Different machine learning methods based on maxillary sinus in sex estimation for northwestern Chinese Han population.

BACKGROUND & OBJECTIVE: Sex estimation is a critical aspect of forensic expertise. Some special anatomical structures, such as the maxillary sinus, can still maintain integrity in harsh environmental conditions and may be served as a basis for sex estimation. Due to the complex nature of sex estimation, several studies have been conducted using different machine learning algorithms to improve the accuracy of sex prediction from anatomical measurements. MATERIAL & METHODS: In this study, linear data of the maxillary sinus in the population of northwest China by using Cone-Beam Computed Tomography (CBCT) were collected and utilized to develop logistic, K-Nearest Neighbor (KNN), Support Vector Machine (SVM) and random forest (RF) models for sex estimation with R 4.3.1. CBCT images from 477 samples of Han population (75 males and 81 females, aged 5-17 years; 162 males and 159 females, aged 18-72) were used to establish and verify the model. Length (MSL), width (MSW), height (MSH) of both the left and right maxillary sinuses and distance of lateral wall between two maxillary sinuses (distance) were measured. 80% of the data were randomly picked as the training set and others were testing set. Besides, these samples were grouped by age bracket and fitted models as an attempt. RESULTS: Overall, the accuracy of the sex estimation for individuals over 18 years old on the testing set was 77.78%, with a slightly higher accuracy rate for males at 78.12% compared to females at 77.42%. However, accuracy of sex estimation for individuals under 18 was challenging. In comparison to logistic, KNN and SVM, RF exhibited higher accuracy rates. Moreover, incorporating age as a variable improved the accuracy of sex estimation, particularly in the 18-27 age group, where the accuracy rate increased to 88.46%. Meanwhile, all variables showed a linear correlation with age. CONCLUSION: The linear measurements of the maxillary sinus could be a valuable tool for sex estimation in individuals aged 18 and over. A robust RF model has been developed for sex estimation within the Han population residing in the northwestern region of China. The accuracy of sex estimation could be higher when age is used as a predictive variable.

Postmortem CT analysis of paranasal sinuses using an experimental model of drowning.

Fluid-filled paranasal sinuses are suggested to be a valuable tool to distinguish between drowning and non-drowning postmortem, yet the mechanisms governing fluid entry remains unknown. We investigate if fluid-filled paranasal sinuses are caused by a passive influx from submersion or an active aspiration mechanism during drowning. The ovine nasal cavity and maxillary sinuses are remarkably similar anatomically to humans, and have been used for endoscopic surgical training in recent decades. We submerged 15 decapitated ovine heads from agricultural waste at a depth of 2 m in flowing water for 1, 8, and 24 h and 7 days. Paranasal sinuses were CT imaged and compared pre- and post-submersion to non-submerged controls. Furthermore, we examined the paranasal sinuses of a single homicide case of a non-drowned submerged subject. Results demonstrate that fluid passively enters the maxillary sinus postmortem in the non-drowned ovine heads following 1 h of submersion. Fluid volume was independent of submersion time and influenced by time out of water as well as handling, since volume was reduced between consecutive CT scans. In contrast to our hypothesis, the filling of the paranasal sinuses is due to passive influx of fluid from submersion rather than an active aspiration during drowning. The observation that paranasal sinuses were fluid-filled in a single medico-legal case of postmortem submersion supports the finding of passive influx. Consequently, careful interpretation of fluid-filled paranasal sinuses is required when bodies are found in water, as the finding cannot distinguish between postmortem submersion and drowning.

GADNN: a revolutionary hybrid deep learning neural network for age and sex determination utilizing cone beam computed tomography images of maxillary and frontal sinuses.

INTRODUCTION: The determination of identity factors such as age and sex has gained significance in both criminal and civil cases. Paranasal sinuses like frontal and maxillary sinuses, are resistant to trauma and can aid profiling. We developed a deep learning (DL) model optimized by an evolutionary algorithm (genetic algorithm/GA) to determine sex and age using paranasal sinus parameters based on cone-beam computed tomography (CBCT). METHODS: Two hundred and forty CBCT images (including 129 females and 111 males, aged 18-52) were included in this study. CBCT images were captured using the Newtom3G device with specific exposure parameters. These images were then analyzed in ITK-SNAP 3.6.0 beta software to extract four paranasal sinus parameters: height, width, length, and volume for both the frontal and maxillary sinuses. A hybrid model, Genetic Algorithm-Deep Neural Network (GADNN), was proposed for feature selection and classification. Traditional statistical methods and machine learning models, including logistic regression (LR), random forest (RF), multilayer perceptron neural network (MLP), and deep learning (DL) were evaluated for their performance. The synthetic minority oversampling technique was used to deal with the unbalanced data. RESULTS: GADNN showed superior accuracy in both sex determination (accuracy of 86%) and age determination (accuracy of 68%), outperforming other models. Also, DL and RF were the second and third superior methods in sex determination (accuracy of 78% and 71% respectively) and age determination (accuracy of 92% and 57%). CONCLUSIONS: The study introduces a novel approach combining DL and GA to enhance sex determination and age determination accuracy. The potential of DL in forensic dentistry is highlighted, demonstrating its efficiency in improving accuracy for sex determination and age determination. The study contributes to the burgeoning field of DL in dentistry and forensic sciences.

A nomogram prediction of implant apical non-coverage on bone-added transcrestal sinus floor elevation: A retrospective cohort study.

OBJECTIVES: To identify the risk indicators and develop and validate a nomogram prediction model of implant apical non-coverage by comprehensively analyzing clinical and radiographic factors in bone-added transcrestal sinus floor elevation (TSFE). MATERIAL AND METHODS: A total of 260 implants in 195 patients receiving bone-added TSFE were included in the study. The population was divided into a development (180 implants) and a validation (80 implants) cohort. According to 6 months post-surgery radiographic images, implants were categorized as "apical non-coverage" or "apical covered." The association of risk factors including clinical and radiographic parameters with implant apical non-coverage was assessed using regression analyses. A nomogram prediction model was developed, and its validation and discriminatory ability were analyzed. RESULTS: The nomogram predicting bone-added TSFE's simultaneously placed implant's apex non-coverage after 6 months. This study revealed that sinus angle, endo-sinus bone gain, implant protrusion length, graft contact walls, and distal angle were predictors of implant apical non-coverage. The generated nomogram showed a strong predictive capability (area under the curve [AUC] = 0.845), confirmed by internal validation using 10-fold cross-validation (Median AUC of 0.870) and temporal validation (AUC = 0.854). The calibration curve and decision curve analysis demonstrated good performance and high net benefit of the nomogram, respectively. CONCLUSIONS: The clinical implementation of the present nomogram is suitable for predicting the apex non-coverage of implants placed simultaneously with bone-added TSFE after 6 months.

Three-dimensional changes and influencing factors of tent space following osteotome sinus floor elevation without grafting: A 48-month retrospective radiographic study.

OBJECTIVES: To analyze the three-dimensional stability and morphologic changes of tent space after the osteotome sinus floor elevation (OSFE) procedures without bone grafts. MATERIALS AND METHODS: Forty-six implants placed using the OSFE technique with simultaneous implant placement without bone grafts were included in this retrospective study. Cone-beam computed tomography (CBCT) scans of the augmented sinuses were obtained pre- and postoperatively up to 48 months of follow-up. The maxillary sinus cavity profiles were outlined using three-dimensional virtual reconstruction and superimposition of CBCT scans. The three-dimensional changes in the tent space were measured. A generalized estimating equation (GEE) was used to explore potential factors. RESULTS: The implant survival rate was 97.8%. The mean volume of remaining tent space immediately after surgery was 96.8 ± 70.5 mm3, shrinking to 31.0 ± 24.9 mm3 after 48 months, while the mean percentage of remaining tent space volume decreased to 29.1 ± 20.7%. The tent space volume and the percentage of residual tent space volume only decreased significantly within 12 months after surgery (p = .008, .013). GEE results indicated positive correlations between the percentage of remaining tent space volume and implant protrusion length (p = .000) and apical height (p = .000), with a negative correlation between the sinus floor area immediately after surgery (p = .002) and the healing time (p = .022). CONCLUSIONS: The volume of the tent space rapidly shrank after OSFE without bone grafts. Several factors might influence the tent space stability. Long-term clinical trials with larger sample sizes are necessary to further validate the results.

Peri-implantitis and maxillary sinus membrane thickening: A retrospective cohort study.

OBJECTIVE: The objective of this study is to investigate the association of peri-implantitis (PI) and sinus membrane thickening and to assess the resolution of membrane thickening following intervention (implant removal or peri-implantitis treatment) aimed at arresting PI. MATERIALS AND METHODS: Forty-five patients with 61 implants in the posterior maxillary region were retrospectively included in the study. Twenty-four patients were diagnosed with peri-implantitis (PI) and 21 had peri-implant health (PH). Cone-beam computed tomography (CBCT) scans were evaluated to assess maxillary sinus characteristics, including membrane thickening, sinus occupancy and ostium patency. The CBCT scans taken 6 months after intervention aimed at arresting disease (implant removal or treatment of PI) in the PI group were also appraised and compared to baseline scans. RESULTS: At baseline, all parameters evaluating membrane thickness disorders yielded significant differences between groups (p < .001). Patients with posterior maxillary implants diagnosed with PI were 7× more likely to present membrane thickening compatible with pathology when compared to patients with healthy implants (OR = 7.14; p = .005). Furthermore, the likelihood was 6x greater in implants diagnosed with PI to exhibit moderate membrane thickening (OR = 6.75, p = .001). The patients receiving interventions aimed at arresting PI experienced significant enhancement in all radiographic parameters related to the sinus cavity at the 6-month follow-up (p < .001), though these variations were similarly independent of whether treatment consisted of PI treatment or implant removal. CONCLUSIONS: Maxillary sinus membrane thickening and the permeability/obstruction of the ostium are frequently associated with the presence of PI in posterior implants. Interventions targeting disease resolution effectively reduce membrane thickness to levels compatible with maxillary sinus health.

Comparative study of anatomical features of primary and accessory maxillary ostia between patients with obstructive sleep apnea and healthy controls.

PURPOSE: The purpose of this study was to examine how the size and shape of the maxillary sinus and its ostia (the primary maxillary ostium and accessory maxillary ostium) relate to each other in patients with OSA using computed tomography (CT) scans. Additionally, the study aimed to explore whether or not obstructive sleep apnea (OSA) had an effect on these structures. METHODS: CT images of patients diagnosed with OSAS and healthy participants were evaluated to compare the patency, location, dimension, and presence of PMOs and AMOs using the Mann-Whitney U, Student t, and chi-square tests. Also, intragroup correlations were analyzed by Spearman's correlation test. RESULTS: Among 139 patients with OSA and healthy controls, there were significant variations in the average length (p = 0.001) and width (p = 0.008) of PMOs among the study groups. The mean maxillary sinus volume was significantly decreased in the OSA group (p = 0.001). A significant decrease in the maxillary sinus volume was observed in the OSA group (p = 0.001). In the OSA group, a significant correlation was observed between PMO obstruction and the presence of AMO (p = 0.004). The healthy group had significant correlations (r = 0.755, p = 0.000) between the vertical height and the distance between PMO and the maxillary sinus floor. Correlation analyses revealed positive, strong correlations between study variables such as the mean length and width of AMO and the vertical height of the maxillary sinus (r = 0.566, p = 0.000) in the OSA group. CONCLUSIONS: The current study indicated significant differences in sinus volume, PMO occlusion, and AMO-related dimensions between patients with OSA and healthy controls.

Prelacrimal recess approach for maxillary sinus inverted papilloma: a 15-year experience from a single center.

PURPOSE: This large retrospective, single-center, follow-up study investigated the endoscopic prelacrimal recess approach (PLRA) for treating maxillary sinus inverted papilloma (MSIP). METHODS: Between January 2007 and November 2022, patients with MSIP treated with PLRA were enrolled. Data on clinical manifestations, imaging, and surgical procedures were collected. The visual analog scale (VAS) scores for maxillofacial numbness and nasal symptoms and the SNOT-22 nasal symptom scores were statistically analyzed. RESULT: Of 122 patients (68 males and 54 females) enrolled in the study, with a mean age of 50.75 ± 12.84 years (26-80 years), 111 patients underwent PLRA, nine underwent modified PLRA, one converted to an endoscopic medial maxillectomy (EMM), and one to an endoscopic modified Denker's approach. The average follow-up was 86.60 (13-192) months, the recurrence rate was 3.28%, and 29 patients (23.77%) complained of maxillofacial numbness one month postoperatively, which disappeared in most cases one year after surgery. Five patients (4.10%) experienced mild numbness at the end of the follow-up period. Maxillary sinus ostium contracture or atresia occurred in two cases (1.64%). After surgery, the VAS nasal symptom scores improved significantly (P < 0.001). SNOT-22 indicated that the most common postoperative symptom was thick nasal discharge. CONCLUSION: PLRA is a flexible first-choice surgical treatment for maxillary sinus inverted papilloma and can be modified according to the extent of the lesion, the surgeon's experience and technique, and surgical instruments. That can help achieve complete resection and reduce recurrence and surgical complications. Upper teeth numbness, the most common postoperative complication, tends to disappear after 1 year.

Intravascular papillary endothelial hyperplasia of the maxillary sinus extending into the contralateral nasal cavity.

INTRODUCTION: Intravascular papillary endothelial hyperplasia (IPEH) predominantly occurs in the subcutaneous and dermal regions and rarely originates from the sinonasal mucosa. CASE PRESENTATION: We report on the case of a 58-year-old male patient who presented with progressive bilateral nasal obstruction, left-sided epiphora, and intermittent epistaxis. Computed tomography revealed a soft tissue opacity in the left maxillary sinus with intersinusoidal nasal wall demineralization, extending into the surrounding ethmoid cells and the right nasal cavity through a contralateral deviation of the nasal septum. Contrast-enhanced T1-weighted magnetic resonance imaging further confirmed these findings. The IPEH originating from the maxillary sinus extended into the contralateral nasal cavity, and it was successfully removed using an endoscopic endonasal approach, avoiding overly aggressive treatment. CONCLUSION: This case report highlights the diagnostic challenges of IPEH in the sinonasal region and the importance of considering IPEH as a differential diagnosis in patients presenting with nasal obstruction, epiphora, and intermittent epistaxis.

Minimally Anterior Medial Maxillary Approach (MAMMA): a novel technique for a wide access to the maxillary sinus.

PURPOSE: To describe a novel endoscopic technique to approach the maxillary sinus (MS), the Modified Anterior Medial Maxillary Approach (MAMMA), preserving the inferior turbinate (IT) and the nasolacrimal duct (NLD). To perform radiological measurements and describe a case series to study the feasibility and limits of MAMMA. METHODS: Computed tomography (CT) scans (n = 150 nasal cavities) were used to calculate areas of the MAMMA to define surgical limits and extensions. Measurement of distances to critical anatomy landmarks and total area for the MAMMA were calculated. An instructional case illustrating the surgical technique and outcome was also included. RESULTS: Radiological analysis showed a mean distance from the Piriform Aperture (PA) to the anterior limit of the NLD of 1.03 ± 0.18 cm (range 0.59-1.48) and a mean distance from de PA to the posterior limit of the NLD of 1.57 ± 0.22 cm (range 1.02-2.11). The mean distance from the nasal floor to the Hasner's valve was 1.61 ± 0.27 cm (range 1.06-2.52) and the distance from the nasal floor to the insertion of the IT was 2.20 ± 0.36 cm (range 1.70-3.69). Finally, the mean total area for the MAMMA was 4.04 ± 0.52 cm2 (range 3.17-5.53). No complications or recurrence of the pathology were observed in operated patients. CONCLUSION: The MAMMA provides a wide surgical field of the MS walls comparable to more aggressive techniques, with preservation of the sinonasal and lacrimal function. MAMMA is an effective alternative to treat different MS pathologies including benign recurrent maxillary sinus tumors.

Maxillary sinus angiolymphoid hyperplasia with eosinophilia associated to orbital and cutaneous lesion.

INTRODUCTION: We describe the first case of ALHE in the orbit with extension to the maxillary sinus and the importance of a multidisciplinary approach to achieve removal of the lesion. CASE STUDY: A 72-year-old man presented with epiphora of the left eye and several episodes of recurrent acute dacryocystitis. Magnetic resonance imaging revealed a solid homogeneous mass located in the inferomedial region of the left orbit. In addition, it was associated with destruction of the adjacent ethmoidal wall and upper wall of the left maxillary sinus. Incisional biopsy of the orbital mass was compatible with ALHE. RESULTS: It was decided to perform surgery using an orbital floor approach, left medial wall via subconjunctival and caruncular approach together with an endoscopic nasal approach (ESS), achieving complete removal of the orbital mass and cleaning of the maxillary sinus. After one year of treatment, no tumor recurrence was evident through endoscopy and imaging tests and the patient is asymptomatic. CONCLUSIONS: ALHE is a very rare benign vascular tumor that presents subcutaneous nodules in the head and neck region. We do not know of any case of ALHE in the paranasal sinuses described in the literature, either in isolation or together with orbital or cutaneous ALHE. In conclusion, ALHE disease should be considered as a diagnosis when faced with an orbital mass with extension to the paranasal sinuses, and a complete excision through a combined endonasal and orbital approach prevents recurrence in most cases.

Sinus membrane thickness of healthy endodontically treated maxillary molars.

OBJECTIVE: The study aimed to investigate the sinus membrane thickness (SMT) adjacent to healthy endodontically-treated maxillary molars with or without protruded apical foramen into the sinus cavity using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Images of 207 non-smoker patients aged 18-40 were retrospectively analyzed, 140 were endodontically treated, and 136 were without endodontic treatment. Patients with any sinus pathology, teeth that have symptoms, or poor root filling were excluded. Study groups consisted of Group EM-I (endodontically treated and protruded apical foramen), Group EM-C (endodontically treated and contacted apical foramen), and similarly without endodontic treatment; Group M-I and Group M-C. SMT upon the mesial, distal, and palatal roots was measured. One-way ANOVA and Student's t-tests were performed. RESULTS: Group EM-I had the thickest sinus membrane compared to other groups (p = 0.013). SMT values were 2.37-2.60 mm in Group EM-I, and 1.34-1.58 mm in other groups. Thickening (> 2 mm) percentages were 33.45% in Group EM-I and between 4.25 and 8.25% in other groups. No statistical difference was detected between first and second molars and genders (p > 0.05). CONCLUSION: When the apical foramen protruded into the sinus cavity, the conventional root canal treatment caused a minimal (between 2.37 mm and 2.60 mm) sinus membrane thickening with a rate of 33.45% based upon CBCT examinations.

Cone Beam Computed Tomographic Evaluation of Schneiderian Membrane Thickness.

OBJECTIVE: This study aimed to determine the measurements and classification of Schneider membrane thickness correlated to age and sex factors using cone beam computed tomography (CBCT). METHODS: The study included CBCT images for 100 maxillary sinuses of 50 consecutive patients, and the thickness of the maxillary sinus membrane (Schneiderian membrane) was measured in coronal view from the lowest point in the floor of the maxillary sinus to the highest point. The thickness of the Schneiderian membrane was classified into 4 types. RESULTS: The study result revealed that out of the total cases, 45% of sinus membranes were classified as type 2, while only 10% were classified as type 4. The most frequent type of membrane thickness diagnosed in the age group 20 to 30 as type 1, whereas in age groups 31 to 40 and 41 to 50, regarding sex, type 4 was more obvious in males with membrane thickening >6 mm. CONCLUSIONS: Measurement and classification of sinus membrane thickness can be performed accurately with CBCT, and it is affected by age and sex factors.

Mini Crestal Sinus Lift With Bone Grafting and Simultaneous Insertion of Implants in Severe Maxillary Conditions as an Alternative to Lateral Sinus Lift: Multicase Study Report of Different Techniques.

The present study evaluates the efficacy and clinical outcomes of crestal sinus lift techniques used to elevate the sinus floor simultaneously with bone grafting and implant placement as a possible and reproducible alternative to lateral sinus lift. Patients underwent different crestal sinus elevation techniques. The heterologous biomaterial was used as graft material, and multiple implants were placed simultaneously after sinus augmentation. Radiographic and clinical examinations were performed during follow-up. All procedures were successfully performed without any apparent perforation of the Schneider membrane. The sinus floor was augmented with an average height of 5 mm (range: 2.8-7.4 mm). The implants healed smoothly with healing screws. Peri-implant marginal bone was stable with a mean follow-up of 50 months (range: 33-71 mo). No complications were observed during the follow-up. Based on the limited data collected in this study, the new crestal sinus elevation approach can effectively raise the sinus floor and reduce the incidence of postoperative complications. Other cases with long-term follow-up are needed to confirm and improve this crestal sinus lift technique.

Rhinogenic Headache: The Dehiscence of Infraorbital Nerve.

Rhinogenic headache (RH), arising from nasal and sinus pathologies, present a diagnostic challenge due to their diverse etiologies. This study investigates a unique case where RH coincides with infraorbital nerve dehiscence, delving into the intricate relationship between sinonasal anatomy and neurovascular complications. The infraorbital nerve contacted a cyst in the maxillary sinus. Centripetal endoscopic sinus surgery was performed to open the maxillary sinus and remove the cyst. After 3 months of follow-up, the patient had a notable improvement in symptoms with a reduced headache. This case highlights the significance of considering uncommon anatomic variations, such as infraorbital nerve dehiscence, within the context of RH. Diligent history-taking and appropriate use of radiologic investigations are pivotal for guiding clinicians toward an accurate diagnosis and determining the most appropriate course of treatment.

The Ethmomaxillary Sinus-A False Duplicate Maxillary Sinus.

Functional endoscopic sinus surgery consistently benefits from good anatomical knowledge and modern imaging techniques. Ethmoid air cells migrate in specific topographical sites near the ethmoid. Posterior ethmoid air cells that descend into the maxillary sinus (MS) are ethmomaxillary sinuses (EMSs) that into the superior nasal meatus. Few previous studies found EMSs in 0.68% to 16.48% of cases. An EMS differs from a Haller's infraorbital cell nearing the ethmoidal infundibulum. A posterior ethmoid air cell intercalated between the ethmoid, MS and sphenoidal sinus is a Sieur's cell, but it could also be regarded as an EMS. An EMS should be discriminated from a maxillary recess of the sphenoidal sinus. An EMS could determine Onodi's maxillary bulla into the MS. The false duplicate MS described by Zuckerkandl consists of a MS draining into the middle nasal meatus adjoined by an EMS draining into the superior nasal meatus. These are separated by the ethmomaxillary septum. The latter may be confused with an intrasinus septum of the MS if the drainage pathways are not adequately documented. Therefore, a case-by-case anatomic identification of the pneumatic spaces nearing the MS should be performed before surgical endoscopic approaches of the nose and sinuses.

Large Rhinolith in Nasal Cavity and Extension to Maxillary Sinus in a Cocaine User.

Although rhinoliths are rare, they deserve attention and should be considered in the differential diagnoses of calcified lesions that can affect the nasal cavity and maxillary sinus region. This article reports a case of a large rhinolith in the nasal cavity caused by cocaine use. Initially, the patient denied drug use, leaving several uncertainties regarding the diagnosis, including recurrent sinusitis. However, after the histopathologic results, the patient admitted to previous cocaine use, emphasizing the importance of honesty in the medical history to guide diagnostic hypotheses, as well as the awareness of the diagnostic possibility of a rhinolith to assist in treatment.

Cavernous Sinus Syndrome Caused by Noninvasive Fungal Maxillary Sinusitis.

It is rare that cavernous sinus complications are caused by maxillary sinus lesions because the locations of these lesions are some distant from each other. The authors describe an unusual presentation that the primary lesion was located in the maxillary sinus and triggered cavernous sinus syndrome and optic nerve symptoms. The most likely possibility was that the infection traveled retrograde along the vascular plexus. Removal of maxillary sinus lesions and establishment ventilation may achieve source control.

Clinical Approach to Dental Root Canal Filler-Induced Maxillary Sinus Fungal Mass Using Transnasal Endoscopy.

Accidentally extruded root canal filler within the sinuses may induce maxillary sinusitis with fungal mass. The authors describe 2 cases of gutta-percha-induced fungal masses in the left maxillary sinus of 2 women. The lesions were evaluated preoperatively using both computed tomography and magnetic resonance imaging, providing comprehensive insights into the condition. In one patient, the lesion was located such that it could be resected through the middle meatal antrostomy alone. However, the second patient presented with an anteroinferiorly situated lesion that necessitated not only a transnasal approach but also an endoscopic modified medial maxillectomy. Both patients recovered uneventfully after surgery. This case series is the first published report of 2 cases of gutta-percha-induced maxillary sinus fungal masses, with their imaging findings, successfully treated through different routes through transnasal endoscopic surgery. These reports highlight the need for a collaborative approach between dental practitioners and otolaryngologists. In addition to the patient's wishes, surgical interventions must consider the unique characteristics of each case and the potential for collaboration across different medical specialties.

Infratemporal Fossa Schwannoma Surgery via a Combined Prelacrimal Recess, Caldwell-Luc, and Distal Intraoral Approach.

BACKGROUND: The deep location of infratemporal fossa (ITF) combined with the abundant vascular plexus in it increased the difficulty of removing the mass in ITF through endoscope surgery approach. However, under appropriate circumstances, the excision of ITF tumors through a combined prelacrimal recess, Caldwell-Luc, and distal intraoral approach can be safely performed with minimal impact on the surrounding tissues. CASE PRESENTATION: The Department of Neurology received a 69-year-old male patient who had been experiencing headache, dizziness, and numbness from the mastoid region of his left ear to the corner of his mouth for a duration of 22 days. Cranial magnetic resonance imaging revealed the presence of a tumor located in the ITF. Following transfer to our department, surgical intervention was performed using a combined approach involving the prelacrimal recess, the anterior wall of maxillary sinus, and lateral ITF to successfully remove the tumor. Postoperative pathologic examination confirmed schwannoma as its nature. The patient was discharged in excellent condition without any functional impairment. CONCLUSIONS: On the basis of this case, the authors believe that this combined approach can offer a distinct endoscopic perspective and adequate surgical workspace, which is crucial for tumor removal while preserving the integrity of surrounding normal tissues. Moreover, the utilization of multiple small incisions has minimal impact on postoperative recovery.