Dental ecology is the study of how teeth respond to the environment through

natural selection or during the life of an animal (Cuozzo i Sauther, 2012).

Tooth wear is a very useful variable in this discipline because it can reflect

feeding ecology, animal fitness, survival and age. The positive correlation

between age and occlusal tooth wear has been demonstrated in both human and

wild mammal populations, including several primates, deers, gazelles, koalas,

racoons, wolves and leopards.

Introduction

• Field data record

Immobilization of study subjects and acquisition

of tooth casts (left mandible) of 36 individuals.

Final sample size: 7 youngs + 5 adults

Material & Methods

Beatriz Fernández Jané

Study site

AIM HIPOTHESYS

How age can explain the

differences on tooth wear in

alpine marmot (Marmota

marmota).

Adults present higher tooth wear than

youngs (<1 year) , which produces:

a) Lower dental complexity

b) Lower crown relief

c) Higher interproximal wear

Pyrenees

Catalan Pyrenees: mountain range on

North East of Spain

Study locations:

La Cerdanya 1900 - 2300 m

Vall d’Aran

Habitat: subalpine grassland dominated

by true grasses, like Festuca sp.

Cerdanya 1900 - 2300 m

Vall d’Aran 1500 - 2000 m

• Laboratory methods

Obtaining the positive tooth casts with standard

methodology (Galbany et al., 2010).

• Analysis of tooth casts : first molar

Calculi of three descriptive quantitative variable of dental morphology.

• Statistical analysis

T-student, to compare youngs with respect to adults using R Stadistical program.

Relief indexRelation between 3D area and the

projected area.

Dental compexity (OPC,

Orientation Patch Count)Contiguous points (minimum 3) with

the same orientation that grouped

together configure a unit called patch.

Interproximal wearMeasured as mesiodistal length, the

distance on the occlusal surface

between the central points where

teeth in the same jaw come into

contact.

Generation

3D image

Generation

topografic

map

Generation

orientation

map

Step...

Localitation of Pyrenees in Europe.

YOUNG ADULT

OPC =45,731 OPC= 32, 561

Upper, 3D image of young and adult molar. Lower, the

respective orientation maps and the OPC value of this.

1 mm 1 mm

...to obtain

Results & Discussion

Relief index

Conclusions

T-student, to compare youngs with respect to adults using R Stadistical program.

This variable does not reveal significant differences between

the two age groups (p>0.05). But adults show lower values.

This result suggest that the angularity of tooth crown surfaces

is conserved despite tooth wear. Some studies in primates

have reached the same conclusion (Ungar i M’Kirera, 2003).

Maybe the current sample size does not include individuals

with enough age to show a significant decrease on cusps

angularity.

1) Sample size: too small to see differences in some variables.

2) Big heterogeneity in adult class because it includes all individuals of more than one year

together.

3) Another factors that might influence on tooth wear:

• Interpopulation differences: change of habitat, feeding behavior and genetic differences.

• Sex: behavioral differences (ex. feeding behavior) and female reproductive effort.

• Social structure: dominance rank can have effects in grazing and diet qualities.

This variable does not show significant differences between

the two age groups (p>0.05).

More individuals and a higher variability of age classes are

likely needed to see statistical differences. Moreover, there

are other factors that might influence this variable, including

the eruption of the molars, tongue and bucal contraction, or

the action of oclusion on dental crowns.

Interproximal wear

References:

- Cuozzo FP & Sauther ML. 2012. What is dental ecology? American Journal of Physical Anthropology 141(suppl 50): 89.

- Galbany J, Altmann J, Pérez-Pérez A & Alberts SC. 2011. Age and individual foraging behavior predict tooth wear in Amboseli baboons. American Journal of Physical Anthropology 144(1): 51-59.

- Ungar PS & M'Kirera F. 2003. A solution to the worn tooth conundrum in primate functional anatomy. PNAS vol. 100, no. 7: 3874-3877.

Limitations

Dental complexity

Dental complexity in adults is significantly (p<0.001) lower

than in youngs.

As age increases, the complexity of the dental morphology

decreases due to contact between the molars of the

mandible and maxillary (attrition), as well as contact with

food (abrasion).

• The obtained results suggest that age has an effect on dental

complexity, which decreases with the age.

• Dental wear could be used in further studies as a possible

indicator of diet in marmots, or even reflect a possible habitat

degradation if there is a change or modification in the consumed

vegetation.

• Future studies could show that tooth wear is related to some

behavioral variable, as is the position of the individual in the

social structure, or reproductive effort of females.

OP

C

Age class

Young

Re

lie

fin

de

x

Age class

Young

Me

sio

dis

talle

ng

ht

(mm

)

Age class

Young

Boxplot of mesiodistal length. Boxplot of relief index. Boxplot of Orientation Patch Count.

4.2

4

.3

4.4

4

.5

4.6

4

.7

Young AdultAdultAdult

1.8

0

1.8

5

1.9

0 1

.95

2

.00

2

.05

25

30

3

5 4

0 4

5