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

The relationship between structures affecting maxillary sinus ventilation and maxillary sinus volume: a CT study

PURPOSE

This study aims to identify anatomical variations inside and outside the maxillary sinus (MS), determine their prevalence and coexistence, and investigate their relationship with MS volume in individuals without MS pathology, using ImFusion Suite software.

METHODS

Analysis of 330 paranasal CT scans obtained from the radiology archive (2018-2021) was performed using the ImFusion Suite program. Anatomical variations, including accessory ostium, Haller cells, ethmomaxillary sinus, concha anomalies, septa, and impacted teeth, were identified and their frequency of coexistence was determined. MS volume and nasal septum deviation (NSD) angle were measured. The relationship between MS volume and gender, as well as the impact of anatomical variations on MS volume, was analyzed. Statistical analyses were conducted using SPSS software.

RESULTS

The most common anatomical variation was NSD (98%), while the least common was ethmomaxillary sinus (9.4%). Middle and inferior concha hypertrophy were more frequent in males, whereas concha bullosa and impacted teeth were more prevalent in females (p < 0.05). A normal anatomical appearance on CT scans was observed in only 2.1% of cases (3.5% in males; 1.1% in females), with a notable coexistence of multiple variations. MS volume was significantly higher in males (right: 16.79 ± 5.23 cm3; left: 16.39 ± 5.61 cm3) than in females (right: 14.44 ± 4.54 cm3; left: 14.59 ± 4.62 cm3) (p < 0.05). MS volume was significantly smaller when the NSD angle was ≥9° and larger in the presence of septa.

CONCLUSION

This study provides a comprehensive analysis of anatomical variations in the MS and their relationship with MS volume. The findings indicate that septa increase MS volume, while a higher NSD angle (≥9°) is associated with reduced MS volume. Other variations, including accessory ostium, Haller cells, and concha anomalies, showed no significant impact on MS volume. These results highlight the importance of detailed radiological evaluation in clinical and surgical planning.

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.

Can human sex be estimated based on the dimensions of the maxillary sinuses? A systematic review of the literature on cone-beam and multi-slice computed tomography

PURPOSE

To critically appraise and summarize the potential of linear and/or volumetric dimensions of the maxillary sinuses obtained with cone-beam and multi-slice computed tomography.

METHODS

A bibliographic search was conducted in seven databases in August 2023. Cross-sectional retrospective studies using linear and volumetric measurements of the maxillary sinuses obtained with cone-beam and multi-slice computed tomography for sex estimation and presenting numerical estimation data were included. Narrative or systematic reviews, letters to the editor, case reports, laboratory studies in animals, and experimental studies were excluded. The critical appraisal and certainty of evidence were assessed using the guidelines described by Fowkes and Fulton and GRADE, respectively.

RESULTS

A total of 656 studies were found, 32 of which were included. A total of 3631 individuals were analyzed and the overall sex estimation rate ranged from 54.9 % to 95 %. When compared with isolated measurements, combined linear measurements of the right and left maxillary sinuses, such as width, length, and height, provided a higher rate of sex estimation (54.9-95 %). In most of the studies (62.5 %), all measurements were higher in men than in women. Multiple methodological problems were found in the studies, especially distorting influences in 84.4 % of the answers. The certainty of evidence varied from very low to low.

CONCLUSIONS

The combination of height, width, and length measurements of the right and left maxillary sinuses from cone-beam and multi-slice computed tomography can be useful in the estimation of sex of humans. Further primary studies are needed to increase the certainty of evidence.

PROSPERO REGISTER

CRD42020161922.

Sex Estimation With Three-Dimensional Analysis of the Maxillary Sinus From Computed Tomography Images

Sex estimation from human skeletal relics is essential in creating an individual's biological profile. This study was performed to examine whether the dimensions and volume of the maxillary sinus can be used to estimate sex. The maxillary sinus's volume, length, width, and height were obtained on the paranasal computed tomography images of 232 adult subjects (116 males and 116 females). All parameters were significantly higher in males except for the right maxillary sinus length (P < 0.05). The highest precision for sex determination was the right maxillary sinus volume (68.1%). The ability of the maxillary sinus parameters to define sex was 78.6% for males and 58.6% for females. The precision of sex estimation of the maxillary sinus parameters was 68.2%. The volume and dimensions of the maxillary sinus can be useful for sex estimation in forensic sciences with a relatively close accuracy rate to reference value (close to 70%). The volume and dimensions of the maxillary sinus can be used for sex estimation together with other bony structures in the skull in cases where the entire skeleton is not available.

Evaluation of the differences in the localization of the lingula mandibulae according to pubertal development in children: A new anthropological and forensic approach

OBJECTIVE

This study aims to investigate changes in lingula mandibulae localization before and after puberty and sex differences.

DESIGN

288 panoramic radiographs evaluated retrospectively were divided into four groups according to pubertal development: under and over 10 years old for females and under and over 11 years old for males. Four anatomic sites were used as reference points: (a) the anterior border of the ramus; (b) the posterior border of the ramus; (c) the deepest point of mandibular notch; and (d) the angulus mandibulae. The ratio of the distances from the lingula mandibulae to points (a) and (b) and the ratio of the distances from the lingula mandibulae to points (c) and (d) were determined. Two-way ANOVA was performed to assess differences between subgroups based on sex and puberty, and a Bonferroni post-hoc test was performed for multiple comparisons.

RESULTS

Puberty and sex has a significant interaction effect on the vertical location of the lingula mandibulae. Postpubertal lingula mandibulae is positioned proportionally more anteriorly by prepubertal localization. In addition, the lingula mandibulae is situated more posteriorly in females compared to males. A significant interaction effect of puberty and sex was observed in relation to the vertical positioning of the lingula mandibulae.

CONCLUSIONS

The spatial localization of the lingula mandibulae and its spatial displacement with age can be used both in estimating sex and the onset of puberty. Changes in the localization of lingula mandibulae according to pubertal development and sex can be used in forensic and anthropological contexts.

Sex estimation using maxillary sinus volume for Chinese subjects based on cone-beam computed tomography

BACKGROUND

Sex estimate is a key stage in forensic science for identifying individuals. Some anatomical structures may be useful for sex estimation since they retain their integrity even after highly severe events. However, few studies are focusing on the Chinese population. Some researchers used teeth for sex estimation, but comparison with maxillary sinus were lack. As a result, the objective of this research is to develop a sex estimation formula for the northwestern Chinese population by the volume of the maxillary sinus and compare with the accuracy of sex estimation based on teeth through cone-beam computed tomography (CBCT).

METHODS

CBCT images from 349 samples were used to establish and verify the formula. The volume of both the left and right maxillary sinuses was measured and examined for appropriate formula coefficients. To create the formula, we randomly picked 80% of the data as the training set and 20% of the samples as the testing set. Another set of samples, including 20 males and 20 females, were used to compare the accuracy of maxillary sinuses and teeth.

RESULTS

Overall, sex estimation accuracy by volume of the left maxillary sinus can reach 78.57%, while by the volume of the right maxillary sinus can reach 74.29%. The accuracy for females, which can reach 91.43% using the left maxillary sinus, was significantly higher than that for males, which was 65.71%. The result also shows that maxillary sinus volume was higher in males. The comparison with the available results using measurements of teeth for sex estimation performed by our group showed that the accuracy of sex estimation using canines volume was higher than the one using maxillary sinus volume, the accuracies based on mesiodistal diameter of canine and first molar were the same or lower than the volume of maxillary sinus.

CONCLUSIONS

The study demonstrates that measurement of maxillary sinus volume based on CBCT scans was an available and alternative method for sex estimation. And we established a method to accurately assess the sex of the northwest Chinese population. The comparison with the results of teeth measurements made the conclusion more reliable.

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.

Comparative study of cranial measurements between sexes from Brazil and The Netherlands: A cone-beam computed tomography study

The objective of this study was to better understand human variation by comparing cone-beam computed tomography-based cranial measurements between both sexes of individuals from two distinct populations: Brazilian and Dutch. Cone-beam computed tomography volumes of 311 patients between 20 and 60 years from Brazil and The Netherlands were selected. Two radiologists performed 16 linear measurements in the maxillary sinuses and mandibular canal. Kruskall-Wallis test compared measurements of the two cranial structures between male and female for the two populations and four age ranges (20-30, 31-40, 41-50, 51-60). Mann-Whitney test compared individual measurements obtained from the cranial structures between male and female for each population, and between both populations for both sexes. Intra- and inter-observer reliability was assessed by intraclass correlation test (α = 0.05). No significant differences were found in the linear measurements among the experimental groups including sex, population and age group for both cranial structures (p > 0.05). Most of the cranial linear measurements were significantly higher for male than those for female irrespective of the population (p ≤ 0.05). When the populations were compared regardless of sex, Brazilians presented four significantly higher measurements, and Dutch presented seven significantly higher measurements (p ≤ 0.05). The assessed cranial structures did not differ between Brazilian and Dutch populations for both sexes and four age ranges. Multiple linear measurements differed between both populations with a predominance of larger dimensions for the Dutch population.

Assessment of Anatomical Uniqueness of Maxillary Sinuses through 3D-3D Superimposition: An Additional Help to Personal Identification

Paranasal sinuses represent one of the most individualizing structures of the human body and some of them have been already analyzed for possible applications to personal identification, such as the frontal and sphenoid sinuses. This study explores the application of 3D-3D superimposition to maxillary sinuses in personal identification. One hundred head CT-scans of adult subjects (equally divided among males and females) were extracted from a hospital database. Maxillary sinuses were segmented twice from each subject through ITK-SNAP software and the correspondent 3D models were automatically superimposed to obtain 100 matches (when they belonged to the same person) and 100 mismatches (when they were extracted from different individuals), both from the right and left side. Average RMS (root mean square) point-to-point distance was then calculated for all the superimpositions; differences according to sex, side, and group (matches and mismatches) were assessed through three-way ANOVA test (p < 0.017). On average, RMS values were lower in matches (0.26 ± 0.19 mm in males, 0.24 ± 0.18 mm in females) than in mismatches (2.44 ± 0.87 mm in males, 2.20 ± 0.73 mm in females) with a significant difference (p < 0.001). No significant differences were found according to sex or side (p > 0.017). The study verified the potential of maxillary sinuses as reliable anatomical structures for personal identification in the forensic context.

Accuracy comparison of tooth volume and mesiodistal diameter measurements for sex dimorphism based on cone-beam computed tomography: a study for the northern Chinese population

Sex estimation based on teeth could help to narrow the scope for individual identification. According to the different teeth morphology among both genders, we plan to establish a sex estimation method for the northern Chinese population through mesiodistal diameter and teeth volume measurements and compare the accuracy of the two methods. In this study, measurements were taken from cone-beam computed tomography images collected from 142 males and 140 females aged 21-59 years. The mesiodistal diameter and volume of the left canines and the first molars in both upper and lower jaws were measured and analyzed for suitable coefficients. We selected 80% samples as the training set to set up the logistic regression formulas and 20% as the test set to obtain accuracy. The accuracy of sex estimation by mesiodistal diameter can reach 87.50%, and the volume is up to 78.57%. The measurement of mesiodistal diameter is less time-consuming. This work established and tested a method to estimate sex for the northern Chinese population. Results showed that sex estimation based on the mesiodistal diameter of teeth has higher accuracy than the method based on teeth volume.

Automatic sex estimation using deep convolutional neural network based on orthopantomogram images

Sex estimation is very important in forensic applications as part of individual identification. Morphological sex estimation methods predominantly focus on anatomical measurements. Based on the close relationship between sex chromosome genes and facial characterization, craniofacial hard tissues morphology shows sex dimorphism. In order to establish a more labor-saving, rapid, and accurate reference for sex estimation, the study investigated a deep learning network-based artificial intelligence (AI) model using orthopantomograms (OPG) to estimate sex in northern Chinese subjects. In total, 10703 OPG images were divided into training (80%), validation (10%), and test sets (10%). At the same time, different age thresholds were selected to compare the accuracy differences between adults and minors. The accuracy of sex estimation using CNN (convolutional neural network) model was higher for adults (90.97%) compared with minors (82.64%). This work demonstrated that the proposed model trained with a large dataset could be used in automatic morphological sex-related identification with favorable performance and practical significance in forensic science for adults in northern China, while also providing a reference for minors to some extent.

A comparison of maxillary sinus diameters in Chinese and Yemeni patients with skeletal malocclusion

BACKGROUND

This study aimed to compare the maxillary sinus dimensions and surface area in accordance with skeletal malocclusion, gender and ethnicity factors in a sample of Chinese and Yemeni patients.

METHODS

This cross-sectional study analysed 180 maxillary sinuses using 180 lateral cephalometric radiographs. The patients were subdivided into two ethnic groups: Chinese and Yemeni. Each ethnic group comprised 90 patients, and men and women were divided equally. Each ethnic group was classified into three skeletal classes using ANB and Wits appraisal (skeletal Classes I, II and III). Pearson's correlation coefficient was also used to assess the relationship between maxillary sinus dimensions and cephalometric parameters.

RESULTS

Men had larger maxillary sinuses than women; skeletal Class II had a higher length and surface area increase than other skeletal classes, although skeletal Classes I and II were almost equal in height. Except for the maxillary sinus length, none of these findings were statistically significant. The maxillary sinuses in Chinese are larger than those in Yemenis (P = 0.000). These variables were positively correlated with SNA, SNB and Co-A. The maxillary sinus length and Co-Gn were positively correlated. The NA-APO and NA-FH angles were also correlated with the maxillary sinus surface area. However, the gonial and GoGn-Sn angles negatively affected the maxillary sinus dimension and surface area.

CONCLUSIONS

Men had larger maxillary sinuses than women in both ethnic groups, and Chinese individuals had larger maxillary sinuses than Yemenis. Skeletal Class II malocclusion of both ethnicities had larger maxillary sinus dimensions. Furthermore, the maxillary sinus dimensions correlated with cephalometric parameters.

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.

Effect of orthodontic maxillary posterior en masse intrusion anchored with miniplates on maxillary sinuses volume. Retrospective CBCT study

OBJECTIVE

To evaluate, by means of cone beam computed tomography (CBCT), the volume change of maxillary sinuses in patients that underwent orthodontic maxillary posterior en masse intrusion anchored with miniplates.

MATERIALS AND METHODS

The sample consisted of pretreatment (T1) and posttreatment (T2) CBCT scans obtained from 14 patients (4 male and 10 female), with a mean age of 32.4 years, that underwent orthodontic maxillary posterior en masse intrusion anchored with miniplates in the zygomatic crest. The mean treatment duration was 20 months and the mean intrusion movement was 2.4 mm. Maxillary sinus volume was measured by means of the software ITK SNAP (version 3.8.0) in T1 and T2 CBCT scans. The changes in sinuses volume were calculated by T1-T2 values. Data were analyzed statistically with Wilcoxon test at 5% of level of significance and the method error was analyzed with Wilcoxon test, intraclass correlation and Dahlberg's formula.

RESULTS

The mean difference (T1-T2) was -242.85 mm³ (p = 0.396) for the right sinus and -32.5 mm³ (p = 0.875) for the left sinus. A slight increase in the volume of the sinuses was shown although these results were not statistically significant.

CONCLUSION

The orthodontic maxillary posterior en masse intrusion anchored with miniplates did not influence significantly the maxillary sinus volume.

Morphological evaluation of the incisive canal with reference to gender and age: A cone-beam computed tomography study

Background

The incisive canal (IC) is an important anatomical structure in the premaxilla that should be considered during many dental procedures.

Aims

The objective of this study is to associate the IC morphology and dimensions with reference to gender and age by means of cone-beam computed tomography (CBCT).

Patients and Methods

A retrospective study was conducted using archived CBCT records of patients who sought treatment at the Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia. OnDemand 3D Imaging software was utilized in image reconstruction and measurement determination. The parameters evaluated were the IC shape and dimensions in a sagittal and coronal view at two levels: palatal opening and nasal opening. The variables were compared according to age and gender using one-way Analysis of Variance (ANOVA) and Kruskal Wallis tests. Confidence level was obtained at P < 0.05.

Results

Out of the 370 CBCT images assessed, only 100 images fulfilled the inclusion criteria; 50 males and 50 females. No substantial variance in IC shapes was found in both the sagittal and coronal perspectives with reference to age and gender. Likewise, there was no statistical variation in IC dimensions with reference to age. On the other hand, there was a statistical difference in IC length when correlated with gender as the male subjects had longer IC as compared to females (P < 0.01).

Conclusion

There is no association between IC morphology, age and gender. However, substantial variation in IC length was observed between genders.

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.

Do the dimensions of the hard palate have a relationship with the volumes of the upper airways and maxillary sinuses? A CBCT study

Background

As the hard palate is a central structure of the skull, and its close relationship with the nasal cavity, oral cavity, and maxillary sinuses, it would be of interest to study if there is a relationship between this bone and other structures of the stomatognathic system. Thus, this study aimed to assess the dimensions of the hard palate and associate them with sex, and skeletal and breathing patterns. Also, to investigate if there is a relationship between these dimensions and the volumes of the upper airways and maxillary sinuses.

Methods

Two hundred and ninety-eight CBCT scans of patients were classified according to sex, and skeletal and breathing patterns. Then, the linear dimensions of width and height of the hard palate at the regions of the first premolars and first molars, and the volumes of the upper airways and maxillary sinuses were measured using the CS 3D Imaging and ITK-SNAP software, respectively. Data were submitted to multi-way analysis of variance and linear regression, with a significance level of 5% (α = 0.05).

Results

Sex and facial type influenced the hard palate dimensions (p < 0.05). Males had greater width and height of the hard palate than females (p < 0.0001). It was observed greater width for brachycephalics at the first premolars region (p = 0.0032), and greater height for dolichocephalics at the first premolars (p = 0.0154) and first molars (p = 0.0038) regions. Skeletal malocclusion and breathing pattern did not influence the measurements of the hard palate (p > 0.05). There was a significant relationship between the width and height of the hard palate at the premolar’s region and the total volume of the upper airways (p = 0.018, and p = 0.038), and between both dimensions of the hard palate at the molar’s region and the total volume of the maxillary sinuses (p < 0.0001).

Conclusions

The hard palate dimensions are influenced by sex and facial type, but not by skeletal malocclusion or breathing pattern. Also, there is an association between these dimensions and the volumes of the upper airways and maxillary sinuses.

Influence of skeletal class and facial type on nose dimensions in a Brazilian subpopulation: a CBCT study

Evaluating factors that may influence the nose dimensions and, therefore, contribute to the singularity of a person, is important for obtaining a precise facial reconstruction (FR) in forensic anthropology. Thus, the aim in this study was to evaluate the influence of sex, skeletal class, and facial type on nose dimensions of Brazilian individuals using cone-beam computed tomography (CBCT) scans. CBCT images of 54 males and 67 females were classified according to skeletal class (class I, II, or III) and facial type (brachycephalic, dolichocephalic and mesocephalic). Linear and angular measurements of the nose were performed using the CS 3D Imaging software. The measurements obtained for males and females were compared by one-way ANOVA. Two-way ANOVA was used to compare the measurements in the different skeletal classes and facial types. Significance level was set at 5%. All linear measurements were greater in males (p < 0.05); the angular measurements, however, did not differ between sexes (p > 0.05). Linear and angular measurements of class III males were significantly different from the other classes; the same was observed for the angular measurements in females (p < 0.05). Regarding facial types, some linear measurements were significantly greater in dolichocephalics males (p < 0.05). For females, there was no influence of facial type (p > 0.05), except for the nasal convexity angle. Nose dimensions differed in specific points among different skeletal classes and facial types, and there was sexual dimorphism in all linear nose dimensions. This information may be applicable for nose reconstructions, allowing more reliable FR.

Forensic Evaluation of Highmore Antrum Sexual Dimorphism by Cone Beam Computed Tomography: A Retrospective Study of a Peruvian Population

Objective:

The aim of this study was to evaluate Highmore antrum sexual dimorphism by cone-beam computed tomography (CBCT) in a Peruvian population.

Materials and Methods:

This was a retrospective analytical study. The sample consisted of 190 CBCT scans. Inter-observer concordance was performed previously obtaining an intraclass correlation coefficient (ICC) of 0.99 for the width, length, and height of the right and left maxillary sinus. Then the dimensions of the maxillary sinus (left and right) were measured. All statistical analyses were performed using the Student's t test and Lambda de Wilks, establishing a level of significance of P < 0.05.

Results:

It was observed that on the right side of the maxillary sinus there were only statistically significant differences between the width, height, area, perimeter, and volume of the Highmore's antrum and sex with a P < 0.05. Statistically significant differences were observed between sex and the width, height, area, perimeter, and volume of the Highmore's antrum in the right side of the maxillary sinus (P < 0.05), whereas the left side only showed statistically significant differences between the height and volume of the Highmore's antrum and sex (P < 0.05).

Conclusion:

The maxillary sinuses have significant sexual dimorphism, with the parameter of height showing the greatest dimorphism according to the discriminant analysis.

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.

Automatic CT image segmentation of maxillary sinus based on VGG network and improved V-Net

PURPOSE

The analysis of the maxillary sinus (MS) can provide an assessment for many clinical diagnoses, so accurate CT image segmentation of the MS is essential. However, common segmentation methods are mainly done by experienced doctors manually, and there are some challenges such as low efficiency and precision. As for automatic methods, the initial seed points and adjustment of various parameters are required, which will affect the segmentation efficiency. Thus, accurate, efficient, and automatic segmentation method of MS is critical to promote the clinical application.

METHODS

This paper proposed an automatic CT image segmentation method of MS based on VGG network and improved V-Net. The VGG network was established to classify CT slices, which can avoid the failure of CT slice segmentation without MS. Then, we proposed the improved V-Net based on edge supervision for segmenting MS regions more effectively. The edge loss was integrated into the loss of the improved V-Net, which could reduce region misjudgment and improve the automatic segmentation performance.

RESULTS

For the classification of CT slices with MS and without MS, the VGG network had a classification accuracy of 97.04 ± 2.03%. In the segmentation, our method obtained a better result, in which the segmentation Dice reached 94.40 ± 2.07%, the Iou (intersection over union) was 90.05 ± 3.26%, and the precision was 94.72 ± 2.64%. Compared with U-Net and V-Net, it reduced region misjudgment significantly and improved the segmentation accuracy. By analyzing the error map of 3D reconstruction, it was mainly distributed in ± 1 mm, which demonstrated that our result was quite close to the ground truth.

CONCLUSION

The segmentation of the MS can be realized efficiently, accurately, and automatically by our method. Meanwhile, it not only has a better segmentation result, but also improves the doctor's work efficiency, which will have significant impact on clinical applications in the future.

Variations in pulp volume between normotensive and hypertensive individuals on CBCT imaging

OBJECTIVES

To compare the pulp volume of individuals with altered and normal systemic blood pressure (BP) in order to verify if high BP promotes dimensional modifications in the pulp space.

MATERIALS AND METHODS

Cone beam computed tomography scans of 91 patients (49 females and 42 males, mean age 31.7 ± 6.38 years) who had a healthy maxillary canine were selected. Values of arterial BP measured at two dental visits were used to classify the sample as normal BP (< 130 × 80 mmHg) and altered BP (≥ 130 × 80 mmHg); 49 patients had normal BP and 42 had altered BP. One oral radiologist evaluated each patient's pulp and tooth volumes, using semi-automatic segmentation, and the tooth length. Data were submitted to Student's t test and logistic regression, with a significance level of 5% (p < 0.05).

RESULTS

Pulp volume (p = 0.0027), pulp volume/tooth volume (p = 0.0013), and pulp volume/tooth length (p = 0.0007) ratios were greater in the altered BP group. Conversely, there was no difference in tooth volume between the groups (p = 0.0697). A logistic regression model (p = 0.0002) using pulp volume and age enabled the development of a formula for predicting altered BP, with 68% accuracy.

CONCLUSIONS

Individuals with altered systemic BP have greater pulp volumes than those with normal BP. The formula developed in this study may indicate the presence of altered BP.

CLINICAL RELEVANCE

As arterial hypertension is a silent disease that produces no warning signs or symptoms, identification of modifications in the pulp volume in cone beam computed tomography scans may be an adjuvant sign of the diagnosis of this disease.

Age and sex estimation based on pulp cavity volume using cone beam computed tomography: development and validation of formulas in a Brazilian sample

OBJECTIVES

To develop and validate formulas for age and sex estimation based on the pulp cavity volume of teeth using cone beam CT.

METHODS

The sample was composed of 116 cone beam CT scans from Brazilian individuals of both sexes, ranging in age from 13 to 70 years. A total of 232 teeth (upper central incisors and canines) were evaluated. Two calibrated examiners determined pulp cavity volumes using the ITK-SNAP software. Pearson's correlation test was used to assess the correlation between chronological age and pulp volume. Linear and logistic regression models were developed for age and sex estimation, respectively, and were validated in another sample of 72 teeth.

RESULTS

Pearson's correlation coefficients between age and pulp volume were negative and significant (p < 0.0001) for both teeth (r = -0.8782 for central incisors and r = -0.8738 for canines). The age estimation formulas showed good determination coefficients (adjusted R² = 0.7614 to 0.8367). For sex estimation, when the age was known, the coefficients were also good (adjusted R² = 0.649 to 0.812). However, when the age was unknown, the coefficients of the sex estimation formulas were low (adjusted R² = 0.047 to 0.393). Validation showed high accuracy of age estimation in individuals older than 35 years, as well as high accuracy of sex estimation when the age was known.

CONCLUSIONS

Our formulas provided excellent results and can be applied to the Brazilian population. The best results were observed for age estimation in females and for sex estimation when the age was known.

Accuracy of ITK-SNAP software for 3D analysis of a non-regular topography structure

OBJECTIVES

To evaluate the accuracy of ITK-SNAP software for measuring volumes of a non-regular shape structure, using cone beam computed tomography (CBCT) scans, besides for developing a mathematical model to correct the software measurement error in case it existed.

METHODS

A phantom made by moulding a rubber duck's head was filled with total (38,000 mm³) and partial volumes of water (7000 mm³, 14,000 mm³, 21,000 mm³, 28,000 mm³ and 35,000 mm³), which constituted the gold standards. The sound phantom and the phantom filled with different volumes of water were scanned in a Picasso Trio CBCT unit set at 80 kVp, 3.7 mA, 0.2 mm³ voxel and 12 × 8.5 cm field of view. Semi-automatic segmentation was performed with ITK-SNAP 3.0 software by two trained oral radiologists. Linear regression analyzed the relation between ITK-SNAP calculated volumes and the gold standard. Intraclass correlation coefficient was applied to analyze the reproducibility of the method. Significance level was set at 5%.

RESULTS

Linear regression analysis showed a significant relationship between ITK-SNAP volumes and the gold standard (F = 22,537.3, p < 0.0001), with an R² of 0.9993. The average error found was 4.7 (± 4.3) %. To minimize this error, a mathematical model was developed and provided a reduction of it. ICC revealed excellent intra-examiner agreements for both examiners 1 (ICC = 0.9991, p < 0.0001) and 2 (ICC = 0.9989, p < 0.0001). Likewise, inter-examiner agreement was excellent (ICC = 0.9991, p < 0.0001).

CONCLUSION

The software showed to be accurate for evaluating non-regular shape structures. The mathematical model developed reduced an already small error on the software's measurements.

Evaluation of volume of the sphenoid sinus according to sex, facial type, skeletal class, and presence of a septum: a cone-beam computed tomographic study

We have used cone-beam computed tomographic (CT) images to retrospectivelyevaluate the influence of sex, skeletal class, facial type, and the presence of septa on the volume of the sphenoid sinus in 172 images from 85 men (mean (SD) age 28 (2) years) and 87 women (mean (SD) age 30 (1) years). Skeletal class and facial type were calculated for each patient from multiplanar reconstructions using NemoCeph® software. Volumetric analysis of the sphenoid sinus was made with the help of the ITK-SNAP® 3.4.0 segmentation software, while the presence or absence of septa in the sphenoid sinus was evaluated with the Carestream 3D Imaging® software 3.4.3. We analysed the results using two-way ANOVA, Student's independent sample t test, and Fisher's exact test, as appropriate, and probabilities of <0.05 were accepted as significant. Sex (p=0.0946), facial type (p=0.790), and skeletal class (p=0.120) had no significant influence on the volume of the sphenoid sinus, and nor did the volumes of the right and left sphenoid sinuses (p=0.0923), or the presence of a septum within the sinus (p=0.330) in its volume.