Case report

A body at an advanced stage of decomposition was found and transported to the Forensic Medicine Department (SML) of a city in southern Brazil. Given the impossibility of identification through other methods, the assistance of the forensic odontology service was requested to perform the necessary examinations. Following police inquiries, the family of the presumed victim was located and contacted. The family provided a CT scan with access to the original DICOM files, which was used to support the forensic odontological comparison. The forensic odontology team received only the cranial segment of the body, which was in an advanced state of decomposition, including skeletalized portions, areas of liquefaction, and a sectioned cranial vault for the examination of the cranial cavity.

The cranial segment was subjected to radiological examination of the paranasal sinuses to assess the remaining bony structures (Fig. 1). Subsequently, the mandible was removed to facilitate a detailed forensic odontological examination (Fig. 2).

Fig. 1: Radiographs of the paranasal sinuses: (A) frontal view and (B) lateral view

Fig. 2: Maxillary (A) and mandibular (B) dental arches in occlusal view, with individual teeth identified according to FDI dental notation

A comparison between postmortem and antemortem examinations was performed, and no unexplained discrepancies were observed, with multiple positive matches recorded.

The morphology of the frontal sinus in the AM and PM examinations was analyzed, allowing for a detailed comparative assessment. To demonstrate morphological compatibility between the imaging of the missing person and the victim, direct comparisons were performed (Figs. 3 and 4), as well as the superimposition of a virtual 3D model onto a two-dimensional (2D) image. For the superimposition, a digital model of the frontal sinus was generated from the CT scan provided as antemortem material. This file was then imported into a virtual 3D environment, where it was adjusted in scale and rotation to align with the postmortem radiographic image, using the width of the frontal sinuses as a reference. Compatibility between the analyzed data was confirmed by the correspondence of anatomical structures in the anterior view (Fig. 5).

Fig. 3: Forensic odontological comparison between an axial CT slice of the maxilla and the occlusal view of the maxillary arch, showing morphological compatibility as well as correspondence between present and absent teeth, their rotational position, and the presence of prostheses on anterior teeth

Fig. 4: Forensic odontological comparison between an axial CT slice of the mandible and the occlusal view of the mandibular arch, showing morphological compatibility as well as correspondence between present and absent teeth, their rotational position, and the presence of silver amalgam restorations.

Fig. 5: Process generating a digital 3D model of the frontal sinus from the reference CT. Below, this file was adjusted for scale and rotation on the PM radiograph, demonstrating morphological compatibility between the two records. The degree of radiographic image opacity is indicated in each segment