Is the Maxillary Sinus Really Suitable in Sex Determination? A Three-Dimensional Analysis of Maxillary Sinus Volume and Surface Depending on Sex and Dentition

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.

Comparison of different methods of analysis of maxillary sinus volume and validation of a new proposal using cone beam computed tomography

PURPOSE

develop and validate a formula, through a discriminant analysis of sex estimation, evaluating maxillary sinus in cone beam computed tomography scans in a Brazilian population, comparing this formula with two other existing ones.

METHODS

190 cone beam CT scans of Brazilian adults were retrospectively evaluated by an independent examiner. Measurements were performed in the right and left MS region: height, width, length, distance between the breasts, distance between infraorbital foramina, and volume in the ITK software. The sample was divided into female and male. T test, ANOVA, Tukey test and the ROC Curve was performed (p > 0,05).

RESULTS

statistically significant differences were found in relation to the maximum height of the MS both right (p = 0,001) and left (p = 0,026) between sexes and the maximum length in the right MS (p = 0,01). Regarding the comparison of MS volume according to the different analysis methods, statistically significant differences were found between sexes for the right MS when using the method by Bangi et al. (p = 0,012) and the volume of the left MS in females (p < 0,001). Comparing the three classification models, statistically significant differences were found between the proposed method and the classification by Bangi et al. (p < 0.007). The ROC curve showed greater accuracy in the classification proposed in this work.

CONCLUSION

the new proposed formula obtained better predictions of sexual dimorphism, when compared to classifications already described in the literature.

Reliability of gender determination from paranasal sinuses and its application in forensic identification-a systematic review and meta-analysis

This systematic review aims to determine whether linear or morphometric analysis of paranasal sinuses can be used for accurate determination of gender and to appraise which sinus can be evaluated for accurate gender determination.A comprehensive search of the specialized databases (PubMed/MEDLINE, Science Direct, Clinical Key, ProQuest, Google Scholar, Epistomonikos, LILACS, OpenGrey) and other institutional repositories was performed for including the studies which assessed paranasal sinuses for gender determination. Quality assessment was carried out with the AQUA tool. The meta-analysis was performed with the eligible study data at 95% CI and p ≤ 0.05 in the random-effects model.Forty-six studies evaluating frontal sinus (13), maxillary sinus (26), frontal and maxillary sinus (5), or three paranasal sinuses (2) were included. All the included studies assessed height, length, width, and volume, respectively, and other additional parameters (area, perimeter) if wherever applicable. Frontal sinus had significantly higher values for males compared to females except for left height (LH) and left volume (LV). Maxillary sinus measurements were significantly higher in males contrasted to females except for LH. Sub-group analyses revealed that analyses involving the population had statistically significant results for all the measured parameters for both the sinuses (p < 0.05 and p = 0.00, respectively).Measurements obtained from assessing sinuses reveal that there are variations in size, among populations in different geographic regions. Hence, more studies with improved sample sizes and standardized measurement protocols should be carried out on different populations to see the diversity and their reliability.

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.

Three-Dimensional CBCT Based Evaluation of the Maxillary Sinus by Facial Index

The maxillary sinus growth is initiated 3 months after birth, and it grows lateral and inferior until the pneumatization of the alveolar bone occurs. The facial skeleton has recently been determined as affecting the maxillary sinus, prompting additional studies on changes in the size of the maxillary sinus. This study aimed to determine the size of the maxillary sinus using a 3D program after categorizing South Korean adults according to their facial index (FI) classification. The participants of this study were 60 patients in their 20s, who visited the orthodontic department of Dankook University Dental Hospital (approval no. DUDH IRB 2015-12-022). The CBCT of the patients were extracted and measured as 3D images using Mimics (version 22.0, Materialise, Leuven, Belgium). Upon categorizing the subjects based on their FI classification, they were grouped into the mesoprosopic, leptoprosopic, and hyperleptoprosopic types. A one-way ANOVA was performed to evaluate the mean differences of the maxillary sinus, depending on the FI classification. In this study, the maxillary sinus tended to be wider in those with mesoprosopic type, and tended to be higher in the hyperleptoprosopic type, suggesting a need for clinicians to focus to the shape of the face during clinical treatments.

Effects of missing teeth and nasal septal deviation on maxillary sinus volume: a pilot study

PURPOSE

Tooth extraction and the projection of the tooth roots into the maxillary sinus are reported to greatly reduce the bone height from the alveolar ridge to the maxillary sinus floor, while missing teeth are reported to lead to the expansion of the maxillary sinus, all of which are important considerations during dental implant treatment for the maxillary molar region. Therefore, assessing the anatomical characteristics of the maxillary sinus acting as complicating factors is crucial before sinus augmentation. We conducted a three-dimensional examination of the effects of missing teeth and nasal septal deviation (NSD) on maxillary sinus volume (MSV).

METHODS

We selected participants with two or more missing teeth from patients who underwent maxillary sinus augmentation for a unilateral free-end saddle between April 2019 and December 2020. We calculated the MSV and NSD using cone-beam computed tomography (CBCT). We compared the relationships of the presence/absence of teeth and NSD with MSV bilaterally in each patient using the Wilcoxon t-test. p-values < 0.05 denoted statistical significance.

RESULTS

This study included 30 patients (30 sinuses; 12 men, 18 women). The average patient age was 58.2 ± 10.2 years (men, 60.4 ± 3.7 years; women, 59.2 ± 4.5 years; range, 40-77 years). The mean number of missing teeth was 2.98 ± 1.01: 13 patients had two missing teeth and 17 had three or more missing teeth. Nine patients (30%) had NSD. The mean MSV on the ipsilateral and contralateral sides of the NSD was 21.50 ± 3.84 cm3 and 22.10 ± 3.56 cm3, respectively; thus, NSD did not affect MSV (p = 0.150). The mean MSV on the edentulous and non-edentulous sides was 21.58 ± 3.89 cm3 and 21.77 ± 4.30 cm3, respectively; thus, the MSV was significantly smaller on the edentulous side (p = 0.00036).

CONCLUSION

Although this study was a limited preoperative study, three-dimensional measurement of the maxillary sinus with CBCT in partially edentulous patients revealed that missing teeth lead to substantial reductions in MSV, while NSD was not associated with MSV.

[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.

Evaluation of maxillary sinus volume in different craniofacial patterns: a CBCT study

INTRODUCTION

Few studies have compared the relationship of MSV in the different craniofacial patterns. Hence, the purpose of this research was to evaluate maxillary sinus volume in different craniofacial patterns using cone-beam computed tomography.

MATERIALS AND METHODS

This cross-sectional study included 100 pre-orthodontic patients mean aged 26.40 ± 6.77 (age ranged 21-64) years divided into different anteroposterior and vertical skeletal groups. From the cone beam computed tomography images using MIMICS 14.1 software, three-dimensional image of the maxillary sinus was constructed, and its volume was calculated.

RESULTS

The mean maxillary sinus volume was 20,279.50 ± 7800.33 mm³. Among the anteroposterior skeletal groups, the mean maxillary sinus volume in skeletal Class II group is significantly larger than class III group (P < 0.05). Among the vertical skeletal groups, High-angle groups tend to have the largest maxillary sinus volume, though there were no significant differences among the groups (P > 0.05). Similarly, males have significantly larger maxillary sinus volume than females (P < 0.05). There was a positive correlation between ANB and maxillary sinus volume (P < 0.01).

CONCLUSION

Maxillary sinus volume is significantly larger in skeletal class II than in skeletal class III group and in males than in females (P < 0.05). These inferences have several implications in orthodontics, endodontics and oral surgery.

Volumetric and linear evaluation of the sphenoidal sinus of a Brazilian population, in cone beam computed tomography

The determination of sex from skeletal remains has been widely used in biological profile reconstruction since these are some of the last structures to perish after death. The sphenoid sinus is located deeply in the skull and is enveloped by diverse structures within the sphenoid body. It is, therefore, less predisposed to injuries and/or pathological changes. The aim of this study is to evaluate the possibility of determining sex in a Brazilian population by means of linear and volumetric measurements of the sphenoid sinus, in addition to identifying and quantifying the presence of extensions of this sinus in cone beam computed tomography (CBCT) scans. In total 268 CBCT scans were analysed, from patients aged between 22 and 70 years old, of which 145 were female, and 123 were male. The images, representative of a Brazilian population, were selected by a dental radiologist from a CBCT image bank. The volumetric measurements were made by means of the segmentation software ITK-SNAP 3.0® and the linear inferio-superior, latero-lateral and anteroposterior measurements, as well as the presence of extensions of the sphenoidal sinus, were made using the CS Imaging Software®. The results of this study suggested that when comparing men and women, there were no statistical differences in the linear measurements and extensions of the sphenoidal sinus, although the values were considerable in the extensions for the pterygoid processes and greater wings of the sphenoid bone, particularly in women. However, there was a statistically significant difference when the sphenoidal sinus volume was compared, as it was larger for men (11.364 mm³ ± 4.229 mm³) than for women (10.000 mm³ ± 3.615 mm³). In summary, the sphenoidal sinus volumetric measurements in CBCT exams are useful for determining the sex of unknown individuals.

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.

Variability of Paranasal Sinus Pneumatization in the Absence of Sinus Disease

Background: Paranasal sinus pneumatization is a complex process, and numerous computed tomography (CT) studies document developmental variations in the setting of underlying sinus disease. The purpose of this study was to investigate variation in paranasal sinus pneumatization in a population of nondiseased subjects using a metric validated for tracking individual anatomic variants as well as total sinus volume.

Methods: A total of 591 consecutive sinus and maxillofacial CT scans were considered for study inclusion. After patients with inflammatory sinus or respiratory disease were excluded, 323 CT scans were scored using the Assessment of Pneumatization of the Paranasal Sinuses (APPS) instrument, and relevant demographic data were recorded for each scan. APPS findings were compared according to demographic characteristics and laterality.

Results: Laterality and sex were associated with differences in paranasal sinus pneumatization in a nondiseased population. Based on APPS score, the left side (4.95) was more pneumatized than the right (4.74, P=0.006), and males (10.16) were more extensively pneumatized than females (9.18, P=0.005). We found no correlation of age with sinus pneumatization (ρ=0.025). The probability of perceptible asymmetry in any given individual's paranasal sinus pneumatization was 69%, and the probability of left-sided dominance was 53%.

Conclusion: Substantial anatomic variation exists in paranasal sinus anatomy, even among patients without sinus disease. Significant differences are found between males and females and between the left and right sides. Continued systematic research of paranasal sinus anatomy may facilitate a standard for CT sinus assessment that will aid clinician evaluation of anatomic variation and surgical decision making.

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.

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.

Three-dimensional evaluation of maxillary sinus volume in different age and sex groups using CBCT

AIM

Sinus maxillaris is an important anatomical formation in many branches of dentistry due to its proximity to the field of work. Various methods have been used in literature to measure the maxillary sinus volume (MSV) such as cadavers, stereology, two-dimensional conventional radiographs, computed tomography (CT), magnetic resonance imaging (MRI). The aim of this study is to evaluate the change of maxillary sinus volume according to age and gender with MIMICS 19.0 (Materialise HQ Technologielaan, Leuven, Belgium) which is one of three-dimensional modeling software.

MATERIALS AND METHODS

This study was performed in 200 patients selected by a retrospective review of the archives of the Dicle University, Faculty of Dentistry, Department of Oral and Maxillofacial Radiology. Patients were divided into five age groups (18-24 years, 25-34 years, 35-44 years, 45-54 years, and ≥ 55 years) and by sex. Cone-beam computed tomography (CBCT) images of the patients were transferred to the MIMICS software and the MSV was measured. All statistical analyses were performed using the SPSS (Statistical Package for Social Sciences, version 21) software.

RESULTS

There was no statistically significant difference between the right and left maxillary sinus volume according to the findings obtained from our study, and maxillary sinus volume in males was found to be significantly higher than that of females. Another finding of our study is that the maxillary sinus volume decreases with age increase. Especially it was also found that the sinus volume in males in the 18-24 age group was statistically significantly higher than females.

CONCLUSION

Consequently, maxillary sinus volume measurements can be made on CT, CBCT, MRI scans using reconstruction software.

The effect of ectodermal dysplasia on volume and surface area of maxillary sinus

PURPOSE

Ectodermal dysplasia (ED) is a congenital syndrome characterized by abnormal development of ectodermal structures, such as skin, hair, nails, teeth, or salivary glands. Patients with ED demonstrate craniofacial dysmorphology, midfacial hypoplasia and hypodontia. The aim of this study is to evaluate volume and surface area of maxillary sinus and craniofacial structures in patients with ectodermal dysplasia (ED) using cone-beam computed tomography (CBCT) images.

METHODS

The CBCT images of 20 patients with ED (study group) and 20 healthy individuals (control) which are equal in terms of age and gender were evaluated. After a three-dimensional analysis and segmentation of each maxillary sinus, the volume and surface area were calculated. Craniofacial dimensions were measured on the sagittal planes of the CBCT images. The results of the ED and control groups were statistically compared.

RESULTS

The right and left sinus volumes and surface areas were significantly lower in the ED group than in the control group (p < 0.05) while the SNA was significantly higher (p < 0.05). ANB and SN-GoMe were also lower in patients with ED than in controls (p < 0.05). The difference in SNB values between the two groups was not significant (p > 0.05).

CONCLUSIONS

The volumes and surface areas of both maxillary sinuses were found to be smaller in patients with ED compared to healthy individuals. Class III malocclusion with maxillary retrusion is a characteristic craniofacial feature of these patients.

Surgeons' Performance Determining the Amount of Graft Material for Sinus Floor Augmentation Using Tomography

This study aimed to assess the performance of surgeons in determining the amount of graft material required for maxillary sinus floor augmentation in a preoperative analysis using cone-beam computed tomography images. A convenience sample of 10 retrospective CBCT exams (i-CAT®) was selected. Scans of the posterior maxilla area with an absence of at least one tooth and residual alveolar bone with an up to 5 mm height were used. Templates (n=20) contained images of representative cross-sections in multiplanar view. Ten expert surgeons voluntarily participated as appraisers of the templates for grafting surgical planning of a 10 mm long implant. Appraisers could choose a better amount of graft material using scores: 0) when considered grafting unnecessary, 1) for 0.25 g in graft material, 2) for 0.50 g, 3) for 1.00 g and 4) for 1.50 g or more. Reliability of the response pattern was analyzed using Cronbach's a. Wilcoxon and Mann-Whitney tests were performed to compare scores. Regression analysis was performed to evaluate whether the volume of sinuses (mm3) influenced the choose of scores. In the reliability analysis, all values were low and the score distribution was independent of the volume of the maxillary sinuses (p>0.05), which did not influence choosing the amount of graft material. Surgeons were unreliable to determine the best amount of graft material for the maxillary sinus floor augmentation using only CBCT images. Surgeons require auxiliary diagnostic tools to measure the volume associated to CBCT exams in order to perform better.

Development and validation of a formula based on maxillary sinus measurements as a tool for sex estimation: a cone beam computed tomography study

BACKGROUND

As sex estimation is an important step to delineate the biological profile, the development of tools employing anatomical structures which may maintain their integrity even after extreme events, such as the maxillary sinus, become useful for forensic identification. Thus, the aim in the present study was to develop and validate a formula for sex estimation through measurements in the maxillary sinuses in a Brazilian population, using cone beam computed tomography (CBCT) scans.

MATERIAL AND METHODS

Linear and volumetric measurements in the maxillary sinus were performed bilaterally in 94 CBCT scans from 45 males (mean age 25.2 ± 0.79) and 49 females (mean age 23.7 ± 0.50). The OnDemand 3D software was employed for linear measurements (height, length and width of, and the largest distance between the right and left maxillary sinuses), while the ITK-SNAP 3.0 segmentation software was used to acquire the volume. The data obtained was applied to a mathematical model for sex estimation. To validate the developed formula, another sample composed of 60 CBCT images of Brazilian individuals was tested.

RESULTS

Overall, maxillary sinuses' measurements were significantly higher in males, without statistically significant differences between the right and left sides within each group. The most dimorphic measurement was the height, with an accuracy of 77.7% regarding sex estimation. The formula created lead to a sex estimation of 87.8% for females and 80% for males, with an overall accuracy of 84%. When the formula validity was tested in another sample, it showed an accuracy of 82.4%.

CONCLUSION

The formula developed through measurements in the maxillary sinus using CBCT scans showed an accuracy of 84% for sex estimation and can be applied as a complementary method for human identification in the Brazilian population.

3D-evaluation of the maxillary sinus in cone-beam computed tomography

Background

There are few studies measuring the dimensions of the maxillary sinus, being mostly based on computed tomography imaging and rarely being based on cone-beam computed tomography (CBCT). The aim of this study was to measure the 3D osseous and soft tissue defined volume and surface area of the maxillary sinus. Further, possible associations with patient-specific and sinus-related variables were evaluated.

Methods

A total of 128 maxillary sinuses in 64 patients were analyzed using cone-beam computed tomography data. Surface area and volume of the osseus maxillary sinuses as well as of the remaining pneumatized cavities in cases of obliterated sinuses were calculated by the implant planning software SMOP (Swissmeda AG, Baar, Switzerland). Further, patient-specific general variables such as age, gender, and dentition state as well as sinus-related factors including apical lesions, sinus pathologies, and number of teeth and roots communicating with the maxillary sinus were recorded.

Results

For osseus bordered sinuses, mean surface area was 39.7 cm² and mean volume 17.1 cm³. For the remaining pneumatized cavities, mean surface area was 36.4 cm² and mean volume 15 cm³. The calculated mean volume of obliterated sinuses (42.2% of all sinuses were obliterated) was 5.1 cm³. Further, an association between the obliterated volume and the presence of pathologies was detected. Male patients showed a significantly higher mean osseus volume compared to female patients. No association was apparent between a patient’s age or dentition state and sinus volume, nor for communicating tooth roots and sinus pathologies or unilateral opacity and apical radiolucency. There was also no significant association between bilateral obliterated sinuses and the scan date being in autumn/winter.

Conclusions

The present study showed that the CBCT is suitable for the evaluation of the maxillary sinus. The implant planning software SMOP and its included volume measuring tool are valuable for the analysis of the maxillary sinus, and possible relations with the dentition can be analyzed.

Three-dimensional CAD/CAM imaging of the maxillary sinus in ageing process

OBJECTIVES

During the physiological ageing process atrophy of the alveolar bone appears in vertical direction. This bone resorption causes pushing the limits of the maxillary sinus at the expense of a degraded bone. The sinus volume increases due to the facial development in children and adolescents or during the ageing process due to the loss of teeth and bone mass. The main aim of this study is to determine the sinus shape and sinus floor morphology related to age.

MATERIALS AND METHODS

Human adult male and female cadaveric heads (aged 37 to 83 years) with different dental status were used. The three-dimensional CAD/CAM software was used to scan the solid impressions of the maxillary sinus to visualize the real sinus shape and sinus floor. Subsequently, other findings are shown in tables and evaluated graphically.

RESULTS

The maxillary sinus morphology, its relationship to the nasal cavity, the sub sinus alveolar bone height, displacement of the lowest and highest points of sinus, and the sinus relationship to the roots of the upper teeth were studied and evaluated. Some septa, crests, and the prominent infraorbital canal were also found in the area of the sinus floor.

CONCLUSIONS

This paper provides a unique view on the maxillary sinus and its changes during the ageing process with preserved topographical relations in a representative sample of the Slovak population. The visualization of the maxillary sinus anatomy is necessary in the diagnosis and treatment plans for dental implants and during current surgical procedures.

Computed tomography-based volumetric tool for standardized measurement of the maxillary sinus

Volume measurements of maxillary sinus may be useful to identify diseases affecting paranasal sinuses. However, literature shows a lack of consensus in studies measuring the volume. This may be attributable to different computed tomography data acquisition techniques, segmentation methods, focuses of investigation, among other reasons. Furthermore, methods for volumetrically quantifying the maxillary sinus are commonly manual or semiautomated, which require substantial user expertise and are time-consuming. The purpose of the present study was to develop an automated tool for quantifying the total and air-free volume of the maxillary sinus based on computed tomography images. The quantification tool seeks to standardize maxillary sinus volume measurements, thus allowing better comparisons and determinations of factors that influence maxillary sinus size. The automated tool utilized image processing techniques (watershed, threshold, and morphological operators). The maxillary sinus volume was quantified in 30 patients. To evaluate the accuracy of the automated tool, the results were compared with manual segmentation that was performed by an experienced radiologist using a standard procedure. The mean percent differences between the automated and manual methods were 7.19% ± 5.83% and 6.93% ± 4.29% for total and air-free maxillary sinus volume, respectively. Linear regression and Bland-Altman statistics showed good agreement and low dispersion between both methods. The present automated tool for maxillary sinus volume assessment was rapid, reliable, robust, accurate, and reproducible and may be applied in clinical practice. The tool may be used to standardize measurements of maxillary volume. Such standardization is extremely important for allowing comparisons between studies, providing a better understanding of the role of the maxillary sinus, and determining the factors that influence maxillary sinus size under normal and pathological conditions.