Applications of Micro-CT Imaging in Age-At-Death Estimates of Maya Dogs

Figures & data

Figure 1. Measurements for crown height on canines, shown as A) tooth width at CEJ; B) total pulp cavity width; and C) crown height.

Figure 2. Measurements for pulp cavity closure ratios on mandibular M1s: A) width of the distal root; B) width of the pulp cavity for the distal root; C) width of the pulp cavity for the mesial root; D) width of the mesial root; E) width of the crown at CEJ; and F) crown height.

Figure 3. Measurement for enamel thickness categorisation.

Table 1. Cuspal enamel thickness categories following Crossley (1995).

Category Name	Measurement Range
Category 1	0.1-0.3 mm
Category 2	0.4-0.6 mm
Category 3	0.7-1.0 mm
Category 4	1.0 mm+

Table 2. Age ranges and corresponding categories developed for the purposes of the present study, adapted from Nomokonova et al. 2020. In domestic dogs, canines erupt between four and six months, while mandibular M₁ crowns erupting at five to seven months of age (Hale 2005; Lobprise and Dodd 2019). Note that specimens classified as ‘juveniles’ constitute permanent teeth with fully-developed roots, but are estimated to be under 12 months in age.

Age (months)	Class Name
4–11	Juvenile
12–23	Young Adult
24–60	Prime Adult
>60	Senior Adult

Figure 4. Bivariate plot of pulp cavity closure ratio to enamel thickness for the Moxviquil and Tenam Puente specimens. A linear trendline for the maxillary canine specimens is shown. The three specimens encircled in orange represent likely juvenile specimens from Moxviquil with unusually low pulp cavity closure ratios and unusually thin enamel.

Figure 5. Linear regression of maxillary canine pulp cavity closure ratios to age in months of Moxviquil and Tenam Puente specimens.

Figure 6. Linear regression of mandibular canine pulp cavity closure ratios to age in months of Moxviquil and Tenam Puente specimens.

Figure 7. Linear regression of the mesial root of mandibular first molar pulp cavity closure ratios to age in months of Moxviquil and Tenam Puente specimens.

Figure 8. Linear regression of the distal root of mandibular first molar pulp cavity closure ratios to age in months of Moxviquil and Tenam Puente specimens.

Table 3. Pulp cavity closure ratios and enamel thickness measurements for Moxviquil (PIERACH) and Tenam Puente (RETP) dogs with associated age-at-death. Pulp cavity ratios were calculated using the methods illustrated in Figures 1 and 2, while enamel thickness was calculated using the methods illustrated in Figure 3. Pulp cavity age estimates were calculated using the regression equations calculated from Nomokonova et al. 2020: Figures 4–7. Cuspal enamel thickness categories follow Crossley 1995 (see Table 1). Age categories are assigned by categories outlined in Table 2.

Specimen	Site	Tooth Type	Side	Pulp Cavity Ratio, canine and mesial roots	Pulp Cavity Ratio, distal roots	Pulp Cavity Age estimate (months)	Cuspal Enamel Thickness (mm)	Cuspal Enamel Thickness Category	Age Category
83–3	PIERACH	CMand	L	0.7908	N/A	34.79	0.693	2	Prime adult
61–5	PIERACH	M1	L	0.3240	0.4128	6.076	0.160	1	Juvenile?
61–6	PIERACH	M1	R	0.2853	0.4748	5.243	0.180	1	Juvenile?
71–4	PIERACH	M1	R	0.2944	0.2925	5.429	0.180	1	Juvenile?
310–1	RETP	M1	R	0.234	N/A	4.310	0.800	3	Juvenile
153–1	RETP	CMand	R	0.4706	N/A	10.25	0.859	3	Juvenile
294–1	RETP	CMand	R	0.6540	N/A	20.64	0.694	2	Young adult
181–2	RETP	CMax	L	0.7517	N/A	30.80	0.309	1	Prime adult
185–7	RETP	M1	R	N/A	0.7853	29.21	0.636	2	Prime adult
230–1	RETP	M1	R	0.6150	0.6507	18.37	0.391	1	Young adult

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