**3.1.1 Dental caries**

40 Contemporary Approach to Dental Caries

The two first samples show contrasting socioeconomic status, whether we consider that the populations were clear separated in the Mikulčice settlement. In order to compare the "urban" samples with a clear different lifestyle, we chose to study a third sample coming

The archaeological site of Prušánky, is situed at less than 10 km from Mikulčice. This geographical closeness does not reflect proximity in the lifestyle. Indeed, the cemetery associated at this site represents a rural population (Beeby et al., 1982). The location near the power center induces clear exchanges between the two community, but the lifestyle is different. This second site seemed to be self-sufficient (Klanica, 2006a). 676 burials

The last sample under study comprises 173 juvenile individuals from newborn to late adolescent. In the figures and table, this sample is named Prušánky and is abbreviated "Pk".

MkB, the "aristocratic" and churchmen sample, representing the highest social class of

MkK, the "middle social class" (above all "craftsmen), who are poorer than the

Their teeth should reflect these life conditions and socioeconomic status. All the skeletal remains are deposited in the Department of Anthropology of the National Museum in

This study is only based on dental health and lifestyle and on the potential influence of the socioeconomic status on caries prevalence and enamel composition. However, it has been completed by an analysis on the same influence but on bone growth and composition.

The resulting dental sample consists of 6123 observed teeth. Table 1 gives the details for

In dental stress and caries assessment it is clearly desirable to record the least subjective stages and observations, in order to minimize the intra- and inter-observer errors (Danforth et al., 1993), both of which are often significant. The intra- and inter-observer error, for the protocol proposed below, has been tested and has been published in a previous paper (Garcin et al. 2010). As the protocol is the same in this study, we do not remind the results but we expose the features quoted and the statistical procedures

Both dental caries and enamel hypoplasia have been recorded because they give different information on enamel susceptibility to develop lesions. International dental charts were

used to identify the teeth (such as n° 18 to 11 for upper right permanent teeth).

accompanied by Moravian archaeological remains were excavated (Klanica, 2006b).

And Pk, the rural place, where the lifestyle contrasts with the two others.

**2.2.4 Comparison with other data** 

the site;

Prague.

**3. Methods** 

each sample.

individuals of MkB;

**3.1 Recording dental health and defects** 

employed for comparisons.

from a rural cemetery in the hinterland of Mikulčice.

Thus the three samples show different socioeconomic status:

The presence of caries was scored in all tooth types that is to say on deciduous and permanent teeth when detected macroscopically. When there was a doubt on caries development because of the tooth preservation, the development of the lesion was tested by a dental probe.

Four features were observed and scored for the lesions:

	- Stage 1: small lesion which affects only the enamel and less than 10% of the tooth surface;
	- Stage 2: medium lesion which affects both enamel and dentin and spread from 10% to 50% of the tooth surface;
	- Stage 3: large lesions penetrating all the dental tissues, enamel, dentin and pulp. They take more than 50% of the tooth surface.

These simple stages are easy to define, thus the results of scoring would be less prone to errors, because in archaeological record there are some cases of complex observations (Hillson, 2001), even if we cannot totally avoid subjectivity in such study. This subjectivity is all the more right when we attempt to analyze dental enamel hypoplasia.

### **3.1.2 Dental enamel hypoplasia**

Hypoplastic defects occur in three forms: linear, pitting and plane. However, their expression is different on deciduous and permanent dentition (Lukacs et al., 2001a; Lukacs et al., 2001b; Ogden et al., 2007). We chose to take into consideration the enamel hypoplasia only on the permanent teeth for the quoted features. Nevertheless, a paragraph in the results will be devoted to the different expressions of enamel hypoplasia on deciduous teeth. The presence of macroscopically observed enamel hypoplasia was noted in all types of permanent teeth.

Four characteristics have been recorded:


Socioeconomic Influence on Caries Susceptibility in Juvenile Individuals

**3.2 Estimating age-at-death** 

of all deciduous teeth;

second molars.

taken into account.

**3.3 Statistical procedures** 

tooth loss were applied.

 \*

with Limited Dental Care: Example from an Early Middle Age Population … 43

In archaeological samples, the first step for anthropological studies is the age-at-death estimation. This estimation will be useful to compare the different sites, because, dentition is also related to age. Currently, the most reliable methods to estimate an age are those based on dental mineralization and developmental stages (Boldsen et al., 2002; Ritz-Timme et al., 2000; Scheuer & Black, 2000b; Schmitt, 2005). We chose to estimate age-at-death in our sample with the method of Moorrees et al. (1963a,b), because we are working on teeth and we wanted a uniform method and no combination of several methods. Moreover, we just needed some different stages to compare our sites, that is why we classified the individuals in 5 age classes (usually used in historical demography): 0, 5-9, 10-14, and 15-19 years.

A last comparison has been made using the dental mineralization sequences. This approach use the mineralization stages of Moorrees et al. (1963a,b), as a base for determining a dental sequence. These basic sequences (one for each individual) are in a second time grouped following the big tooth developmental phases in order to simplify the data (many

Group 1: from the beginning of deciduous crown formation to the end of the emergence

Group 2: latency period of deciduous teeth. The permanent incisors and the first

 Group 3: this group corresponds to the mixed dentition. The first deciduous teeth are replaced by permanent incisors (most standard sequence). The first molar emerges

 Group 4: stability period where the roots of permanent teeth (incisors and first molars) complete their formation. The roots of the other teeth just initialize their mineralization. Group 5: secondary phase of tooth emergence for permanent canine, premolars and

Group 6: completion of the permanent dentition (except third molars which were not

The analyses were performed in three steps. First, in order in order to calculate the frequencies of dental enamel hypoplasia, the total number of available teeth, fully erupted and/or isolated, has been used for observation. Tooth germs in both the mandible and maxilla were not taken into account. With the same objective, frequencies of dental caries were calculated using only the teeth in occlusion. The usual calibrations (Erdal & Duyar, 1999; Hillson, 2001; Lukacs, 1995) adjusting the proportions of tooth type and *ante mortem*

In a second time, inter-population comparisons were conducted using the non-parametric χ² statistical. Finally, we studied the interrelationship between caries and hypoplastic defects

 The emergence is a localized phenomenon, which corresponds to the appearance of the tooth in the mouth. We distinguish the clinical emergence where the tooth pierces the gingival tissue from the

combinations are possible). Six final groups are defined and used for comparison:

anatomically\*. This is the first step of permanent teeth emergence.

permanent molars complete their crown formation.

The illustration of the six resulting groups is presented in fig. 5.

anatomical emergence where the tooth passes over the alveolar bone.


Fig. 3. Illustration of the three-stage severity scale for scoring dental caries (photos: V. Gonzalez-Garcin)

Fig. 4. Illustration of the three-stage severity scale for scoring dental enamel hypoplasia (photos: V. Gonzalez-Garcin)

The distance between the cement-enamel junction and the defect for the calculation of the time of appearance of the defect (Reid & Dean, 2000), was not taken because we only made macroscopical analysis. Charts relative to age differ according to different authors and thus mineralization is not really taken into account. In such large studies, with this method the stages cannot provide accurate chronological sequences (Fitzgerald & Saunders, 2005; Hillson & Bond, 1997; Ritzman et al., 2008). However, a global chart has been made in order to evaluate which developmental stage is the most concerned by enamel hypoplasia.

#### **3.2 Estimating age-at-death**

42 Contemporary Approach to Dental Caries

 Stage 1: the defect is macroscopically detectable, but is less than 0.1mm width; Stage 2: the defect is obvious, but the enamel is not distorted around the line; Stage 3: is the most severe with formation of shoving on the enamel surface; The location of the defect is the third of the affected crown: cemento-enamel junction

Fig. 3. Illustration of the three-stage severity scale for scoring dental caries (photos: V.

Fig. 4. Illustration of the three-stage severity scale for scoring dental enamel hypoplasia

to evaluate which developmental stage is the most concerned by enamel hypoplasia.

The distance between the cement-enamel junction and the defect for the calculation of the time of appearance of the defect (Reid & Dean, 2000), was not taken because we only made macroscopical analysis. Charts relative to age differ according to different authors and thus mineralization is not really taken into account. In such large studies, with this method the stages cannot provide accurate chronological sequences (Fitzgerald & Saunders, 2005; Hillson & Bond, 1997; Ritzman et al., 2008). However, a global chart has been made in order

third, middle third or occlusal third.

Gonzalez-Garcin)

(photos: V. Gonzalez-Garcin)

In archaeological samples, the first step for anthropological studies is the age-at-death estimation. This estimation will be useful to compare the different sites, because, dentition is also related to age. Currently, the most reliable methods to estimate an age are those based on dental mineralization and developmental stages (Boldsen et al., 2002; Ritz-Timme et al., 2000; Scheuer & Black, 2000b; Schmitt, 2005). We chose to estimate age-at-death in our sample with the method of Moorrees et al. (1963a,b), because we are working on teeth and we wanted a uniform method and no combination of several methods. Moreover, we just needed some different stages to compare our sites, that is why we classified the individuals in 5 age classes (usually used in historical demography): 0, 5-9, 10-14, and 15-19 years.

A last comparison has been made using the dental mineralization sequences. This approach use the mineralization stages of Moorrees et al. (1963a,b), as a base for determining a dental sequence. These basic sequences (one for each individual) are in a second time grouped following the big tooth developmental phases in order to simplify the data (many combinations are possible). Six final groups are defined and used for comparison:


The illustration of the six resulting groups is presented in fig. 5.
