Computed tomography measurements of different dimensions of maxillary and frontal sinuses

EVALUATION OF MAXILLARY SINUS VOLUME BY CONE BEAM COMPUTED TOMOGRAPHY IN ASTHMA PATIENTS

OBJECTIVE

The study aims to evaluate maxillary sinus volume in asthmatic patients.

METHODS

Patients who applied to the faculty of dentistry between January 2014 and December 2023 were retrospectively screened. Cone beam computed tomography images of 312 maxillary sinuses (156 people) consisting of asthmatic patients and controls were included in the study. Radiographic images in the study were obtained with a Newtom 5G (FP, Quantitative Radiology, Verona, Italy) cone beam computed tomography device. SimPlant Pro 16 program (Materialise NV, Leuven, Belgium) measured maxillary sinus volumes. SPSS 25.0 software (IBM SPSS, Inc.) was used to analyze statistical data.

RESULTS

As a result of the tests, the right and left maxillary sinus volumes of asthmatic patients were significantly smaller than the control group. No significant relationship was found between age and maxillary sinus in both the study and control groups. Gender distribution was equal between the groups. There was no significant difference between the groups in terms of age. No significant difference was found between the right and left maxillary sinus volumes.

CONCLUSION

Considering that there is no other study in the literature measuring maxillary sinus volume in asthmatic patients, this study may guide future research.

Volumetric analysis of maxillary sinuses for gender determination: Manual vs.3D segmentation

The effectiveness of manual calculations versus 3D segmentation techniques in volumetric analysis of maxillary sinuses for gender determination is of interest. Maxillary sinuses, which vary anatomically due to factors like age, ethnicity, and gender, are crucial in forensic and anthropological contexts. Traditional methods, relying on two-dimensional imaging, are often time-consuming and prone to errors, whereas 3D segmentation offers a more precise and efficient approach. This research evaluates both methods in terms of reliability, accuracy, and practical use, potentially influencing their application in clinical and forensic settings. The findings may also enhance understanding of anatomical variations in maxillary sinuses across populations, contributing to more accurate gender determination.

Cephalometric Analysis of Maxillary Sinus for Gender Determination Using Lateral Cephalogram: A Novel Retrospective Study in the North Indian Population

BACKGROUND

Underlying disorders of the maxillary sinus (MS), including a history of sinus surgeries, chronic sinusitis, or congenital anomalies can potentially impact sinus function and structure, necessitating careful evaluation and management. Moreover, intact sinuses are crucial in gender determination in forensic anthropology. The present study was undertaken to check the accuracy and reliability of MS in gender determination using morphometric parameters.

MATERIALS AND METHODS

This retrospective study was carried out on 74 lateral cephalograms (37 males and 37 females) aged between 18 to 50 years from the North Indian population. The MS area was measured using a NewTom CBCT machine (NewTom, Imola, Italy) with slicer software. The anatomical landmarks for the sinus were identified, and the area was calculated in square millimeters (mm2).

RESULTS

In terms of surface area, females had a mean of 13,210.40 mm2 with a standard error of 713.46. Males, however, exhibited a higher mean surface area of 18,713.82 mm2, but with a significantly larger standard error of 3,371.70. The difference in MS area between males and females was statistically significant (p<0.01). In the receiver operating characteristic (ROC) curve, the area under the curve (AUC) was 0.77, suggesting good discriminative ability.

CONCLUSION

The MS area on lateral cephalograms shows significant sexual dimorphism. Overall, the findings suggest that the MS surface area can be a useful anatomical feature for distinguishing between male and female North Indian subjects, given the statistically significant difference and the good discriminative performance indicated by the ROC curve analysis.

Human identification: an investigation of 3D models of paranasal sinuses to establish a biological profile on a modern UK population

Medical imaging is a valuable source for facilitating empirical research and provides an accessible gateway for developing novel forensic anthropological methods for analysis including 3D modelling. This is especially critical for the United Kingdom (UK), where methods developed from modern UK populations do not currently exist. This study introduces a new approach to assist in human identification using 3D models of the paranasal sinuses. The models were produced from a database of 500 modern CT scans provided by University College London Hospital. Linear measurements and elliptic Fourier coefficients taken from 1500 three-dimensional models across six ethnic groups assessed by one-way ANOVA and discriminant function analysis showed a range of classification rates with certain rates reaching 75-85.7% (p < 0.05) in correctly classifying age and sex according to size and shape. The findings offer insights into the potential for employing paranasal sinuses as an attribute for establishing the identification of unknown human remains in future crime reconstructions.

Evaluation of maxillary sinus changes following molar distalization using clear aligners: A three-dimensional study

OBJECTIVE

To evaluate the impact of molar distalization with clear aligners (CAs) on maxillary sinus parameters and its proximity to the root apices of maxillary molars using Cone Beam Computed Tomography (CBCT).

METHODS

The study involved pre- and post-treatment CBCT images of 27 adult patients. MIMICS 21.0 software was used to measure maxillary sinus volume and surface area, while Invivo Dental 6.0 program was used to measure the sinus diameters and proximity of the maxillary molar root apices to the sinus floor.

RESULTS

Post-treatment, there was a marked increase in the average volume and surface area of the maxillary sinus on both sides; however, changes in dimensions were not statistically significant. Sinus proximity to the root apices of the maxillary molars showed statistically significant differences, particularly on the left side for all roots. Gender and age impacted the outcomes, with males and younger individuals showing more pronounced changes. No significant differences were observed between the left and right sinuses in all parameters.

CONCLUSION

Molar distalization with CAs increases maxillary sinus parameters, more notably in younger and male patients. All molar teeth roots moved toward the sinus, particularly the mesiobuccal root of the maxillary second molar protruded to the sinus.

Computed Tomography Evaluation of Frontal Sinus Volume in Migraine Patients

This study aimed to assess the frontal sinus volume (FSV) on computed tomography (CT) scans in migraine patients. Cranial and paranasal CT images from 75 migraine patients (mean age: 39.14±13.63 y) and 23 control cases (mean age: 38.78±13.32 y) were analyzed retrospectively. Three-dimensionally reconstructed images of frontal sinuses were generated. Total FSV, anterolateral, and transverse diameters of the head were measured. The presence/absence and nature of supraorbital foramen and notches were evaluated. The total FSV was 8.02±5.97 cm 3 in the migraine group and 8.38±4.83 cm 3 in the control group, with no significant differences between them. Mean FSV values showed no statistically significant difference between females (7.79±5.85 cm 3 ) and males (9.12±6.66 cm 3 ) within and between the groups. Single notch was the most observed structure in both groups, with bilateral presence being the most common. Double foramen and notch were observed only in the migraine group, and the coexistence of both structures was higher in the migraine patients than in controls. There was no statistical difference in FSV between migraine and control groups, nor based on sex. Overall, the frontal region anatomy, particularly the exit locations of the supraorbital or supratrochlear foramen/notches, may be influenced by hyperplasia/hypoplasia of FSV. Therefore, assessing FSV using CT may be crucial for surgical planning in migraine patients undergoing open or endoscopic approaches to the frontal region.

Radiographic assessment of maxillary sinus membrane and lateral wall thickness using cone-beam CT in different facial types in southwestern Saudi Arabia

The anatomy of the edentulous posterior maxilla and maxillary sinus possess unique challenges in implant dentistry. The purpose of this study was to assess maxillary sinus membrane thickness (MT) and lateral wall thickness (LWT) in different facial index profiles and to describe the clinical implications. A retrospective image analysis of 75 CBCT scans was done, which yielded a total of 150 sinus images. The facial index was calculated as per the formula given in the text and grouped as euryprosopic, mesoprosopic and leptoprosopic. The images obtained were of 36 women (48%) and 39 men (52%), with maximum subjects in 30-39 years age group. MT and LWT were measured at three different points on the radiograph at every 3mm from the base of the sinus floor in premolar and molar regions of each image. Results showed females had significant differences from males in LWT in both premolar and molar regions (p = 0.018 and 0.032 respectively). Subjects in 40-49 years of age had significant differences (p = 0.021) in MT in premolar region only. Also, difference in MT in premolar and molar regions were also statistically significant. Lastly, the present study did not find any statistically significant difference in MT and LWT in all three facial indices groups. It can be concluded that different facial indices have no positive correlation with maxillary sinus membrane thickness and lateral wall thickness. Hence, surgical complications are avoidable with proper detailed knowledge and appropriate identification of the anatomic structures characteristic to the maxillary sinus.

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.

Sex Estimation From the Paranasal Sinus Volumes Using Semiautomatic Segmentation, Discriminant Analyses, and Machine Learning Algorithms

ABSTRACT

The aims of this study were to determine whether paranasal sinus volumetric measurements differ according to sex, age group, and right-left side and to determine the rate of sexual dimorphism using discriminant function analysis and machine learning algorithms. The study included paranasal computed tomography images of 100 live individuals of known sex and age. The paranasal sinuses were marked using semiautomatic segmentation and their volumes and densities were measured. Sex determination using discriminant analyses and machine learning algorithms was performed. Males had higher mean volumes of all paranasal sinuses than females ( P < 0.05); however, there were no statistically significant differences between age groups or sides ( P > 0.05). The paranasal sinus volumes of females were more dysmorphic during sex determination. The frontal sinus volume had the highest accuracy, whereas the sphenoid sinus volume was the least dysmorphic. In this study, although there was moderate sexual dimorphism in paranasal sinus volumes, the use of machine learning methods increased the accuracy of sex estimation. We believe that sex estimation rates will be significantly higher in future studies that combine linear measurements, volumetric measurements, and machine-learning algorithms.

Maxillary sinus in gender determination: a morphometric analysis using cone beam computed tomography

Gender determination of skeletal remains is an important forensic procedure in the identification process. Maxillary sinus remains intact even when the skull and other bones may be badly disfigured. Cone beam computed tomography (CBCT) can provide precise information about complex anatomical structures, as it is characterized by rapid volumetric image acquisition with high resolution. The present study aimed to assess the accuracy of maxillary sinus measurements using cone beam computed tomography in gender determination and to develop a formula using discriminate function analysis. Bilateral maxillary sinus images (left and right) were acquired for 200 patients (100 females and 100 males) and different parameters (width, length, height, area, perimeter, and volume) were measured and evaluated. Mean and standard deviation of both maxillary sinuses measurements were calculated and compared. The data was subjected to discriminative statistical analysis and analyzed using an unpaired t-test. The difference between all these variables was statistically significant between males and females. Based on discriminant analysis, the most pronounced variable in the differentiation of gender groups was maxillary sinus height. Gender assessment was established correctly with an accuracy of 75% for females and 64% for males with an overall accuracy of 69.5%. Adding other independent variables to the model did not result in an improvement in overall accuracy. Cone beam computed tomography measurement of maxillary sinus can be used as an aid in forensic anthropology for gender determination.

Volumetric Changes of the Paranasal Sinuses with Age: A Systematic Review

BACKGROUND

There are four pairs of paranasal sinuses: maxillary, ethmoidal, frontal, and sphenoidal. It is common to see changes in size and shape throughout life, so understanding the effect of age on sinus volume can help in radiographic studies and in planning dental and surgical procedures in the sinus-nasal region. The aim of the present systematic review was to perform a qualitative synthesis of available studies which assess the volumetric characteristics of the sinuses and their changes according to age.

MATERIALS AND METHODS

The present review followed PRISMA 2020 guidelines. A systematic advanced electronic search was performed in five databases (Medline (via PubMed), Scopus, Embase, Cochrane, and Lilacs) in June-July 2022. Studies that assessed the volumetric changes of paranasal sinuses with age were eligible for inclusion. A qualitative synthesis of the methodology and results of the included studies was performed. Quality assessment was performed using the NIH quality assessment tool.

RESULTS

A total of 38 studies were included in the qualitative synthesis. Most authors who studied the maxillary and ethmoidal sinuses concluded that it begins its development from birth until the maximum peak of growth, from which it begins to decrease in volume with age. Results regarding the volumetric changes of the frontal and sphenoidal sinuses are mixed.

CONCLUSIONS

Based on the results of the studies included in the present review, it can be concluded that the volume of the maxillary and ethmoidal sinus appears to decrease with age. Conclusions on the volumetric changes of the sphenoidal and frontal sinuses require further evidence.

Three-dimensional evaluation of the maxillary sinus in patients with different skeletal classes and cranio-maxillary relationships assessed with cone beam computed tomography

The objective was to evaluate the relationship between the dimensions of the maxillary sinuses (MSs) and various cephalometric parameters. MS volume (MSV), MS surface (MSS), linear maximum depth (LMD), linear maximum width (LMW), and linear maximum height (LMH) were calculated on CBCT scans of 99 adults. Two sets of two-way (ANOVA) assessed the influence respectively of ANB and SNA angles and of the gender on MS dimensions. Pearson's correlation was calculated between MS dimensions and different cephalometric variables. Reliability and accuracy of the proposed method was tested with intra-operator and inter-operator intraclass correlation coefficient (ICC). Two-way ANOVA showed no statistically significant difference in MSV, MSS and LMH between ANB groups, whilst males were associated with bigger sinuses. LMW showed statistically significant difference in both ANB and gender groups. LMD showed no statistically significant difference. The second Two-way ANOVA showed significantly larger MSV, MSS and LMD in patients with increased or reduced SNA angle but not between genders. LMW and LMH also showed a significant difference between genders. All linear measurements showed a significant interaction of the two factors. The intra-observer and inter-observer ICC scored high for all the tested measurements. MSV and MSS showed a positive correlation with S-N, PNS-A, S-Go, N-Me, N-Ans and the distance between Mx points. LMW had a negative correlation with Ba-S-N angle and N-Me, LMH with Ba-S-N angle, S-Go and Mx r-Mx l and LMD with N-Me and N-ANS. LMW had a positive correlation with Mx r-Mx l, LMH with S-N, S-N^Ans-Pns, N-Me, N-Ans and LMD with S-N, Ba-S-N, PNS-A, S-Go and distance between Mx points. In conclusion, MSV and MSS did not differ between the three skeletal classes, males showed significantly larger MS than in females. Concerning the influence of the cranio-maxillary relationship (SNA) and gender on MS dimension, subjects with a retrusion (SNA < 80°) or protusion (SNA > 84°) of the maxillary alveolar bone had larger MSV, MSS, LMW, LMH and LMD than subjects with a normal cranio-maxillary relationship (SNA 82 ± 2°). A statistically significant high positive correlation was observed between S-N, Pns-A, S-Go, Mx-R/Mx-r and MS dimension. Further studies that evaluate similar outcomes in different races may be able to enrich our knowledge on this topic.

Does maxillary sinus size affect the risk for zygomatic complex fractures?

The purpose of the study was to measure the maxillary sinus sizes in patients with and without zygomatic bone fractures. In this cross-sectional study computed tomography data of a case group of consecutive treated patients with displaced zygomatic bone fractures were compared to a control group with mandibular fractures. Maxillary sinus sizes were measured in width, height, depth, and volume. We compared sinus sizes between the case and control group, followed by a subgroup analysis of slightly and severely displaced fractures using T-tests. We identified 89 cases, thereof 46 with slightly and 43 with severely displaced fractures. The control group consisted of 110 patients. The mean sinus volume of the case group (19,313 mm³  ± 5237) was significantly larger than in the control group (17,645 mm³  ± 4760; p = 0.02). Subgroup analyses revealed that this difference in volume was more pronounced between patients with severely displaced fractures (20,354 mm³  ± 5416; p = 0.003) and the control group. In two-dimensional measures, only sinus height was significantly greater in the case group (37.41 mm ± 4.25 vs. 35.33 mm ± 4.88; p = 0.002). The same holds for the subgroup with severely displaced fractures (38.27 mm ± 3.91; p = 0.001). Sinus width and depth showed no significant differences between the groups. A maxillary sinus volume larger than 20,000 mm³ is a predictive risk factor for a displaced zygomatic bone fracture. Greater sinus height indicates a larger surface area of the zygomaticomaxillary buttress that decreases the resistance to facial trauma.

Human maxillary sinus size, shape, and surface area: Implications for structural and functional hypotheses

OBJECTIVES

Although research into human maxillary sinus (MS) morphology has overwhelmingly focused on sinus volume, other aspects of morphology (e.g., overall shape, mucosal surface area) factor prominently in hypotheses regarding MS form and function. Here, we investigate MS volume in conjunction with measures of MS shape and surface area in a large, diverse sample of modern humans. We test whether variation in MS volume is associated with predictable changes in MS shape (i.e., allometry) and investigate the influence of MS size-shape scaling on mucosal surface area dynamics.

MATERIALS AND METHODS

Measures of MS volume and surface area were obtained from computed tomographic (CT) scans of 162 modern human crania from three ancestral backgrounds-Equatorial Africa, Europe, and East Asia. 3D coordinate landmarks and linear measurements were also collected. Multivariate analyses were employed to test for associations between MS volume and other morphological variables.

RESULTS

Significant associations between MS volume and 3D shape were identified both across and within the subsamples. Variation in MS volume was found to predominantly relate to differences in MS height and width dimensions relative to MS length. This pattern of allometric scaling was found to differentially influence total mucosal surface area and the SAV ratio.

CONCLUSION

This study suggests that variation in MS volume is disproportionately mediated by MS width and height dimensions. This finding has implications for hypotheses which structurally link MS morphology to craniofacial ontogeny and those which suggest that MS morphology may perform adaptive physiological functions.

Flexible endoscopy in the visualization of 3D-printed maxillary sinus and clinical application

Background

During postoperative follow-up, the visible range of maxillary sinus (MS) is limited, even combining 0° and 70° rigid endoscopes together. Flexible endoscope has been used in larynx examinations for a long time, but rarely in nasal cavity and sinus. We aimed to evaluate the application values of rigid and flexible endoscopes for visualization of MS.

Methods

We followed up 70 patients with lesions in MS via both rigid and flexible endoscopes. In addition, we used thin-slice CT image of the sinus to create a MS model and divided it into two parts for 3D printing. The inner surface of the 3D-printed sinus was marked with grid papers of the same size (5 mm × 5 mm), then the visual range under rigid endoscopes with different angle and flexible endoscopes was calculated and analyzed.

Results

In clinical follow-up, we found that flexible endoscopy can reach where rigid endoscopy cannot, which is more sensitive than medical imaging. Endoscopes showed the largest observation range of the posterolateral wall, more than half of which can be visualized by 0° endoscope. Almost all of the posterolateral wall can be revealed under 45° endoscope, 70° endoscope and flexible endoscope. The visual range of each wall under flexible endoscope is generally greater than that under rigid endoscopes, especially of the anterior wall, medial wall and inferior wall.

Conclusion

There was obviously overall advantage of using flexible endoscope in postoperative follow-up of MS lesions. Flexible endoscopy can expand the range of observation, and improve the early detection of the recurrent lesion. We recommend flexible endoscope as a routine application.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-022-09410-8.

Analysis of predisposing factors in unilateral maxillary sinus fungal ball: the predictive role of odontogenic and anatomical factors

BACKGROUND

The pathogenesis of maxillary sinus fungal ball (MSFB) is explained by aerogenic and odontogenic factors. We evaluated the predisposing factors, including intranasal anatomical and dental factors for increased diagnostic accuracy.

METHODOLOGY

In this study, 117 patients who underwent endoscopic sinus surgery for unilateral MSFB were included. Preoperative computed tomography (CT) scans were used to analyze the presence of anatomical variations (anterior and posterior nasal septal deviation (NSD), concha bullosa (CB), infraorbital cell (haller cell), paradoxical middle turbinate, everted uncinate process and MS size). Dental factors including history of dental procedures and findings on CT scans were reviewed.

RESULTS

Anterior and posterior NSD toward non-affected side were significantly associated with the presence of FB. The presence of CB and infraorbital cell was higher in the non-affected side rather than in the lesion side. Compared to non-affected MS, FB-presence MS was shallower and had a larger height to depth ratio. The presence of dental history was significantly higher on FB-presence MS than non-affected MS. In multivariable analysis, posterior NSD toward non-affected side, dental history increased the aOR of MSFB, while the presence of CB and infraorbital cell decreased the aOR of MSFB.

CONCLUSIONS

The occurrence of MSFB seems to be associated with ipsilateral odontogenic factors, followed by anatomic variations including posterior NSD toward non-affected side and absence of CB and infraorbital cell.

Three-dimensional linear and volumetric computed tomography analysis of the frontal sinus

The frontal sinus is one of the four paranasal sinuses in humans, and knowledge of its anatomy is important when performing surgery involving the frontal bone or sinus. Although many studies have measured the frontal sinus using radiography and computed tomography (CT), few studies have evaluated by using three-dimensional (3D) analysis. The purpose of this study was to analyze the frontal sinus using 3D reconstruction analysis and determine the differences in linear and volumetric measurements between sexes, sides, and ages. The sample comprised 281 facial CT scans: 173 and 108 from males and females, respectively. The width, height, and length of each frontal sinus and total volume were all larger in males than in females. Almost all linear and volumetric measurements were larger in young adults than in older for both sexes, but not all of the differences were statistically significant. Linear and volumetric measurements were larger for males than females regardless of age group. There were no statistically significant differences between the right and left sides except the width in males. The size of the frontal sinus was strongly influenced by sex and age. The measurements reported here might be useful for improving surgical procedures involving the frontal sinus.

Histomorphometric evaluation of different graft associations for maxillary sinus elevation in wide antral cavities: a randomized controlled clinical trial

OBJECTIVES

Pneumatization of the maxillary sinus can make it difficult, if not impossible, to install osseointegrated implants, and undertake their eventual functional rehabilitation, which may ultimately require regenerative techniques to achieve. This randomized controlled study proposed conducting a histological evaluation of the behavior of different graft materials in wide maxillary sinuses, at a height of 8 to 10 mm from the alveolar ridge, combined with bone remnants less than 3mm.

MATERIALS AND METHODS

Thirty-six patients underwent a sinus elevation procedure through the lateral window. The sinuses were randomly filled with the following materials (n=12/group): group 1, xenogenic bone + autogenous bone (ratio 70:30, respectively); group 2, xenogenic bone + L-PRF; and group 3, xenogenic bone. At 8 months, bone biopsies of engrafted sites were harvested and analyzed histomorphometrically in order to quantify newly formed bone tissue.

RESULTS

The results showed a greater area of newly formed bone for G1, averaging 2678.37 (1116.40) μm², compared with G2 at 984.87 (784.27) μm², and G3 at 480.66 (384.76) μm² (p < 0.05). Additionally, fewer xenogenic bone particles and a large amount of connective tissue were observed in G2.

CONCLUSIONS

In maxillary sinuses with large antral cavities, autogenous bone combined with xenogenic bone seems to demonstrate better graft remodeling and improve bone formation, compared with the addition of L-PRF.

CLINICAL RELEVANCE

L-PRF produces few advantages regarding new bone formation in the wide maxillary sinuses.

TRIAL REGISTRATION

Brazilian Clinical Trials Registry (REBEC) number RBR-2pbbrvg.

Fully Automatic Segmentation, Identification and Preoperative Planning for Nasal Surgery of Sinuses Using Semi-Supervised Learning and Volumetric Reconstruction

The aim of this study is to develop an automatic segmentation algorithm based on paranasal sinus CT images, which realizes automatic identification and segmentation of the sinus boundary and its inflamed proportions, as well as the reconstruction of normal sinus and inflamed site volumes. Our goal is to overcome the current clinical dilemma of manually calculating the inflammatory sinus volume, which is objective and ineffective. A semi-supervised learning algorithm using pseudo-labels for self-training was proposed to train convolutional neural networks, which consisted of SENet, MobileNet, and ResNet. An aggregate of 175 CT sets was analyzed, 50 of which were from patients who subsequently underwent sinus surgery. A 3D view and volume-based modified Lund-Mackay score were determined and compared with traditional scores. Compared to state-of-the-art networks, our modifications achieved significant improvements in both sinus segmentation and classification, with an average pixel accuracy of 99.67%, an MIoU of 89.75%, and a Dice coefficient of 90.79%. The fully automatic nasal sinus volume reconstruction system was successfully obtained the relevant detailed information by accurately acquiring the nasal sinus contour edges in the CT images. The accuracy of our algorithm has been validated and the results can be effectively applied to actual clinical medicine or forensic research.

A Replicable and Reproducible Digital Method for Quantifying Maxillary Sinus Airway Changes after Sinus Lifts Using the Lateral Window Approach Technique-A Retrospective Study

In the present retrospective study, we aimed to assess the replicability and reproducibility of a novel digital measurement technique for analyzing the volumes of the left and right maxillary sinuses and the nasal and maxillary sinus airway complex after a sinus lift procedure using the lateral window approach, to provide an accurate measurement technique for easily applying in clinical practice and to allow pre-operative assessment of maxillary sinus lift surgery, avoiding complications and making surgery more predictable. Material and Methods: Thirty patients with partially edentulous posterior maxilla were selected and submitted to bilateral sinus lift using the lateral window approach technique, with grafting materials selected and submitted to cone beam computed tomography (CBCT) scans, both pre- and postoperatively. Then, datasets were uploaded to therapeutic digital planning software to measure the volume of the right and left maxillary sinuses and the nasal and maxillary sinus airway complex. Gage R&R statistical analysis was performed to assess the replicability and reproducibility of the digital measurement technique. Results: The variability attributable to the novel digital measurement technique was 3.4% for replicability and 3.4% for reproducibility of the total variability of the samples. Conclusion: The novel digital method proposed is a replicable and reproducible technique for analyzing the volume of the right and left maxillary sinuses and the nasal and maxillary sinus airway complex after a sinus lift using the lateral window approach technique, allowing an accurate pre-operative assessment of maxillary sinus lift surgery, avoiding complications and making surgery more predictable.

Evaluation of available height, location, and patency of the ostium for sinus augmentation from an implant treatment planning perspective

Purpose

The objective of this study was to evaluate the amount of height available for a maxillary sinus augmentation procedure without blocking the ostium and jeopardizing the drainage of the ostiomeatal complex using cone-beam computed tomography (CBCT) imaging.

Materials and Methods

A total of 200 sinonasal complexes comprising 100 dentate and 100 edentulous scans were retrospectively assessed using CBCT. Invivo 5.0, a CBCT reconstruction program, was used for image evaluation. The coronal section demonstrating the ostiomeatal complex was selected as a reference view to perform measurements of the sinus. The measurements were done by 2 evaluators in separate sessions. Comparative analyses of measurements were performed between dentate and edentulous patients and between male and female patients.

Results

The safe height to which the sinus can be elevated without compromising the integrity of the ostiomeatal complex was calculated for each sinus. In the presence of significant mucosal thickening, the height available for augmentation was calculated by subtracting the height of mucosal thickening from the sinus floor to the location of the ostium. In this study, the available height was approximately 27.05 mm for dentate and 23.40 mm for edentulous patients. The inter-operator reliability was excellent for all the parameters evaluated.

Conclusion

This retrospective study with a limited number of patients from a single university-based site shows that CBCT is valuable in evaluating the location and patency of the ostium for planning sinus augmentation procedures for dental implant placement.

Development and validation of a new formula for sex estimation based on multislice computed tomographic measurements of maxillary and frontal sinuses among Brazilian adults

OBJECTIVES

To evaluate the accuracy of the measurements of the maxillary sinus (MS) and frontal sinus (FS) in sex estimation among Brazilian adults using multislice computed tomography (MCT) and to develop and cross-validate a new formula for sex estimation.

METHODS

The present cross-sectional research was conducted in two phases: (1) development of a formula on the basis of the measurements of both the sinuses (50 males and 50 females); and (2) validation study (20 males and 20 females). The linear measurements (height, width and diameter) were assessed using the RadiAnt DICOM software. A new formula for sex estimation was developed (multivariate statistical approach) and validated. Receiver operating characteristic curves, area under the curve, sensitivity, specificity, positive and negative predictive values, accuracy and likelihood ratio were estimated.

RESULTS

Males displayed higher mean values (width, height and diameter) of the FS and MS (p < 0.05). The MS was a better predictor in sex estimation (males vs females), compared to the FS (accuracy between 61-74% and 58-69%, respectively). The distance between the right and left MS displayed the highest accuracy (74%). The sensitivity, specificity and accuracy of the new formula were 80%, 95.5% and 87.5%, respectively. 63.1% reduction was observed in the number of predictive values for sex estimation (individuals older than 30 years).

CONCLUSIONS

The present MCT measurements showed a higher accuracy in the estimation of sex in males. The highest accuracy was associated with the distance between the right and left MS. The new formula displayed high precision for sex estimation.

Volumetric growth analysis of maxillary sinus using computed tomography scan segmentation: a pilot study of Indonesian population

The aim of this study is to investigate the volumetric measurements of the maxillary sinus among Indonesian population through computed tomography (CT) scan semi-automated segmentation. This project collected 802 retrospective head CT scan archives from Department of Radiology, Hasan Sadikin Hospital, Bandung, Indonesia between 2019-2020. Patients with craniofacial anomalies/pathology fracture in proximity of the maxillary sinuses, and mediocre image quality were excluded from this study resulting only 97 CT scan archives (194 maxillary sinuses; 52 males; 45 females; age range 0-25 years old). Three-dimensional craniofacial structures were reconstructed and volumetric measurements of the maxillary sinus were computed through semi-automated segmentation using ITK-SNAP. This study recorded the initial phase of maxillary sinus pneumatization during infancy. The maxillary sinus developed until reaching the maximum of average maxillary sinus volume at 13,278.73 mm³ in 16 to 20 years old group in which afterwards fell to 12,325.21 mm³. There was no difference found between right and left maxillary sinus volume. This study revealed that the pneumatization of maxillary sinus begin during infancy and climb until reaching the second decade of life, in which after that slowly decrease. Moreover, no difference between right and left maxillary sinus volume was detected. The volumetric dimension of maxillary sinus presented in this study may serve as the basis knowledge surgical intervention of maxillary sinus and its related structures.

The Comparison of Piriform Aperture, Paranasal Sinuses, and Cranial Dimensions

OBJECTIVE

Piriform aperture, paranasal sinuses, and the cranium dimensions were compared with each other and we investigated the alterations depending on the age and gender in these structures. Before the endoscopic sinus surgery, anatomic variations in sinusoidal region and the occurring differences should be considered. The detection of these variations plays important roles in the prevention of complications which may happen in surgery or in obtaining a successful surgical result.

MATERIALS AND METHODS

Piriform aperture maximum width, frontal sinuses, sphenoidal sinuses, maxillary sinuses, and cranium widths and height length was measured from the regions that we were determined. Three hundred ninety three cases' computed tomography images were compared. The individuals without any head trauma, pathology, and surgical history in sinusoidal region were analyzed retrospectively. The detected measurements were studied among the paranasal sinuses, piriform aperture, and calvaria dimensions.

RESULTS

It was observed that the dimensions of paranasal sinuses were decreased and the dimension of piriform aperture was increased depending on age. In all individuals, a relationship in positive direction in a manner that piriform aperture width increases as the size of the cranium width increases. Morphologic alterations take place in the dimensions of paranasal sinuses as a result of bone deformations occurring in the bone structure depending age and gender in adult individuals.

Assessment of the relationship between the maxillary sinus and the canine root tip using cone beam computed tomography

BACKGROUND

The purpose of the present study is to investigate the relationship between the maxillary sinus and the canine root apices in cone beam computed tomographic images (CBCT) and to assess the amount of extension of the maxillary sinus to the anterior region of the jaw in different sexes and age groups.

METHODS

CBCT of 300 individuals (154 males and 146 females) over 20 years (with a mean age of 35.12 ± 8.40 years) were evaluated. The subjects were categorized into three age groups (20-30, 30-40, and 40-50 years). When the maxillary sinus extended to the canine area, the vertical distance between them was measured, and their relationship was classified into three types: I (more than 2 mm distance), II (less than 2 mm distance or in-contact), and III (interlock).

RESULTS

413 out of 600 maxillary sinuses (68.8%) were extended into the canine area or beyond. Among them, 15 maxillary sinuses pneumatized into the incisor area (2.5%). The prevalence of the maxillary sinuses extended to the anterior region of the jaw was not significantly different between genders. However, it was significantly less frequent in the older age group and more frequent on the left side. In addition, the mean amount of anterior extension of the maxillary sinus (mm) was significantly lower in the older age group. Type I was the most frequent vertical relationship between the maxillary sinuses and canine apices with no significant difference in gender, side, and age groups.

CONCLUSIONS

In most cases, the maxillary sinus extended to the canine area and sometimes reached the incisor region. This necessitates paying more attention to the maxillary anterior sextant during surgical procedures.

Morphometric and volumetric evaluation of maxillary sinus in patients with chronic obstructive pulmonary disease using cone-beam CT

OBJECTIVES

The purpose of present study is to assess the maxillary sinuses patients with COPD morphometrically and volumetrically using cone-beam computed tomography (CBCT) images and compared these findings according to in age and gender of control groups.

METHODS

CBCT images of 80 individuals that exist from 40 patients with COPD and 40 healthy individuals (6 females, 34 males) in the tomography archive were retrospectively analyzed. The volume and surface area of maxillary sinuses in COPD and control group were measured by semi-automatic segmentation method and obtained findings were statistically examinated according to age, gender.

RESULTS

The study was observed that there was no statistically significant difference between the right maxillary sinus area and the groups, but left maxillary sinus and total sinus area of COPD group were observed to be significantly lower than the control group (p < 0.05). Maxillary sinus volume was found to be statistically significantly lower in patients with COPD than in healthy controls (p < 0.05).

CONCLUSIONS

CBCT is a practical and effective imaging method for the evaluation of maxillary sinuses. It is thought that inflammatory diseases that cause sinonasal changes such as COPD may affect maxillary sinus sizes.

[Automated system of the determination of maxillary sinus morphometric parameters]

THE AIM OF THE STUDY

Was to compare manual, semi-automatic and automatic methods for determining the maxillary sinus volume using cone beam computed tomography (CBCT).

MATERIAL AND METHODS

CBCT images from 48 patients (96 maxillary sinuses) with no history of sinus and alveolar bone surgery, who were presented to Minsk medical centers, were used in this study. Neural network training was performed on CBCT scans of 42 patients (84 maxillary sinuses).The height, depth and width of the sinus were measured manually on CBCT scans of 6 patients (12 maxillary sinuses). Maxillary sinus volume (V) was calculated by the formula: V=height´depth´1/3 width. Semi-automatic segmentation was carried out by an expert radiologist. The convolutional neural network technology was applied for maxillary sinus automatic segmentation.

RESULTS

The largest values were revealed by using the automatic method for sinus volume measurement. These values were within the 95% confidence interval (±4.29 cm³) of the average sinus volume obtained from semi-automatic method.

CONCLUSION

The data obtained using the convolutional neural network technique (artificial intelligence) has a high correlation with the results of sinus morphometric analysis acquired through manual and semi-automatic methods. Automatic maxillary sinus segmentation technique does not require special user knowledge. This method is reproducible and it is implemented in a short time interval.

Ancestry-based variation in maxillary sinus anatomy: Implications for health disparities in sinonasal disease

Paranasal sinus drainage is mediated by mucociliary transport and gravity. However, human orthograde posture, along with the superior positioning of the maxillary sinus (MS) ostium, increases reliance on the mucociliary system. Previous research has thus suggested that differences in MS size and shape may impede mucociliary clearance, potentially contributing to disparities in sinusitis susceptibility. To further investigate this hypothesis, this study collected 29 three-dimensional (3D) coordinate landmarks and seven linear measurements of MS morphology from 167 computed tomography (CT) scans of crania of European, East Asian, or Equatorial African ancestry. MANOVA results reveal the Asian-derived individuals are characterized by both a significantly taller MS (F = 14.15, p <  0.0001) and a significantly greater distance from the MS floor to the ostium (F = 17.22, p <  0.0001) compared to those of European and African ancestry. A canonical variate (CV) analysis conducted on 3D landmark data provides corroborative results, distinguishing Asian-derived individuals predominantly on the basis of a relatively lower MS floor. As a greater distance between the MS floor and ostium may impede mucociliary clearance, our results suggest MS anatomy may be a more prominent factor in chronic sinusitis among individuals of Asian ancestry compared to those of European and African ancestries. This provides tentative evidence of an anatomical etiology for chronic sinusitis even in the absence of anatomical variants/abnormalities (e.g., nasal polyps, concha bullosa, Haller's cells, and Agger nasi cells). Further research into the relationship between MS anatomy and sinusitis, in addition to socioeconomic inequalities of healthcare, is warranted to continue evaluating possible contributions to health disparities.

Volumetric Investigation of Sphenoid Sinus in an Elderly Population

The aims of this study were to determine the sphenoid sinus volume in an Austrian population, evaluate the relationship between volume and different types of pneumatization and investigate possible age-related sphenoid sinus volume degeneration in the elderly. A total of 50 human cadaver including 25 male and 25 female samples (=100 sphenoid sinuses, age range 65-100, mean age 84.52 ± 9.50) were selected to obtain volume and anatomical variants of pneumatization by using sphenoid sinus casts, made of quadrofunctional hydrophilic addition reaction silicone. The mean sphenoid sinus volume was 4.79 ± 2.39 cm. Males showed statistically significant larger sinus volumes than females (P = 0.048). The volume differed statistically significant for the different types of pneumatization (P < 0.001). The combined type of sphenoid sinus pneumatization presented the largest volume with 7.20 cm, followed by lateral, clival, sphenoid body, presellar, and conchal sinus type with 5.72, 5.63, 4.25, 2.08, and 0.5 cm, respectively. No significant correlation between age and sphenoid sinus volume was found (P = 0.707). This study highlights the close relationship between volume and morphology of sphenoid sinus and confirms ethnic variability. Moreover, our data shows no age-related volume degeneration.

The Risks of Complications During Endoscopic Sinus Surgery in Cystic Fibrosis Patients: An Anatomical and Endoscopic Study

OBJECTIVE/HYPOTHESIS

An increasing proportion of adult cystic fibrosis (CF) patients is being referred to endoscopic sinus surgery (ESS) in order to relieve the symptoms of chronic rhinosinusitis (CRS). Given that CFTR mutations profoundly alter sinonasal development, we want to explore the relationship between their peculiar surgical anatomy and the risk of postoperative complications.

STUDY DESIGN

Retrospective case-control study.

METHODS

Paranasal sinuses CT scans of 103 CF adult patients with CRS were compared to those belonging to a cohort of 100 non-CF adult patients to explore their anatomical differences. Secondly, CF and non-CF patients who received primary/revision ESS were analyzed in order to assess their preoperative CT scan in terms of surgically relevant variants, and according to the CLOSE checklist. Surgical outcomes were statistically compared in order to explore the differences between groups.

RESULTS

CF group presented more frequently with smaller and less pneumatized paranasal sinuses and a higher Lund-Mckay score compared with controls. No anatomical differences emerged in terms of genotype stratification. Non-CF CRS patients undergoing ESS showed a significantly deeper olfactory fossa and a more frequent supraorbital pneumatization compared to CF patients (P < .001 and P = .031, respectively). Whereas this latter group underwent more often aggressive surgical procedures (P = .001), no difference in terms of postoperative adverse events was found (P = .620).

CONCLUSIONS

Despite receiving more often aggressive ESS procedures, adult CF patients do not show an increased risk of postoperative complication and this may be linked to a different proportion of anatomical and surgically-relevant variants.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E2481-E2489, 2021.

A Method Based on 3D Shape Analysis Towards the Design of Flexible Instruments for Endoscopic Maxillary Sinus Surgery

The emergence of steerable flexible instruments has widened the uptake of minimally invasive surgical techniques. In sinus surgery, such flexible instruments could enable the access to difficult-to-reach anatomical areas. However, design-oriented metrics, essential for the development of steerable flexible instruments for maxillary sinus surgery, are still lacking. This paper proposes a method to process measurements and provides the instrument designer with essential information to develop adapted flexible instruments for limited access surgery. This method was applied to maxillary sinus surgery and showed that an instrument with a diameter smaller than 2.4 mm can be used on more than 72.5% of the subjects' set. Based on the statistical analysis and provided that this flexible instrument can bend up to [Formula: see text] it is estimated that all areas within the maxillary sinus could be reached through a regular antrostomy without resorting to extra incision or tissue removal in 94.9% of the population set. The presented method was partially validated by conducting cadaver experiments.

[Surgical anatomy of the maxillary sinus]

BACKGROUND

Improved understanding of the microanatomy of the paranasal sinuses, including its individual variations, makes a substantial contribution to current progress in endonasal endoscopic microsurgery. Microanatomy of the sinuses is an active field of present scientific investitations.

MATERIALS AND METHODS

A comprehensive review on microanatomy of the maxillary sinus is presented from the perspective of contemporary endonasal endoscopic microsurgery.

RESULTS

The range of variation of the individual microanatomy of all sections of the maxillary sinus is presented, in particular to minimize secondary sugical tissue trauma, to avoid complications (e.g. on orbital tissues) and as a basis for the prelacrimal access to the maxillary sinus.

CONCLUSION

Improved understanding of the range of microanatomical variations reduced the burden on the patient while opimizing the effectiveness of the necessary surgical manipulations.

A cone-beam computed tomographic assessment of the proximity of the maxillary canine and posterior teeth to the maxillary sinus floor: Lessons from 4778 roots

INTRODUCTION

When tooth roots protrude into the maxillary sinus, apical root resorption and tipping may occur during horizontal tooth movement across the sinus floor. Three-dimensional cone-beam computed tomography (CBCT) images may provide detailed information without distortion and overlap. We evaluated the relationships between the maxillary tooth root apices and the maxillary sinus floor using CBCT.

METHODS

We evaluated 4778 roots from 76 men (aged 27.6 ± 10.4 [mean ± standard deviation] years; range, 18-69 years), and 225 women (aged 30.4 ± 12.0 years; range, 18-68 years). The positional relationships between the maxillary tooth root apices, including the canine, premolar (first and/or second), and molar (first and/or second), and the inferior wall of the maxillary sinus were comprehensively evaluated on 2 cross-sectional CBCT images (ie, the sagittal and coronal planes). These distances were measured in both images simultaneously.

RESULTS

The sagittal plane distances were significantly larger than coronal plane distances, except for the distobuccal root of the first molar. Pearson correlation test revealed a significant negative correlation between the distance and the patient's age.

CONCLUSIONS

Our study provides valuable information for planning orthodontic tooth movement through the maxillary sinus, which may help to predict the occurrence and severity of root resorption.

Segmentation procedures for the assessment of paranasal sinuses volumes

BACKGROUND

The paranasal sinuses are complex anatomical structures, characterised by highly variable shape, morphology and size. With the introduction of multidetector scanners and the development of many post-processing possibilities, computed tomography became the gold standard technique to image the paranasal sinuses. Segmentation allows the extraction of metrical and shape data of these anatomical components that can be applied for diagnostic, education, surgical planning and simulation, and to plan minimally invasive interventions in otorhinolaryngology and neurosurgery.

DISCUSSION

Our aim was to provide a review of the existing literature on segmentation, its types and application, and the data obtained from this procedure. The literature search was conducted on PubMed (including Medline), ScienceDirect and Google Scholar databases, using the keywords as follows: 'paranasal sinuses', 'frontal sinus', 'maxillary sinus', 'sphenoid sinus', 'ethmoid sinus', in all possible combinations with the keywords 'segmentation' and 'volumetric analysis'. Inclusion criteria were: articles written in English, on living human subjects, on the adult population and focused on paranasal sinuses analysis.

CONCLUSION

This article provides an overview of the types and main application of segmentation procedures on paranasal sinuses, and the results provided by the studies on this topic.

Volumetric study of the maxillary sinus in patients with sinus pathology

Objectives

The aim of this study is 1) to obtain the area and volumes of the maxillary sinuses in patients affected by clinically unilateral sinus pathology by comparing the results to the contralateral sinus and 2) to determine the importance of the volumetric measures when diagnosing the percentage of sinus obliteration.

Materials and methods

A single-centre observational retrospective clinical study was conducted in 214 patients with clinically unilateral sinus pathologies. Linear (mm), area (mm2) and volume (mm3) measurements were taken from Cone Beam Computed Tomography (CBCT) images of the affected sinus as well as from the contralateral ones. Histopathological study was performed using haematoxylin/eosin and PAS or Groccot stains. The lesions were classified into non-specific sinusitis, polyps, inverted papilloma, fungal sinusitis, cysts, mucocele and other lesions. Chi-squared test, ANOVA for independent samples and Pearson test were used for the statistical analysis.

Results

A total of 100 sinuses were measured in 50 patients (28 men and 22 women, with an age of 43.6 years (SD = 18.3), 50 pathological and 50 healthy contralateral sinuses. The three-dimensional occupation volume of the affected sinuses was 97.1 mm³ (62.5%) vs. 40.6 mm³ (22.8%) in the healthy ones (p<0.0001). The medial-lateral width of the sinus in the frontal plane was significantly higher in the cysts group (32.4 mm, CI: 23–41.8 mm).

Conclusion

In medical terms, the global percentage of occupation determined using the classic manual determination method does not differ from the three-dimensional percentage calculated using specific complex software.

Intraoperative Sphenoid Sinus Volume Measurement as an Alternative Technique to Intraoperative Computer Tomography

Isolated sphenoid sinus disease (ISSD) is where there is a group of pathologies characterized by inflammation in one or both sphenoid sinuses. Although computer tomography (CT)-based 3D reconstruction remains the gold standard among noninvasive approaches to ISSD diagnostics, no standardized techniques for direct intraoperative measurements of the sphenoid sinus volume in ISSD patients have been documented. We suggest a novel technique for the intraoperative measurement of the sphenoid sinus volume. Our technique is based on filling the sinus with 0.01% methylene blue solution after an endoscopic endonasal sphenoidotomy. The proposed technique was applied to 40 ISSD patients during surgery. Obtained intraoperative measurements were compared to noninvasive measurements from 3D reconstructions based on preoperative CT scans. Our results demonstrated that the obtained measurements did not exhibit significant differences exceeding 0.4 cm³, with CT-scan-based measurements in 39 out of 40 cases (p < 10⁻⁶, Wilcoxon sign-rank nonparametric test), thus confirming the accuracy of the proposed technique. Disagreements between direct intraoperative and CT-based measurements in a single case have been attributed to the presence of remaining pathological masses in the sinus, which was further confirmed during the secondary check of the operated sinus. Accordingly, we suggest that the agreement between the CT-based and intraoperative volume measurements can be used as an indicator of the successful elimination of all pathological masses from the sinus without having to perform an adequate exposure of the entire sphenoid sinus to reduce intraoperative bleeding. The proposed technique is accurate and does not require the involvement of specialized intraoperative CT scanners and avoids additional radiation exposure for the patient during an additional postoperation CT scan to confirm the success of the surgery.

Cadaveric Simulation of Endoscopic Endonasal Procedures: Analysis of Droplet Splatter Patterns During the COVID-19 Pandemic

Objective

The primary mode of viral transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is thought to occur through the spread of respiratory droplets. The objective of this study was to investigate droplet and splatter patterns resulting from common endoscopic endonasal procedures.

Study Design

Cadaver simulation series.

Setting

Dedicated surgical laboratory.

Subjects and Methods

After instilling cadaver head specimens (n = 2) with fluorescein solution, endoscopic endonasal procedures were systematically performed to evaluate the quantity, size, and distance of droplets and splatter following each experimental condition.

Results

There were no observable fluorescein droplets or splatter noted in the measured surgical field in any direction after nasal endoscopy, septoplasty with microdebrider-assisted turbinoplasty, cold-steel functional endoscopic sinus surgery (FESS), and all experimental conditions using an ultrasonic aspirator. Limited droplet spread was noted with microdebrider FESS (2 droplets, <1 mm in size, within 10 cm), drilling of the sphenoid rostrum with a diamond burr (8, <1 mm, 12 cm), and drilling of the frontal beak with a cutting burr (5, <1 mm, 9 cm); however, the use of concurrent suction while drilling resulted in no droplets or splatter. The control condition of external activation of the drill resulted in gross contamination (11, 2 cm, 13 cm).

Conclusion

Our results indicate that there is very little droplet generation from routine rhinologic procedures. The droplet generation from drilling was mitigated with the use of concurrent suction. Extreme caution should be used to avoid activating powered instrumentation outside of the nasal cavity, which was found to cause droplet contamination.

Objective computerised assessment of residual ridge resorption in the human maxilla and maxillary sinus pneumatisation

OBJECTIVES

Atrophic resorption of the maxillary alveolar ridge is a complication that makes implantological rehabilitation critical. Our aim was to develop a novel computer aided procedure for the accurate quantitative assessment of maxillary residual ridge resorption including pneumatisation of the maxillary sinus that goes beyond previously described approaches and to apply it to a large dataset.

MATERIALS AND METHODS

To develop and refine the method, we performed a retrospective analysis using computed tomography data from 405 patients to generate segmented, three-dimensional models of zygomaticomaxillary bones and maxillary sinuses. Using anatomical landmarks and orientation lines or planes, all models were aligned automatically to subsequently generate cross-sectional images (n = 2835), enabling the classification of atrophy as well as the quantification of volumes and caudal extensions of the maxillary sinuses.

RESULTS

We developed and implemented an accurate and reproducible workflow for the semi-automated analysis of volumetric maxillary images. Comprehensive statistical analysis of the large quantitative dataset revealed various correlations of maxillary process heights and sinus volumes with atrophy class, age and region and identified conjectural trends over the patient group.

CONCLUSIONS

The method was used successfully to process a large dataset to classify atrophy, to measure alveolar height parameters, and to quantify maxillary sinus volume, bottom volume and pneumatisation.

CLINICAL RELEVANCE

Apart from the anthropometric value of the generated dataset, the method could be applied to provide additional and more accurate data to assess the necessity of bone augmentation in the context of three-dimensional planning before implantation.

Three-Dimensional Evaluation of Maxillary Sinus Changes in Growing Subjects: A Retrospective Cross-Sectional Study

This study aims to evaluate changes of maxillary sinuses in growing subjects. Cone Beam Computed Tomography (CBCT) scans of 146 patients were divided according to gender and age (6–8, 9–11, 12–14 years old). Left, right and total maxillary sinus volume (MSV-R, MSV-L, MSV-Tot) and surface (MSS-R, MSS-L, MSS-Tot), left and right linear maximum width (LMW-L, LMW-R), depth (LMD-R, LMD-L) and height (LMH-R, LMH-R) were calculated using Mimics Research 22. Kruskal–Wallis Test and showed a statistically significant increase in both genders for all variables. Pairwise comparisons in females are always statistically significant in: LMH-R, LMH-R, MSS-Tot, MSV-Tot. All other variables showed a statistical significant increase between 9–11 and 12–14, and between 6–8 and 12–14 age groups, apart from LMSW-R, LMSW-L, LMSD-R, LMSD-L between 6–8 and 12–14 age groups. Pairwise comparisons in males are always and only statistically significant between 9–11 and 12–14, and between 6–8 and 12–14 groups. Symmetrical measurements (right and left) evaluated using Wilcoxon test retrieved no statistical significant difference. Comparisons between measurements on male and female subjects using Mann–Whitney test showed a statistical significant difference in 6–8 years group in MSV-R, MSV-L and MSV-Tot, and in 12–14 age group in MSV-R, MSV-L, MSV-Tot, MSS-r, MSS-l, MSS-Tot, MSW-R, MSW-L, MSD-R, MSD-L. Intraclass Correlation Coefficient (ICC) assessing inter-operator and intra-operator concordance retrieved excellent results for all variables. It appears that maxillary sinus growth resembles the differential peak of growth in male and female subjects. Sinuses starts to develop early in female subjects. However, in the first and last age group female sinuses are statistically significantly smaller compared to male ones. In male subjects, sinus growth occurs mainly between the second and third age group whilst in female subjects it starts between the first and second age group and continues between the second and the last. Sinus has a vertical development during the peak of growth, which is the main reason for its increase in volume.

The maxillary sinus: physiology, development and imaging anatomy

OBJECTIVES

The maxillary sinus is of paramount importance for otolaryngologists, rhinologists, oral and maxillofacial surgeons, head and neck and dental and maxillofacial radiologists. A comprehensive review article concerning the physiology, development and imaging anatomy was undertaken.

METHODS

Relevant literature pertaining to the physiology of the sinonasal cavity, development of the paranasal sinuses and imaging anatomy of the maxilla and maxillary sinus from 2000 to 2019 was reviewed. Emphasis was placed on literature from the last 5 years.

RESULTS

Extensive recent research using imaging has provided new insights into the development of the maxillary sinus, the other paranasal sinuses and the midface. The fundamental physiological concept of mucociliary clearance and its role in sinus health is emphasized. The paranasal sinuses are an integral part of a common mucosal organ formed by the upper and lower airway.An in-depth understanding of the soft-tissue and neurovascular relationships of the maxillary sinus to the deep fascial spaces and branches of the trigeminal nerve and external carotid artery respectively is required to evaluate and report imaging involving the maxillary sinus.Sinusitis of rhinogenic, rather than odontogenic origin, originates from nasal inflammation followed by anterior ethmoid disease and secondary obstruction of the ostiomeatal unit. The role of anatomical variants that predispose to this pattern of disease is discussed in detail with illustrative examples.The maxillary sinus is intimately related to the roots of the posterior maxillary teeth; the high frequency of mucosal disease and sinusitis of odontogenic aetiology is now well recognized. In addition, an understanding of the anatomy of the alveolar process, morphology of the alveolar recess of the maxillary sinus and neurovascular supply are essential both for deliberate surgical intervention of the sinus and complications related to oral surgical procedures.

CONCLUSIONS

An understanding of the fundamental principles of the development, physiology, anatomy and relationships of the maxillary sinus as depicted by multi-modality imaging is essential for radiologists reporting imaging involving the paranasal sinuses and midface.

Sexual dimorphism of maxillary sinuses in children and adolescents - A retrospective CT study

BACKGROUND

In the postnatal period, some sexual dimorphism is observed from the moment of birth, but it is most pronounced from puberty. The aim of the study based on CT images was to assess possible sexual dimorphism of the maxillary sinus in children aged 0-18.

METHODS

The retrospective analysis of CT images of the head (assessed as normal by radiologists) of 170 patients aged 0-18 (85 females and 85 males) was performed. The maxillary sinuses of every patient were bilaterally measured in three planes. Three diameters were obtained: maximum transverse (horizontal) diameter (the maxillary sinus width, MSW); maximum vertical diameter (the maxillary sinus height, MSH) and maximum antero-posterior diameter (maxillary sinus length, MSL). The automatic CT image segmentation algorithm was used (Syngo Via for Oncology, Siemens) to establish maxilla retrospective analysis of CT images of the head (assessed as normal by radiologists) of 170 patients aged 0-18 (85 females and 85 males) was performed. The maxillary sinuses of every patient were bilaterally measured in three planes. Three diameters were obtained: maximum transverse (horizontal) diameter (the maxillary sinus width, MSW); maximum vertical diameter (the maxillary sinus height, MSH) and maximum antero-posterior diameter (maxillary sinus length, MSL). The automatic CT image segmentation algorithm was used (Syngo Via for Oncology, Siemens) to establish maxillary sinus volume (MSV). The coefficient of variation used in the study allowed the biological variation between sexes to be observed.

RESULTS AND CONCLUSIONS

The sexual dimorphism of maxillary sinus parameters is variable and depends on the phase of ontogenesis. All investigated parameters of maxillary sinuses are larger in males at 2-3 years (except for the length, which is larger in females by the end of three years, between six and nine years and after 15 years). The sexual dimorphism is less evident during the first year of age, and the most evident between 15 and 16 years. During the first two years, females are dominant with all parameters being larger than in males. The maxillary sinus length is developmentally the most stable parameter of maxillary sinuses, because throughout the investigated ontogenesis, the sexual differences are very similar. The most evident sexual dimorphism is observed in the volume of the maxillary sinus.

Anatomical relationship between the maxillary posterior teeth and the sinus floor according to an anterior overbite

OBJECTIVE

To evaluate the vertical relationship between the maxillary sinus floor (MSF) and the maxillary posterior teeth (MPT) according to an anterior overbite.

SETTINGS AND SAMPLE POPULATION

The patients were divided into three groups according to an anterior overbite. The open bite group (OBG) included patients with an anterior overbite of ≤0 mm, the normal overbite group (NBG) included patients with an overbite of 0-3 mm, and the deep bite group (DBG) included patients with an overbite ≥3 mm. Thirty patients were randomly matched into each group based on age and sex.

MATERIALS AND METHODS

The distances and vertical relationship between the MSF and the MPT was analysed using cone-beam computer tomography. The vertical relationship between the two was classified as either favourable or unfavourable for the intrusion of the posterior teeth.

RESULTS

A higher ratio of patients in the OBG had MPT positioned close to the MSF than the DBG. Intrusion of the posterior teeth was unfavourable for an average of 87.2%, 77.2% and 70.2% molars in the OBG, NBG and DBG, respectively.

CONCLUSIONS

The vertical distance between the MSF and the MPT is associated with an anterior overbite. The posterior teeth were in an unfavourable position for the orthodontic intrusion in the OBG as compared to the other groups. Additional caution is needed when planning orthodontic intrusion treatment for patients with an anterior open bite. But, there were some individual variations within each group.