Feasibility of spheno-occipital synchondrosis fusion stages as an indicator for the assessment of maxillomandibular growth: A mixed longitudinal study.

OBJECTIVES: This study aimed to assess the relative growth rates (RGRs) of the maxilla and mandible at varying fusion stages of the spheno-occipital synchondrosis (SOS), thereby elucidating the potential of SOS stages in predicting maxillomandibular growth. MATERIALS AND METHODS: A total of 320 subjects (171 boys and 149 girls), aged 6 to 18 years, were retrospectively included. Each subject had a minimum of two longitudinal cone-beam computed tomography (CBCT) images, with no more than one interval of SOS fusion stage change between the two scans. Subjects were categorized based on their SOS fusion stages and genders. The RGRs of the maxilla and mandible at various SOS fusion stages were measured and compared using longitudinal CBCT images. RESULTS: Significant statistical differences were observed in maxillomandibular RGRs across various SOS fusion stages. In girls, the sagittal growth of the maxilla remained stable and active until SOS 3, subsequently exhibited deceleration in SOS 4-5 (compared to SOS 3-4, P < .05) and continued to decrease in SOS 5-6. Whereas in boys, the sagittal growth of the maxilla remained stable until SOS 4, and a deceleration trend emerged starting from SOS 5 to 6 (P < .01 compared to SOS 4-5). Mandibular growth patterns in both genders exhibited a progression of increasing-accelerating-decelerating rates from SOS 2 to 6. The highest RGRs for total mandibular length were observed in SOS 3-4 and SOS 4-5. CONCLUSION: Spheno-occipital synchondrosis fusion stages can serve as a valid indicator of maxillomandibular growth maturation.

Tailored Surgical Access to the Cavernous Sinus and Parasellar Region: Assessment of Cavernous Sinus Entry Corridors and the Periclinoid and Pericavernous Surgical Maneuvers.

BACKGROUND: Lesions involving the cavernous sinus (CS) represent some of the most challenging pathologies of the skull base owing to the dense traversing and surrounding neurovasculature. Extradural exposure and preparation of this region, whether as initial preparation for a combined intra-extradural approach or as the main avenue of surgical exposure, can enlarge surgical corridors and minimize the need for brain retraction in this very confined space. We provide a detailed assessment of the entry corridors to the CS that are available within each approach, the surgical exposure and freedom provided by each of these corridors, and demonstrate how extradural and intradural preparation of these corridors can be used to widen the available working space and facilitate surgery. METHODS: Pterional, frontotemporal-orbital, frontotemporal-orbitozygomatic, frontotemporal-zygomatic, perilabyrinthine transtentorial, and endoscopic transnasal transsphenoidal approaches were performed on cadaveric heads to access the perisellar and CS regions. Periclinoid maneuvers (extradural cutting of the meningo-orbital band, anterior clinoidectomy, unroofing of the optic canal, opening of the superior orbital fissure, displacement of the extra-annular structures, opening of the annulus of Zinn, and interdural dissection), pericavernous maneuvers (intradural cutting of the distal dural ring, mobilization of the supraclinoid internal carotid artery, opening of the oculomotor porus, and mobilization of cranial nerve (CN) III), peritrigeminal extensions (extradural mobilization of CN V2 [maxillary] and/or V3 [mandibular]), and other surgical maneuvers were performed and evaluated. The CS was divided into 8 anatomical compartments and 9 entry corridors were described, and exposure and freedom were assessed accordingly. RESULTS: Intradurally, the standard unextended pterional, frontotemporal-orbital, and frontotemporal orbitozygomatic transsylvian approaches provided access solely to the parasellar entry corridor into the superior wall of the CS. Expanding these approaches with extradural periclinoid maneuvers allowed for subsequent application of the intradural pericavernous maneuvers and enlargement of the parasellar corridor and exposure of the carotid cave. Extradurally, the frontotemporal-orbital approach could be expanded via application of periclinoid maneuvers, which provided access to the anterior portions of the main lateral wall entry corridors. The frontotemporal-orbitozygomatic approach could also be expanded with periclinoid maneuvers to provide extradural access to all 6 lateral wall entry corridors. The extradural frontotemporal-zygomatic approach only provided exposure following interdural dissection, which allowed for access to the inferolateral entry corridors into the lateral wall. Extradural peritrigeminal extension in the frontotemporal-orbitozygomatic and frontotemporal-zygomatic approaches allows for enlargement of the supramaxillary and pre- and postmandibular corridors. The perilabyrinthine approach to the posterior wall was enlarged with opening of Dorello's canal and the endoscopic transnasal transsphenoidal approach was enlarged with opening of the optic canal. CONCLUSIONS: Targeted extradural preparation optimizes exposure and significantly improves access to deep-seated targets by enhancing surgical maneuverability through the unlocking of neurovascular structures and widening of surgical corridors without the need for additional brain retraction.

Comparison of spheno-occipital synchondrosis maturation stages with three-dimensional assessment of mandibular growth.

BACKGROUND: This study aimed to compare spheno-occipital synchondrosis (SOS) maturation stages with a three-dimensional assessment of mandibular growth. METHODS: This is a cross-sectional study of a retrospective type, in which cone-beam computed tomography (CBCT) images of 500 patients aged 6 to 25 years (226 males and 274 females) were analyzed. The SOS was evaluated using the four-stage scoring system; completely open, partially fused, semi-fused, or completely fused. The SOS scoring and three-dimensional cephalometric measurements were analyzed by Invivo 6.0.3 software. Descriptive and analytical statistics were performed, and a P-value < 0.05 was considered statistically significant. RESULTS: There was a statistically significant difference in mandibular measurements among SOS maturation stages in both sexes (P < 0.05). The skeletal growth increments of mandibular variables across the SOS stages had higher mean differences between SOS stages 2 and 3 than those between stages 1 and 2 and stages 3 and 4 in both sexes. The mandibular growth curves increased with chronological age (earlier in females) and SOS maturation stages (mostly in stages 1, 2, and 3 than stage 4). CONCLUSIONS: The SOS maturation stages are valid and reliable mandibular skeletal indicators as evaluated with three-dimensional cephalometric mandibular measurements. The findings of growth increments and constructed growth curves of mandibular growth might be helpful in diagnosis and treatment planning.

Endoscopic Endonasal Anterior Clinoidectomy: Volumetric Assessment and Feasibility.

BACKGROUND: Transcranial removal of the anterior clinoid process (ACP) provides access to the clinoidal segment of the internal carotid artery as well as superolateral decompression of the optic canal. Endoscopic endonasal approaches (EEAs) can access the entire medial and inferior portions of the optic canal, but no data exist to support what proportion of the anterior clinoid could be safely resected via an EEA. METHODS: A cadaveric anatomical study was performed with removal of the ACP in 3 major steps in order of difficulty and risk. At each step, the removal was stopped when no more bone of the ACP could be seen without traction on neural structures. After each step, a CT scan was performed to allow volumetric measurement of the remaining ACP. RESULTS: Twenty ACPs in 10 cadaveric heads were removed to various degrees using the described stepwise technique. The mean portion of the ACP resected by each step was 21%, 46%, and 27%, respectively. Cumulated ACP removal at the end of step 3 was 94%, with complete removal achieved in 35% of the specimens. CONCLUSIONS: Using the safe route above the optic canal, removal of 21% of the ACP can be achieved via EEA. Although substantially more of the ACP can be drilled by accessing the optic strut, the benefits of pursuing additional removal must be weighed against the significant risks of drilling in this narrow corridor bordered by the internal carotid artery, the third cranial nerve, and the optic nerve.

Assessment of magnetic resonance imaging criteria for the diagnosis of cavernous sinus invasion by pituitary tumors.

Cavernous sinus invasion (CSI) by pituitary tumors is associated with subtotal resection and persistent endocrinopathy. The Knosp classification is a magnetic resonance imaging (MRI) tool used to define CSI in the 2017 World Health Organization Classification. However, alternative criteria may have superior diagnostic performance. This study aimed to assess the diagnostic performance of four MRI criteria, using a combination of endoscopy and day 1 MRI as the reference standard for CSI. A cross-sectional study was conducted including patients treated with endoscopic endonasal transsphenoidal surgery for pituitary macroadenomas, recruited from a tertiary pituitary multidisciplinary center in Sydney, Australia between September 2013, and February 2021. The diagnostic performances of four MRI criteria were assessed: the Knosp criteria, percentage encasement of the internal carotid (PEICA), venous compartment obliteration (VCO), and the Fernandez-Miranda classification. Reference CSI was defined using a combination of intraoperative endoscopy and day 1 MRI. A total of 210 cavernous sinuses (105 patients), were analyzed, (51.7 ±â€¯16.3yrs, 43% female), of which 18% had CSI. CSI was best diagnosed by Knosp ≥ 2 (63% sensitivity and 89% specificity), PEICA ≥ 28% (84% sensitivity and 77% specificity) and VCO of ≥ 3 compartments (65% sensitivity and 89% specificity). CSI was unlikely if any of the following signs were present: Knosp < 1, PEICA < 28%, preservation of the medial or superior compartments or sparing of the superior Fernandez-Miranda compartment (negative predictive value 95%, 95%, 94%, 91% and 92% respectively). In conclusion, alternatives to the Knops criteria including PEICA and VCO can aid CSI diagnosis.

Pituitary society expert Delphi consensus: operative workflow in endoscopic transsphenoidal pituitary adenoma resection.

PURPOSE: Surgical workflow analysis seeks to systematically break down operations into hierarchal components. It facilitates education, training, and understanding of surgical variations. There are known educational demands and variations in surgical practice in endoscopic transsphenoidal approaches to pituitary adenomas. Through an iterative consensus process, we generated a surgical workflow reflective of contemporary surgical practice. METHODS: A mixed-methods consensus process composed of a literature review and iterative Delphi surveys was carried out within the Pituitary Society. Each round of the survey was repeated until data saturation and > 90% consensus was reached. RESULTS: There was a 100% response rate and no attrition across both Delphi rounds. Eighteen international expert panel members participated. An extensive workflow of 4 phases (nasal, sphenoid, sellar and closure) and 40 steps, with associated technical errors and adverse events, were agreed upon by 100% of panel members across rounds. Both core and case-specific or surgeon-specific variations in operative steps were captured. CONCLUSIONS: Through an international expert panel consensus, a workflow for the performance of endoscopic transsphenoidal pituitary adenoma resection has been generated. This workflow captures a wide range of contemporary operative practice. The agreed "core" steps will serve as a foundation for education, training, assessment and technological development (e.g. models and simulators). The "optional" steps highlight areas of heterogeneity of practice that will benefit from further research (e.g. methods of skull base repair). Further adjustments could be made to increase applicability around the world.

Use of a Surgical Stepdown Protocol for Cost Reduction After Transsphenoidal Pituitary Adenoma Resection: A Case Series.

OBJECTIVE: No established standard of care currently exists for the postoperative management of patients with surgically resected pituitary adenomas. Our objective was to quantify the efficacy of a postoperative stepdown unit protocol for reducing patient cost. METHODS: In 2018-2020, consecutive patients undergoing transsphenoidal microsurgical resection of sellar lesions were managed postoperatively in the full intensive care unit (ICU) or an ICU-based surgical stepdown unit based on preset criteria. Demographic variables, surgical outcomes, and patient costs were evaluated. RESULTS: Fifty-four patients (27 stepdown, 27 full ICU; no difference in age or sex) were identified. Stepdown patients were also compared with 634 historical control patients. The total hospital length of stay was no different among stepdown, ICU, and historical patients (4.8 ± 1.0 vs. 5.9 ± 2.8 vs. 4.4 ± 4.3 days, respectively, P = 0.1). Overall costs were 12.5% less for stepdown patients (P = 0.01), a difference mainly driven by reduced facility utilization costs of -8.9% (P = 0.02). The morbidity and complication rates were similar in the stepdown and full ICU groups. Extrapolation of findings to historical patients suggested that ∼$225,000 could have been saved from 2011 to 2016. CONCLUSIONS: These results suggest that use of a postoperative stepdown unit could result in a 12.5% savings for eligible patients undergoing treatment of pituitary tumors by shifting patients to a less acute unit without worsened surgical outcomes. Historical controls indicate that over half of all pituitary patients would be eligible. Further refinement of patient selection for less costly perioperative management may reduce cost burden for the health care system and patients.

Geographic Variation in Costs of Transsphenoidal Pituitary Surgery in the United States.

BACKGROUND: Geographic variations in health care costs have been reported for many surgical specialties. OBJECTIVE: In this study, we sought to describe national and regional costs associated with transsphenoidal pituitary surgery (TPS). METHODS: Data from the Truven-MarketScan 2010-2014 were analyzed. We examined overall total, hospital/facility, physician, and out-of-pocket payments in patients undergoing TPS including technique-specific costs. Mean payments were obtained after risk adjustment for patient-level and system-level confounders and estimated differences across regions. RESULTS: The estimated overall annual burden was $43 million/year in our cohort. The average overall total payment associated with TPS was $35,602.30, hospital/facility payment was $26,980.45, physician payment was $4685.95, and out-of-pocket payment was $2330.78. Overall total and hospital/facility costs were highest in the West and lowest in the South (both P < 0.001), whereas physician reimbursements were highest in the North-east and lowest in the South (P < 0.001). There were no differences in out-of-pocket expenses across regions. On a national level, there were significantly higher overall total and hospital/facility payments associated with endoscopic compared with microscopic procedures (both P < 0.001); there were no significant differences in physician payments or out-of-pocket expenses between techniques. There were also significant within-region cost differences in overall total, hospital/facility, and physician payments in both techniques as well as in out-of-pocket expenses associated with microsurgery. There were no significant regional differences in out-of-pocket expenses associated with endoscopic surgery. CONCLUSIONS: Our results show significant geographic cost disparities associated with TPS. Understanding factors behind disparate costs is important for developing cost containment strategies.

Assessment of the Optic Foramen Shape and Size in Human Fetuses.

OBJECTIVE: This study was aimed to obtain data on the dimensions of the optic foramen in human fetuses for early childhood surgeries. METHODS: Twenty-five formalin-fixed fetuses (16 boys and 9 girls) with average age 21.68 ±â€Š3.12 gestational weeks (range, 16-28 weeks) in the inventory of Anatomy Department, Faculty of Medicine were included in the study. The surface area, width, and height of the optic foramen were bilaterally measured using a digital image analysis software. RESULTS: The forms of the optic foramen were described as oval shaped (72%, 36 foramina) and round shaped (28%, 14 foramina). The surface area, width, and height of the optic foramen were found as 2.40 ±â€Š1.02 mm, 1.83 ±â€Š0.59 mm, and 1.58 ±â€Š0.36 mm, respectively. The measurements of the parameters related to the optic foramen were not statistically different in terms of sides and sexes (P > 0.05). Linear functions for the height, width and surface area of the optic foramen were calculated as: y = 0.711 + 0.040 × weeks, y = -0.019 + 0.086 × weeks, and y = -0.400 + 0.129 × weeks, respectively. CONCLUSION: The linear functions in this study can be used to estimate the dimensions of the optic foramen. The calculated regression equations, representing the growth dynamic of the optic foramen showed that the surface area, width, and height were increasing according to gestational ages between 16 and 28 weeks. Microanatomical knowledge related to the optic foramen may be beneficial for surgeons to avoid iatrogenic injury in infants and for anatomists to understand the development of the fetal skull base.

Computed Tomography Scan Assessment of the Anatomy of the Pterygomaxillary Junction and Its Relevance in Le Fort I Osteotomy.

Knowledge of the morphometry and types of pterygomaxillary junction (PMJ) during Le-Fort I osteotomy is an important consideration in the reduction of intraoperative complications. The PMJ is known to display population variations and with the recent increase in these surgical interventions in Kenya, a detailed description of the PMJ is warranted. Computed tomography scan images of PMJ obtained from 63 patients were analyzed at the level of the posterior nasal spine to assess types and the morphometry of the PMJ. A fissure type of PMJ was present in 65.9% (83/126 sides) while a synostosis type was present in 34.1% (43/126). Bilateral fissures were found in 58.73% (37/63), bilateral synostosis in 26.98% (17/63), and an asymmetric PMJ in 15.25% (9/63). The average height, width, and thickness of the PMJ were 17.45 ±â€Š5.26 mm, 10.24 ±â€Š1.97 mm, and 6.40 ±â€Š1.97 mm respectively. Males had a significantly greater height (P = 0.003) and width (P = 0.000). The average width was greater in cases with a synostosis as compared with those with a fissure (P = 0.019). Average distance of greater palatine canal was 40.41 ±â€Š2.28 mm and 7.19 ±â€Š2.20 mm from the piriform rim and the pterygoid fossa respectively. The PMJ among Kenyans is characterized by a higher occurrence of synostosis, greater height, and thickness compared with previous findings from other populations. The results of this study can be helpful for surgeons in selecting the most appropriate techniques to achieve successful pterygomaxillary disjunction and minimize avoid attendant complications such as vascular and nerve injuries.

Impact of Medicaid insurance on outcomes following endoscopic transsphenoidal pituitary surgery.

OBJECTIVE: Despite the rise of studies in the neurosurgical literature suggesting that patients with Medicaid insurance have inferior outcomes, there remains a paucity of data on the impact of insurance on outcomes after endonasal endoscopic transsphenoidal surgery (EETS). Given the increasing importance of complications in quality-based healthcare metrics, the objective of this study was to assess whether Medicaid insurance type influences outcomes in EETS for pituitary adenoma. METHODS: The authors analyzed a prospectively acquired database of EETS for pituitary adenoma from 2005 to 2018 at NewYork-Presbyterian Hospital, Weill Cornell Medicine. All patients with Medicaid insurance were identified. As a control group, the clinical, socioeconomic, and radiographic data of all other patients in the series with non-Medicaid insurance were reviewed. Statistical significance was determined with an alpha < 0.05 using Pearson chi-square and Fisher's exact tests for categorical variables and the independent-samples t-test for continuous variables. RESULTS: Of 584 patients undergoing EETS for pituitary adenoma, 57 (10%) had Medicaid insurance. The maximum tumor diameter was significantly larger for Medicaid patients (26.1 ± 12 vs 23.1 ± 11 mm for controls, p < 0.05). Baseline comorbidities including diabetes mellitus, hypertension, smoking history, and BMI were not significantly different between Medicaid patients and controls. Patients with Medicaid insurance had a significantly higher rate of any complication (14% vs 7% for controls, p < 0.05) and long-term cranial neuropathy (5% vs 1% for controls, p < 0.05). There were no statistically significant differences in endocrine outcome or vision outcome. The mean postoperative length of stay was significantly longer for Medicaid patients compared to the controls (9.4 ± 31 vs 3.6 ± 3 days, p < 0.05). This difference remained significant even when accounting for outliers (5.6 ± 2.5 vs 3.0 ± 2.7 days for controls, p < 0.05). The most common causes of extended length of stay greater than 1 standard deviation for Medicaid patients were management of perioperative complications and disposition challenges. The rate of 30-day readmission was 7% for Medicaid patients and 4.4% for controls, which was not a statistically significant difference. CONCLUSIONS: The authors found that larger tumor diameter, longer postoperative length of stay, higher rate of complications, and long-term cranial neuropathy were significantly associated with Medicaid insurance. There were no statistically significant differences in baseline comorbidities, apoplexy, endocrine outcome, vision outcome, or 30-day readmission.

Comparative preoperative characteristics and postoperative outcomes at a private versus a safety-net hospital following endoscopic endonasal transsphenoidal resection of pituitary adenomas.

OBJECTIVE: Sociodemographic disparities in health outcomes are well documented, but the effects of such disparities on preoperative presentation of pituitary adenomas (PA) and surgical outcomes following resection are not completely understood. In this study the authors sought to compare the preoperative clinical characteristics and postoperative outcomes in patients undergoing PA resection at a private hospital (PH) versus a safety-net hospital (SNH). METHODS: The authors conducted a retrospective review over a 36-month period of patients with PAs who underwent endoscopic endonasal transsphenoidal surgery performed by the same attending neurosurgeon at either a PH or an SNH at a single academic medical institution. RESULTS: A total of 92 PH patients and 69 SNH patients were included. SNH patients were more likely to be uninsured or have Medicaid (88.4% vs 10.9%, p < 0.0001). A larger percentage of SNH patients were Hispanic (98.7% vs 32.6% p < 0.0001), while PH patients were more likely to be non-Hispanic white (39.1% vs 4.3%, p < 0.0001). SNH patients had a larger mean PA diameter (26.2 vs 22.4 mm, p = 0.0347) and a higher rate of bilateral cavernous sinus invasion (13% vs 4.3%, p = 0.0451). SNH patients were more likely to present with headache (68.1% vs 45.7%, p = 0.0048), vision loss (63.8% vs 35.9%, p < 0.0005), panhypopituitarism (18.8% vs 4.3%, p = 0.0031), and pituitary apoplexy (18.8% vs 7.6%, p = 0.0334). Compared to PH patients, SNH patients were as likely to undergo gross-total resection (73.9% vs 76.1%, p = 0.7499) and had similar rates of postoperative improvement in headache (80% vs 89%, p = 0.14) and vision (82% vs 84%, p = 0.74), but had higher rates of postoperative panhypopituitarism (23% vs 10%, p = 0.04) driven by preoperative endocrinopathies. Although there were no differences in tumor recurrence or progression, loss to follow-up was seen in 7.6% of PH versus 18.6% (p = 0.04) of SNH patients. CONCLUSIONS: Patients presenting to the SNH were more often uninsured or on Medicaid and presented with larger, more advanced pituitary tumors. SNH patients were more likely to present with headaches, vision loss, and apoplexy, likely translating to greater improvements in headache and vision observed after surgery. These findings highlight the association between medically underserved populations and more advanced disease states at presentation, and underscore the likely role of academic tertiary multidisciplinary care teams and endoscopic PA resection in somewhat mitigating sociodemographic factors known to portend poorer outcomes, though longer-term follow-up is needed to confirm these findings.

Radiomorphometric assessment of the pterygoid hamulus as a factor promoting the pterygoid hamulus bursitis.

BACKGROUND: The pterygoid hamulus (PH) is a small protrusion on the base of the pterygoid process of the sphenoid bone. PH is a site of insertion of many muscles and ligaments. Its topography can determine predilection for developing the pterygoid hamulus bursitis (PHB). MATERIALS AND METHODS: The study was conducted based on the morphometric analysis of 100 PHs on cone beam computed tomography scans. RESULTS: Based on statistical analysis, we found numerous significant correlations between the morphometric parameters. CONCLUSIONS: Considering our results, it can be concluded that the main pathogenic factor in PHB is an extensive medial deviation of the pterygoid hamulus in the frontal plane.

Simple assessment of the localization of posterior communicating artery aneurysms to the anterior petroclinoid ligament.

The microsurgical management of posterior communicating artery (PCoA) aneurysms can be modified depending on their localization, with respect to the tentorial edge consisting of the anterior petroclinoid ligament (APCL). However, the imaging of APCL has been impractical to date. In this study, we evaluated a simple method for assessing the relationship between PCoA aneurysms and APCL, using three-dimensional computed tomographic angiography (3D-CTA). We retrospectively reviewed all surgically treated cases of PCoA aneurysms via the pterional approach in our institute from May 2013 to August 2018. To predict the localization of the aneurysms, three anatomical lines were drawn on non-subtracted volumetric 3D-CTA as follows: 1. the apex of the anterior clinoid process to the posterior border of the trigeminal depression of the petrosal bone (AACP-PBTD); 2. AACP to the superior edge of the arcuate eminence (AACP-SEAE); 3. the base of the ACP to the superior edge of the arcuate eminence (BACP-SEAE). The relative location of each line to the PCoA aneurysms was compared with actual intraoperative findings. Fifty-six aneurysms were included. The sensitivity, specificity, and positive and negative predictive values of the superior localization of the aneurysm of the AACP-TDPB line were 93.8%, 40.0%, 38.5%, and 94.1%, respectively. Those of the AACP-SEAE line were 93.8%, 42.5%, 39.5, and 94.4%, respectively. In contrast, those of the BACP-SEAE line were 93.8%, 97.5%, 93.8%, and 97.5%, respectively. The BACP-SEAE line is a simple and practical landmark in predicting APCL.

Assessment of dimensions of pneumatisation of the anterior clinoid process in middle Anatolian population by computed tomography.

BACKGROUND: The anterior clinoid process (ACP) is usually removed during surgical procedures of the cellar region. The ACP may be different length and width in people; it may be also pneumatic. Therefore, we aimed to determine dimensions and rates of pneumatisation of the ACP in the large study group with clinically importance. MATERIALS AND METHODS: One thousand and thirty-one (592 female, 439 male) cranial computed tomography (CT) of the middle Anatolian population was used in this study. The length and basal width of the ACP were measured on the cranial CT. Also; incidence and degree of ACP pneumatisation were identified. RESULTS: The width of the right and left ACPs in females were 10.80 ± 2.27 mm and 10.53 ± 2.07 mm, respectively. The width of the right and left ACPs in males were 11.08 ± 2.39 mm and 10.98 ± 2.35 mm, respectively. The length of the right and left ACPs in females were 8.32 ± 2.40 mm and 8.34 ± 2.35 mm, respectively. The length of the right and left ACPs in males were 8.87 ± 2.62 mm and 8.93 ± 2.64 mm, respectively. There was statistically significant difference between males and females in ACP dimensions, except for the width of the right ACP. Pneumatisation of the ACP was observed on the right side in 46 (9.3%) cases, on the left side in 53 (10.6%) cases, and bilaterally in 32 (6.5%) cases. Incidence of pneumatisation of the ACP was decreased in the age group of 1 month to 20 years. While the incidence of bilateral pneumatisation of the ACP was higher in individuals aged 21-40. CONCLUSIONS: Radiologically recognising pneumatisation and anatomical variations of the ACP may be helpful in decreasing the incidence of surgical complications during anterior clinoidectomy.

The Measurement of Various Anatomical Structures and Assessment of Morphometric Development of Fetal Skull Base.

BACKGROUND: As the skull base has a complex anatomy, we underline the importance of anomalies for side asymmetry. It is useful to investigate relationship between anatomical structures for the surgical procedure orientations. Dural adherence, enlarged superior petrosal sinus, influence of neural crest cells, and cranial base ossification are among the factors in morphometric growth on skull base. MATERIAL AND METHODS: Twenty-five fetuses of an estimated gestational age ranging from 17 to 34 weeks were studied in the Anatomy Laboratory of Mersin University Medical Faculty. Craniotomy was made to each fetus and brain hemispheres were dissected. We put plates, passing from the external points of lateral and anterior-posterior borders of fetus heads that are perpendicular to each other. An analytical calculation was formulated for the angle of foraminae to the root of zygoma by using different formulations depending on their posterior or anterior location to the root of zygoma. Statistical method was based on correlation analysis, simple regression, independent 2 group t tests, SPSS20.0, and MedCalc 11.5 (MedicReS, New York, NY). RESULTS: Neither side dominance for the jugular foramen, nor the differences of foramen rotundum, spinosum, and ovale to anterior skull wall, root of zygoma, and to midline were found to be significant. CONCLUSION: There is a debate on asymmetry of foramina of the skull base. No certain consensus about the initiation time and the causes of asymmetry in the past was documented. Studies are to be encouraged to further enlighten pre-postnatal factors affecting the fetal skull base morphometrism.

Volumetric assessment of sphenoid sinuses through segmentation on CT scan.

PURPOSE: Computed tomography represents the gold standard for the assessment of morphological characteristics of sphenoid sinuses, whose anatomy has acquired a novel interest because of the recent introduction of transsphenoidal surgery and robot-assisted procedures. One of the most relevant parameters for planning surgical intervention is the volume of sphenoid sinuses, and with time few population studies have been published. However, at present, no data are available concerning the relation between volume and anatomical variants of sphenoid sinuses. METHODS: We retrospectively evaluated head CT-scans of 100 patients (age range 25-99 years; mean age males 45.0; mean age females 50.5 years) to calculate the volume of sphenoid sinuses through automatic segmentation. Possible statistically significant differences according to sex and variants of pneumatization, and type of sinus were assessed, respectively, through Student's t test and one-way ANOVA test (p < 0.05). RESULTS: Average volume of sphenoid sinuses in males was 10.005 ± 5.101 cm3, in females 7.920 ± 3.176 cm3. Differences according to sex were statistically significant (p < 0.05). Patients with pneumatization of pterygoid processes, dorsum sellae and anterior clinoid processes had a significantly higher volume than unaffected subjects. Moreover, differences of volume according to the type of sphenoid sinus were statistically significant (p < 0.05). CONCLUSIONS: Results show that volume of sphenoid sinuses strongly depend upon the type of sinus and possible pneumatization variants. Moreover, the important of ethnic variability is confirmed.

Intraoperative magnetic resonance imaging assessment of non-functioning pituitary adenomas during transsphenoidal surgery.

PURPOSE: To review the utility of intraoperative imaging in facilitating maximal resection of non-functioning pituitary adenomas (NFAs). METHODS: We performed an exhaustive MEDLINE search, which yielded 5598 articles. Upon careful review of these studies, 31 were pertinent to the issue of interest. RESULTS: Nine studies examined whether intraoperative MRI (iMRI) findings correlated with the presence of residual tumor on MRI taken 3 months after surgical resection. All studies using iMRI of >0.15T showed a ≥90% concordance between iMRI and 3-month post-operative MRI findings. 24 studies (22 iMRI and 2 intraoperative CT) examined whether intraoperative imaging improved the surgeon's ability to achieve a more complete resection. The resections were carried out under microscopic magnification in 17 studies and under endoscopic visualization in 7 studies. All studies support the value of intraoperative imaging in this regard, with improved resection in 15-83% of patients. Two studies examined whether iMRI (≥0.3T) improved visualization of residual NFA when compared to endoscopic visualization. Both studies demonstrated the value of iMRI in this regard, particularly when the tumor is located lateral of the sella, in the cavernous sinus, and in the suprasellar space. CONCLUSION: The currently available literature supports the utility of intraoperative imaging in facilitating increased NFA resection, without compromising safety.

Radiologic assessment of third molar tooth and spheno-occipital synchondrosis for age estimation: a multiple regression analysis study.

For forensic age estimation, radiographic assessment of third molar mineralization is important between 14 and 21 years which coincides with the legal age in most countries. The spheno-occipital synchondrosis (SOS) is an important growth site during development, and its use for age estimation is beneficial when combined with other markers. In this study, we aimed to develop a regression model to estimate and narrow the age range based on the radiologic assessment of third molar and SOS in a Turkish subpopulation. Panoramic radiographs and cone beam CT scans of 349 subjects (182 males, 167 females) with age between 8 and 25 were evaluated. Four-stage system was used to evaluate the fusion degree of SOS, and Demirjian's eight stages of development for calcification for third molars. The Pearson correlation indicated a strong positive relationship between age and third molar calcification for both sexes (r = 0.850 for females, r = 0.839 for males, P < 0.001) and also between age and SOS fusion for females (r = 0.814), but a moderate relationship was found for males (r = 0.599), P < 0.001). Based on the results obtained, an age determination formula using these scores was established.