Figure 10-4. - Fingerprinting
Dental ID, like fingerprint ID, is a definitive means of positive identification of unknown human remains. It also is routinely acceptable as evidence in court. It has several significant advantages, and only a few disadvantages when compared with fingerprint identification. The bulk of the remaining chapter will center on dental ID.
Dental evidence tends to survive much better than does soft tissue evidence such as facial characteristics or fingerprints. Teeth are calcified structures and are the hardest substance in the human body, even harder than bone. Because they are calcified, they are resistant to the environmental effects that destroy soft tissue evidence. Thus teeth are not destroyed by immersion in water, by desiccation (drying up), or by decomposition. Even in cases of skeletalization of remains, teeth are available for ID purposes. In addition, teeth are relatively resistant to destruction by fire. However, teeth can be destroyed in rare instances by heat if the temperatures are greater than 1000°F and the teeth are unprotected by the soft tissues of the cheeks and lips. Figure 10-5 shows intact dentition of a charred mandible. Teeth are further protected by the soft tissue mass of the tongue. The roots of the teeth are encased in the alveolar bone, providing an additional layer of protection. Therefore, even in fires where temperatures approach 1600°F, teeth are ordinarily found intact within the oral cavity and can be used for ID when all other means have been destroyed. In addition to the teeth, the materials used for dental restorations are also resistant to destruction by the environment, even more so than the natural teeth themselves. Gold alloys, as shown in figure 10-6, fused porcelain, synthetic porcelain, and porcelain denture teeth all will withstand temperatures exceeding 1600°F. Silver amalgam, the most commonly used restorative material, will resist temperatures up to 1600°F.
The human dentition is composed of 32 teeth, each of which may be restored, unrestored, or missing. When restored, any of the 5 different surfaces may be involved in the restoration. The number of potentially different dental chartings, considering even one restorative material, is astronomically large (1 x 1048 ). In addition to restorations, the tooth crown form, rootContinue Reading