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Cadaver Heads (cadaver + head)
Selected AbstractsVisualization of anterior skull base defects with intraoperative cone-beam CTHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 4 2010Gideon Bachar MD Abstract Background The role of cone-beam CT (CBCT) in demonstrating anterior skull base defects (ASBDs), differing in size and location, was investigated. The study was designed to describe the potential advantage of CBCT in the setting of an intraoperative cerebrospinal fluid (CSF) leak. Methods In all, 120 ASBD were evaluated in 5 cadaver heads. Orthogonal and oblique slices were reconstructed. Observer studies assessed the visibility of ASBD in each location as a function of defect size. Results For 1-, 2-, and 4-mm defects, the percentage that were undetectable ranged from 20% to 33%, 0% to 14%, and 0% to 5%, respectively. Confident breach detection increased with defect size and was most challenging in the lateral lamella and cribriform. CBCT permitted confident detection of ASBD as small as about 2 mm in the fovea ethmoidalis and planum. Oblique views were found to be superior to orthogonal planes. Conclusions The ability to identify ASBD depended on the size and location of defect. Oblique viewing planes were optimal for ASBD visualization. © 2009 Wiley Periodicals, Inc. Head Neck, 2010 [source] Pterygopalatine Fossa Infiltration Through the Greater Palatine Foramen: Where to Bend the NeedleTHE LARYNGOSCOPE, Issue 7 2006FRACP, FRACS, Richard Douglas MD Abstract Objective: In the literature, there has been controversy regarding the length of the greater palatine canal. If the pterygopalatine fossa is infiltrated in an attempt to reduce bleeding during sinus surgery, this information is important to be able to place local anesthetic with maximal effect and the least likelihood of complications. Study Design: The authors conducted a prospective cadaver-based study using high-definition computed tomography (CT) scans. Methods: Twenty-two cadaver heads were CT scanned and the greater palatine canal length, pterygopalatine fossa height, and thickness of the soft tissue in the roof of the mouth were measured on parasagittal images using the CT scanner workstation. Results: The mean length of the greater palatine canal was 18.5 mm (95% confidence interval [CI] = 17.9,19.1) and the mean height of the pterygopalatine fossa was 21.6 mm (95% CI = 20.7,22.5). The mean thickness of the soft tissue in the roof of the mouth overlying the foramen of the greater palatine canal was 6.9 mm (95% CI = 6.2,7.6). Conclusion: To perform an effective infiltration of the pterygopalatine fossa, the needle should be bent at 25 mm from the tip at an angle of 45°. [source] Patterns of Innervation of the Anterior Maxilla: A Cadaver Study with Relevance to Canine Fossa Puncture of the Maxillary Sinus,THE LARYNGOSCOPE, Issue 10 2005Simon Robinson FRACS Abstract Objectives/Hypothesis: Complications from canine fossa puncture of the maxillary sinus are caused by damage to the anterior superior alveolar nerve (ASAN) and the middle superior alveolar nerve (MSAN). The aim of this study was to elucidate the pattern of ASAN and MSAN within the anterior maxilla and to secondly determine suitable surgical landmarks to aid in accurately localizing the area of the canine fossa least likely to produce complications when a trocar is passed into the maxillary sinus. Methods: Anatomic dissection of the anterior face of the maxilla from 20 cadaver heads was performed. The pattern and presence of the ASAN and MSAN was identified on each side and tabulated. Landmarks for the safest entry point for canine fossa puncture were determined, and each side had a puncture placed using these landmarks. Any disruption of nerves was noted. Results: Multiple differing patterns of ASAN were identified. The ASAN emerged from its foramen as a single trunk in 30 (75%) sides and in a double trunk in 10 (25%). In 24 (60%), single or multiple branches from the ASAN trunks were identified. A MSAN was identified in 9 (23%) maxillae. The safest entry point for a canine fossa puncture was where a vertical line drawn through the mid-pupillary line was bisected by a horizontal line drawn through the floor of the pyriform aperture. Conclusions: There is significant variation in the pattern of ASAN and MSAN within the anterior face of the maxilla. By using the newly described landmarks when performing a canine fossa puncture, there is reduced risk of damage to these nerves and provides a reliable point to enter the maxillary sinus. [source] Paraclinoid and cavernous sinus regions: Measurement of critical structures relevant for surgical procedureCLINICAL ANATOMY, Issue 1 2005Frederic Collignon Abstract Determination of the safest distance the falciform ligament can be incised from its origin to the orbital apex. Measurement of the distance between the oculomotor foramen and the IV nerve in the lateral wall of the cavernous sinus. Evaluation of the optic strut as an accurate landmark between the intradural (subarachnoid) and extradural segment of the internal carotid artery (ICA). Ten fixed human cadaver heads were examined for a total of 20 sides. A frontotemporal craniotomy, an orbito-optic osteotomy, and extradural anterior clinoidectomy were carried out followed by opening the falciform ligament, circumferentially releasing the distal dural ring and dissection of the lateral wall of the cavernous sinus under the operating microscope. We measured: 1) the distance between the entry of the III nerve and the point where the IV nerve crosses over it into the cavernous sinus; 2) the distance the falciform ligament can be incised along the optic nerve laterally until the IV nerve is encountered at the orbital apex; 3) the distance between the optic strut and the lateral part of the distal dural ring; and 4) the distance between the optic strut and the ophthalmic artery. All measurements were made in millimeters, using small calipers. The distance between the optic strut and the lateral part of the distal dural ring ranges from 3,7.5 mm (mean = 5.47 mm). In all our specimens, the ophthalmic artery was found distally from the optic strut in the intradural space at a distance ranging from 0.5,7 mm (mean = 3.35 mm). The distance between the entry of the third nerve and the IV nerve into the cavernous sinus ranged from 7,15 mm (mean = 10.9 mm). The distance between the origin of the falciform ligament and the IV nerve at the level of the orbital apex ranged from 9,15 mm (mean = 10.75 mm). The falciform ligament and the optic sheath should not be opened longer than 9 mm along the lateral optic nerve or injury to the IV nerve can occur. Starting at the oculomotor foramen, the opening of the cavernous sinus should be limited to 7 mm to avoid injuring the IV nerve. Finally, the optic strut can be a reliable bony landmark that separates the subarachnoid space and extradural compartments along the anterior and medial ICA. Clin. Anat. 18:3,9, 2005. © 2004 Wiley-Liss, Inc. [source] | ||||||||||