The animal model has been widely used in the biomaterials field. However, there are no morphometric patterns to create critical size defects in different areas used in implantology and oral surgery, based on the anatomy and histology of the rabbit’s tissue. Thus, the aim of this study is to provide measurements and limits for future research on the different anatomical regions used to evaluate biomaterials and/or surgical procedures in rabbits as animal models. Twenty-two rabbit heads were used in the study. The soft tissue was removed and the calvaria, body of the mandible divided into three regions, the ramus of the mandible, total mandible length and lower cortical sinus thickness were measured. The mean, standard deviation and confidence of each region were recorded. The height of the mandibular ramus was 30.1 mm and 29.7 mm for the right and left sides, respectively, while the total body of mandible was 67.2 mm. Also, the thickness of calvaria and lower cortical sinus were 1.5 mm and 1.1 mm, respectively. In conclusion, the limited dimensions of anatomical structures should be considered when working with critical size defects in rabbits to avoid complications or accidents during the specimen’s surgery.