ROUGHOSCOPY: FUNDAMENTALS, CLASSIFICATION AND USES - ANATOMY AND PHYSIOLOGY - 2025

The rugoscopia is the study of the palatal rugae for identifying an individual. Palatal ridges (rugas) are the transverse ridges or elevations located in the anterior third of the hard palate, behind the upper teeth and the incisive papilla. They are the irregularities that are felt with the tip of the tongue in the roof of the mouth.

Numerous studies place its first description in 1732. Jacob B. Winslow, a Danish-born but naturalized French anatomist, gives a detailed explanation of palatal rumps in his work Exposition anatomique de la structure du corps humain, in which he hints at the possibility of identifying corpses by analyzing these structures.

However, it was more than a century and a half later that Allen (1889) and Kuppler (1897), in separate essays, formally proposed the possibility of identifying racial groups and individuals by studying the anatomy of the hard palate. Years later, rugoscopy would be accepted as a forensic identification method along with date and odontoscopy.

At present the use of rugoscopy is universally accepted and has been fundamental in the resolution of criminal cases, especially in those involving corpses or bodies with massive anatomical damage. Forensics jokingly comment that "fingerprints burn, teeth and palate not."

Fundamentals

The first publications of Winslow already speak about the unique characteristics of palatal rugas between different individuals. Decades of studies have confirmed this idea.

The bones that make up the hard palate - Maxillary and Palatine - have a particular rough surface on their underside, covered by a mucosa rich in collagen.

Collagen fibers are accompanied by adipose tissue and other structures that give it its own shape and structural support. A specific type of hydrophilic glycosaminoglycans goes hand in hand with collagen fibers and gives them a different direction to each one, which ends up drawing a unique pattern of palatal ruffles for each individual.

Palatine wrinkles form between weeks 12 and 14 of intrauterine life. They take a little longer than fingerprints to appear. Once fully developed, they remain unchanged for the rest of life and even remain unchanged long after death.

An advantage of rugoscopy is that the hard palate is protected by its anatomical location. On the side the cheeks provide protection and cushioning.

In front are the lips and teeth, which offer a very hard shield and difficult to break through. Finally it has the tongue underneath, a resistant muscle that prevents its traumatic damage.

characteristics

All the above conditions offer rugoscopy 4 fundamental characteristics as an identification method:

Uniqueness

Being unrepeatable, only an individual can have a certain specific pattern.

Immutability

It never changes its shape or its position even when subjected to violent compression actions, intentional or not.

Individuality

Even in identical twins there are notable differences.

Perenniality

Or perpetuity. It is the same before the person is born and after the death.

Classification

Identification of an individual through rugoscopy requires prior recognition. The first dental and palatal records were carried out through impression with moldable material. Initially wax and rubber were used, then alginate and today silicone is used.

Another possibility is the radiological record. Imaging studies are performed on the majority of patients who undergo dental procedures, be it a simple X-ray, a CT scan or an MRI. All of these are useful for recognizing palatal rumps and being able to classify them.

There are several described classifications of palatal rugas, including:

Basauri method

It is one of the most recognized classifications by forensic doctors and dentists, being accepted in litigation and criminal trials. Classify the wrinkles in:

Six simple types

- Point (A1)

- Straight (B2)

- Angle (C3)

- Winding (D4)

- Curve (E5)

- Circle (F6)

The combination of two or more of these produces the polymorphic types.

Four compound types

- Ye (ancient Y Greek)

- Chalice

- Racket

- Branch

Da Silva classification

It uses the same simple Basauri types, but only assigns them a number. The compound lines are formed by joining the simple lines, whose identification code will be the sum of the numbers of each simple line that makes it up.

Cormoy system

Classify the wrinkles according to their length, direction and unification.

According to the length:

- Main creases> 5 mm

- Accessory wrinkles between 3 and 4 mm

- Fragmentary lines <3 mm

According to the direction

- Forward

- Backward

- Perpendicular

According to the unification

- Convergent: different origins in the middle raphe with final union.

- Divergent: same origin in the middle raphe with final separation.

Trobo Classification

It is very similar to Da Silva's classification, substituting the numbers for the first 6 letters of the alphabet. Those closest to the midline of the palate are identified with the capital letter and the furthest in lowercase. Compound rugas are identified by a letter X.

Applications

As mentioned in the previous sections, the main use of rugoscopy is the identification of people. Although it is common for the individuals to be identified to have passed away, rugoscopy is sometimes an alternative to recognize criminals, lost people with Alzheimer's or disoriented psychiatric patients.

Source: Pixabay.com

In catastrophic situations with massive deaths, rugoscopy has proven helpful. This method is especially relevant when the corpses have suffered significant damage to their anatomy and classical identification procedures are useless. Its application in air accidents and floods has already been successful.

Forensic dentistry - a specialty that deals with rugoscopic studies - is already accepted as a vital instrument in criminal cases.

There are not few cases in which the findings of this instrument have decided trials and helped to convict criminals. Strict dental records are recommended throughout the world because of this.

References

1. Mohammed RB, Patil RG, Pammi VR, Sandya MP, Kalyan SV, Anitha A. Rugoscopy: Human identification by computer-assisted photographic superimposition technique. Journal of Forensic Dental Sciences. 2013; 5 (2): 90-95. Available at: ncbi.nlm.nih.gov/
2. Shamim T. The reliability of palatal rugoscopy in forensic identification. Annals of Saudi Medicine. 2013; 33 (5): 513. Available at: annsaudimed.net/
3. Gadicherla P, Saini D, Bhaskar M. Palatal rugae pattern: An aid for sex identification. Journal of Forensic Dental Sciences. 2017; 9 (1): 48. Available at: jfds.org
4. Poojya R, Shruthi CS, Rajashekar VM, Kaimal A. Palatal Rugae Patterns in Edentulous Cases, Are They A Reliable Forensic Marker? International Journal of Biomedical Science: IJBS. 2015; 11 (3): 109-112. Available at: ncbi.nlm.nih.gov/
5. Grimaldo-Carjevschi M. Rugoscopy, Cheiloscopy, Occlusography and Occlusoradiography as identification methods in forensic dentistry. A review of the literature. Venezuelan Dental Act. 2010; 48 (2). Available at: actaodontologica.com
6. Bayón-Porras A. Discrimination of race and sex through the use of rugoscopy. Final degree project in dentistry. University of Seville - Faculty of Dentistry. Available at: idus.us.es/
7. Ramos-Matute GA. Forensic palatal rugoscopy as a method of human identification through comparative analysis. Journal of the Faculty of Medical Sciences. 2015; 2 (1): 37-42. National Autonomous University of Honduras. Available at: bvs.hn/