Seminar: Forensic Odontology
By: Dr. Sanober Wasim
Department of Forensic Medicine and Toxicology,
JN Medical College, AMU, Aligarh.
Forensic Dentistry has been defined by Keiser – Nielsen as that branch of odontology which in the interest of justice deals with the proper handling and examination of dental evidence and with the proper evaluation and presentation of dental findings.
The first formally reported ease of dental identification was that of the 80 years old warrior John Talbot, Earl of Shrews bury, who fell in the battle of Castillon in 1453.
The first forensic odontologist in the United States was Dr. Paul Revere who identified the extremed body of Dr. Joseph Warren, a revolutionary the British in 1775 through a bridge of silver and ivory that he had constructed two years previously.
Dental evidence was first accepted in the United States court in the Webster – Parkman case. Dr. J.W. Webster allegedly stabbed, dismembered on Nov., 23, 1849 in Bostan charred fragments of mineral teeth fused to gold were recognized as those of the deceased by Dr. Nathan Parkman. This evidence was enough for the jury to a verdict of guilty of premeditated murder against Dr. Webster who was subsequently hung.
The first treatise on forensic odontoly was written by Dr. Oscar Amoedo in 1898 and was entitled L’Art Dentaire en Medicine Legale. Dr. Oscar is also known as father of Forensic Odontology.
In 1937 in Chantilly, a murder was convicted on the evidence of the bite marks that the victim inflicted during her struggle for life.
In 1946 Welty and Glasgow devised a system in which as many as 500 cards with dental data could be sorted in one minute by a computer.
The following year Taltersall wrote that he advoscted the Hollerith system of punch cards and thought this would be very beneficial in compiling dental data.
The scope of this specialty has expanded since the end of the 1939-1945 was due to the quarter intensity of international traffic coincident are destroyed and often teeth and dental restoration are the only means of idea tificat available.
Internationally there is an obvious growth of interest in this field there are organizations such as the Scandinavian society of Forensic Odontology, the Federation Dentaire International. The Canadian Society of Forensic Sciences, the American society of Forensic Odonto9logy and the American Academy of Forensic Sciences.
The international Journal of Forensic Dentistry and the Forensic Odontology Section of INFORM are important references for members of Forensic team involved in Odontology.
Mammalian dentition is mostly diphodont (two dentitions – deciduous and permanent) heterodont (morphology differs in different parts of the mouth) dentition attached to the joins by gomphoses (fibrous liganentous material embedded into the surface of the jroot and into the surface of the bone which envelops the roots.
A mammalian tooth may be considered as consisting of seven component parts – namely (Diagram)
The alveolar cavities with contain teeth are formed around the 3rd or 4th month of IOL Dev. of tooth begins with the format of cellulas tooth germ within the alveolar bone, in the shape of the crown. Apposition and calcification of enamel and dentin take place within the germ and the crown is completely formed and calcified before any positional changes occur. Root to formation begin after completion of the crown and as root becomes longer the crown erupts through the bone and finally comes out of the jaws. The root is completed some time after the tooth is on full functional occlusion. The teeth calcify from crown to neck to roots.
During eruptioin of a permanent tooth, the overlying root and its deciduous predecessor simultaneously undergoes absorption until only the crown remains. The unsupported crown their falls off.
Temporary, deciduous or milk teeth are so is no. 4 incisor, 2 canines and 4 molars in each jaw.
Permanent teeth are 32 in no 4 incisors, 2 canine 4 premolar and 6 molars in each jaw. Developmentally they are divided Into:
a) Supper added Permanent teeth: are those which do not have deciduous predecessors. All the permanent molars are super add. perm. Teeth. They erupt behind the temporary teeth.
b) Successional Permanent teeth: those, which erupt in place of deciduous teeth. They are ten in each jaw.
Incisors: The crown is shaped like Chisel and is convex on its labial surface and concave on lingual surface except near the neck, where the surface becomes convex. The neck is slightly constructed. The root is single.
Canines: - They are larger that the incisors. The crown is large and conical, very concave on its labial surface and slightly concave on its lingual surface. Its masticatory edge tapes to a blunt point, which projects slightly beyond the level of the other teeth.
The root is single, larger and thicken than that of an incisor.
Premolars or Bicuspids They are smaller and shorter than the canines. The crown of each is nearly circular in cross section and slightly compressed mesio distally. The chewing surface has two cusps. The root is usually single but may be double.
Molar They ar largest with broad crown. The crown is cubical; convex on its labial and lingual surfaces, and flattened on its mesial and distal surfaces. It has three four or five cusps. Each upper molar has three root and lower two.
1. Malpractice and all aspects which may eventually bad to criminal charges in the form of fraud.
2. Neglect, where damages may be sought.
3. Identification of individual remains where death is not due jto lsuspiciious circumstances.
4. Identification of a living person – less of memory.
5. Major or mass disaster – the identification of wetion of an air craft or train disaster or a fire in a public building.
1) living Person
2) Dead person
1) In food stuff
2) On the assailant
3) On the victim
i) Self inflicted
ii) Inflicted by another
1) Universal System
Each tooth is given one no which is 1 through 16 for upper and 17 through 32 for lower.
2) Palmer’s notation
The teeth is numbered 8 to 1 starting from 3rd molar and moving to the midline.
With arch denoting the respective quadrant.
= rt upper
= left upper
= rt lower
= left lower
3) FOI two digit system Federation Dentaire Internationale. Similar to Palmar’s notation but uses a no. for the quadrant sign and that no. is placed before the tooth.
4) Modified For system Even first no. designate left side (2,4)
Odd first no. designate right side (1,3)
Identification by tooth
Mongoloid – Shovel shaped incisor.
Presence of a cusp on the anterior portion of the buccal surface of the lower molars.
Sidges on the lingual surface of incisiors.
Rounded and large lower st molar.
- flat lingual surface on the incisors
- cusp of carabelli +nt
- 3 cusps in 2nd molars.
- Lower 1st molar longer and once tapering.
- Small and square lower 1st molar.
- Average tooth size larger than Europeans.
- Three rooted molars common.
- Missing lower incisor and 3rd molar common.
- Impacted 3rd molar if that with 5 or more cusps.
Endemic dental fluorosis given characteristic marking of enable with yellow brown and white areas.
Incidence of caries is more in civilized countries due jto large sugar intake in the diet.
Cast steel and aluminium crowns frequently originate in Europe.
In expensive gold plated crowns common in far East.
Dental caries + overall low degree of restorative dentistry and large no. of previous extradition is endicative of low sociocion status.
V shape mendible in males. U shaped in female.
In permanent dentition roots larger in males.
Skull and teeth are more prominent in males.
Detection of chrom in the dental pulp of males.
There is a relatively high degree of accuracy in age estimation through histologic methods of IU tooth form with begins from 3rd – 4th month of IUL.
Birth – 6 months – mineralization of the deciduous crowns and the overall state of tooth dev.
6-13 months state of eruption of deciduous teeth
1-14 years eruption pattern and histologic information
14-15 year development calefaction of apex, eruption of 3rd molar.
Late 20’s onwards position of gingival attachment.
Amount of attrition apical resorption.
Eruption of tooth
- Abraded tooth due to habit of biting on one’s glasses, pipe, pens, pencils, bobby pins.
- Dark generalized slain is heavy users of tobacco and caffeine.
- Oral abrasion in mucisians from playing an instrument, traffic officers who blow whistles, aabitial lenson and soft drink users.
- Generalized break down in habitual users of narcoties.
- Colour changes in user of betel nuts.
- Destruction of crown and circular defect around the neck of the tooth in chronic users of opium and methaimphetamine.
- Cu causes a green silver a black and lead, aniline and bismith a bluish colour particularly at the neck of the teeth or at the marginal part of the gum.
Cocaine abuses black colour of teeth H2SO4 – Ethnic groups can be identified through chalky white certain customs.
Filling and mutilatioin of teeth in certain African and Australian tribe.
Extensive wear on the teeth of Eskimos and Indians who constantly chew leather.
Panting of teeth in Japanese women.
Bite mark evidence is mainly supportive and is of little value unless properly developed and interpreted.
Bites on human tissue are found primarily is 2 types of homicide.
1. Grs. Involving sexual activity.
2. Abused child homicide victims.
In the sexual activity gr. The bite demonstrates excellent detail and many lives, there is a discoloration in the center indicating a such mark.
Bites in the battened child gr. Are diffuse and exhibit poor details. Laceration are frequent indication they were inflicted in a faster manner than previously described.
It has been obscived that bite marks can never be assumed to reproduce accurately the dental cord teen of the originator because only a limited no. of teeth are included and the material in which the mark has been left whether it be human skin or food stuff will probably be an unsatisfactory impression malenation unknown qualities of immediate and later shunt age and distooth.
In all bite ark cases it is imperative that photo graphs be made as soon as possible because of probable subsequent distortion of the evidence. The photographs are taken in both color and black and white with the light directed at different angles to demonstrate the alignment of individual teeth and their relationship to the opposite arch. It is important to photo graph a mille meter rate with the bite mark as evidence for reference and in case of human skin to have an anatomical land mark included.
Quite often there is a characteristic colour at the necksand crowns of teeth which were 1st described by Bell in 1835; now referred to as Pink Teeth.
It is thought to be associated with rapid decomposition in which the hemoglobin from the blood in the pulps forced into lthe dentainal tubules, thereby produary a pink tooth.
Human bite marks are usually semi circular or crescentric caused by the fronth teethwith a gap at either side due to the separation of upper and lower jaw.
Examination of the dental status of a suspect is done only after written consent. A tooth by tooth written record with diagram plaster models mounted in a good articulator and several bite marks produced in wase, plasticine are taken.
A cast of the mouth of suspect is taken and transparency of his bite is compound with that of the unknown bite.
The methods used to record the dental data are diagrammatic chart.
Present and future needs in the field of forensic odontology.
U 7-9 m
L 10-12 m
1st m - 12-14 m
Canine 17-18 m
2nd m 20-30 m
1st m - 6-7 yrs.
CI 6-8 yrs.
LI - 7-9 yrs.
1st bicusped 9-11 yrs.
2nd bicupid 10-12 yrs.
Canine 11-12 yrs.
2nd molar 12-14 yrs.
3rd molar 17-25 yrs.
Present and future needs in the field of forensic odontology
Internatinal standardization of charting
Centalised international registry of missing persons.
Research in bite marks saliva washy lip prints sex determination