Importance of frontal sinus radiographs for human identification

Investigating the link between frontal sinus morphology and craniofacial characteristics with sex: A 3D CBCT study on the South Indian population

Background: Measurement of craniofacial parameters plays an important role in sex determination in forensic science. The present study was done using cone beam computed tomography (CBCT) scans to evaluate the morphologic structure of the frontal sinuses and compare it with the width of nasal, cranial, maxillary and mandibular width which might help us in sex determination. Methods: A cross-sectional retrospective study was conducted using 142 full field of view (FOV) scans of patients archived from the department. The width of the nose, cranium, maxilla, and mandibular width was measured and compared with the frontal sinus between the two sexes. Results: A paired t-test was done to compare the linear measurements for both sexes' right and left frontal sinuses. The measurements were higher in males when compared to females. There was a statistically significant asymmetry (larger dimension on the left side) of the anterioposterior (p-value of 0.012) and superior-inferior dimensions in males (p-value of 0.135). Spearman's correlation showed that frontal sinus correlated with other craniofacial parameters like nasal, cranial, maxillary and mandibular width among both sexes. The frontal sinus, nasal, cranial, maxillary and mandibular widths were higher in males when compared to females (independent t-test). Discriminant function scores showed 66-68% accuracy to discriminate sex, using the anteroposterior dimension and mandibular width. Conclusions: The measurement of craniofacial parameters using CBCT can aid in determining the sex of unidentified and decomposed bodies.

Pott's puffy tumor in a 23-month-old: Youngest known case of a rare disease

This case report describes a child who developed Pott's puffy tumor and was treated at the Children's Mercy Hospital in Kansas City. In addition to a discussion of a case, a review of the literature was completed on this topic describing the typical embryology and development of the frontal sinus, and the epidemiology, diagnosis, and treatment of Pott's puffy tumor. The patient was a 23-month-old boy who developed Pott's puffy tumor after recovery from influenza. The patient presented to the hospital with progressing edema of the unilateral eye that spread bilaterally within a few days. A CT scan demonstrated pansinusitis, developed frontal sinuses, right periorbital cellulitis, and medial forehead subperiosteal abscess. Functional endoscopic sinus surgery and transcutaneous abscess drainage were urgently performed and the patient made a full recovery following a course of ertapenem and levofloxacin. The presence of a developed frontal sinus in a 23-month-old is an unexpected radiologic finding. This case represents the youngest patient reported in the literature to develop this rare complication of frontal sinusitis.

Are coding systems of frontal sinuses anatomically reliable? A study of correlation among morphological and metrical features

Frontal sinuses are of special interest for personal identification thanks to their high variability. A common procedure for comparing ante-mortem and post-mortem material is based on coding systems classifying frontal sinuses according to their morphological and metrical characteristics. However, the calculation of possible combinations is performed on the hypothesis that all the classified features are independent one from each other. This study aims at analysing the correlation among morphological and metrical characteristics of frontal sinuses. Two hundred CT scans of patients equally divided between males and females were segmented through the ITK-SNAP software. Number of accessory septations, scalloping and supra-orbital cells, side asymmetry and superiority, breadth, height, length and volume were extracted from the frontal sinuses of each subject. A possible relationship among morphological and metrical features was analysed through Pearson's correlation test, Mann-Whitney test or chi-square test according to the type of compared data (p < 0.05). In general, a positive correlation was found for all comparisons among metrical measurements (breadth, height, depth and volume) and number of septations, scalloping and supra-orbital cells (p < 0.05), but not between the number of scalloping and supra-orbital cells. In addition, side of asymmetry was positively related with side of superiority of the upper profile of frontal sinuses (p < 0.05). This study proved that morphological and metrical characteristics of frontal sinuses are strictly related one with each other: therefore, the coding systems based on these features should be applied with caution for personal identification, as the number of possible combinations is lower than reported by literature.

Three-dimensional analysis of sphenoid sinus uniqueness for assessing personal identification: a novel method based on 3D-3D superimposition

Sphenoid sinuses are considered the most variable structures of human body: therefore, they may be used for personal identification, through the application of 3D segmentation procedures. This study aims at proposing a new protocol for personal identification based on 3D-3D superimposition of sphenoid sinuses segmented from head CT scans. Adult subjects (equally divided among males and females) who underwent two head CT scans were extracted from a hospital database. Sphenoid sinuses were segmented through ITK-SNAP software and the corresponding 3D models were automatically superimposed to obtain 40 matches (when they belonged to the same person) and 260 mismatches (when they were extracted from different individuals). The RMS (root mean square) point-to-point distance was then calculated for all the superimpositions: differences according to sex and group (matches and mismatches) were assessed through the Mann-Whitney test (p < 0.05). On average, the RMS value was almost ten times smaller in matches (0.22 ± 0.11 mm) than in mismatches (2.16 ± 0.57 mm) with a statistically significant difference according to group (p < 0.05), but not to sex (p > 0.05). The study proposed a new method for assessing personal identification from segmented 3D models of sphenoid sinuses, useful in the forensic contexts where other methods might not be implementable or successful.

Human identification by FSS system adapted to cephalometric radiographs

The aim of this study was to verify the applicability and reproducibility of the FSS system [8] adapted for frontal and lateral cephalometric radiographs of the frontal sinus for human identification purposes. Eighty lateral and frontal digital cephalometric radiographs from a private Dental Radiology service's database were evaluated. Evaluations were performed in a dimmed lighting room, using a 4.200 lux lightbox with mask, ultrafan paper and pencil with a 0.5 diameter tip. The sheet of paper was superimposed on the radiograph to obtain the outlines of the frontal sinus and two examiners made the drawings independently at two different times, with a minimum period interval between evaluations. To obtain the linear physical measurements of the frontal sinus, a digital pachymeter was used. Later, all the discrete variables were codded for the statistical analysis. All variables were tested by means of the Cohen's Kappa test. The intraexaminer agreement ranged from good to perfect (p<0.001), while the interexaminer agreement ranged from regular to perfect (p<0.001). The use of frontal and lateral cephalometric radiographs was found to be reproducible and reliable for human identification by an adaptation of FSS system.

Sex determination in forensic odontology: A review

Forensic odontology is the application of dental principles to legal issues. Sex determination is a subdivision of forensic odontology and it is very important especially when information relating to the deceased is unavailable. Sex determination becomes the first priority in the process of identification of a person by a forensic investigator in the case of mishaps, chemical and nuclear bomb explosions, natural disasters crime investigations, and ethnic studies. This article reviews upon the various methods used in sex determination.

Human identification through frontal sinus 3D superimposition: Pilot study with Cone Beam Computer Tomography

As a unique anatomical feature of the human body, the frontal sinus morphology has been used for identification of unknown bodies with many techniques, mostly using 2D postero-anterior X-rays. With the increase of the use of Cone-Beam Computer Tomography (CBCT), the availability of this exam as ante-mortem records should be considered. The purpose of this study is to establish a new technique for frontal sinus identification through direct superimposition of 3D volumetric models obtained from CBCT exam, by testing two distinct situations. First, a reproducibility test, where two observers independently rendered models of frontal sinus from a sample 20 CBCT exams and identified them on each other's list. In the second situation, one observer tested the protocol and established on different exams of three individual. Using the open source DICOM viewer InVesallius(®) for rendering, Mesh Lab(®,) for positioning the models and CloudCompare for volumetric comparison, both observers matched cases with 100% accuracy and the level of coincidence in a identification situation. The uniqueness of the frontal sinus topography is remarkable and through the described technique, can be used in forensic as an identification method whenever both the sinus structure and antemortem computer tomography is available.

Assessment of frontal sinus dimensions to determine sexual dimorphism among Indian adults

BACKGROUND

Sex identification of unknown individuals is important in forensic sciences. At times when only skull remains are found and other means of identification fails, radiographs of frontal sinus can be used for identification. Frontal sinus morphology is unique to individual and can be used effectively in person identification; whereas its use in determining sexual dimorphism is limited.

AIM

To determine sexual dimorphism among Indians by evaluating frontal sinus pattern using postero-anterior radiograph.

MATERIALS AND METHODS

The right and left areas, maximum height and width of frontal sinus were determined in 300 digital postero-anterior view radiographs obtained from 150 males and 150 females aged between 18-30 years. The measurements were carried out by transferring the image to Adobe(®) Photoshop(®) CS3 extended. Comparison of values were done using student's t-test and accuracy of sex determination was assessed through Logistic regression analysis.

RESULTS AND CONCLUSIONS

One hundred and forty seven males and 142 females show presence of frontal sinus with seven individuals showing unilateral/bilateral absence of frontal sinuses. The mean values of the frontal sinus height, width and area are greater in males. Right frontal sinus is larger than the left sinus in both the sex. The mathematical model based on logistic regression analysis gives an average concordance index for sex determination of 64.6%. Thus, frontal sinus provides average accuracy in sex determination among Indian population. This may be due to its greater variation in morphology.

Use of frontal sinus and nasal septum patterns as an aid in personal identification: A digital radiographic pilot study

OBJECTIVES

To examine and classify the variations in the pattern of frontal sinus and nasal septum as observed on the posterior anterior Cephalometric radiographs, and to propose the possible use of the same in personal identification.

MATERIALS AND METHODS

This study was conducted on 50 individuals visiting the department, whose age ranged from 25 to 50 years. The radiographs of 25 males and 25 females were recorded using a Kodak 8000 C and Dental Imaging Software Viewer 6.3.4. Frontal sinus (symmetry and lobulations) and nasal septum patterns (deviations) were observed and classified.

RESULTS

Frontal sinus symmetry was observed in 29 (58%) individuals and asymmetry was observed in 16 (32%). Frontal sinuses were absent (bilateral aplasia) in two individuals (4%). Unilateral aplasia was seen in three individuals (6%). Straight nasal septum was seen in 11 (22%), right deviation in 21 (42%), and left deviation in 15 (30%) individuals. Sigmoid was seen in one male (2%), reverse sigmoid in one male (2%), and other pattern type in one female (2%). Both frontal sinus and nasal septum patterns were assessed together for each individual. Out of 50 individuals, 41 unique combinations of frontal sinus and nasal septum were found. However, there were nine individuals whose patterns matched one of the patterns of the 41 individuals.

CONCLUSION

We observed that the frontal sinus and nasal septum patterns had considerable individual variation. A combined use of both the patterns, as observed on the radiographs, could serve as an adjunct to other methods of personal identification.