Macroanatomical, Histological and Microtomographic Study of the Teeth of the Komodo Dragon (Varanus komodoensis)—Adaptation to Hunting

SIMPLE SUMMARY: The goal of this study was a detailed analysis of the mandibular teeth structure of the Komodo dragon (Varanus komodoensis), based on macroscopic, histological and computed microtomography examinations. The samples were collected post mortem from two adult female Komodo dragons from Wroclaw Zoo. Macroscopically, each mandibular tooth is laterally flattened and its dental crown has an arcuate shape with the typical denticles of a tooth’s caudal margin. The base of the tooth is filled with abundant plicidentine with secondary lamellae. The cavity in the central part of the tooth is well visible, while collagen fibers fill the spaces between the inner lamellae. In the epiphyseal part, the tooth wall is thin and contains numerous dentin trabeculae that grow into the tooth cavity. The dentine is most developed in the mid-tooth, where numerous tubules are observed. The presence of plicidentine, a small number of odontoblasts and a relatively large amount of adipose tissue cells are typical of the mandibular teeth of V. komodoensis. ABSTRACT: The present study aimed to characterize the macrostructure and microstructure of the mandibular teeth of the Komodo dragon (Varanus komodoensis) and the methods it uses to obtain food. Examinations were performed using a stereoscopic microscope, autofluorescence method, histological method and computed microtomography. A detailed macro- and micro-structural description of V. komodoensis mandibular teeth were made. The mandibular teeth are laterally flattened along their entire length and the dental crown is hooked caudally. The part of the nasal margin of the tooth crown is irregular, while the caudal margin of the tooth is characteristically serrated, except for the tooth base area. There are longitudinal grooves on the lingual and vestibular surfaces up to the lower third of the tooth height. The mandibular tooth is surrounded by a cuff made of the oral mucosa, containing the opening of the venom gland. In the histological structure of the tooth, the enamel covering the tooth crown and the dentin under the enamel are distinguished. The inside of the tooth, except its basal part, is filled with the tooth chamber, while the inside of the lower part of the tooth is filled with plicidentine, which corresponds to external furrows on the enamel. The plicidentine arrangement resembles a honeycomb. A small amount of dentine folds reach up to the tooth apex. Characteristic features of the structure of the mandibular teeth in V. komodoensis may indicate their significant role, in addition to the venom glands, in obtaining food in the natural environment of this species.