In clinical practice we use a number of different methods.

1) actual measurement from the cement-enamel junction (that's where the crown enamel meets the root of the tooth) to the bone edge.The bone in health is situated ~2mm below the cemento enamel junction and this distance seems to remain the same between the actual bone and where the connective tissue joins the tooth at the base of a periodontal pocket. So you would measure the length and subtract 2mm to get the actual periodontal disease induced attachment loss. 

2) radiographically you can measure the same thing but express it as a percentage of root length of the tooth.

If you have the skull I would suggest simple measurement as the most accurate.

I hope This  given book may help you to get information on this present topic

The Archaeology of Human Bones

By Simon Mays

• Please find more information in the article "Periodontal disease - etiology, classification, and diagnosis" In: Alt et al. Dental Anthropology, Springer, Wien, NY, page 227-246.

Simon Mays has recently reviewed the measurement of alveoloar bone loss, in the context of age-at-death estimation, in the AJPA. The article is titled "Resorption of mandibular alveolar bone following loss of molar teeth and its relationship to age at death in a human skeletal population."

Generally, calipers are used to measure from the CEJ to the superior margin of the alveolar process along the anterior margin of the mandible below each molar. There is the issue of inter-population comparison to consider when making sense of these measurements and I suppose this is quite imprecise if the jaws in question are fragmented and finding the CEJ involves some estimation. I've always followed Ubelaker's protocol that is used at The Smithsonian Institute which matches Alt's citation. 

As mentioned, a common method is to measure the distance from the CEJ to the alveolar margin but there are problems with this concerning continuing eruption of the tooth (due to attrition) so it is not without issues. I prefer Kerr's (1998) method where each septum is recorded using a 5 stage scoring system. This gets around issues with continuing eruption and focuses on the actual state of the bone - it also allows you to distinguish between active and quiescent phases as well as mild i.e. gingivitis, and aggressive periodontitis. 

Hi Laura,

References are below. I've included another paper by Westerlain et al.( 2011), which has a good discussion on the topic. Both provide a good description of the scoring system.

Kerr, N. W. 1991. Prevalence and Natural History of Periodontal Disease in Scotland - The Mediaeval Period (900-1600 A. D.). Journal of Periodontal Research 26(4): 346–354.

Wasterlain, Sofia N, Eugénia Cunha, and Simon Hillson. 2011. Periodontal Disease in a Portuguese Identified Skeletal Sample from the Late Nineteenth and Early Twentieth Centuries. American Journal of Physical Anthropology 145(1): 30–42.