The Use of CBCT in Evaluating the Health and Pathology of the Maxillary Sinus

Association of Cigarette Consumption and Mucosal Thickening in the Paranasal Sinuses on MRI

OBJECTIVE

To investigate the impact of cigarette consumption on mucosal thickening in paranasal sinuses and the relationships of smoking-related factors and dental status with mucosal thickening at different maxillary sinus locations using MRI.

MATERIALS AND METHODS

This retrospective study investigated 1094 paranasal sinuses on MRIs by correlating mucosal thickening with smoking-related factors. Presence/absence of maxillary posterior teeth was correlated with mucosal thickening on the maxillary sinus floor and other sinus locations.

RESULTS

Compared with nonsmokers, current and former smokers exhibited similarly more mucosal thickening in the maxillary (58.9%/62.8% vs 38.3%, P < .01) and ethmoid (22.7%/17.1% vs 6.6%, P < .01) sinuses, but not in the sphenoid sinus (P = .08) and similarly more mucosal thickening on the medial/superior walls of the maxillary sinus (40.4%/41.5% vs 18.4%, P < .01). Patients with mucosal thickening in the maxillary and ethmoid sinuses had greater daily cigarette consumption and years of smoking than those without mucosal thickening in these sinuses (P < .01). Edentulous individuals had more mucosal thickening on the maxillary sinus floor compared to dentate individuals (43.7% vs 32.2%, P < .01).

CONCLUSION

Cigarette consumption is associated with increased mucosal thickening in paranasal sinuses, with a dose-response association. This thickening may be persistent after quitting smoking. Cigarette smoking may have a more pronounced impact on the sinus mucosa in areas near the primary maxillary ostium, while dental status may be more likely to affect that on the maxillary sinus floor.

Unilateral Sinus Disease: What Is, and Is Not Odontogenic Sinusitis?

The differential diagnosis of unilateral sinus disease (USD) is broad, and while concerning etiologies like sinonasal neoplasia, invasive fungal sinusitis, and cerebrospinal fluid rhinorrhea should always be considered, most cases are due to noninvasive inflammatory or infectious conditions. To diagnose USD appropriately, clinicians must integrate the clinical history and examination, nasal endoscopy, computed tomography (CT), and possibly MRI. Odontogenic sinusitis (ODS) is the most common cause of unilateral maxillary sinus opacification on CT, with 45% to 75% of such cases being odontogenic in nature. This study provides USD diagnostic considerations and reinforces the diagnostic approach to ODS.

Collaboration between otolaryngologists and oral surgeons in maxillary sinus elevation planning

BACKGROUND

The collaboration between otolaryngologists and dental providers is crucial for the planning and execution of maxillary sinus elevation (MSE) procedures, which are integral to successful dental implant placements.

PURPOSE

This article examines the essential role of otolaryngological assessments in identifying potential sinonasal risks that could impact the outcomes of MSE.

MATERIALS AND METHODS

A comprehensive narrative review of existing literature was conducted.

DISCUSSION

The review underscores the importance of thorough preoperative evaluations, including patient history, computed tomography (CT) or cone-beam CT (CBCT) scans, and nasal endoscopy, to mitigate sinonasal health risks. It details various clinical scenarios and patient assessments, emphasizing a systematic approach to diagnosing and managing sinonasal conditions proactively. The discussion reveals that while some sinus conditions may not significantly affect MSE success, conditions impacting mucociliary clearance and sinus drainage are critical risk factors requiring otolaryngological intervention. Additionally, the article introduces a grading system to assist clinicians in identifying patients who would benefit from otolaryngological evaluations prior to MSE.

CONCLUSION

This review highlights the value of interdisciplinary collaboration and standardized protocols in enhancing the predictability and safety of MSE procedures, ultimately improving patient outcomes.

Visibility of alveolar bone thicknesses on CBCT images-a study on minimum bone requirements using various reconstruction techniques, viewing modes, and resolutions

OBJECTIVES

To evaluate at which thickness marginal bone becomes visible to the observer on cone-beam computed tomography (CBCT) images and how reconstruction technique and viewing mode affect assessment.

MATERIALS AND METHODS

Fourteen anterior teeth from six human mandibles were examined with two CBCT resolution protocols: standard- and high-resolution. Distance from the cementoenamel junction to the visible marginal bone level (MBL) was measured in three groups of reconstructed CBCT images: multiplanar reformation (MPR) with grey scale, MPR with inverted grey scale, and 3D rendering. These measurements were used to identify the bone level where marginal bone width should be measured on histological photographs of sliced teeth. Gold standards comprised measurements of bone thickness at the superior MBL on histological photographs.

RESULTS

MPR grey scale images exposed at high-resolution settings yielded highest validity: bone widths of 0.173 mm (buccal) and 0.356 mm (lingual) were necessary for visibility on a CBCT image. 3D-rendered lingual surfaces exposed with high-resolution settings had lowest validity. Intra-observer agreement for all CBCT and histological measurements was high.

CONCLUSION

The best CBCT resolution protocol, reconstruction technique, and viewing mode for analyzing buccal and lingual surfaces of the alveolar bone margin are images exposed with a high-resolution protocol, reconstructed using MPR, and viewed in grey scale. Bone thickness required to be visualized was twice lingually compared to buccally.

CLINICAL RELEVANCE

The visualization of bone thickness in CBCT requires a greater thickness on the lingual side compared to the buccal side. 3D-rendered reconstructions should be avoided when evaluating thin bony structures.

Temporomandibular Joint Disorders and Pain Confounders: An Awareness Study

OBJECTIVES

Temporomandibular disorders (TMD) are the most common nonodontogenic cause of orofacial pain, leading to morbidity and impairment. TMD presents a diagnostic challenge due to many aetiologies that exhibit comparable symptoms and refer pain to the temporomandibular joint (TMJ) region. Patients may be referred to dental specialists without accounting for all pain sources. This study aims to identify radiographic confounders (RCs) that can be mistaken for TMD in patients undergoing TMJ assessment using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

A review of 369 CBCT oral maxillofacial radiology reports of the TMJ acquired between July 2020 and June 2023 was completed. Pertinent RCs were classified as endodontic lesions, impacted dentition, sinus pathologies, root fractures, soft tissue calcifications, and others. The chi-squared test assessed the significance of the relationship between RCs and patient variables.

RESULTS

A total of 283 RCs were identified in 202 of the 369 cases (54.7%). The most frequent findings included sinus abnormalities (32.5%), endodontic lesions (15.2%), impacted dentition (12.7%), and elongated/calcified stylohyoid process (9.2%). Significant associations were found between sinus pathologies with TMD signs (P = .009) and gender (P = .001).

CONCLUSION

Our results indicate that RCs that mimic TMD-related symptoms are prevalent in patients referred for TMJ CBCT imaging.

CLINICAL RELEVANCE

Clinicians should be aware of these RCs when diagnosing complaints related to the TMJ. We recommend clinicians first obtain dental clearance and investigate all other potential sources of a patient's complaint before initiating referrals to avoid unnecessary costs and delays in patient care.

Evaluation of anatomical variants and pathological findings of the maxillary sinus prior to sinus floor elevation: A Cone Beam CT retrospective study in 660 patients

Background

Maxillary sinuses may present a wide spectrum of anatomical variations and pathological lesions whose recognition is mandatory for the clinician, especially prior to any surgical intervention in the area, such as in cases of sinus floor elevation. The goal of this study was the evaluation, mapping and prevalence of sinus anatomical variants and pathoses in Cone Beam Computed Tomography (CBCT) scans of dental patients.

Material and Methods

660 CBCT examinations of adult patients involving both sinuses were obtained (between 2017 and 2023) and analyzed. The following anatomic variants and pathologic findings were evaluated: antral septa (AS), posterior superior alveolar artery (PSAA), sinus hypoplasia, sinusitis, odontogenic cysts, retention cysts, antroliths, and various less common lesions (e.g.: benign fibro-osseous dysplastic lesions, neoplasms etc.). Investigation of the association of the findings with patients' age and gender was performed using the Chi-square test (X2), Fisher's exact test, t-test, and ANOVA (P<0.05). Differences in prevalence between findings, based on their location (right and/or left sinus), were investigated using z-test and t-test.

Results

AS were found in 38.6%, and PSAA was identifiable in 90.2% (mean distance from the sinus floor=6.44 mm) of the patients respectively. 3% of patients had hypoplasia, 15.6% sinusitis, 2.7% odontogenic cysts, 16.1% retention cysts, 8.6% antroliths, and 1.7% uncommon lesions (e.g. malignant neoplasms and fibrous dysplasia). A statistically significant association was found between gender and PSAA diameter, PSAA distance from the sinus floor, hypoplasia, sinusitis, and retention cysts, as well as a statistically significant association between age and PSSA diameter and sinusitis.

Conclusions

The prevalence of various anatomical variants and pathologic findings of the maxillary sinus did not differ based on their location. However, some of these findings appear to be related to either gender or age. CBCT is a valuable diagnostic tool to identify various anatomical variants and pathological findings of the maxillary sinus. Key words:Sinus, anatomy, pathology, CBCT.

Association between maxillary sinus floor perforation by dental implants and mucosal thickening: A cone-beam computed tomography study

OBJECTIVE

To investigate the association of perforation of the maxillary sinus floor by dental implants with mucosal thickening and to describe its characteristics in perforated cases.

STUDY DESIGN

One-hundred and twenty-nine maxillary sinuses of 93 patients presenting 202 dental implants in the maxillary posterior region were retrospectively assessed in cone-beam computed tomography scans and classified according to maxillary sinus perforation, bone graft, mucosal thickening, and mucosal appearance. Logistic regression determined the chance of mucosal thickening in perforated maxillary sinuses. The chi-square test compared categorical variables between maxillary sinus perforated or not by implants and maxillary sinus with or without mucosal thickening. The significance level assumed was 5 % (α = 0.05).

RESULTS

There was perforation of 60 maxillary sinuses floor (46.5 %) by 74 dental implants. The chance of mucosal thickening was higher when the implant tip was trespassing on the maxillary sinus floor (p < 0.001). There was a significant association between maxillary sinus mucosal thickening and perforation by a dental implant with the tip trespassing the maxillary sinus floor (p < 0.05).

CONCLUSION

Maxillary sinus mucosal thickening is associated with sinus floor perforation by dental implants and does not depend on the number of implants perforating it.

CLINICAL RELEVANCE

There is an association between dental implants' perforation of the maxillary sinus floor and the thickening of the maxillary sinus. In those cases, the appearance of the mucosa thickening may be irregular, local, or total opacification of the sinus cavity.

Artificial intelligence system for automatic maxillary sinus segmentation on cone beam computed tomography images

OBJECTIVES

The study aims to develop an artificial intelligence (AI) model based on nnU-Net v2 for automatic maxillary sinus (MS) segmentation in cone beam computed tomography (CBCT) volumes and to evaluate the performance of this model.

METHODS

In 101 CBCT scans, MS were annotated using the CranioCatch labelling software (Eskisehir, Turkey) The dataset was divided into 3 parts: 80 CBCT scans for training the model, 11 CBCT scans for model validation, and 10 CBCT scans for testing the model. The model training was conducted using the nnU-Net v2 deep learning model with a learning rate of 0.00001 for 1000 epochs. The performance of the model to automatically segment the MS on CBCT scans was assessed by several parameters, including F1-score, accuracy, sensitivity, precision, area under curve (AUC), Dice coefficient (DC), 95% Hausdorff distance (95% HD), and Intersection over Union (IoU) values.

RESULTS

F1-score, accuracy, sensitivity, precision values were found to be 0.96, 0.99, 0.96, 0.96, respectively for the successful segmentation of maxillary sinus in CBCT images. AUC, DC, 95% HD, IoU values were 0.97, 0.96, 1.19, 0.93, respectively.

CONCLUSIONS

Models based on nnU-Net v2 demonstrate the ability to segment the MS autonomously and accurately in CBCT images.

Autologous leucocyte and platelet rich in fibrin (L-PRF) - is it a competitive solution for bone augmentation in maxillary sinus lift? A 6-month radiological comparison between xenografts and L-PRF

Maxillary lateral sinus floor elevation, or external sinus lift, is a widespread surgical intervention in the dental field. Insertion of implants in the posterior region of the maxilla often requires reconstruction of the remaining native bone that has insufficient volume.

Background and aims

Much of the research published involves using artificial products, like xenografts and resorbable collagen membranes, after a prior Cone Beam Computer Tomography (CBCT) investigation. Nowadays, more accessible access, less financial costs, a biological approach, and faster healing are objectives that surround this procedure. Leucocytes and platelets rich in Fibrin (L-PRF) are a natural component with a high concentration of growth factors. Due to its regenerative properties and lack of complications, it is used in several medical fields, like orthopedics, dermatology, and oral surgery. This retrospective study aims to compare results in bone height and volume obtained through external sinus lift, either by using xenografts or autologous plasma rich in fibrin, by evaluating the quantity of new bone formation from a radiological point of view.

Methods

Fifty-eight Caucasian patients were included in this retrospective study; 48 were submitted to xenograft procedure, and 10 were selected for L-PRF grafting material with simultaneous implant placement. Lack of clinical and histological studies performed on patients with L-PRF surgeries limited us in choosing a larger group for the radiological analysis. CBCT evaluation was performed before surgery and 6 months after. All patients selected for the study presented good general and oral health, acute oral and sinus infections excluded; smoking and periodontal disease were also criteria of exclusion. Two operators performed the measurements in pre-established landmarks in different time frames. The two independent groups were compared with the Wilcoxon rank-sum test for quantitative data. Qualitative characteristics were described as counts and percentages. All analyses were performed in an R environment for statistical computing and graphics.

Results

Mean bone height gain in the xenograft group in the regions was as follows: 7.44 for the anterior landmark, 12.14 for the median and 8.28 for the distal. The mean group height gained for the L-PRF group was 0.1 anteriorly, -0.18 for the median measurement, and 0.23 distally. We obtained excellent overall reliability for all the height measurements between the two operators.

Conclusions

Further studies must be conducted to establish new sets of surgical protocols in case L-PRF alone is found to be a reliable, stable, biological alternative to the well-documented xenografts in external sinus lifts. Radiological results, although promising, must be further applied in long term clinical survival of the implants in the grafted sites. Also, studies combining L-PRF in conjunction with xenograft might bring improved clinical results in terms of reduced postoperative complications and accelerated healing.

A Cone Bean Computer Tomography Investigation of the Newly Formed Mandibular Anterior Ridge following the Treatment of an Extended Comminuted Fracture: A 12-Year Follow-Up

Introduction

Extensive comminuted fractures are associated with tooth loss that ultimately leads to dimensional changes in the hard and soft tissues of the alveolar ridge. Reconstruction of the lost mandibular anterior ridge is very complex due to the natural curvature of the region. Case Presentation. In this case report, the combination of the modified shell technique with autologous bone plates and the guided bone regeneration (GBR) technique was performed on an 18-year-old patient after a comminuted fracture, to ensure new bone formation in the anterior ridge with a natural curvature. After the treatment progressed without complications, three dental implants were placed. Annual cone beam computed tomography (CBCT) images were obtained and evaluated using the GNU Image Manipulation Program (GIMP© 2.10). This allowed measurements of the buccal and lingual bone around the implants, showing the annual bone loss in a twelve-year observation period. Discussion. The treatment of the comminuted fracture and the combination of the modified shell technique with autologous bone plates, the GBR technique, and implant placement can be considered successful. The three dental implants were osseointegrated in 2010, with the buccal bone level averaging 1.31 mm below the implant shoulder and the lingual bone level 1.57 mm above the implant shoulder. In 2021, the measurements showed a bone loss of 0.99 mm at the buccal implant shoulder and 0.69 mm at the lingual implant shoulder.

Conclusion

The combination of the modified shell technique with autologous bone plates and the GBR technique is a reliable method to ensure new bone formation in the anterior ridge. The use of CBCT is an excellent method to evaluate bone resorption around dental implants, but due to minimal bone resorption in the observation period, an annual CBCT examination is exaggerated.

Change in Maxillary Sinus Mucosal Thickness in Patients with Preoperative Maxillary Sinus Mucosal Thickening as Assessed by Otolaryngologists: A Retrospective Study

Background and Objectives: Maxillary sinus pathologic conditions may increase the risk of complications during posterior maxillary sinus augmentation surgery. The purpose of this study was to evaluate the changes in participants with preoperative maxillary sinus mucosal thickening and to assess this factor as a preoperative risk indicator for sinusitis after maxillary dental implantation. Materials and Methods: We compared the preoperative and postoperative maxillary sinus mucosal thickness (MSMT), the distance between the maxillary sinus ostium and sinus floor (MOD), and the MSMT/MOD ratio. The participants were divided into three groups (sinus augmentation, bone grafting, and no grafting). Results: The mean preoperative MSMT was 4.3 ± 2.0 mm, and the mean MSMT/MOD ratio was 0.13 ± 0.05. No postoperative sinusitis was observed in these patients, including cases caused by anatomical variations. The mean postoperative MSMT was 4.5 ± 2.3 mm, and the mean postoperative MSMT/MOD ratio was 0.15 ± 0.06. There was no statistically significant difference between the groups at each time point (p > 0.05). Conclusions: The study found no significant change in MSMT at post-treatment evaluation, even when considering different subgroups. It underscores the importance of preoperative maxillary sinus radiographic assessments and collaboration between dentists and otolaryngologists for better outcomes in patients with preoperative maxillary sinus mucosal thickening.

The Impact of Maxillary Sinus Pneumatization on the Quality of the Alveolar Bone in Dentated and Edentulous Patients: A Cone-Beam Computed Tomography Radiographic Analysis

Background This study aimed to describe the morphometric differences of maxillary alveolar bone's height, width, and densitometric differences in the posterior region where maxillary sinus pneumatization occurred. Methodology A cross-sectional, cone-beam computed tomography (CBCT) study used 123 CBCT images as a non-randomized convenient sample of sinus pneumatized cases. Bone height, bone width (in mm), and average density of the remaining ridge of all patients were used as study variables. Analysis of the qualitative variables were as frequency and percentages. Parametric Student's t-test and non-parametric chi-squared tests were used to compare the groups. The significance level was set at a p-value ≤0.05. Results The sample included CBCT radiographs for patients who had a mean age of 42.79 ± 12.32 with males constituting 69 (56.1%) of the patients. There was no gender difference between the present and missing teeth at the measured sites of the first premolar, second premolar, first molar, and second molar (p > 0.05). The mean measurements of height and average bone density were significantly higher in the dentate sites; however, the mean width was higher in the edentulous sites (p = 0.001). Conclusions Average bone height and density were significantly decreased at the edentulous sites of sinus pneumatized cases than the dentate sites with no gender difference.

The CBCT Retrospective Study on Underwood Septa and Their Related Factors in Maxillary Sinuses-A Proposal of Classification

Introduction. The presence of bone septum in the maxillary sinus is one of the most common anatomical findings. So-called Underwood septa (US) are an atypical bone formation in the maxillary sinuses. Mostly they are quite easily found in CBCT studies and have major importance in sinus lift procedures in dental surgery. Furthermore, the shape, location, and size of the bony septa are important in each maxillary sinus surgery. Material and methods. A retrospective study of 120CBCT scans from the authors' own database was conducted. Results. Approximately 37.5% of each CBCT was associated with the occurrence of US, while just 25% had a full septum, and a total of only 14 patients had a half septa. More females have US, while healthy pneumatized maxillary sinus is most commonly found (82.22%). There is no correlation between the occurrence of silent sinus syndrome (p = 0.174), mucosal thickening (p = 0.325), or retention cyst formation (p = 0.272). Most sinuses are without any opacification in CBCT evaluation (91.11%), while other syndromes are not statistically relevant. Conclusions. It seems that the occurrence of Underwood septa is not statistically related to any clinical, radiological, or pathological condition within the sinus (p > 0.05). Furthermore, a more full or partial appearance of US was found in female patients.

Application of Cone Beam Computed Tomography in Risk Assessment of Lower Third Molar Surgery

Risks of lower third molar surgery like the inferior alveolar nerve injury may result in permanent consequences. Risk assessment is important prior to the surgery and forms part of the informed consent process. Traditionally, plain radiographs like orthopantomogram have been used routinely for this purpose. Cone beam computed tomography (CBCT) has offered more information from the 3D images in the lower third molar surgery assessment. The proximity of the tooth root to the inferior alveolar canal, which harbours the inferior alveolar nerve, can be clearly identified on CBCT. It also allows the assessment of potential root resorption of the adjacent second molar as well as the bone loss at its distal aspect as a consequence of the third molar. This review summarized the application of CBCT in the risk assessment of lower third molar surgery and discussed how it could aid in the decision-making of high-risk cases to improve safety and treatment outcomes.

Current Applications of Deep Learning and Radiomics on CT and CBCT for Maxillofacial Diseases

The increasing use of computed tomography (CT) and cone beam computed tomography (CBCT) in oral and maxillofacial imaging has driven the development of deep learning and radiomics applications to assist clinicians in early diagnosis, accurate prognosis prediction, and efficient treatment planning of maxillofacial diseases. This narrative review aimed to provide an up-to-date overview of the current applications of deep learning and radiomics on CT and CBCT for the diagnosis and management of maxillofacial diseases. Based on current evidence, a wide range of deep learning models on CT/CBCT images have been developed for automatic diagnosis, segmentation, and classification of jaw cysts and tumors, cervical lymph node metastasis, salivary gland diseases, temporomandibular (TMJ) disorders, maxillary sinus pathologies, mandibular fractures, and dentomaxillofacial deformities, while CT-/CBCT-derived radiomics applications mainly focused on occult lymph node metastasis in patients with oral cancer, malignant salivary gland tumors, and TMJ osteoarthritis. Most of these models showed high performance, and some of them even outperformed human experts. The models with performance on par with human experts have the potential to serve as clinically practicable tools to achieve the earliest possible diagnosis and treatment, leading to a more precise and personalized approach for the management of maxillofacial diseases. Challenges and issues, including the lack of the generalizability and explainability of deep learning models and the uncertainty in the reproducibility and stability of radiomic features, should be overcome to gain the trust of patients, providers, and healthcare organizers for daily clinical use of these models.