They say the eyes are the window to the soul, but the spaces above them can reveal a person’s identification. These holes in the skull can fill the “holes” in a forensic investigation when a dead body is discovered.
“The frontal sinuses are so variable among people. They’re the fingerprint of the skull,” says Lauren Butaric, Ph.D., associate professor of anatomy.
Dr. Butaric recently received a two-year $357,871 grant from the National Institute of Justice (NIJ) to better understand how the structures of the frontal sinuses can be applied more precisely in forensic settings. She focuses her research on craniofacial variation, particularly the internal structures of the skull and ways they vary. The unique structure of the frontal sinuses makes it useful to forensic scientists and medicolegal practitioners to identify unknown decedents, such as those discovered at potential crime scenes.
“Let’s say a skull is found in the woods,” she says. “Performing DNA analysis is expensive, there are no fingerprints and analysis of the dental remains may be inconclusive. In these cases, the frontal sinus may be used for identification purposes.”
That isn’t new, she adds. Several methods exist to objectively assess the sinuses by matching antemortem and postmortem radiographs and/or CT scans. However, these methods “have not been thoroughly validated and there is no consensus on the most appropriate method,” she stated in her grant application. Greater understanding of the methods will support more accurate identification of decedents.
Heather Garvin, Ph.D., D-ABFA, associate professor of anatomy, is a co-principal investigator on the project, and students also will be involved.
“Although objective methods of analyzing the sinuses have been published, because of the lack of consensus, practitioners rely merely on visual comparisons, which isn’t seen as the most scientific,” Dr. Garvin says.
In the NIJ study, researchers will test the accuracy and error rates of eight methods for frontal sinus identifications that utilize such measures as a sinus specimen’s height, length, visual appearance, size and age. Each method’s applicability to traditional radiographs and CT scans also will be assessed.
The study’s ultimate goal is development of a set of empirically based guidelines that meet the Daubert standard, used in federal courts and some state courts to assess whether an expert witness’s scientific testimony is based on scientifically valid reasoning.
“For evidence to be forensically used in court, it has to be precise and repeatable,” Dr. Butaric says. “We want to identify the most reliable method forensic investigators can use based on a set of guidelines and the evidence they have. We’re not necessarily creating a single gold standard for analysis, but rather a single place investigators can go to choose the best method that’s workable and applicable to the situation and resources they have. They will be able to give citations based on our study’s report.”
DMU’s Human Skeletal Biology Lab is ideal for the study given Dr. Butaric’s expertise on craniofacial variation and the qualifications of Dr. Garvin, who is among approximately 90 board-certified forensic anthropologists in the nation and the only one in Iowa. She assists the state medical examiner’s office in scene recoveries, skeletal identifications, interpretation of skeletal trauma and testifying in court as necessary. The two faculty members are past recipients of an internal DMU research grant related to assessing error rates in using the frontal sinuses of the skull to identify deceased individuals, given the high level of precision required in a court of law.
Another advantage is that while the study will involve a large sample of specimens, it won’t require acquiring them from scratch.
“What’s really cool is we already have a lot of these samples and a large collection of x-rays and CT scans based on my research and Dr. Garvin’s research. Plus a lot of databases are available online,” Dr. Butaric says. “Especially in today’s day and age when traveling is discouraged and many institutions are closed due to the pandemic, we won’t have to travel. It’s all available at our fingertips as researchers.”
DMU students already have been engaged in and will continue to work on the study. The grant also will support the hiring of a post-doctoral researcher and provide some tuition funding for students in the University’s newly minted Master’s of Anatomy Thesis Track. Dissemination of the study’s results will entail at least five peer-reviewed publications, presentations at national conferences as well as NIJ reports.
“While it is going to be a lot of work to complete this study, when you get a grant, it’s because you have a clear plan and clear goals you can document,” she says. “I also look forward to the help DMU students and our post-doctoral researcher will bring. Mentorship is a big part of this grant and what a lot of grant-funders are looking for.”