I bet you’ve never heard of forensic odontology.
It’s a highly specialised branch of dentistry that plays a vital role in estimating the age of unknown deceased individuals, and analysing bite marks, primarily to aid law enforcement and judicial systems.
When bodies are burned, decomposed, or otherwise unidentifiable through fingerprints or DNA, these specialists identify victims by comparing post-mortem dental findings with ante-mortem (before death) dental records.
Teeth are often used because they are the hardest part of the body, allowing them to withstand extreme fire, water and time better than other soft tissues.
Bite mark analysis is a forensic method used to identify individuals based on the patterns left by their teeth on a victim, object or other surfaces.
In addition, this niche group of dental specialists are also called upon during mass disaster scenarios (like plane crashes or natural disasters) to identify victims through their unique teeth structures.
While there is no official count of forensic odontologists globally, Malaysia has nine of them presently, with a few others in training.
“I’m the seventh one to qualify, and can you believe that even the police are not aware that we exist!” says Universiti Malaya (UM) Faculty of Dentistry senior lecturer and forensic odontologist Dr Rabiah Al-Adawiyah Rahmat.
The first forensic odontologist in Malaysia is Dr Rabiah’s mentor, Prof Emeritus Dr Phrabhakaran Nambiar, who specialises in both dental forensics and maxillofacial radiology.
He is widely credited with establishing and raising the standards of the field in the country.
A recognised method
Forensic post-mortems are carried out by a forensic pathologist, and if he deems it necessary, calls upon the forensic entomologist to determine the time of death based on insects found on or near a decomposing body.
Dr Rabiah says: “Depending on the case, we wait for the forensic pathologist to ‘summon’ us for a post-mortem, especially when the face of the unknown deceased is compromised, i.e. mutilated, decomposed or skeletonised, or there is only a skull, or when there are bite marks on the body.
“Our area of expertise is the neck and up.”
When a major catastrophe occurs, the three accepted methods by police worldwide for disaster victim identification are DNA analysis, fingerprint analysis and dental records.
“Not many people know, but we are as equally important as the other two and can stand on our own.
“Let’s say there is a plane crash, and if we can identify the body using one of these three methods, it is enough.
“We might also be able to identify them through medical records, but this is considered a secondary identification and is not enough.
“We still need the dental records, so in these scenarios, we are doing dental identification – not age estimation – to identify the body,” explains Dr Rabiah, who was involved in the ante-mortem findings of the MH17 flight tragedy in 2014, where 298 people perished, 43 of them Malaysians.
Although she was only a dental officer then, Prof Emeritus Phrabhakaran gave her the opportunity to be involved in identifying the victims.
Along with other experts, Dr Rabiah’s challenging task was to match the dental records of the victims with the data provided by investigators.
To avoid bias, the person who does the post-mortem is not the same one who looks into the ante-mortem data.
She recalls: “I stayed here to assist Prof Phrabhrakaran, who led the ante-mortem team that gathered all the dental records of the victims from all over Malaysia.
“We had to do it really fast, transcribe and prepare the collected data to hand over to the authorities.
“We managed to get more than 30 records.”
This sparked her interest in this speciality, and later, led her to pursue a PhD in forensic dentistry at the University of Adelaide in Australia.
However, prior to that, to ensure that Dr Rabiah was really suited for the field, her mentor sent her to the mortuary weekly to observe post-mortems and get used to seeing dead bodies.
This went on for a year, and eventually, she got comfortable in the environment.
She says: “My feeling is more towards empathy and it’s best not to know their stories, but as humans, we all want to know how the death happened.
“When I see a dead child, sometimes it affects my emotions, but when I see the perpetrator who also died, I get angry.”
The identification process
Dental identification is similar to doing dental checks.
A forensic odontologist examines specific aspects of the teeth, like morphology and pathology.
This includes the person’s teeth decay, fillings, fractures and unique root shapes; tooth position/arrangement; and root translucency and discolouration.
Dr Rabiah says: “First, we do a dental examination and check the jaw as this can estimate the original sex, then take a full X-ray of the mouth.
“Sometimes, we may have a suspicion of who the deceased is if he or she was found in a house.
“Most likely, it is the occupant of the house, so we’ll try to find the dental records of the person, although this can prove difficult as they may not have gone to the dentist.
“Once we get the records, we will translate them and compare with our findings to confirm the identity (primary identification method), then only the age estimation comes in,” she says.
In the past, based on the mandible (lower jaw), the forensic pathologist can give a rough age estimation, e.g. 30-40 or 40-60 years, but this does not help the police as the range is too wide.
Dr Rabiah says: “To narrow the age range, we now use one tooth by removing it from the deceased – it comes off easily and we insert it back after examination.
“For burnt bodies, because it is charred, the crown of the teeth is usually fragile, but we can still get the root.”
When someone is dying in a fire, their lips will part and the heat will cause part of the teeth to be damaged, but the roots are still there because they are embedded in the bone.
“That’s the beauty of teeth – they have protection from the bone, and the tongue will also give coverage to the teeth so the teeth at the back are usually intact,” she says.
More complex cases
Interestingly, if the front teeth are charred but not crumbled, the forensic odontologists are called in to stabilise the teeth.
They do this by using tapioca flour as glue.
“We spray it on so that the teeth will stay intact, at least until we bring the body back to the mortuary.
“I learnt this while I was in Australia.
“As age estimation is very population specific, we choose which tooth (i.e. molar, premolar, third molar, incisors or canine) to examine according to our available local data.
“For complex cases, we might need to examine more than one tooth.
“Even within our multiethnic population, the data is different.
“We found that Malays and Chinese are similar, probably because we are Mongoloids, but Indians are different, so we do have data just for Indians,” says Dr Rabiah.
If the body is heavily decomposed or skeletonised, or if only dental remains exist, cone-beam computed tomography (CBCT) – a technology very similar to medical CT imaging – is used to estimate the age of the person by analysing pulp-tooth volume, tooth structure and restorative work.
If the deceased has no teeth or dental records cannot be found, the experts then get the age estimation range based on the thickness and shape of the mandible.
Once, the UM team had a case where a body was brought in with an indented skull and injuries to its front and back.
“During the post-mortem, both the forensic pathologist and I had the same opinion – that a sharp object such as an arrow had penetrated the skull, and because the force was fast, it had indented the skull.
“The police may also call us if they find a tooth resembling a human tooth, e.g. in a cave, which could be from an orang utan as their teeth resembles human teeth.
“We do the age estimation and the forensic anthropologist will examine the skeletal remains to determine how long it has been there,” explains Dr Rabiah.
Verifying the living
Forensic odontology is not limited to dead bodies as these specialists, most of whom are practising dentists, can also verify the identities of live persons suspected of pretending to be someone else.
This is based on their teeth, skull and jaw, along with sex (as someone could have changed their gender) and ethnicity.
Or they can be called to give an expert opinion.
For example, they do age estimation for illegal immigrants and undocumented Malaysians.
“Age estimation is more important for the living.
“We had cases of foreign child labour where their documents show them to be 16 or 17 years old.
“Our government cannot simply deport them unless they are 18 and above, so, to confirm the child’s legal age, the authorities seek our help.
“This is crucial as it determines the fate of the child, so what we do is check the teeth, which may still be developing.
“We take X-rays, measure their teeth, then do a calculation based on a formula to get a rough age estimation,” says Dr Rabiah.
This method is more precise compared to other biological indicators such as measuring the skeletal maturity (bone age) of the wrists or hands.
She adds: “Bone is more affected by diet, so if the child is lacking nutrition or calcium, it won’t grow, but teeth will always erupt at the scheduled age unless the child has developmental anomalies.
“Even if the child doesn’t get enough milk, the teeth will still develop.”
After a decade in forensic odontology, Dr Rabiah is still fascinated by it.
She says: “During my first year as a dental officer in the Health Ministry, I saw a lot of patients in a day and was doing scaling, root canals, fillings, etc.
“I said to myself, I can’t be sitting on a dental chair, looking inside people’s mouths daily for the rest of my life.
“So I tried to find a way out and was hoping to be an oral surgeon, but it didn’t happen and I landed in this field.
“Now I love what I do.”
Soon, Dr Rabiah intends to pursue another speciality in oral maxillofacial radiology.
