A pedicled buccal periosteal flap for the closure of oro-antral fistula.

BACKGROUND: An oroantral fistula is a communication between the maxillary antrum and oral cavity. This pathological communication is formed mainly due to dental extraction of maxillary premolars and molars. Adequate management should include closing the oroantral fistula and eliminating sinus infections to prevent recurrence and sinusitis. PURPOSE: This study aimed to evaluate the effectiveness of using the pedicled buccal periosteal flap for closing an oroantral fistula without changing the native intraoral structure. PATIENTS & METHODS: Patients with oroantral fistulas were included in this study. The patients were examined clinically by Valsalva test and cheek-blowing test, the hole was probed, and the extent of the underlying bone defect was determined radiographically using computed tomography preoperatively. All patients underwent surgical closure of oroantral fistula using a pedicled buccal periosteal flap. RESULTS: All 10 patients obtained satisfactory results with marked improvement in the function of the maxillary sinus and complete healing of oroantral fistula with no recurrence except in Case No. 5, who had a recurrence of the oroantral fistula, also there was no statistically significant difference between the vestibular depth preoperatively and postoperatively. CONCLUSION: A pedicled buccal periosteal flap is a novel technique for oroantral fistula closure as it preserves vestibular depth with a tension-free closure flap and harbors the advantages of the regenerative potential of the periosteum. REGISTRATION DATE: 14/8/2023 REGISTRATION NUMBER: NCT05987943.

Preservation or removal of the lateral nasal wall in endoscopic management of maxillary sinus neoplasia: A comparison of approach related morbidity.

BACKGROUND: The endoscopic modified medial maxillectomy (MMM) and prelacrimal approach (PLA) are two routinely performed endoscopic approaches to the maxillary sinus when access via a middle meatal antrostomy is insufficient. However, there is no data in the literature that has compared outcomes and complication profile between the two procedures to determine which approach is superior. OBJECTIVE: To compare the approach related morbidity of PLA and MMM. METHODS: A retrospective cohort study of all consecutive adult patients undergoing either MMM or PLA from 2009 to 2023 were identified. The primary outcome was development of epistaxis, paraesthesia, lacrimal injury, iatrogenic sinus dysfunction within a minimum of 3 months post-operative follow up. RESULTS: 39 patients (44 sides) underwent PLA and 96 (96 sides) underwent MMM. There were no statistically significant differences between the rates of paraesthesia (9.1 % vs 14.6 %, p = 0.367) or prolonged paraesthesia (2.3 % vs 5.2 %, p = 0.426), iatrogenic maxillary sinus dysfunction (2.3 % vs 5.2 %, p = 0.426) or adhesions requiring removal (4.5 % vs 4.2 %, p = 0.918). No cases of epiphora or nasal cavity stenosis occurred in either arm in our study. CONCLUSIONS: According to our data, the endoscopic modified medial maxillectomy and prelacrimal approach are both equally safe approaches with their own benefits to access.

Elective neck dissection versus elective neck irradiation in cT3/4N0 maxillary sinus squamous cell carcinoma: a propensity score matching analysis.

BACKGROUND: Maxillary sinus squamous cell carcinoma (MS-SCC) is an infrequent malignancy, and determining the optimal neck management for patients with cT3/4N0 MS-SCC remains a topic of ongoing debate. The purpose of this study was to compare the prognoses and quality of life outcomes of patients who underwent either elective neck dissection (END) or elective neck irradiation (ENI) for cT3/4N0 MS-SCC. METHODS: In this retrospective study, we enrolled patients with surgically treated cT3/4N0 MS-SCC, and the impact of different neck management strategies on regional control and disease-specific survival was compared using propensity score matching. The effect of surgical intervention on quality of life was evaluated using the Mann-Whitney U test. RESULTS: Of the 120 patients included, 36 underwent END. After propensity score matching, our analysis indicated that END did not lead to superior outcomes than ENI, as demonstrated by comparable rates of regional control (p = 0.990) and disease-specific survival (p = 0.999). However, in the 70 returned questionnaires, patients who underwent END reported higher scores in the domains of appearance, chewing, and speech than did patients who underwent ENI. CONCLUSIONS: Our findings suggest that while END and ENI contribute to similar prognoses, END yields superior functional outcomes.

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.

Maxillary sinus augmentation via the bone lid technique: A prospective, radiographic case series.

BACKGROUND: Maxillary sinus augmentation is one of the most performed procedures to increase the bone quantity of the atrophic maxilla to allow implant placement. The aim of the present case series was to describe a surgical protocol to perform maxillary sinus augmentation with the "bone lid technique," and its outcomes in a cohort of patients eligible for the procedure. METHODS: After the initial clinical evaluation, a cone-beam computed tomography (CBCT) examination was performed for preoperative assessment. Patients were then scheduled for surgical intervention. At 6-9 months follow-up, patients underwent a second CBCT scan to evaluate bone height following bone graft and to schedule implant placement. RESULTS: A total of 11 patients were enrolled in the study with a total of 13 sinus lift procedures. Membrane perforation was registered in 4 cases (30.76%). Mean surgical time was 67.69 min (SD 6.51). Postoperative period was uneventful in all patients, in the absence of complications. The mean graft volume increase was 2.46 cm3 (SD 0.85), and the mean height increase was 14.27 mm (SD 3.18). Mean membrane thickness was 1.40 mm (SD 0.75). In all the 4 cases with sinus membrane perforation, the membrane had a thickness lower than 1 mm. CONCLUSIONS: The present study highlights that the maxillary sinus augmentation with bone lid repositioning could provide repeatable results in terms of bone height increase. The technique appears reliable both in terms of bone gain and absence of complications. KEY POINTS: The bone lid technique for maxillary sinus augmentation provides repeatable results in terms of bone height increase. The favorable clinical outcomes can be related to an enhancement of bone formation due to the unique osteoconductive and osteoinductive properties of autogenous bone, along with a reduction of soft tissue ingrowth. Complications were not observed in any of the patients following the surgical procedures. The risk of Schneiderian membrane perforation is inversely proportional to membrane thickness; the thinner the membrane is, the higher the risk to perforate it.

Post-treatment magnetic resonance imaging predicts outcomes of maxillary sinus cancer treatment using super-selective intra-arterial infusion of high-dose cisplatin with concomitant radiotherapy (RADPLAT).

OBJECTIVES: This study aimed to evaluate the prognostic value of magnetic resonance imaging (MRI) findings in predicting local recurrence in patients with maxillary sinus cancer treated with super-selective intra-arterial infusion of high-dose cisplatin with concomitant radiotherapy (RADPLAT). METHODS: This single-center retrospective study included consecutive patients with maxillary sinus squamous cell carcinoma, who underwent RADPLAT between October 2016 and September 2021. MRI was performed before (within 2 weeks) and 1 month after (post-treatment MRI) the start of treatment. Tumor reduction rates and pre-treatment cross-sectional areas were calculated from the maximum cross-sectional areas on pre- and post-treatment MRI T2-weighted axial images. Statistical analyses, including receiver operating characteristic analysis, were performed to assess the predictive value of the tumor reduction rates. RESULTS: Twenty-four patients were included in this study. Recurrence occurred in seven patients with a median time of 213 days. The tumor reduction rates were significantly higher in the benign post-treatment changes group compared to the recurrence group (median, 0.814 vs. 0.174; p < 0.001). The cut-off value for the reduction rate between the groups was 0.3578. No significant difference was observed in the maximum pre-treatment cross-sectional area between the groups (p = 0.664). The inter-observer agreement for the tumor areas was excellent. CONCLUSIONS: The tumor reduction rate calculated from MRI T2-weighted images may be a predictor of local recurrence in patients with maxillary sinus cancer treated with RADPLAT. Patients with lower reduction rates may benefit from early salvage surgeries.

[Proposal for the delineation of postoperative primary clinical target volumes in maxillary sinus and nasal cavity cancers]. / Proposition de délinéation des volumes cibles anatomocliniques postopératoires de la tumeur primitive des cancers du sinus maxillaire et des cavités nasales.

In this article, we propose a consensus delineation of postoperative clinical target volumes for the primary tumour in maxillary sinus and nasal cavity cancers. These guidelines are developed based on radioanatomy and the natural history of those cancers. They require the fusion of the planning CT with preoperative imaging for accurate positioning of the initial GTV and the combined use of the geometric and anatomical concepts for the delineation of clinical target volume for the primary tumour. This article does not discuss the indications of external radiotherapy (nor concurrent systemic treatment) but focuses on target volumes when there is an indication for radiotherapy.

Missed Maxillary Sinus Ostium Syndrome and its Management.

The inflammatory process involving the maxillary sinus is often exacerbated by a functional obstruction due to laterally displaced uncinate process which obstructs the infundibulum and the natural ostium. Physiologically the drainage pathway may be adequate but during periods of inflammation resulting in nasal oedema, the ostium/infundibulum interface is inadequate, preventing adequate ventilation and drainage of the maxillary sinus. Incomplete removal of the uncinate process without including the natural ostium may result in failure and recurrence. This method of Middle meatal antrostomy that does not include the natural ostium of the maxillary sinus, leads to the missed ostium sequence and continued sinus disease. Here a case of missed maxillary sinus syndrome and its management is presented. A 28-year-old man with complaints of post nasal drip and Left facial pain for 4 months. 3 years prior the patient underwent functional endoscopic sinus surgery (FESS), following surgery patient had recurrent episode of sinusitis. Diagnostic nasal endoscopy revealed presence of mucopurulent discharge in left middle meatus, CT scan Paranasal sinus was suggestive of opacity in left maxillary sinuses and in left middle meatus with wide maxillary antrostomy. Revision FESS surgery was performed, where two ostia were present was converted into single wide middle meatal antrostomy using a back bitting forceps and microdebrider to avoid maxillary sinus mucus recirculation phenomenon. On follow up 1 year later, patient had no symptoms of repeated sinusitis. Missed maxillary sinus ostium syndrome has to be recognized and timely addressed by joining the natural and surgically created ostia as single wide middle meatal antrostomy window. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-023-04385-x.

Closed head injury combined with orbital blowout fracture and displacement of the eyeball into the maxillary sinus in a 14-year-old boy: a case report.

BACKGROUND: Trauma-induced orbital blowout fracture (OBF) with eyeball displacement into the maxillary sinus is rare. CASE PRESENTATION: We present the case of a 14-year-old with a closed head injury, OBF, and displacement of the eyeball into the maxillary sinus following a car accident. A prompt transconjunctival access surgery was performed for eyeball repositioning and orbital reconstruction in a single session, mitigating anaesthesia-related risks associated with multiple surgeries. At the 12-month follow-up, his visual acuity was 20/200. Despite limited eye movement and optic nerve atrophy, overall satisfaction with the ocular appearance was achieved. CONCLUSIONS: This report offers novel insights into the mechanisms of OBF occurrence and the development of postoperative complications.

Ameloblastic Carcinoma of the Maxilla With Uncommon Sinus Manifestations.

Ameloblastic carcinoma (AC) represents a distinct challenge in the realm of odontogenic malignancies due to its rarity and aggressive nature. We present a unique case of AC in a 70-year-old male, retired dry cleaner, with symptoms initially suggestive of chronic allergic rhinitis and recurrent acute sinusitis with asymmetric facial edema and paresthesia. Detailed evaluation revealed a prominent mass in the right maxillary sinus with extensive cortical destruction. Pathological assessment post-right maxillectomy identified a high-grade AC with malignant spindle cell transformation. The patient underwent subsequent interventions, including neck dissection and radiation therapy. Twelve months post-presentation, the patient was recovering appropriately without evidence of recurrence of malignancy. This case highlights the diagnostic challenges posed by AC as well as its unique presentations emphasizing the importance of a comprehensive approach and multidisciplinary management. It also raises considerations about potential chemical exposure implications in AC development.

Inflammatory Modifications in Paranasal Sinuses and Ostiomeatal Complex Anatomical Variations in Jet Aircraft Pilots: A Computed Tomography Study.

Introduction Jet aircraft pilots are exposed to huge pressure variation during flight, which affect physiological functions as systems, such as the respiratory system. Objectives The objective of the present investigation was to evaluate inflammatory changes of paranasal sinuses of jet aircraft pilots before and after a jet aircraft training program, using multislice computed tomography (CT), in comparison with a group of nonairborne individuals with the same age, sex, and physical health conditions. A second objective of the present study was to assess the association between the ostiomeatal complex obstruction and its anatomical variations. Methods The study group consisted of 15 jet aircraft pilots participating in the training program. The control group consisted of 41 nonairborne young adults. The 15 fighter pilots were evaluated before initiating the training program and after their final approval for the presence of inflammatory paranasal sinus disease. The ostiomeatal complex anatomical variations and obstructions were analyzed in pilots after the training program. Results Jet aircraft pilots presented higher incidence of mucosal thickening in maxillary sinus and anterior ethmoid cells than controls. Prominent ethmoidal bulla showed significant association with obstruction of the osteomeatal complex. Conclusions Jet aircraft pilots present increased inflammatory disease when compared with nonairborne individuals. The presence of a prominent ethmoidal bulla is associated with ostiomeatal complex obstruction.

One-Stage Lateral Sinus Floor Elevation Using Different Grafts: A Systematic Review of Controlled Clinical Trials.

PURPOSE: The purpose of this systematic review was to assess histological and imaging outcomes related to new bone formation around implants, inserted simultaneously with sinus augmentation, comparing different types of grafts. MATERIALS AND METHODS: Systematic Review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta- Analysis (PRISMA), and the Cochrane Handbook for Systematic Reviews of Interventions. LILACS/BVS, Medline/PubMed, Cochrane Library and Embase databases, including gray literature and manual investigation, were searched to identify clinical trials reporting human histological and imaging data of bone formation around implants, inserted into the maxillary sinus at the same moment of the elevation and augmentation procedure, using several materials. Study selection, risk of bias (Rob 2.0 or ROBINS I), quality of evidence (GRADE), and data collection were performed by two independent reviewers. RESULTS: Of the 1101 potentially eligible articles, 44 were retrieved, 12 were assessed for eligibility and 5 were included in this systematic review (4 randomized and one controlled clinical trials). As a result, 130 grafted sinuses with 179 installed implants in 103 patients, aged between 24 and 79 years and followed up from 6 to 15 months, were analyzed. The heterogeneity between studies did not allow the data to be combined for meta-analyses. All graft materials proved to be viable options for the intervention. The use of BCP was related to higher bone-to-implant contact. CONCLUSION: All the assessed grafts are viable options for the intervention addressed. The use of some material is justified to maintain the sinus volume and allow bone formation in the apical site of implants under the sinus membrane. Longer chair time and the morbidity of the donor site should be considered when choosing autogenous bone. Synthetic biphasic materials can be selected for this intervention due to superior values of %BIC when compared to DBB.

Clinical Outcomes of Maxillary Sinus Floor Perforation by Dental Implants and Sinus Membrane Perforation during Sinus Augmentation: A Systematic Review and Meta-Analysis.

The aim of the present systematic review was to investigate the clinical outcomes after the perforation of the maxillary sinus by dental implants, or after maxillary sinus membrane perforation during sinus lift procedure. Twenty-nine publications were included. Failure rates of implants in cases where perforation of sinus floor had happened (11 studies) was generally low, and only one case of transient sinusitis was reported. The estimated failure rate of these implants was 2.1% (SE 1.0%, p = 0.035). There were 1817 implants (73 failures) placed in augmented sinuses in which the sinus membrane was perforated and 5043 implants (274 failures) placed in sinuses with no perforated membrane, from 18 studies. The odds of implant failure difference between the groups were not significant (OR 1.347, p = 0.197). log OR of implant failure between perforated and non-perforated membrane groups did not significantly change with the follow-up time (-0.004/month; p = 0.500). In conclusion, implant failure rate is generally low either for implants penetrating in the floor of the maxillary sinus or implants placed in augmented sinuses in which the sinus membrane was perforated. The prevalence of postoperative infection/sinusitis is low, and it may depend either on the dimensions of the perforation or on the anatomical predisposition.

Manejo quirúrgico del paciente con patología pseudoquística sinusal: a propósito de un caso / Surgical management of the patient with sinusal pseudocyst pathology: a case report

Introducción: la patología sinusal puede comprometer el éxito del tratamiento de implantes. Existe una elevada incidencia de patología sinusal. El tratamiento de esta patología puede implicar a otros profesionales, lo que supone un mayor coste sanitarios y demora en la realización de los tratamientos de implantes. El objetivo del presente artículo es presentar un caso clínico representativo de la patología pseudoquística del seno maxilar y una alternativa de su manejo quirúrgico simultáneo a la regeneración ósea requerida para su posterior rehabilitación mediante implantes, así como actualizar la evidencia científica disponible. Caso clínico: se presenta una paciente de 46 años con una lesión pseudoquística sinusal que es remitida para rehabilitar mediante implantes en 1.4 y 1.7, por movilidad y dolor en relación a prótesis fija dentosoportada en maxilar derecho. Se realiza el tratamiento quirúrgico de exodoncias, elevación de seno maxilar y eliminación de la lesión pseudoquística de manera simultánea. Discusión: existe controversia sobre el momento idóneo para realizar el tratamiento sinusal. Algunos estudios muestran éxito de la cirugía endoscópica simultáneamente a la eliminación de la fuente odontogénica. Otros han demostrado que realizar primero la cirugía sinusal tiene el mismo porcentaje de curación que realizar primero el tratamiento odontológico. Conclusión: el diagnóstico de la patología y la planificación quirúrgica deben tener en cuenta el tipo de patología, la extensión y las necesidades de tratamiento del paciente. El manejo quirúrgico de la patología sinusal de manera simultánea a la regeneración ósea es una alternativa segura y beneficiosa para el paciente. (AU)

Introduction: Sinus pathology can compromise the success of implant treatment. There is a high incidence of sinus pathology. The treatment of this pathology may involve other professionals, which means higher healthcare costs and delays in carrying out implant treatments. Besides updating available scientific evidence, the objective of this article is to present a representative clinical case of pseudocystic pathology of the maxillary sinus and an alternative to its simultaneous surgical management in the bone regeneration required for subsequent rehabilitation using implants. Clinical case: A 46-year-old patient with a pseudocystic sinus lesion, referred for rehabilitation using implants in 1.4 and 1.7, due to mobility and pain in relation to a tooth-supported fixed prosthesis in the right maxilla. The surgical treatment, consisting of extractions, maxillary sinus elevation and removal of the pseudocystic lesion, was performed simultaneously. Discussion: There is controversy about the ideal time to perform sinus treatment. Some studies show success of endoscopic surgery simultaneously with removal of the odontogenic source. Others have shown that performing sinus surgery first has the same cure rate as performing dental treatment first. Conclusion: Pathology diagnosis and surgical planning must take into account the type and extent of the pathology and the treatment needs of the patient. Surgical management of sinus pathology simultaneously with bone regeneration is a safe and beneficial alternative for the patient. (AU)

Analysis of the Construction of a Predictive Model for Eosinophilic Chronic Rhinosinusitis.

Purpose: This study aimed to determine indices to diagnose and predict eosinophilic chronic rhinosinusitis (ECRS) during the initial clinic visit. Patients and Methods: We retrospectively analyzed 116 patients with chronic rhinosinusitis who underwent endoscopic sinus surgery and were classified according to the postoperative pathological diagnosis. General data and various clinical indicators were analyzed, and indicators with statistically significant differences between groups were further incorporated into a multivariate logistic regression to establish a comprehensive prediction model. The receiver operating characteristic (ROC) curve was used to compare the two significant valuable single factors from previous studies, the difference in CT scores between the ethmoid sinus and the sum difference of the maxillary sinus (EM difference) and the absolute value of peripheral blood eosinophil (bEOS), with a comprehensive prediction model. Results: There were significant differences in history of allergic asthma (p < 0.001), visual analog scale (VAS) score (p=0.005), sino-nasal outcome test-22(SNOT-22) scale score (p=0.004), Lund-Mackay scale score (p=0.017), EM difference (p=0.002), percentage of bEOS (%)(p=0.001), and absolute value of bEOS (×109/L) (p=0.000) between the two groups (p< 0.05). The history of allergic disease, VAS and bEOS were screened out and included in the comprehensive prediction model. The area under the curve (AUC) of the comprehensive prediction model (0.804)> the AUC of the absolute value of the bEOS (0.764)>the AUC of the EM difference (0.655). The AUC of the EM difference and the comprehensive prediction model were statistically different (P=0.025). There was no statistical difference between the absolute value of bEOS and the AUC of the comprehensive prediction model. Conclusion: The comprehensive prediction model covering the three aspects of allergic asthma history, VAS score, and bEOS count had the highest AUC compared to the other predictors and had good predictive power for the diagnosis of ECRS.

Mucosal cyst aspiration in conjunction with maxillary sinus elevation: A clinical cohort study.

INTRODUCTION: Patients with mucosal cysts in the maxillary sinus require special consideration in patients who require implant therapy for the restoration when undergoing implant therapy for the restoration of the posterior maxillary dentition. Treatment strategies for these clinical situations remain controversial in the literature. Thus, this study seeks to describe a safe and effective therapeutic strategy for sinus augmentation in patients with pre-existing maxillary antral cysts. METHODS: A total of 15 patients and 18 sinuses were consecutively enrolled in this cohort study and underwent maxillary antral cyst treatment by needle aspiration and simultaneous maxillary sinus augmentation (MSA). During surgical procedures, threeimplants (Zimmer Biomet, Indiana, USA) were positioned in 11 sinuses and two implants (Zimmer Biomet, Indiana, USA) were positioned in 5 sinuses. RESULTS: Overall implant success and survival rates were 100% and 97.8%, respectively at 1 year and 5-year follow-ups. Crestal bone resorption averaged 0.3 ± 0.2 mm 5-year post-loading, showing bone stability. Implant survival rate at 5-year follow-up expressed predictability of the technique comparable to historical data when MSA was performed alone. Crestal bone resorption averaged 0.3 ± 0.2 mm 5 years post-loading and shows bone stability utilizing mucosal cyst aspiration with concomitant MSA procedures. Quality of life evaluation at 1-week post-op showed similar results to published historical data. In 81% (13 sinuses), the CBCT examination at 5-year follow-up showed no cyst reformation, in 19% (3 sinuses) cyst reformation was visible, but smaller in size when compared to the pre-op CBCT evaluation, and all the patients were asymptomatic. CONCLUSIONS: Maxillary sinus mucosal cyst aspiration with concomitant MSA, may be a viable option to treat maxillary sinus cyst.

Delayed treatment of traumatic eyeball dislocation into the maxillary sinus and treatment algorithm: a case report and literature review.

Orbital floor fractures are commonly encountered, but the dislocation of the eyeball into the maxillary sinus is relatively rare. When it does occur, globe dislocation can have serious consequences, including vision loss, enucleation, and orbito-ocular deformity. Immediate surgical intervention is typically attempted when possible. However, severe comorbidities and poor general health can delay necessary surgery. In this report, we present the surgical outcomes of a 70-year-old woman who received delayed treatment for traumatic eyeball dislocation into the maxillary sinus due to a subarachnoid hemorrhage and hemopneumothorax. Additionally, we propose a treatment algorithm based on our clinical experience and a review of the literature.

Dynamic Navigation Protocol for Direct Sinus Lift and Simultaneous Implant Placement: A Case Report.

AIM: This study aims to evaluate the accuracy associated with the use of a dynamic navigation system for the lateral window opening for a direct sinus floor elevation (SFE) procedure with simultaneous implant placement. MATERIALS AND METHODS: A female patient, aged 27 years, reported to the Department of Implantology seeking treatment for her lost tooth. On radiographic examination, the residual alveolar ridge height was 6 mm in the 26 (left upper first molar) region. For the implant placement, the case was planned to be carried out under dynamic navigation (Navident, Claronav, Canada). To make the lateral window accessible to the sinus floor, an implant trajectory resembling the required window dimensions and prosthetic implant position was planned. Post-surgery cone beam computed tomography (CBCT) was taken to assess the accuracy of the lateral window and implant trajectories using Evalunav (Navident, Claronav, Canada) analysis with dynamic navigation software. RESULTS: There was improved accuracy of the lateral window opening, and the visualization of the lateral window was maintained in real-time throughout the procedure, which was advantageous to eliminate the tearing of the thin sinus membrane. The deviations found in the trajectory of the lateral window in comparison between the planning and post-procedure were: (a) entry was deviated by 2.83 mm; (b) the apex was deviated by 2.52 mm; (c) vertically, the apex was deviated by 0.29 mm; and (d) there was an 8.93° deviation in the angulation of the trajectory. The implant that was placed simultaneously with the SFE's accuracy was in comparison with the position that was planned: (a) entry was deviated by 0.03 mm, (b) the apex was deviated by 0.82 mm, (c) vertically, the apex was deviated by 0.82 mm, and (d) there was a 0° deviation in the angulation of the trajectory. CONCLUSION: Dynamic navigation technology can help overcome complications associated with direct sinus lift procedures by providing highly accurate and precise planning and execution of the surgical procedure. This can lead to improved implant stability and a reduced risk of complications.

Biomechanical analysis of the maxillary sinus floor membrane during internal sinus floor elevation with implants at different angles of the maxillary sinus angles.

OBJECTIVE: This study analyzed and compared the biomechanical properties of maxillary sinus floor mucosa with implants at three different maxillary sinus angles during a modified internal sinus floor elevation procedure. METHODS: 3D reconstruction of the implant, maxillary sinus bone, and membrane were performed. The maxillary sinus model was set at three different angles. Two internal maxillary sinus elevation models were established, and finite element analysis was used to simulate the modified maxillary sinus elevation process. The implant was elevated to 10 mm at three maxillary sinus angles when the maxillary sinus floor membrane was separated by 0 and 4 mm. The stress of the maxillary sinus floor membrane was analyzed and compared. RESULTS: When the maxillary sinus floor membrane was separated by 0 mm and elevated to 10 mm, the peak stress values of the implant on the maxillary sinus floor membrane at three different angles were as follows: maxillary sinus I: 5.14-78.32 MPa; maxillary sinus II: 2.81-73.89 MPa; and maxillary sinus III: 2.82-51.87 MPa. When the maxillary sinus floor membrane was separated by 4 mm and elevated to 10 mm, the corresponding values were as follows: maxillary sinus I: 0.50-7.25 MPa; maxillary sinus II: 0.81-16.55 MPa; and maxillary sinus III: 0.49-22.74 MPa. CONCLUSION: The risk of sinus floor membrane rupture is greatly reduced after adequate dissection of the maxillary sinus floor membrane when performing modified internal sinus elevation in a narrow maxillary sinus. In a wide maxillary sinus, the risk of rupture or perforation of the wider maxillary sinus floor is reduced, regardless of whether traditional or modified internal sinus elevation is performed at the same height.