Lateral Sinus Wall Research Articles

Endoscopic endonasal decompression for traumatic optic nerve injury: how I do it.

Endoscopic Endonasal Decompression for Traumatic Optic Nerve Injury has become an established endoscopic technique. However, Poor sphenoid sinus pneumatization often obscures landmarks, elevating the risk to vital neurovascular structures. By decompressing the orbital apex region and determining the contour of the optic nerve, sequential decompression of the medial wall, superomedial wall, and inferomedial wall of the optic canal. This surgical technique can gradually reveal the contour of the optic canal when the anatomical landmarks on the lateral wall of the sphenoid sinus are unclear, ensuring the surgery can be completed safely and effectively.

Prevention and management of intra-operative complications in maxillary sinus augmentation: A review.

Maxillary sinus floor elevation is usually performed in two different ways: the lateral approach involves the creation of a bony window on the maxillary sinus lateral wall, providing direct access to the sinus cavity for membrane elevation and subsequent graft placement, and the transcrestal approach is considered less invasive. The aim of this article is to describe, based on the literature, how to anticipate, avoid, and manage the intraoperative complications that can occur with both approaches. For both approaches, the most common complication is the sinus membrane perforation. For the lateral approach, an average frequency ranging from 15.7% to 23.1% is reported, but because of the better visibility, their management will be easier compared to the transcrestal approach. Mean perforation rate reported for the transcrestal approach is lower (3.1%-6.4%), but it should be noted that a significant number of perforations cannot be detected and managed given the blind nature of this technique. Anatomical parameters such as sinus width and buccal wall thickness may be a risk factor for one approach and not the other. As it is impossible to assess the resistance of the Schneiderian membrane, the transcrestal approach is more likely to lead to infectious complications in the event of perforation. Others, such as the risk of vascular damage, are encountered only with the lateral approach, which can be prevented easily by dissecting the alveolo-antral artery. For both approaches, prevention is essential and consists in analyzing the anatomy, mastering the surgical technique, and collaborating with the ENT to manage the essentially infectious consequences of intraoperative complications.

Lateral hypopharyngectomy with laryngeal preservation reconstructed with inlay fascio-cutaneous free flaps: clinical and functional outcomes.

Lateral hypopharyngectomy (LH) is one of the organ-preservation surgical strategies available for treatment of selected naïve early squamous cell carcinoma (SCC), as well as for rarer non-SCC tumours and persistent/recurrent/second primaries after chemoradiation of the lateral wall of the piriform sinus. Its reconstructive methods have been the subject of different approaches without a general consensus. The aim of the present study is to describe a retrospective series of LH reconstructed by inlay fascio-cutaneous free flaps, reporting on oncological and functional outcomes. Patients who underwent LH at the Department of Otorhinolaryngology - Head and Neck Surgery of the University of Brescia, Italy, between 2017 and 2023 were retrospectively reviewed. Clinical history, tumour histotype, postoperative complications, functional, and oncological outcomes were collected. Seven patients (6 males, 1 female) were included. In all, 29% had a naïve neoplasm, while 71% had recurrent disease. The final histology included 3 SCC, 2 synovial sarcomas, one liposarcoma, and one single-site mucosal metastasis from cutaneous melanoma. Negative margins were achieved in 6 patients (86%). All patients had swallowing rehabilitation by speech therapists and were able to safely eat a free diet at discharge, except for one who needed a percutaneous endoscopic gastrostomy to support nutritional oral intake. After a mean follow-up of 34.3 months, all patients except one are alive. Our study showed that, in selected cases, it is possible to radically remove lateral hypopharyngeal tumours with laryngeal preservation and free flaps inlay reconstruction, with a low rate of complications and acceptable functional and oncological results.

The oculomotor cistern and pituitary adenomas: anatomical and clinical study.

The oculomotor cistern (OMC) is a meningeal cuff filled with CSF that contains the oculomotor nerve (cranial nerve [CN] III) at the level of the lateral wall of the cavernous sinus. Only a few studies have investigated the involvement of the OMC by pituitary adenomas (pituitary neuroendocrine tumors [PitNETs]), mainly with relatively small case series. The aim of this study was to perform a histomorphological description of the OMC and systematically analyze its involvement by PitNETs from radiological, clinical, and surgical perspectives. Ten hemisellae from formalin-fixed specimens were studied with 3-µm sections. Digital image analysis software was used for morphological and quantitative assessments. Clinical, radiological, surgical, and histological data of patients undergoing endoscopic transsphenoidal surgery for PitNETs at the University of Brescia, Italy, between 2014 and 2021 were recorded. OMC involvement was graded as not compressed, compressed, and invaded. The same surgical team operated on all patients. The OMC had an elliptical shape with an average area of 3.1 mm2 and a length of 5.5 mm. No cisternal points of weakness were recognized in the histomorphological study. Of 315 patients, 246 had complete data: apoplexy and CN III palsy were documented in 6.9% and 8.5%, respectively. OMC compression and invasion were recorded in 106 (43.1%) and 23 (9.3%) patients. Significant associations between OMC involvement and PitNET dimensions (p < 0.001), Knosp grade (p < 0.001), preoperative oculomotor palsy (p < 0.001), Ki-67 percentage (p = 0.009), and recurrence/progression of residual tumor (p = 0.008) were found. A new postoperative CN III palsy was evident in 2%: transient in 4 cases, and persistent in 1 patient treated for a recurrent PitNET who experienced a local infection complication. Preoperative CN III palsy improved in 10 cases. Significant OMC involvement by PitNETs might be underrecognized, but it can be treated using the endoscopic transsphenoidal approach, and it affects patient outcomes.

Is It Time for a Paradigm Shift in the Surgical Management of Trigeminal Schwannomas? Evaluating the Role of the Transorbital Approach: An Anatomo-Clinical Study and Systematic Literature Review

BackgroundEndoscopic transorbital approach emerged in recent years as an effective, minimally invasive route to access Meckel’s cave area. Several case series proved its effectiveness in the surgical treatment of trigeminal schwannomas. Nonetheless, this route provides the advantages of a minimally invasive approach associated with low morbidity rates. In this anatomo-clinical study we illustrate the usefulness of the superior eyelid transorbital approach for the surgical treatment of trigeminal schwannoma guiding the clinical applicability of the anatomical findings into the real surgical practice. MethodsSuperior eyelid transorbital endoscopic approach was performed on eight cadaveric specimens, and the surgical results were confirmed in a retrospective review of all the surgical cases of transorbital surgery performed by the senior authors providing an illustrative case. Finally, we performed a literature review of all the case series of trigeminal schwannomas operated through an endoscopic transorbital approach. ResultsStepwise dissection was divided in 3 phases: skin, endo-orbital and endocranial. The illustrative case provided demonstrate gross total resection of a cavernous sinus type trigeminal schwannomas treated through this route. Literature review revealed 68 cases of trigeminal schwannomas that were successfully treated using the transorbital approach. ConclusionsThe endoscopic transorbital approach may offer a valuable alternative for the surgical treatment of trigeminal schwannomas. This technique provides a minimally invasive, direct and natural “interdural” route to the lateral wall of the cavernous sinus and Meckel's cave.

Transpalpebral transorbital endoscopic lateral approach to the middle cranial fossa: anatomical study in cadaver

Transorbital expanded endoscopic approaches allow different areas of the skull base to be approached. The aim of our study is to analyse the main anatomical bone and neurovascular structures of the middle cranial fossa by means of a transpalpebral transorbital lateral endoscopic approach (TTLEA). An anatomical study was performed on 12 orbital cavities corresponding to 6 cadaver heads. All specimens were previously injected with colored latex through both carotid systems. The mean distance from the orbital rim to the zygomatic-facial foramen and to the zygomatic-temporal foramen was 11 mm and 16 mm respectively. In all cases the meningo-orbital foramen was found at a mean distance from the orbital rim of 34 mm. The superior orbital fissure (SOF) was located posterior to the meningo-orbital foramen at 39 mm. The foramen rotundum and foramen ovale were located separated from each other by 10 mm on average. Anterior to the foramen ovale a bony prominence was observed in all cases. In 11 cases (92%) the entrance of the accessory meningeal artery into the foramen ovale was evident and in one case an accessory foramen was observed. The middle meningeal artery was located in all dissections within the foramen spinosum. The TTLEA offers a wide and direct exposure of the middle cranial fossa. It should be considered as an alternative to transcranial approaches in certain lesions invading the lateral region of the middle cranial fossa, the lateral wall of the cavernous sinus or the infratemporal fossa.

Anatomy of Maxillary Sinus: Focus on Vascularization and Underwood Septa via 3D Imaging.

The study of the maxillary sinus anatomy should consider the presence of two features of clinical importance. The arterial supply course and the presence of the so-called Underwood septa are two important factors to consider when planning surgical treatment to reduce the risk of surgical complications such as excessive bleeding and Schneiderian membrane perforations. This study aimed to investigate the above-mentioned anatomical structures to improve the management of eventual vascular and surgical complications in this area. This study included a total of 200 cone-beam computed topographies (CBCTs) divided into two groups of 100 CBCTs to evaluate the arterial supply (AAa) course through the lateral sinus wall and Underwood's septa, respectively. The main parameters considered on 3D imaging were the presence of the AAa in the antral wall, the length of the arterial pathway, the height of the maxillary bone crest, the branch sizes of the artery in the first group, and the position of the septa, the length of the septa, and their gender associations in the second group. The CBCT analysis showed the presence of the arterial supply through the bone wall in 100% of the examined patients, with an average size of 1.07 mm. With regard to the septa, 19% of patients presented variations, and no gender difference was found to be statistically significant. The findings add to the current understanding of the clinical structure of the maxillary sinus, equipping medical professionals with vital details for surgical preparation and prevention of possible complications.

The lateral transorbital approach to the medial sphenoid wing, anterior clinoid, middle fossa, cavernous sinus, and Meckel's cave: target-based classification, approach-related complications, and intermediate-term ocular outcomes.

The lateral transorbital approach (LTOA) is a relatively new minimal access skull base approach suited for addressing paramedian pathology of the anterior and middle fossa. The authors define target zones for this approach and describe a series of cases with detailed measurements of visual outcomes, including those obtained with exophthalmometry. The authors performed a retrospective analysis of a consecutive series of LTOA patients. Seven target zones were identified: 1) the orbit, 2) the lesser sphenoid wing and anterior clinoid, 3) the middle fossa, 4) the lateral wall of the cavernous sinus and Meckel's cave, 5) the infratemporal fossa, 6) the petrous apex, and 7) the anterior fossa. The authors used volumetric analyses of preoperative and postoperative MR and CT imaging data to calculate the volume of bone and tumor removed and to provide detailed ophthalmological, neurological, and cosmetic outcomes. Of the 20 patients in this cohort, pathology was in zone 2 (n = 10), zone 4 (n = 6), zone 3 (n = 2), zone 1 (n = 1), and zone 5 (n = 1). Pathology was meningioma (n = 10), schwannoma (n = 2), metastasis (n = 2), epidermoid (n = 1), dermoid (n = 1), encephalocele (n = 1), adenoma (n = 1), glioblastoma (n = 1), and inflammatory lesion (n = 1). The goal was gross-total resection (GTR) in 9 patients, all of whom achieved GTR. Subtotal resection (STR) was the goal in 8 patients (5 spheno-orbital meningiomas, 1 giant cavernous sinus/Meckel's cave schwannoma, 1 cavernous sinus prolactinoma, and 1 cavernous sinus dermoid), 7 of whom achieved STR and 1 of whom achieved GTR. The goal was biopsy in 2 patient and repair of encephalocele in 1. Visual acuity was stable or improved in 18 patients and worse in 2. Transient early postoperative diplopia, ptosis, eyelid swelling, and peri-orbital numbness were common. All 9 patients with preoperative diplopia improved at their last follow-up. Seven of 8 patients with preoperative exophthalmos improved after surgery (average correction of 64%). There were no cases of clinically significant (> 2 mm) postoperative enophthalmos. The most frequent postoperative complaint was peri-orbital numbness (40%). There was 1 CSF leak. Most patients were satisfied with their ocular (84%-100% of patients provided positive satisfaction-related responses) and cosmetic (75%-100%) outcomes. The LTOA is a safe minimal access approach to a variety of paramedian anterior skull base pathologies in several locations. Early follow-up revealed excellent resolution of exophthalmos with little risk of clinically significant enophthalmos. Transient diplopia, ptosis, and peri-orbital numbness were common but improved. Careful case selection is critical to ensure good outcome.

Immediate dentoalveolar restoration (IDR) of central maxillary incisor using sinus lateral wall block graft to regenerate loss of facial and palatal bone: Literature review and 1 year follow-up.

Replacement of missing or hopeless teeth in the esthetic zone is one of dentistry's most critical challenges. In the past, multiple surgical procedures have been needed to reconstruct compromised extraction sites. The surgeries have been associated with long healing times and increased morbidity, all the while patients are using either fixed or removable interim restorations. The procedures identified in this paper minimize surgical operating times, healing times, and delays in obtaining definitive restorations by combining multiple surgical procedures in one visit. The procedures are technique sensitive. This particular patient has been followed for 1 year post-operatively with clinical photographs and CBCT scans. Excellent clinical results were obtained. Benefits and limitations of the procedures have also been identified.

A rare case of delayed CSF leakage from the sphenoid sinus due to a stabbing

A patient with a non-missile penetrating brain injury might present fully conscious without any neurological deficit with a small linear laceration on skull as the only sign of injury. We present a 27-year-old man who was referred to us with new onset CSF leakage as rhinorrhea and history of penetrating stab wound injury to his right temporal region, 3 months ago. The imaging showed the tract of removed sharp object which was piercing the calvaria and the temporal lobe from the right temporal bone, entering the lateral wall of the cavernous sinus, adjacent to the siphon of the carotid artery till the lateral wall of the right sphenoid sinus, ultimately its distal tip entered the sphenoid sinus. The patient was treated through an endoscopic endonasal approach to repair the defect of his skull base. As a result, we should be cautious in facing these patients even if they are asymptomatic. Also doing complementary imaging modalities and other evaluations are crucial to not ignore any possible complications based on their history and examinations.

Assessment of neurovascular channels in lateral maxillary sinus wall using cone-beam computed tomography: An imperative clinicians guide for implant placements.

The aim of this study is to evaluate the location and radio morphometric features of the posterior superior alveolar artery (PSAA) in patients undergoing rehabilitation of posterior maxilla and other sinus augmentation surgical procedures by cone-beam computed tomography (CBCT). A total of 816 CBCT scans were included. Various radio morphometric measurements were done to assess the PSAA location, diameter, and distances to the sinus floor and alveolar crest. The PSAA was mostly intraosseous in the maximum in the age group 31-51 years (56%), in males (53.4%), and in dentate patients (57.4%). The artery tends to be wider in older patients. Distances to the sinus floor or the alveolar crest tend to be shorter in women. This study suggests that CBCT is a valuable pre-surgical tool and the evaluation of the PSAA on CBCT images could reduce the likelihood of excess bleeding during surgery in the maxillary posterior region.

The anatomical variations of paranasal sinuses may be related to the formation of antrochoanal polyp by computed tomography imaging study.

There is little investigation into the connection between anatomic variations and the development of antrochoanal polyp (ACP), and the etiology of ACP remains unclear. The study aims to explore the relationship among anatomic variations, maxillary sinus volume, nasal meatus-related parameters, and the occurrence of ACP. There were 127 patients included in this retrospective cross-sectional study with unilateral ACPs hospitalized at Shandong Provincial ENT Hospital between February 2010 and February 2020. Evaluation indicators included anatomic variations, maxillary sinus volume, and nasal meatus-related parameters in 45 children and 82 adults, which were evaluated twice by 3DSlicer software. Parameters were assessed using the Kolmogorov-Smirnov test, followed by paired t-test and Chi-squared test for multiple comparisons. Significant differences were found in the accessory maxillary ostium (AMO) and maxillary sinus retention cyst between two sides (both P<0.001). Maxillary sinus volume and sex had an association of statistical significance on adults' ACP side (P=0.026) and non-antrochoanal polyp (non-ACP) side (P=0.032). The affected side's maxillary sinus volume was significantly larger than the healthy side (P<0.001). The length from the maxillary sinus orifice to the plane of the most lateral margin of the middle turbinate of the ACP side was larger than the non-ACP side in children (P=0.044). Males' length from the maxillary sinus orifice to the plane of the most lateral margin of the middle turbinate of the ACP side was considerably greater than the healthy side (P<0.001). The length from the maxillary sinus orifice to the plane of the most lateral margin of the middle turbinate (P=0.014) and the length from the inferior turbinate to the nasal septum (P=0.013) on the non-ACP side was higher than the affected side in adults. Males' length from the inferior turbinate to the nasal septum was higher on the healthy side than the affected side (P<0.001). Males had a greater maximum length from the maxillary sinus lateral wall to the nasal septum (P=0.024) and the length from the inferior turbinate to the nasal septum (P=0.003) on the non-ACP side than females. Males had a larger maximum length from the maxillary sinus lateral wall to the nasal septum on the ACP side than females (P=0.011). In our study, the occurrence of the AMO, the maxillary sinus's expanded size, and the stenosis of the associated channels around the ostiomeatal complex and common meatus are regarded as probably connected to the formation of ACPs. In addition, the anatomic variations that involve the ostiomeatal complex and may lead to a change in maxillary sinus pressure and nasal ventilation are important factors in the formation of ACPs.

New perspectives in the treatment of the severe atrophic posterior maxilla: interpositional sandwich osteotomy combined with sinus floor grafting - a novel technique

Purpose: Dental implant installation in the posterior maxilla depends fundamentally on the presence of an adequate bone quantity. Tooth loss in the posterior maxilla is followed by extensive loss of the alveolar ridge and increased maxillary sinus pneumatization that often makes implant installation difficult to achieve. Maxillary sinus floor augmentation is traditionally the common surgical technique to overcome this situation. When the deficiency in the vertical dimension relates more to severe ridge resorption, crestal ridge augmentation should also be considered. Posterior maxillary sandwich osteotomy combined with sinus augmentation, using inter–positional bone graft might be a viable option to address this problem. This study describes a successful implementation of this technique to solve a severe vertical osseous ridge defect under the sinus floor. Material and Methods: A two–stage lateral wall sinus floor augmentation combined with inter–positional sandwich osteotomy followed by the insertion of dental implants with adequate length and diameter was performed. Deproteinized natural bovine bone mineral (DBBM) covered by a resorbable collagen membrane were used. Rehabilitation of this area was completed by a standard prosthetic protocol. Results: As a result of completing the above procedure favourable bone mass and form was created to enable implant placement in positions that are optimal from a prosthetic and esthetic point of view in terms of reshaping the alveolar crest and normali- zing the interocclusal distance improving the crown–implant ratio. Conclusion: This case demonstrates a step–by–step illustration of an innovative technique for overcoming a vertical ridge defect combined with increased maxillary sinus pneumatization. It can be concluded that this novel technique is recommended to meet the dimensional requirements of bone augmentation both crestal and intrasinusal in severe atrophic posterior maxilla to achieve an improved alveolar plane, equalized crown–to–implant ratios, and a more favourable gingival shape.

Localization of the position of vital anatomical structures in the lateral wall of maxillary sinus during different surgical intervention using cone beam computed tomography

Background: Proper information about the anatomy of the maxillary sinus is required to avoid any unexpected complications that may arise due to the close relation between the maxillary sinus and posterior superior alveolar artery. Objective: To the current study used cone beam computed tomography CBCT imaging to assess the position of the posterior superior alveolar artery (PSAA) in relationship to the alveolar ridge and the flour of maxillary sinus. Patients and Methods: A number of 95 Iraqi patients participated in this prospective study (53 females, 42 males; age range 20-49 years). From January 2021 to February 2022, attended a 2nd specialised dentistry institution in Baquba city for CBCT scanning for numerous diagnostic and management purposes. Results: According to our study, we detected the presences of artery in (83.68%) of the sample. females showed higher PSAA prevalence than men on both sides, and the difference was significant overall, Also, the existence of artery for each side and total in the intramembranous locating in females is greater than that in males, which may demonstrate that the probability of Bleeding and other side effects is higher in males, since the existence of artery in the intramembranous area in females will reduce the likelihood of traumatic injury throughout any surgical treatment. Conclusion: This research used CBCT to determine the precise location of PSAA in the Iraqi population. This data could assist in decreasing the likelihood of hemorrhage as well as other complications which may happen throughout any surgical treatment, such as dental implant placement, ridge expansion.As well as other surgical interventions in this region. Keywords: Maxillary sinus walls, posterior superior alveolar artery, cone beam computed tomography

Localization of the position of vital anatomical structures in the lateral wall of maxillary sinus during different surgical intervention using cone beam computed tomography

Background: Proper information about the anatomy of the maxillary sinus is required to avoid any unexpected complications that may arise due to the close relation between the maxillary sinus and posterior superior alveolar artery.&#x0D; Objective: To the current study used cone beam computed tomography CBCT imaging to assess the position of the posterior superior alveolar artery (PSAA) in relationship to the alveolar ridge and the flour of maxillary sinus.&#x0D; Patients and Methods: A number of 95 Iraqi patients participated in this prospective study (53 females, 42 males; age range 20-49 years). From January 2021 to February 2022, attended a 2nd specialised dentistry institution in Baquba city for CBCT scanning for numerous diagnostic and management purposes.&#x0D; Results: According to our study, we detected the presences of artery in (83.68%) of the sample. females showed higher PSAA prevalence than men on both sides, and the difference was significant overall, Also, the existence of artery for each side and total in the intramembranous locating in females is greater than that in males, which may demonstrate that the probability of Bleeding and other side effects is higher in males, since the existence of artery in the intramembranous area in females will reduce the likelihood of traumatic injury throughout any surgical treatment.&#x0D; Conclusion: This research used CBCT to determine the precise location of PSAA in the Iraqi population. This data could assist in decreasing the likelihood of hemorrhage as well as other complications which may happen throughout any surgical treatment, such as dental implant placement, ridge expansion.As well as other surgical interventions in this region.

Unusual Locations of Inverted Papilloma.

Inverted papilloma is a tumor found involving the nasal cavity and paranasal sinuses. They are not cancerous but can be locally aggressive. They are most commonly seen involving the lateral wall of nose and maxillary sinus. When the tumor involves the frontal sinus and sphenoid sinus or the post ethmoid cells it presents a surgical challenge. Inverted papilloma almost always occur unilateraly and affect mainly the maxillary sinus. Inverted papilloma arising from the sphenoid and frontal sinuses are rare. Here we present two cases; one involving a 60 year man, with inverted papilloma originating from the frontal sinus and another case where it originated from the sphenoid sinus anterior wall and posterior ethmoidalcell (Onodi cell) and was resected endoscopically.

Transorbital and supraorbital uniportal multicorridor approach to the orbit, anterior, middle and posterior cranial fossa: Anatomic study

IntroductionThe transorbital route has been proposed for addressing orbital and paramedian skull base lesions. It can be complemented by further marginotomies, as per “extended-transorbital approach” and combined with others ventro-basal approaches featuring the concept of “multiportal surgery”. Nevertheless, it cannot address some anatomical regions like the clinoid, carotid bifurcation and the Sylvian fissure. Therefore, we propose a combined transorbital and a supraorbital approach, attainable by a single infra-brow incision, and we called it “Uniportal multicorridor” approach. Research questionThe aim of our study is to verify its feasibility and deep anatomical targets through a cadaveric study. Materials and methodsAnatomic dissections were performed at the Laboratory of ICLO Teaching and Research Center (Verona, Italy) on four formalin-fixed cadaveric heads injected with colored neoprene latex (8 sides). A stepwise dissection of the supraorbital and transorbital approaches (with an infra-brow skin incision) to the anterior tentorial incisura, clinoid area, lateral wall of the cavernous sinus, middle temporal fossa, posterior fossa, and Sylvian fissure is described. ResultsWe analyzed the anatomic areas reached by the transorbital corridor dividing them as follow: lateral wall of the cavernous sinus, middle temporal fossa, posterior fossa, and Sylvian fissure; while the anatomic areas addressed by the supraorbital craniotomy were the clinoid area and the anterior tentorial incisura. ConclusionsThe described uniportal multi-corridor approach combines a transorbital corridor and a supraorbital craniotomy, providing a unique intra and extradural control over the anterior, middle, and posterior fossa, tentorial incisura and the Sylvian fissure, via an infra-brow skin incision.

Morphometric Assessment of Alveolar Antral Artery Using Medical Computed Tomography.

This study aimed to investigate the prevalence, diameter, and position of the alveolar antral artery (AAA) in paranasal sinus computed tomography (CT) images and to correlate the location of the AAA with tooth position, the presence of teeth, and residual alveolar bone height (ABH). A retrospective study was conducted at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, from November 2016 to October 2021. CT images of 100 maxillary sinuses from 50 patients managed for modified endoscopic sinus surgery and sinus lifting by a single surgeon were selected and obtained from the Infinitt picture archiving and communication system radiology system (Infinitt Healthcare Co., Seoul, Korea). The location of the AAA in the lateral wall of the maxillary sinus was evaluated in correlation with the area of the first and second molars (M1 and M2), the presence of teeth, and the residual ABH. In this study, we found that the intraosseous type is the most common type of AAA. Furthermore, the location and distance of the AAA are significantly affected by tooth position, an edentulous state in the case of the first molar, and residual ABH. Pre-evaluation of the diameter, position, and distance to the AAA using CT images is essential to help prevent hemorrhage. The existence and wide range of the AAA distances based on the tooth position, edentulous state, and residual ABH should be considered even if CT imaging cannot locate the AAA.

Effects of Sinus Membrane Stabilization by Dental Implant Placement and Membrane Suturing on Endo-Sinus Bone Gain in Cases of Lateral Sinus Elevation Performed Without Graft Material.

To investigate the effects of sinus membrane stabilization (via suturing) and dental implant placement on the endo-sinus bone formation in lateral sinus elevations performed without grafting. Maxillary sinus elevation surgery using the lateral approach was performed bilaterally on 30 New Zealand white rabbits. The maxillary sinus areas were divided into control and test groups. In the control group, a titanium screw was placed after sinus membrane elevation; in the test group, the sinus membrane was sutured to the lateral walls, and a titanium screw was placed in the center of the alveolar crest. The subjects were sacrificed at 4 and 8 weeks. Then samples were collected, and a microcomputed tomography (micro-CT) analysis was performed. In addition, the volume of newly formed bone, percentage of osseointegration, sinus volume, residual bone height, and implant protrusion length were measured using micro-CT analysis. The sinus volume, volume of newly formed bone, and percentage of osseointegration in the test group were significantly higher than in the control group at 4 weeks (P &#61; .01, P &#61; .04, P &#61; .02, respectively). While the volume of newly formed bone was 17.1 ± 3.08 mm3 in the control group, it was 26.9 ± 14.26 mm3 in the test group at 4 weeks. The volume of newly formed bone significantly decreased from 26.9 ± 14.26 mm3 to 17 ± 3.66 mm3 at 8 weeks (P &#61; .02). No significant difference in residual bone height was found at 4 and 8 weeks (P &#61; .07). No significant difference in implant protrusion length was found between the control and test groups (P &#61; .18). Protrusion length and new bone formation in the sinus showed a negative relationship (P &#61; .01). Suturing the sinus membrane to the lateral sinus wall is an effective approach for increasing osseointegration, bone volume, and sinus volume in the short term. A slow-absorbing suture material can be used to maintain sinus and bone volumes in the long term.

Endoscopic Transorbital Surgery for Trigeminal Schwannoma: Introduction of a Novel Approach: 2-Dimensional Operative Video.

The major indications of endoscopic transorbital approach include spheno-orbital meningiomas, cavernous sinus lesions, and Meckel cave lesion such as trigeminal schwannomas. It can avoid excessive brain retraction and allows for a fast recovery to the normal daily living activity. To access the cavernous sinus, the sagittal crest and meningo-orbital band should be identified and cut. 1. Skin incision along the superior eyelid is performed. 2. Careful dissection of the soft tissue under the orbicularis is required not to injure the orbital septum. 3. After the lateral orbital rim is exposed, the periosteum and periorbita are elevated from the lateral orbital wall. 4. Drilling of the zygomatic bone within the orbit exposes the temporalis muscle first followed by the exposure of the temporal dura. It is essential to obtain adequate working room when the base of the greater sphenoidal wing is drilled. The sagittal crest should be removed, and the meningo-orbital band should be cut to expose the lateral cavernous sinus wall. For successful access through the orbit, endoscopic transorbital approach needs to minimize the retraction of the orbit. To achieve this goal, retraction of the orbit should be limited to a maximum of 10 minutes. This approach can be combined with lateral orbitotomy. It provides a wider working room and makes surgery easier to access the lateral temporal lobe.The patient consented to the procedure, and the participants and any identifiable individuals consented to publication of his/her image. Images at 1:29 reproduced from Corrivetti F, de Notaris M, Di Somma A, et al, "Sagittal crest": definition, stepwise dissection, and clinical implications from a transorbital perspective, Operative Neurosurgery, 22(5), p e206-e212, ©2022, by permission from the Congress of Neurological Surgeons. Video screen capture from The Neurosurgical Atlas at 1:06 used with permission from Aaron Cohen-Gadol; ©The Neurosurgical Atlas, all rights reserved.