trapezius muscle aponeurosis (TMA) were examined to identify topographic landmarks for use in anesthetic blockade of the GON in occipital neuralgia. The course and the diameter of the GON were studied in 40 cadavers (29 females, 11 males), and the points where it pierced the SCM and the TMA were identified. The course of the GON did not differ between males and females. A left-right difference was detected in the site of the GON in the TMA region but not in the SCM region. The nerve became wider towards the periphery. This may be relevant to entrapment of the nerve in the development of occipital neuralgia. In three cases, the GON split into two branches before piercing the TMA and reunited after having passed the TMA, and it pierced the obliquus capitis inferior muscle in another three cases. The GON and the lesser occipital nerve reunited at the level of the occiput in 80% of the specimens. The occiput and the nuchal midline are useful topographic landmarks to guide anesthetic blockade of the GON for diagnosis and therapy of occipital neuralgia. The infiltration is probably best aimed at the site where the SCM is pierced by the GON.

Extra- and intramuscular nerve supply of the muscles of the anterior antebrachial compartment: applications for selective neurotomy and for botulinum toxin injection

Hypertonia of the upper limb due to spasticity causes pronation of the forearm and flexion of wrist and fingers. Nowadays this spasticity is often treated with injections of botulinum toxin and sometimes with selective fascicular neurotomy. To correctly perform this microsurgical technique, it is necessary to get precise knowledge of the extramuscular nerve branching in order to be better able to select the motor branches which supply the muscles involved in spasticity. The same knowledge is required for botulinum toxin injections which must be made as near as possible to the zones where intramuscular nerve endings are the densest, which is also where neuromuscular junctions are the most numerous. Thus, it is necessary to better know these zones, but their knowledge remains today imprecise. The muscles of the anterior compartment of 30 forearms were dissected, first macroscopically, then microscopically, to study the extra- and intramuscular nerve supply and the distribution of terminal nerve ramifications. The results were then linked to surface topographical landmarks to indicate the precise location of motor branches for each muscle with the aim of proposing appropriate surgical approaches for selective neurotomies. Then for each muscle, the zones with the highest density of nerve endings were divided into segments, thus determining the optimal zones for botulinim toxin injections.

Preservation of hearing in patients undergoing microsurgery for vestibular schwannoma: degree of meatal filling

Preservation of hearing has become a standard goal in selected patients undergoing surgery for a vestibular schwannoma (VS). This study was aimed at analyzing the role played by filling of the internal auditory canal (IAC) as well as those played by preoperative hearing quality, and tumor size in the postoperative preservation of serviceable hearing (SH). Three hundred eighty-six patients with VS were treated. Hearing preservation was attempted in 128 cases (33.2%) by using intraoperative monitoring and following a retrosigmoid approach. The maximal extrameatal size of the tumor, its extension within the IAC, and pre- and postoperative hearing quality, according to the Gardner-Robertson classification, were evaluated. Preservation of SH was achieved in 24.2% of the 128 patients. With respect to tumor size, SH was preserved in 39% of 77 patients harboring a tumor 15 mm wide or smaller and in 2% of 51 patients with lesions 16 mm wide or larger (p < 0.001). With regard to filling of the IAC, among 63 patients harboring a tumor 15 mm or smaller, in whom magnetic resonance images were available, SH was preserved in 52.8% of 36 patients with partial filling and in 25.9% of 27 patients with complete filling (p = 0.032). Concerning preoperative hearing quality, in the patients with tumors 15 mm or smaller, SH was preserved in 46.5% of 43 patients with Gardner-Robertson Class I hearing and 29.4% of 34 patients with Class II hearing (p = 0.126). Both tumor size and the extent of IAC filling proved statistically significant in a multivariable analysis (p < 0.001 and p = 0.026, respectively). Incomplete filling of the IAC and a tumor size of 15 mm or smaller are independent favorable factors in SH preservation. Excellent preoperative hearing appears to have a positive impact but does not have statistical significance. Intraoperative monitoring is useful in guiding the dissection; however, the surgeon's knowledge of topographical landmarks and meticulous surgical technique remain the essential factors of success.

A simple and reliable landmark for identification of the supraorbital nerve in surgery of the forehead: An in vivo anatomical study

In this in vivo study, we set out to determine the reliability of the medial margin of the iris as a landmark for the course of the supraorbital neurovascular bundle at the supraorbital rim. Seventy-five patients (73 women and 2 men) undergoing endoscopic brow lift procedures were enrolled, for a total of 150 sides. With the patient focused on a distant point, a line was constructed preoperatively along the mid-sagittal plane, tangential to the medial iris. After general anesthesia and initial dissection, a 27-gauge needle was placed (without the aid of the endoscope) through this line, parallel to the mid-sagittal plane at the orbital rim. Measurements were then taken following creation of the optical cavity. Measurements were taken from the course of the deep (lateral) branch of the supraorbital nerve to the needle. In addition, measurements were taken from the course of the supraorbital nerve to the course of the supratrochlear nerve. In 84 sides, the needle was at the nerve; in 48 sides, the needle was less than 1 mm to the nerve; and in 18 sides, the needle was 2 mm from the edge of the nerve. Overall, the nerve was an average of 0.56 +/- 0.7 mm from the needle, and in no case was the nerve course greater than 3 mm from the landmark. The supratrochlear nerve was located medial to the supraorbital nerve an average of 9.0 +/- 1.0 mm. Based on our findings, the medial iris, as opposed to the mid-pupil line, serves as a reliable topographical landmark for the course of the supraorbital nerve at the supraorbital rim.

Anatomical study of the paraspinal approach to the lumbar spine.

The original description of the paraspinal posterior approach to the lumbar spine was for spinal fusion, especially regarding lumbosacral spondylolisthesis treatment. In spite of the technical details described by Wiltse, exact location of the area where the sacrospinalis muscle has to be split remains somewhat unclear. The goal of this study was to provide topographic landmarks to facilitate this surgical approach. Thirty cadavers were dissected in order to precisely describe the anatomy of the trans-muscular paraspinal approach. The level of the natural cleavage plane between the multifidus and the longissimus part of the sacrospinalis muscle was noted and measurements were done between this level and the midline at the level of the spinous process of L4. A natural cleavage plane between the multifidus and the longissimus part of the sacrospinalis muscle was present in all cases. There was a fibrous separation between the two muscular parts in 55 out of 60 cases. The mean distance between the level of the cleavage plane and the midline was 4 cm (2.4-5.5 cm). In all cases, small arteries and veins were present, precisely at the level of the cleavage plane. We found it possible to easily localize the anatomical cleavage plane between the multifidus part and the longissimus part of the sacrospinalis muscle. First the superficial muscular fascia is opened near the midline, exposing the posterior aspect of the sacrospinalis muscle. Then, the location of the muscular cleft can be found by identifying the perforating vessels leaving the anatomical inter-muscular space.

Transethmoidal approach to the optic canal: Surgical and radiological microanatomy

Background The purpose of the study is to describe anatomic topographic landmarks for transethmoidal approach to optic canal for optic nerve decompression. The study focuses on microsurgical/radiologic anatomies and their relationships in the region of the optic canal and orbit. Methods Human optic canal and related anatomic structures were studied in orbits of 6 formalin preserved adult human cadavers. In addition, anatomic measurements were made with digital vernier caliper on the orbits of 25 adult human skulls. The relation between ethmoidal and sinus was assessed with computed tomography (CT) scan in 25 living human heads needing cranial CT scan for any reason. Results The suture on the conjunction of frontal, maxilla, and lacrimal bones with a location in medial side of the orbit was accepted as a landmark. When the measurements were taken from this landmark, the distances to supraorbital margin were: right(R): 16.76 ± 2.62 mm, left (L): 17.10 ± 1.97 mm, and to infraorbital margin were R: 20.18 ± 3.24 mm, L: 18.94 ± 2.19 mm. The distances to the anterior ethmoidal foramen were R: 19.66 ± 3.96 mm, L: 19.11 ± 2.84 mm, and to the posterior ethmoidal foramen were R: 32.01 ± 2.90 mm, L: 32.62 ± 3.33 mm. Mean distance between the anterior and posterior ethmoidal foramen were R: 12.55 ± 3.4 mm, L: 13.51 ± 4.2 mm. The posterior ethmoidal foramen and optic ring were separated only by the mean distances of R: 5.34 ± 2.81 mm, L: 4.9 ± 3.35 mm. The distance from the suture to the distal (orbital) opening of the optic canal was R: 37.35 ± 2.73 mm, L: 37.52 ± 3.47 mm and to proximal (intracranial) opening of the canal were R: 49.52 ± 2.62 mm, L: 50.94 ± 3.35 mm. The average widths of proximal (intracranial) canal measured were R: 7.43 ± 1.95 mm, L: 7.38 ± 2.01 mm and those of distal canal (orbital) were R: 5.12 ± 1.1 mm, L: 4.95 ± 1.32 mm. The mean lengths of the optic canal were R: 11.19 ± 2.68 mm, L: 12.42 ± 3.38 mm. In radiologic examinations, the mean numbers of anterior group ethmoidal cells were R: 7, L: 6 and those of posterior group ethmoidal cells were R: 4, L: 3. The results of CT demonstrated 7 (14%) Onodi or sphenoethmoidal cells in 50 orbits of living humans. Conclusion The examination of radiologic anatomy in addition to microanatomy can significantly contribute to preoperative and postoperative evaluation of the patients.