Assessment of Incomplete Apical Bone Coverage of Maxillary Premolar and Molar Roots Using Cone Beam Computed Tomography in 161 Dogs.

This retrospective study assessed maxillary premolar and molar teeth and identified roots with incomplete apical bone coverage using cone beam computed tomography in 161 dogs. The associated dorsal anatomic sites that the roots communicated with were the ventral nasal meatus, maxillary recess, infraorbital canal, and pterygopalatine fossa. The study found that all roots of the maxillary premolar and molar teeth have the potential for incomplete apical bone coverage, with 26.7% having incomplete apical bone coverage. No significant association with sex was found. A significant association with weight was found, and this lowered with increasing body weight. Facial index, as a determinate of skull shape, was found to be significant in only 35.7% of roots in univariate and 14.2% of roots in multivariate modeling. Knowledge of the anatomy of these roots plays an important role in safe and effective extraction techniques, in reducing iatrogenic trauma, and in understanding the potential local effects of periodontal and endodontic disease.

Teaching Pterygopalatine Fossa Anatomy Using 3D Images and Physical Model: A Novel Teaching Strategy.

Medical students often struggle to appreciate the anatomy of the pterygopalatine fossa. This is due to the difficulty in understanding the spatial orientation through textbook diagrams, as well as its deeper location and smaller size in cadaveric specimens. Research has proven that three-dimensional visualization enhances the spatial understanding of anatomy. However, studies have not compared the effectiveness of two different instructional designs that cater to 3D visualization. We conducted a mixed methodology (quasi-experimental pre-test/post-test control design with additional qualitative components) study to compare the effectiveness of a physical model and a 3D image in small-group teaching. The students were divided into control and intervention groups based on their roll numbers. The control group utilized a series of 3D images delivered through Microsoft PowerPoint software on computers. The students in the intervention group used a physical model made of cardboard, with colored wires representing the neurovascular structures. We used 20 spatial anatomy-based multiple-choice questions (MCQs) to assess knowledge acquisition before and after the small group discussion. Additionally, we utilized a validated 10-item feedback questionnaire to evaluate participants' perception of the teaching sessions. There was no significant difference in the knowledge gain and perception scores between the control and intervention groups. These findings suggest that a well-designed 3D image can provide an equivalent learning outcome and level of satisfaction compared to a physical model. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-024-02063-3.

Adenoid Cystic Carcinoma of Pterygopalatine Fossa: Report of a Rare Case.

Adenoid cystic carcinoma (ACC) is an uncommon malignant neoplasm that predominantly arises from major and minor salivary glands, accounting for about 1% of head and neck malignancies. ACCs originating from the pterygopalatine fossa (PPF) are extremely rare. In this case report, we present a 77-year-old male patient who experienced a two-year hemi-facial numbness and mild trismus, with intact nasal mucosa. He underwent Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) which revealed opacification of the left PPF with extension to the left infratemporal fossa and osteolytic areas of the sphenoid bone. Histopathology, following blind biopsies, revealed ACC of the PPF, which was subsequently treated with combined therapy (radiotherapy and chemotherapy). Due to their slow and progressive growth, as well as their tendency for perineural invasion, ACCs should always be considered in the differential diagnosis of painless swelling or nerve dysfunction. To our knowledge, this case is the fifth described in the English literature.

Persistent Severe Headache After Removal of Fungus Ball From the Sphenoid Sinus: A Case Report.

OBJECTIVE: Granulomatous invasive fungal sinusitis (GIFS) is a rare and life-threatening disease, whereas fungus ball (FB) is the most common form of noninvasive fungal sinusitis. Both GIFS and FB primarily develop in immunocompetent patients, with the former associated with higher mortality and morbidity. METHODS: A chart review and review of the literature. RESULTS: We present the case of a 77-year-old woman with mixed fungal sinusitis who was successfully treated with voriconazole. CONCLUSIONS: GIFS and FB can coexist in extremely rare cases, known as mixed fungal sinusitis; however, the diagnosis and subsequent treatment of mixed fungal sinusitis can be delayed because of a lack of awareness of the underlying concept. Therefore, it is crucial for clinicians to recognize the concept of mixed fungal sinusitis.

Extracapsular Dissection With Narrow-Band Imaging Using the Transnasal Endoscopic Tri-port Approach for Extracranial Trigeminal Schwannoma: A Case Report.

The pterygopalatine fossa and infratemporal fossa are often approached through an external incision because of their deep facial location, but this can present problems such as facial scarring and deformity. In schwannoma surgery, intraneural dissection is a useful surgical technique for achieving gross total resection while preserving the capsule, including the nerves. For appropriate enucleation and preservation of the functional nerve, it is indispensable to distinguish between the pseudocapsule and the tumor capsule. This case report presents a case of endonasal surgical intervention for an extracranial trigeminal schwannoma employing the tri-port approach and narrow-band imaging.

Angioleiomyoma of the Pterygopalatine Fossa: A Case Report.

Angioleiomyoma (ALM) is a benign neoplasm marked by the presence of blood vessels and smooth muscle cells, commonly located within the subcutaneous or deep dermal layers. Its manifestation in the pterygopalatine fossa is infrequent, thereby posing difficulties in its diagnosis and distinction from other benign tumors within the same anatomical site. In the present case study, an ALM originating in the right pterygopalatine fossa of a 44-year-old female patient was investigated. The patient underwent surgical intervention for the vascular smooth muscle tumor, and there has been no recurrence noted during the postoperative monitoring period.

Automatic pterygopalatine fossa segmentation and localisation based on DenseASPP.

BACKGROUND: Allergic rhinitis constitutes a widespread health concern, with traditional treatments often proving to be painful and ineffective. Acupuncture targeting the pterygopalatine fossa proves effective but is complicated due to the intricate nearby anatomy. METHODS: To enhance the safety and precision in targeting the pterygopalatine fossa, we introduce a deep learning-based model to refine the segmentation of the pterygopalatine fossa. Our model expands the U-Net framework with DenseASPP and integrates an attention mechanism for enhanced precision in the localisation and segmentation of the pterygopalatine fossa. RESULTS: The model achieves Dice Similarity Coefficient of 93.89% and 95% Hausdorff Distance of 2.53 mm with significant precision. Remarkably, it only uses 1.98 M parameters. CONCLUSIONS: Our deep learning approach yields significant advancements in localising and segmenting the pterygopalatine fossa, providing a reliable basis for guiding pterygopalatine fossa-assisted punctures.

Pediatric Pterygopalatine Fossa Schwannoma Presenting as Vision Loss: A Case Report and Literature Review.

Neurosynovial tumors, originating from Schwann cells within nerve sheaths, are benign entities, with 25% to 45% manifesting in the head and neck region. However, occurrences in the pterygopalatine fossa (PPF) are exceptionally rare, and only a handful of cases have been documented. In this report, we present the unique case of a 6-year-old child exhibiting a sizable soft tissue mass in the left PPF, extending into the inferior orbital fissure. The patient underwent successful intranasal endoscopic removal of PPF schwannoma utilizing the prelacrimal recess approach, with postoperative pathology confirming the diagnosis of schwannoma. Schwannomas within the PPF are particularly uncommon, and instances of such tumors in pediatric patients are even more exceptional. This case highlights the diagnostic and therapeutic challenges associated with PPF schwannomas in children, emphasizing the significance of a multidisciplinary approach for optimal management. In addition, a comprehensive literature review is presented to provide insights into the existing knowledge on this rare entity, further contributing to the understanding of pediatric PPF schwannomas.

The effect of injection of 1:100 000 adrenaline solution in the pterygopalatine fossa on intra-operative bleeding during endoscopic sinonasal surgical procedures in chronic sinusitis: a blinded clinical trial.

OBJECTIVE: Rhinosinusitis is one of the most common reasons for a visit to otolaryngology clinics. Some patients are candidates for sinus surgery. Infiltration of 1:100 000 adrenaline in the pterygopalatine fossa was studied, with the aim of evaluating the effect on bleeding in the surgical field. METHODS: This double-blind clinical trial was conducted in 2021-2022 on 40 candidates for endoscopic sinus surgery. For each patient, one side of the pterygopalatine fossa was randomly selected to be infiltrated with a vasoconstrictor. Surgical field bleeding on each side was evaluated. RESULTS: Blood loss was 35.8 ± 20.9 ml in the study group and 38.4 ± 23.7 ml for the control group, with no statistically significant difference between groups (p = 0.49). In addition, there was no difference between the two groups in terms of the surgical field based on Boezaart scores. CONCLUSION: Although there are some recommendations on the usage of vasoconstrictors via the pterygopalatine foramen, debate remains.

Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Endoscopic Endonasal and Endoscopic-Assisted Transmaxillary Transpterygoid Approaches.

Introduction The endoscopic endonasal transpterygoid approach (EETPA) with or without the addition of the endoscopic-assisted sublabial anterior transmaxillary approach (ESTA) has become increasingly utilized for lesions posterior to the pterygopalatine fossa (PPF), including infratemporal fossa (ITF), lateral recess of the sphenoid sinus, Meckel's cave, petrous apex, and parapharyngeal space. The main goal of this study is to develop an educational resource to learn the steps of the EETPA for trainees. Methods EETPA and ESTA were performed in 12 specimens by neurosurgery trainees, under supervision from the senior authors. One EETPA and one ESTA were performed on each specimen on opposite sides. Dissections were supplemented with representative cases. Results After a wide unilateral sphenoidotomy, ethmoidectomy, and partial medial maxillectomy, the anteromedial bone limits of the PPF were identified and drilled out. The pterygoid progress was modularly removed. By enlarging the opening of the posterior and lateral walls of the maxillary sinus through EETPA and ESTA, respectively, the neurovascular and muscular compartments of the PPF and ITF were better identified. The EETPA opens direct corridors to the PPF, medial ITF, middle cranial fossa, cavernous sinus, Meckel's cave, petrous apex, and internal carotid artery. If a more lateral exposure of the ITF is needed, the ESTA is an appropriate addition. Conclusion Despite the steep learning curve of the EETPA, granular knowledge of its surgical anatomy and basic surgical steps are vital for those advancing their learning in complex endoscopic approaches to the ventral skull base when expanding the approach laterally in the coronal plane.

Clinically relevant morphometric analysis of pterygopalatine fossa and its volumetric relationship with adjacent paranasal sinuses: a CT-based study.

OBJECTIVES: This study aimed to perform morphometric measurements of the pterygopalatine fossa (PPF), the transition zone to critical neurovascular structures. The second aim was to investigate the relationship between the volumes of the PPF and the paranasal sinuses and the effect of nasal septum deviation (NSD) types on all these measurements. METHODS: We performed PPF's morphometry and all volume measurements on the CT images of 260 patients (130 male and 130 female, age range 18-79). RESULTS: All volumetric measurements and the angle between foramen rotundum (FR) and pterygomaxillary fissure (PMF) were significantly higher in males than females. In contrast, the distance between sphenopalatine foramen (SPF) and PMF was considerably higher in females than in males. The PPF volume, the distance between the pterygoid canal (PC) and maxillary sinus, and the angle between FR and PMF were significantly higher on the right side than on the left. In contrast, the angle between PC and SPF and between greater palatine canal and PPF were considerably higher on the left side than on the right. The angle between PC and SPF decreased markedly with age. Only sphenoidal sinus volume was significantly smaller on the same side as the septal deviation. There was no correlation between PPF volume with maxillary and sphenoid sinus volumes from adjacent paranasal sinuses. CONCLUSIONS: Volumetric and morphometric data obtained from PPF and paranasal sinuses can aid clinicians in diagnosing and treating patients by guiding them in selecting the right surgical approach or tools, especially in endoscopic procedures.

A Pterygopalatine Fossa Abscess Caused by Streptococcus Constellatus With Ptosis as Initial Presentation: Case Report.

Pterygopalatine fossa (PPF) abscess is an exceedingly rare occurrence. Typically, it has been reported in association with odontogenic infections or hematogenous dissemination. In this report, we present the first case of PPF abscess where no obvious underlying cause or primary infection was evident. The patient initially presented with a 2-week history of left ptosis and persistent headaches, which were subsequently accompanied by fever and limited mouth opening. Based on elevated inflammatory markers and imaging findings, the diagnosis of a PPF abscess was established. Successful treatment was achieved through surgical drainage using an external cervical approach. Cultures from the aspirated pus identified Streptococcus constellatus as the causative agent. This case highlights the importance of considering PPF abscess in patients presenting with ptosis as an initial symptom. When diagnosed, surgical drainage should be considered as a viable therapeutic option.

An endoscopic transnasal prelacrimal recess transmaxillary approach to the pterygopalatine fossa and infratemporal fossa.

Objective: In this paper, the goal of the authors is to present the anatomic nuances and their clinical experience with lesions of the pterygopalatine fossa and infratemporal fossa using an endoscopic transnasal prelacrimal recess transmaxillary approach (PLRMA). Methods: An endoscopic anatomical dissection of three fresh cadaveric heads was performed bilaterally to evaluate the feasibility of the PLRMA. Prior to dissection, stereotactic computed tomography scans were obtained for each head to obtain anatomical measurements. The area of exposure on the posterior wall of the maxillary sinus was determined using stereotaxis. The cases of six patients with schwannomas or epidermoid cysts who underwent the transnasal PLRMA were illustrated. Results: The mean area of exposure on the posterior wall of the maxillary sinus was 9.55 cm2. Total resection was achieved in all six patients. The mean follow-up time was 16 months, and one patient complained of postoperative facial numbness, which resolved gradually. No cases of chronic sinusitis were reported. Conclusions: The endoscopic transnasal PLRMA provides efficient operative exposure to the pterygopalatine fossa and infratemporal fossa. Preserving the integrity of the mucosa on the nasal lateral wall is an advantage of this approach.

Endoscopic-assisted en-bloc pterygomaxillectomy: Identifying an efficient and safe location for the pterygoid osteotomy.

BACKGROUND: For aggressive maxillary sinus and pterygopalatine fossa (PPF) tumors, an en-bloc pterygomaxillectomy may be indicated. METHODS: Five head specimens were used to study the feasibility of an en-bloc pterygomaxillectomy. Eighty-five non-pathological CT scans were used to compare the superior edge of the inferior turbinate (IT) and the middle turbinate tail (MT) as landmarks for the pterygoid osteotomy. RESULTS: Through a combined sublabial-subperiosteal incision and transoral route, a mid-sagittal osteotomy through the hard palate and an axial osteotomy below the infraorbital foramen were performed. For the endoscopic pterygoid osteotomy, an infra-vidian transpterygoid approach was performed, subsequently removing the pterygomaxillectomy en-bloc. As landmarks, the osteotomies at the level of the MT tail and IT resected the pterygoid plates completely, but the IT osteotomy was further away from the vidian canal (7.5 vs. 6 mm). CONCLUSIONS: The endoscopic-assisted en-bloc pterygomaxillectomy is feasible. The IT landmark is safe and ensures complete resection of the pterygoid plates.

Onabotulinum toxin A block of the sphenopalatine ganglion in patients with persistent idiopathic facial pain: a randomized, triple-blind, placebo-controlled, exploratory, cross-over study.

OBJECTIVE: To investigate the efficacy and safety of injecting onabotulinum toxin A (BTA) towards the sphenopalatine ganglion (SPG) using the MultiGuide® in patients with persistent idiopathic facial pain (PIFP). METHODS: This cross-over, exploratory study compared the injection of 25 units BTA versus placebo in patients who met modified ICDH-3 criteria for PIFP. Daily pain diaries were registered for a 4-week baseline, a 12-week follow-up after each injection, and an 8-week conceptual washout period in between. The primary efficacy endpoint was the change from baseline to weeks 5-8 in average pain intensity using a numeric rating scale. Adverse events were recorded. RESULTS: Of 30 patients who were randomized to treatment, 29 were evaluable. In weeks 5-8, there was no statistically significant difference in average pain intensity between BTA versus placebo (0.00; 95% CI = -0.57 to 0.57) (P = 0.996). Following both BTA and placebo injections, five participants reported at least a 30% reduction in average pain during weeks 5-8 (P = 1.000). No serious adverse events were reported. Post-hoc analyses indicated a possible carry-over effect. CONCLUSIONS: Injection of BTA toward the SPG with the MultiGuide® did not appear to provide a reduction in pain reduction at 5-8 weeks, although this finding may be influenced by a carry-over effect. The injection appears to otherwise be safe and well-tolerated in patients with PIFP.Trial Registration: The study protocol is registered in ClinicalTrial.gov (NCT03462290) and EUDRACT (number: 2017-002518-30).

Endonasal Endoscopic Anatomy of the Orbito-Cavernous-Pterygopalatine Interface: Multilayer Anatomical Description and Landmarks to Define the Limits of the Compartments.

BACKGROUND: Despite growing interest in the endoscopic endonasal approach (EEA) to the medial orbital apex (OA), a comprehensive description of the multilayer topology lying at the intersection of the regional compartments is missing. METHODS: An EEA to the OA, pterygopalatine fossa, and cavernous sinus was performed in 20 specimens. A 360° layer-by-layer dissection was performed taking into consideration relevant anatomical aspects of the interface and documented with 3-dimensional technologies. Endoscopic landmarks were analyzed to provide an outline of the compartments and identify critical structures. Additionally, the consistency of a previously described reference called orbital apex convergence prominence was analyzed and a method to identify its position was introduced. RESULTS: The orbital apex convergence prominence was an inconsistent finding (15%). However, a craniometric method introduced in this study proved to be reliable to reach the orbital apex convergence point. Additional structures such as the sphenoethmoidal suture and a 3-suture junction (sphenoethmoidal-palatoethmoidal-palatosphenoidal) helped to identify the posterior limit of the OA and define a keyhole to access the compartments of the interface. We defined the bone limits of the "optic risk zone," an area where the optic nerve is more susceptible to damage. Furthermore, an orbital fusion line (periorbita-dura-periosteum) was identified and divided into 4 segments according to adjacent structures: optic, cavernous, pterygopalatine, and infraorbital. CONCLUSIONS: Understanding cranial landmarks and the folds of the layers covering the orbito-cavernous-pterygopalatine interface can facilitate tailoring an EEA to the medial orbital space and avoid unnecessary exposure of sensitive anatomy in the vicinity.

Soft Air Bullet in the Pterygopalatine Fossa: A Minimally Invasive Endoscopic Approach for Safe Extraction.

Ballistic traumas among civilians are usually from low velocity, low calibre weapons such as soft air guns. The facial skeleton is an area of high aesthetic/functional value, and therefore, this is a showcase for technical description of a minimally invasive endoscopic approach for the removal of a bullet from the pterygopalatine fossae.

The application of 3-dimensional magnetic resonance imaging in nasopharyngeal carcinoma with pterygopalatine fossa invasion.

OBJECT: The pterygopalatine fossa (PPF) is a covert neurovascular pathway in the skull base and connects with numerous intracranial and extracranial spaces. The aim of this study was to explore the magnetic resonance imaging (MRI) features of PPF invasion in patients with nasopharyngeal carcinoma (NPC). MATERIAL AND METHODS: The medical records of 88 patients with stage T3 or T4 NPC were retrospectively analyzed. The 3-Dimensional (3D) volumetric images of MRI were reconstructed for the tiny connecting conduits of the invaded PPFs in the NPC patients. The infiltration incidence of conduits and connected further structures were calculated. RESULTS: Forty-six PPFs from 37 patients were invaded by NPC. The proportions of stage T4 NPC and intracranial extension were higher in patients with PPF invasion than that without PPF invasion (P < 0.05). Each connecting conduit of the PPF had corresponding optimal reconstructed orientation based on 3D volumetric MRI images. The first three most common infiltrated conduits were palatovaginal canal, vidian canal and sphenopalatine foramen, which were adjacent to the nasopharynx. Among the conduits connecting with further structures, the most common infiltrated conduit was pterygomaxillary fissure, followed by foramen rotundum and inferior orbital fissure. Furthermore, The NPC lesions involved stage T4 structures via the conduits from 19.6% of the invaded PPFs. CONCLUSIONS: The application of high-quality reconstruction images based on 3D sequence of MRI in NPC patients proved to be feasible and beneficial for the manifestation of the invaded PPFs and connecting conduits.

The Varied Presentations of Sinonasal Region Schwannomas: Apropos of Four Cases.

Schwannomas of the sinonasal compartment are rare benign neoplasms of peripheral nerve sheath origin and constitute ~ 4% of all head and neck schwannomas. The presentation may simulate a range of benign and intermediate grade pathologies. Management involves surgical excision via open or endoscopic approach. To describe the clinico-epidemiological characteristics and surgical outcomes in sinonasal region schwannoma patients operated at our institute. The study is a descriptive case series of patients with sinonasal region schwannomas treated at our institution. A retrospective search of electronic database of the Department of ENT and Head and Neck Surgeries and Department of Pathology was conducted from January 2013 to January 2019. The various demographic and clinical details of the patients were extracted. A total of four patients operated for sinonasal region schwannoma were identified. The involved sites were nasal dorsum, nasal cavity, pterygopalatine fossa and infratemporal fossa. The mild, non-specific symptoms resulted in patients ignoring their symptoms for a while initially and presenting late. The nasal dorsum lesion was revealed as a surprise during open rhinoplasty for correction of nasal deformity. Complete excision was achieved in all the cases and no recurrence has been noticed during the follow up (varying from 6 months to 6 years) till date. The diverse clinical manifestations and approaches to the treatment of schwannomas in this specific region are discussed. The surgical excision is the standard of care in dealing with these neoplasms. This series highlights the rarity of this pathology in the sinonasal area, diagnostic surprises and the decision making to choose the correct surgical approach for complete excision. Once excised completely, recurrence is not expected.

Glomus Tumor of the Pterygopalatine Fossa: A Rare Case Report.

The pterygopalatine fossa (PPF) is a challenging space and pathological processes in this anatomical space are uncommon. This report presents a case of glomus tumor right PPF in a 65 years old female patient who underwent tumor removal by endoscopic transnasal-transmaxillary approach with preoperative selective embolization of the right internal maxillary artery.