a case study in estimating age based on
TRANSCRIPT
t`•. Acta Med Kinki Univ •
Vol. 36, No. 1 37-40, 2011
A case study in
odontologica
estimating age based
1 findings in skeletal
on forensic
remains
Nobutaka
Department
Okusa, Hitoshi Nishio, Hiroshi Noda and Shinji
of Legal Medicine, Kinki University Faculty of
Osakasayama, Osaka, 589-8511, Japan
Tatsumi
Medicine,
Abstract
A method for estimating age based on oc-
clusal wear of the teeth and palatine suture
morphology has been widely used. This allows us
to estimating age based on macroscopic findings. However, even if the living status and jaw
growth are taken into consideration, the accu-racy of this method is not sufficient. In this
case, a marked difference was observed in esti-
mated age between two methods based on the degree of occlusal wear and palatine sutures.
To avoid this discrepancy, a number of
approaches, including radiography, a comparison
of the morphology of teeth using a study model, and data preparation employing dental charts
are necessary. Some factors, such as distortion,
growth and developmental disorders of the jaw-
bone, diet, occlusal relationship, and habits often
influence age estimation especially when the
dental attrition degree of the tooth is used.
When there is a discrepancy in the estimated
age, caution should be exercised. There is an
individual difference in the status of the syne-
chia. We observed a case that misled us into
presuming younger age. It is rare that estimated age is higher than a real age. Age estimation is
performed from both sides of dental attrition and
palatal suture in this time. This case demon-strated a large discrepancy in age estimation
between dental attrition and sutures of the
palatine bone.
Key words : forensic odontology, dental attri-
tion, age estimation, palatine suture
Introduction
In skeletal or charred remains lacking the soft
tissue, hard tissues such as the teeth, bone, nails,
and hair provide important information. In
particular, the teeth are important because the influences of external physical and chemical
factors are slight. Many methods for estimating
age from skeletal remains have been reported.
Ogata et al. evaluated part of the skull based on
radiographs and the palatine sutures, and esti-
mated the age.' Kimura et al. estimated age
based on the degree of occlusal wear by employ-
ing Takei's method for personal identification.2
Tomaru et al. estimated age based on the
degree of occlusal wear of the mandibular inci-
sors, and reported a correlation between the
occlusal wear index and age.' In our depart-
ment, we have also made an identification by
superimposition using dental films in a previous
case, as well as for suspect identification.4'5 In
this paper we report a case in which there was a
marked difference between the age estimated
based on the degree of occlusal wear and that
based on the palatal sutures of skeletal remains.
Case
In April in a previous year, a primary school
student playing in the mountains discovered a
skeletonized femur, and reported it with his
mother to the police. During a search of the
vicinity, the right femur, right tibia, mandible,
and skull were discovered. Since the sites of
discovery differed among these bones, we anal-
yzed to determine whether the bones belonged to
Received September 15, 2009 ; Accepted January 24, 2011
37
N. Okusa et al.
the same person and estimated age.
Forensic odontological findings
The autopsied cadaver had 2 mandibular and 7 maxillary remaining teeth (total, 9 teeth). The
postmortem missing teeth were the left central incisor, left lateral incisor, left canine, left first and second premolars, left first and second molars, and the right central incisor (8 teeth) in the maxilla and the left canine, left first and second premolars, and the right first and second
premolars (5 teeth) in the mandible (total, 13 teeth) (Figs. 1, 2, 3). There was a maxillary fracture with a border between the hard and soft
palates ; almost all horizontal plates of palatine bone is lacked. Alveolar bone of maxillary right
Fig. 1
• y4 , •
• , .-.;
4T
E
.. , • . .-. • • e .
sk A. ;,::.
i1 •-:-., . v , ' ' t-.,?..:1 .
1
: . . t:-tf- •-.,,
•.,
LI
Occlusal surface of maxillary dentition. Breakage is
seen in the boundary of the hard and soft palate. All
almost horizontal plate of palatine bone is lacked.
Showing missing tooth was right second molar, right
first molar, right first and second premolars, right
central incisor, left central incisor, left lateral incisor,
left canine, left first and second premolars, left first
and second molars. There is no treatment the remain-
ing teeth.
)
Fig. 2 Front of maxillary dentition
molar is lacked. And it is unknown whether the
maxillary right second molar was present. Con-
cerning the palatine sutures, since there were clear incisor sutures on the left and right sides
and the left transverse palatal suture, the age was
estimated to be about 20-30 years. However,
occlusal wear was marked in the anterior area of the mandible, and the cusps and edges had large-
ly disappeared (Figs. 3, 4). The exposure of
dentin was seen observed in zonal patterns. In addition, when the method of Takei was used, it
was calculated with 60.4 years old, suggesting an
age of more than 60 years. No treatment scars
were noted in the remaining teeth.
Discussion
In living bodies and cadavers for analysis,
worn, treated, and carious teeth are often mixed.
In this case, the degree of occlusal wear is
examined. In skeletal remains, the palatine
sutures are also examined. We found that, the
YL
%. •
r'
• 17
. -••••
Obit. Pfleidt - '
Fig. 3 Occlusal surface of mandib exposed in the front tooth.
The front tooth overlaps
Showing missing tooth w,
premolars, left canine, premolars. There is no tre
teeth.
•
Fig. 4 Front
cusp is
"jc.
of mandibular dentition. Dentin is
tps because of crowding.
as left first and second
right first and second
treatment on the remaining
if 04-
N,. yr F1
of mandibular dentition.
dental attrition.
Incisal edge and
38
A case study in estimating age based on forensic odontological findings in skeletal remains
estimated age based on the degree of occlusal wear (young age) markedly differed from that based on the palatal sutures (advanced age). The age difference was about 30 years, which may be associated with jaw growth, the ingested types of food, occlusal relationship, and habits. Among
jaw deformities and growth abnormalities, man-dibular protrusion due to maxillary hyperplasia or mandibular hyperplasia is often observed, as well as maxillary protrusion, cross bite, and open bite. Cases of maxillary undergrowth due to the
prevention of maxillary sinus enlargement by chronic sinusitis during the growth period have been reported. Thus, a more careful and detailed interpretation of findings is important. This case showed no mandibular overgrowth due to the mandible deformity. Excluding the mandibular
protrusion, the crowding of the mandibular anterior teeth could be suspected. Therefore, we speculate that insufficient growth space during infancy induced occlusal abnormality, and exces-sive tooth contact in the crowding area during mastication caused occlusal wear abnormality. However, Abe et al. classified malocclusion into
superoinferior, anteroposterior, horizontal, crowding, and spaced dental arches, and perfor-med mastication experiments using various types of food. These experiments demonstrated that it was difficult to eat many types of food with superoinferior or anteroposterior malocclusion.6 Miyatani et al. measured the mean occlusal force during mastication in patients with maloc-clusion, and reported that the patients had a lower occlusal force than normal occlusion. In addition, compared with females, males show no significant correlation between masticatory abil-ity and maxillofacial or dental arch morphol-ogy.' Therefore, mild crowding except greater number of teeth does not markedly affect the masticatory muscle strength or masticatory abil-ity.8 In this case, we speculate that the mas-ticatory muscle or ability had not been affected, but excessive occlusal wear due to crowding in addition to physiological occlusal wear was the reason for the estimation of more than 60 years of age.
Concerning the palatal sutures, the closure state markedly varies among individuals, and the age estimated based on sutures is lower than the chronological age. As Sakaue et al. showed, estimation of the minimal age based on macro-scopic findings alone, tends to cause errors even if attention is paid to the occlusal relationship.9
In addition to macroscopic findings, radiogra-
phy is sometimes used. X-ray films provide information on the degree of tooth calcification,
the presence or absence of the pulp, and treat-
ment states. The possibility of locating antemor-
tem films is high, and these films can be useful
data for comparison. In addition, the morphol-
ogy and state of crowns can be evaluated in a
study model, and dental charts can be produced.
Therefore, radiography in addition to macro-
scopic findings provides data to support dental
charts and is also useful for comparison with a
study model. These methods are indispensable
for the accurate estimation of age and subsequent
rapid identification. This rare case, which
showed a large discrepancy in age estimation
between dental attrition and sutures of the
palatine bone, led us to reconsider not only the accuracy of the usual estimation methods but
also various factors of aging from anatomi-
physiological findings and the roentgenological
point of view. In conclusion, it is necessary to combine several findings derived from alveolar
bone degree without depending on one estimate
alone both sides of the dental attrition degree
and the suture to improve the reliability of the
age estimation. Forensic age estimation from
skeletal remains is still important. We should
take occlusal growth into consideration if the
estimated age shows inconsistency.
References
1. Ogata K, Sukegawa Y (1989) A part of example of
forensic odontology examination of heated brainpan. Jpn J Legal Med 43 : 214 (in Japanese)
2. Kimura T, Innami T, Takizawa N, Tsunoda R,
Tsutsumi H, Ueno M, Yokosawa S, Komuro T, Takei T (1986) Example of one thing of odontology depart-ment opinion's becoming important clue of identifica-
tion. Nihon University Dental Journal 60: 219-223
(in Japanese) 3. Tomaru Y, Uchiyama Y, Kobayashi K, Kudo Y, Mikami H, Endo M, Tsukamoto T, Terazawa K (1993) Age Estimation from Tooth Attritions of lower Inci-
sors-Discussion on the Amano's Method-. Jpn J Legal Med 47 : 13-17 (in Japanese)
4. Tatsumi S, Ogata K, Shinoda 0, Mizohata M, Noda
H, Yamaguchi M, Sugiyama S (2001) One example of identification by superimposes that uses dental film. Jpn J Legal Med 55 : 394 (in Japanese)
5. Tatsumi S, Noda H, Sugiyama S (2002) An Instance of identification of the Sudpect by Superimposition the Dentition. The Research and Practice in Forensic
Medicine 45 : 147-152 (in Japanese)
39
N. Okusa et al.
6. Abe Y, Miyatani M, Tategi C, Takahisa S, Ishii T, Nomura M, Mogi E, Sueishi K, Kawano M, Yanagis-awa S (2008) About the relation to physical properties
of the malocclusion and food-Physical properties- of the seen food. The first report food result of the
questionnaire. The journal of Tokyo Dental College Society 108 : 405 (in Japanese)
7. Miyatani M, Abe M, Tategi C, Takahisa S, Ishii T, Nomura M, Mogi E, Sueishi K, Kawano M, Yanagis-
awa S (2008) About the relation to physical properties of the malocclusion and food-Physical properties- of
the seen food. -Biting strength of malocclusion person
who enumerated food not to chew the second report easily. The Journal of Tokyo Dental College Society
108: 405 (in Japanese)
8. Nagata Y, Inoue M, Rensya H, Nagaya K, Kanbara T (2007) About the relation among the chew ability, biting strength, and craniofacial morphology. Journal
of Osaka Odontological Society 70: 193-203 (in Japanese)
9. Sakaue K, Adachi N (2007) A verification of the
method for estimating age-death using Maxillary suture obliteration in Japanese. Jpn J Legal Med 61 : 121-128 (in Japanese)
40