The Relationship Between the Zygomatic Arch and the Floor of the Middle Cranial Fossa

2010 ◽  
Vol 66 (suppl_2) ◽  
pp. ons363-ons369 ◽  
Author(s):  
Hayan Dayoub ◽  
William B. Schueler ◽  
Hakeem Shakir ◽  
Kristopher T. Kimmell ◽  
Eric H. Sincoff
Keyword(s):  
Computed Tomography ◽  
Muscle Thickness ◽  
Middle Cranial Fossa ◽  
Cranial Base ◽  
Zygomatic Arch ◽  
P Value ◽  
Temporalis Muscle ◽  
Computed Tomography Scans ◽  
Cranial Fossa ◽  
Vertical Height

Abstract OBJECTIVE Access to the floor of the middle cranial fossa (MCF) is often required for approaches to cranial base lesions. This study measures the craniocaudal distance between the zygomatic arch (ZA) and the floor of the MCF from a random sample of high-resolution computed tomography scans of the cranial base. Methods Forty computed tomography scans were imported into an OsiriX station and reconstructed in multiple planes. The most caudal point of the MCF was determined in each computed tomography scan. The distances between that point and the root of the zygoma and the middle point of the ZA were calculated. The thickness of the temporalis muscle and the vertical height of the zygoma were also calculated. A 2-tailed, paired Student t test was used to compare right and left measurements with a 95% confidence interval and P value <.05 as statistically significant. RESULTS The foramen ovale was consistently the lowest point of the MCF. The average root-to-floor measurement was 5.05 ± 0.42 mm above the floor of the MCF and distance of the mid-zygoma to the floor was 1.94 ± 0.61 mm above the floor of MCF. The average temporalis muscle thickness and vertical height of the ZA were 22.22 ± 0.36 mm and 8.10 ± 0.13 mm, respectively. The muscle-to-floor measurement (muscle thickness + mid-zygoma-to-floor measurement) was 24.16 ± 0.74 mm. Conclusion The routine use of a zygomatic osteotomy in approaches to the MCF does not provide very much increased exposure. However, in patients with exceptionally thick temporalis muscles or a high ZA, a zygomatic osteotomy may be helpful in providing exposure of the floor of the MCF.

scholarly journals Extensions of the Sphenoid Sinus

Neurosurgery ◽  
2010 ◽  
Vol 66 (4) ◽  
pp. 797-816 ◽  
Author(s):  
Jian Wang ◽  
Sharatchandra Bidari ◽  
Kohei Inoue ◽  
Hong Yang ◽  
Albert Rhoton
Keyword(s):  
Computed Tomography ◽  
Sphenoid Sinus ◽  
Middle Cranial Fossa ◽  
Cranial Base ◽  
Sellar Region ◽  
Computed Tomography Images ◽  
Suprasellar Region ◽  
Cranial Fossa ◽  
Minimally Invasive Access ◽  
Selection Of

Abstract OBJECTIVE The transsphenoidal approach has been extended in recent years from tumors of the sellar region to lesions involving other areas bordering the sphenoid sinus including the cavernous sinus, Meckel's cave, middle cranial fossa, planum sphenoidal, suprasellar region, and clivus. The goal of this study was to examine various pneumatized extensions of the sphenoid sinus that may facilitate extended approaches directed through the sinus. METHODS The sphenoid sinus and its surrounding structures were examined in 18 cadaver heads, and the results were correlated with the findings from 100 computed tomography images of the sinus. The sellar type of the sphenoid sinus in which the pneumatization extended beyond the anterior sellar wall was further classified according to the various extensions of the sinus. METHODS The sphenoid sinus and its surrounding structures were examined in 18 cadaver heads, and the results were correlated with the findings from 100 computed tomography images of the sinus. The sellar type of the sphenoid sinus in which the pneumatization extended beyond the anterior sellar wall was further classified according to the various extensions of the sinus. RESULTS The sellar type of the sphenoid sinus was classified into the following 6 basic types based on the direction of pneumatization: sphenoid body, lateral, clival, lesser wing, anterior, and combined. The recesses and prominences, formed by pneumatization of the sinus, act as “windows” opening from the sinus in different areas of the cranial base and may facilitate minimally invasive access to lesions in the corresponding areas. CONCLUSION The variations in the extensions of pneumatization of the sphenoid sinus may facilitate entry into areas bordering the sphenoid sinus and play a role in the selection of a surgical approach to lesions bordering the sinus.

scholarly journals Euclidean Relationship between the Superior Semicircular Canal and the Arcuate Eminence

2019 ◽  
Vol 81 (02) ◽  
pp. 165-171 ◽  
Author(s):  
Aida Nourbakhsh ◽  
Yang Tang ◽  
Brian S. DiPace ◽  
Daniel H. Coelho
Keyword(s):  
Semicircular Canal ◽  
Euclidean Distance ◽  
Three Dimensional ◽  
Middle Cranial Fossa ◽  
Surgical Anatomy ◽  
P Value ◽  
Middle Fossa ◽  
Superior Semicircular Canal ◽  
Cranial Fossa ◽  
Academic Teaching Hospital

Abstract Objective This study was aimed to better characterize the surgical anatomy of the floor of the middle cranial fossa using three dimensional Euclidean relationships between the arcuate eminence (AE), the superior semicircular canal (SSC), and the geniculate ganglion (GG). Study Design Submillimeter distances were recorded from computed tomography (CT) scans of 50 patients (100 sides). The AE, apex of the SSC, and the GG were identified and three dimensional distances measured. Setting The study was conducted at a tertiary academic teaching hospital. Main Outcome Measures In this study, Euclidean distance was obtained from AE to SSC by using a fixed anatomical landmark (GG) as the origin. Results On average, the AE is 2.1 ± 0.3 mm lateral, 2.5 ± 0.1 mm superior, and 2.1 ± 0.3 posterior to the SSC. Thirty percent (30/100) of patients had an AE that was less than 2 mm superior to SSC. The AE was medial to the SCC in 13% samples and anterior to the SSC in 18% samples. The results also show that there was no difference in mean distance between sides (1.08 mm; 95% confidence interval [CI] =  − 2.67–0.52; p-value = 0.29) or gender (0.56 mm; 95% CI =  − 1.34, 2.45; p-value = 0.86). Conclusions This study represents a comprehensive analysis of the relational anatomy of the floor of the middle fossa to date. In quantifying relationships between the AE, SSC, and GG, and by understanding the variability of these relationships in some planes, the middle fossa surgeon can feel more comfortable with this most challenging approach.

Osteoplastic Pterional Craniotomy Revisited

2011 ◽  
Vol 68 (suppl_1) ◽  
pp. ons125-ons129 ◽  
Author(s):  
Ealmaan Kim ◽  
Johnny B. Delashaw
Keyword(s):  
Computed Tomography ◽  
Muscle Function ◽  
Bone Flap ◽  
Temporalis Muscle ◽  
Pterional Approach ◽  
3 Dimensional ◽  
Pterional Craniotomy ◽  
Computed Tomography Scans ◽  
Brain Aneurysms ◽  
Additional Labor

Abstract BACKGROUND: A standard pterional approach with a free bone flap to treat brain aneurysms was first introduced and popularized by Yaşargil. OBJECTIVE: To describe a modified pterional craniotomy technique and that mobilizes part of the sphenoid wing and the pterion in a block with the temporalis muscle to enhance cosmetic results. METHODS: A subperiosteal corridor is provided inferiorly by separating the temporalis muscle from the underlying bone in a retrograde dissection. Inferior chisel cuts from the front and back enter the sphenoid wing, enabling removal of part of the sphenoid wing and the pterion in 1 piece, along with the bone flap. Forty patients with aneurysms were treated in this fashion, and the cosmetic outcome was examined at 6 months postoperatively. RESULTS: Thirty-seven patients (92.5%) demonstrated an unremarkable degree of temporalis muscle atrophy. Excellent configuration and fusion of the pterional bone flap were observed on 3-dimensional computed tomography scans. CONCLUSION: With the use of this muscle-preserving and bone-sparing pterional approach and with little additional labor, temporalis muscle function is preserved and improved cosmesis is obtained.

scholarly journals Assessment of Masseter Muscle Thickness in OSMF Patients - A Computed Tomography Study

2020 ◽  
Vol 7 (52) ◽  
pp. 3176-3179
Author(s):  
Choubarga Naik ◽  
Bimal Krishna Panda ◽  
Anisha Avijeeta ◽  
Barnanshu Pattnaik ◽  
Subha Soumya Dany ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ct Scan ◽  
Masseter Muscle ◽  
Oral Submucous Fibrosis ◽  
Precancerous Lesion ◽  
Muscle Thickness ◽  
Ct Scans ◽  
P Value ◽  
Ct Scanner ◽  
Medical College

BACKGROUND Oral submucous fibrosis (OSMF) is the most common precancerous lesion, prevalent mostly in South East Asia. The habit of betel nut or gutkha chewing is the main cause for this. There is a direct association between gutkha chewing habit and development of OSMF, the reason being exaggerated forces on the masseter muscle due to vigorous chewing for prolonged period of time. So, the present study was done to evaluate the thickness of masseter muscle in OSMF patients. METHODS A total of 25 subjects were included in the study from January 2015 to December 2017. 25 OSMF patients belonging to the age group of 25-50 years who attended the outpatient department of Veer Surendra Sai Medical College and Hospital, Burla, with masseteric hypertrophy and betelnut or gutkha chewing habit for more than 5 years, were included in the study. The computed tomography (CT) scans were obtained using Siemens Somatom Sensation 4-slice CT scanner. During the scanning period, the patients were asked to keep their mouth gently closed and relaxed. Axial sections of the CT scans were assessed for masseter muscles. The thickness of the muscle was calculated using image-analysing software and the measurements made were in millimeter (mm). Tabulation was done and statistical analysis was done using Mann-Whitney U test. RESULTS The thickness of masseter muscle of right side was found to be more than the left side in all patients except for one patient and the outcome was statistically significant with one tailed p value < 0.01. CONCLUSIONS The duration and frequency of the habit were found to be directly proportional to masseter muscle thickness and also with the clinical progression of the disease. Similarly, we also concluded from our study that there exists an association of masseter muscle hypertrophy with OSMF, and CT scan meas KEYWORDS OSMF, Masseter Muscle, CT Scan

Anatomy and Significance of the Temporal Fat Pad in Apert Syndrome

1994 ◽  
Vol 31 (3) ◽  
pp. 224-227 ◽  
Author(s):  
Rick J. Smith ◽  
Ian T. Jackson
Keyword(s):  
Lateral Displacement ◽  
Three Dimensional ◽  
Middle Cranial Fossa ◽  
Apert Syndrome ◽  
Temporal Region ◽  
Fat Pad ◽  
Temporalis Muscle ◽  
Temporal Fossa ◽  
Cranial Fossa ◽  
Normal Controls

Abnormal temporal region anatomy In Apert syndrome described in the literature includes inferior and lateral displacement of the middle cranial fossa, effacement of the temporal fossa, and thinning of the temporalis muscle. Four patients with Apert syndrome were noted to have hyperplasia of the bilateral superficial temporal fat pads, which could be contoured surgically. A case is presented with reformatted three-dimensional computed tomography (3-D CT) scans with intraoperative documentation of Increased temporal fat as compared to normal controls.

Use of Reconstructed Sagittal Computed Tomography Images to Plan Middle Cranial Fossa Surgery

2001 ◽  
Vol 111 (12) ◽  
pp. 2095-2099
Author(s):  
Krista L. Olson ◽  
Spiros Manolidis ◽  
L. Anne Hayman ◽  
Ling-Ling Chan ◽  
Katherine H. Taber
Keyword(s):  
Computed Tomography ◽  
Middle Cranial Fossa ◽  
Computed Tomography Images ◽  
Cranial Fossa ◽  
Middle Cranial Fossa Surgery

Latent superior canal dehiscence syndrome unmasked by stapedotomy for otosclerosis

2009 ◽  
Vol 124 (4) ◽  
pp. 428-430 ◽  
Author(s):  
A Hope ◽  
P Fagan
Keyword(s):  
Computed Tomography ◽  
Middle Cranial Fossa ◽  
Oval Window ◽  
Stapes Surgery ◽  
Vestibular Evoked Myogenic Potentials ◽  
Vestibular Evoked Myogenic Potential ◽  
High Resolution Computed Tomography ◽  
Superior Canal Dehiscence ◽  
Cranial Fossa ◽  
Canal Dehiscence

AbstractObjective:This report describes a novel case in which superior canal dehiscence syndrome was unmasked by successful stapes surgery for otosclerosis.Methods:Case report and literature review regarding superior canal dehiscence syndrome.Introduction:Superior canal dehiscence syndrome is a rare but well described condition in which audiovestibular symptoms are caused by noise or straining. A dehiscence of the superior semicircular canal in the floor of the middle cranial fossa is responsible, and acts as a ‘third window’ into the inner ear.Case history:A patient with confirmed otosclerosis underwent second-side stapedotomy, with good audiometric outcomes. Unfortunately, surgery was complicated by immediate post-operative vertigo and persistent auditory symptoms. A diagnosis of superior canal dehiscence syndrome was eventually made, on the basis of low threshold vestibular evoked myogenic potentials and characteristic computed tomography findings. Superior canal resurfacing resulted in complete resolution of symptoms.Discussion:The otosclerotic focus in the oval window prevented the development of symptoms from this patient's superior canal dehiscence syndrome. Surgical stapedotomy created a third window and resulted in immediate post-operative imbalance and auditory symptoms.Conclusion:The diagnosis of superior canal dehiscence syndrome should be considered in patients with persistent audiovestibular symptoms after stapes surgery. High resolution computed tomography of the temporal bone and vestibular evoked myogenic potential testing, if available, are the investigations of choice in confirming the diagnosis.

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