One of the most challenging research is human identification in crime or disaster. Cheiloscopy is one of the upcoming aid in forensics. Identifying the identity is the fundamental form of Legal medicine and civil cases. Forensics is one of the forms of investigation to arrive at a result in an unanswerable crime or man-made disaster. The word forensic derived from the Latin word ‘forensics’ means ‘in open court’ or in ‘public’ or pertaining to the forum. Odontology refers to the study of teeth and their effects. Further, forensic dentistry plays a major role in identifying man-made or natural disasters that may not be identifiable through conventional methods such as visual recognition or even fingerprints.
In addition, dental evidence play a very crucial role in criminal investigations such as bite marks, etc. The other forms of investigations in forensics include dactyloscopy (fingerprint analysis), dental records ( included teeth, etc), DNA analysis. Moreover, if the evidence for these methods is missing, for soft tissue analysis we need a reliable method. Cheiloscopy is one of the most valuable methods in forensic dentistry. The study of lip prints in a case of dental evidence helps in a disaster. Hence, this article highlights the importance of cheiloscopy in forensic dentistry.
WHAT IS CHEILOSCOPY?
The word cheiloscopy is derived from the Greek word cheilos meaning lips. Cheiloscopy is one of the upcoming aid in forensics. It deals with the identification of lip prints or lip patterns. To clarify, the study of lip prints termed cheiloscopy. Similar to fingerprints, DNA pattern lip prints have a unique role. Using lip prints sex determination is also possible. There are lots of grooves on lips, similar to fingerprints. Hence, using this, identification is made possible in a crime.
Before moving on to the topic, we should know about lip anatomy. Lip is one of the most sensitive mobile soft tissue of the body. The lip contains muscles, skin, sebaceous glands, and mucous membrane. The two parts of the lip include the upper lip and lower lip. To clarify, the upper lip portion formed by the labial portion and the lower lip portion formed by labial commissures.
Lip has two coverings includes mucosal as well as cutaneous covering. The most important portion of the lip is the vermilion border. This plays a crucial role in maintaining lip impressions. This portion has a mucosal portion, thin epithelial portion, vascularized part, and few sebaceous glands. The grooves present in lips also play a very important role. In addition, the lip performs functions like swallowing, drinking, emotional activities, etc.
HISTORY OF CHEILOSCOPY:
Cheiloscopy was first described by Anthropologist Fisher. Lip prints described as a tool in forensic, in 1932 by Edmond Locard, one of the greatest criminologists in France. In 1950, Synder described the importance of lip grooves and also found that these lip grooves are as unique as fingerprints. A lot of studies done about cheiloscopy. Interestingly found that this will be effectively similar to dactyloscopy.
CLASSIFICATION OF LIP PRINTS (CHEILOSCOPY):
Martin Santos was the first person to suggest a classification for lips. Basically, he classified lips into simple lips and compound lips. Further, based on the grooves present it’s classified into:
|SIMPLE LIPS||Straight grooves |
|COMPOUND LIPS||Bifurcated grooves|
The wrinkles and grooves present in the lips, have been termed by Tsuchihashi as ‘sulci labiorum ruborum’. Further, these grooves are termed as lip prints. Therefore, based on the presence of grooves, he further classified into six types, they include:
|Type I a||Clear cut vertical grooves, run across the entire lip.|
|Type I b||Similar to type 1, do not cover the entire lips.|
|Type II||Branched grooves.|
|Type III||Intersected grooves|
|Type IV||There will be the presence of radicular grooves|
|Type V||Grooves that cannot be morphologically differentiated.|
There are many classifications such as Renaud classification etc. Hence, the above two classifications, are the most common classifications used and practised widely.
LIP PRINT TRACES:
Firstly, lip prints may be left at crime scenes and can provide a direct link to the suspect. In crime cases, murders rape the traces of lip prints left behind. Using a magnifying lens, the traces of lip prints should be looked at on window glasses, mugs, glass doors, cutlery things, paintings, cigarette ends, etc. And also, lip prints leave traces similar to fingerprints. They also leave traces in food products like tooth marks. Hence, lip prints have the same value as dactyloscopy traces. Mostly, women have clear-cut vertical grooves and branched grooves ( type 1 and 2 ). Men have intersected and radicular grooves ( type 3 and 4). Hence, using lip pints sex determination is also possible.
COLLECTION OF LIP PRINTS:
Most importantly, the three types of lip prints left in the criminal cases include,
Visible lip prints:
These types of lip prints will be visible directly, at crime scenes. Moreover, they don’t need to be visualized properly. Such types of lip prints termed visible lip prints.
Hidden or latent lip prints:
They are not visible in direct eyes, need a special types of instruments or processes for visualization. Meanwhile, such types of lip prints referred to as hidden or latent lip prints.
Three-dimensional lip prints:
Lip prints left behind as soft gel-like areas are not visible. And also, these types of lip prints can be taken in photography as well.
After the collection of these types of lip prints, using aluminium powders, aluminium oxides, magnetic oxides, fluorescent dyes the lip prints, traced from glasses, plastic things, etc. Therefore, these traces will be obtained on the paper by cellophane tape, etc. Further, if lip traces are found with lipstick marks they play a very important role.
LIP STICK AND LIP PRINT TRACES:
Lipstick one of the most attractive cosmetic. Most of the women get attracted to the different shades of lipstick. The recent forensic research involves lipstick prints in crime cases. Moreover, the traditional use of lipsticks was essential to leave behind coloured traces of lip prints. In recent years, however, lipsticks have been developed that do not leave any traces. Such lipsticks referred to as smear-less lipsticks.
The two types of lip prints left as traces include:
- Conventional lip prints
- Persistent lip prints.
Conventional lip prints:
Consequently, this refers to lipstick smears that may be left often as evidence in criminal cases.
Persistent lip prints:
Persistent lip prints refer to, the traces, not left behind as evidence in cases. In recent years, the cosmetic industry started to manufacture lipstick, which doesn’t leave any sort of traces. Hence, these kinds of lipsticks don’t leave any sort of visible traces.
EXCEPTIONAL CRITERIA FOR CHEILOSCOPY:
It’s quite difficult to find or to assess the lip prints if there is scaring in the lips
In case any sort of cosmetic surgery done on lips for scarring. As lasers might affect the grooves and fissures present in the lips.
The lip morphology might be altered. For example, smaller size lips or larger sizes are quite difficult to analyze. Further, any kind of surgery performed on the lips. Therefore, these have a high impact on fissures and grooves, and lips. Analyzing will be quite difficult in these conditions.
After finding the traces of the lip prints in crime scenes. The analyses performed using aluminium powder or magnesium powder. The powders applied to the traces and analyses to be done. And also, aluminium oxides, fluorescent dyes, magnetic oxides also been used to find lip traces, similar to fingerprints. Moreover, in old studies, they have found that the red furrow present in the lips is unique only for humans. Interestingly, many studies, done long back; found positive results for cheiloscopy.
Recently, the Japanese have found smear-less lipsticks for lip prints. If this kind of lipstick applied, doesn’t leave any kind of smears, lip traces will be done in an easier way. Moreover, still studies going about this. Another study, to determine the sex using lip prints and need further research to be done.
ROLE OF FORENSIC DENTISTS:
Forensic odontology plays a very important role in abuse cases, among persons of all age groups. Morphologically using teeth we can determine the age of a person. And also, using the skeletal remains, the alignment of teeth we can also determine the sex, whether the person is male or a female. Moreover, forensic dentists maintain accurate dental records by providing accurate information to the legal authorities. Therefore, this prevents malpractice and fake information. Further, they also play a crucial role in identifying unknown persons.
Above all, forensic dentists take dental impressions, radiographs of the dental remains, attend the autopsy, and takes photographs. And also identification of dental remains begins by comparing the teeth, as well as the occlusion, with the available dental records. Moreover, forensic dentists also compare anti mortem and post mortem dental radiographs. Subsequently, this step is the most crucial step in determining a person’s identity. Therefore, a forensic dentist should have the knowledge and to arrive at the result.
To conclude, forensics plays a very important role in investigations and criminal cases. In addition, the other methods in forensics include DNA imaging, bite marks, dental profiling, etc. Hence, cheiloscopy is an upcoming aid in forensics. Further development leads to identification in an easier way.