To explore the effective treatment for patients with severe systemic diseases and peri-implantitis, animal models are the most crucial subjects to help investigators to reveal the mechanisms underlying these disorders. Murine models both mice and rats are the most commonly used animal models in research because of their lower cost, biological relevance to human being, and available of genetic mutated strains. However, because of the body size of rat and mouse, it is difficult to have appropriate site in oral cavity to place implant as lager animals such as dog [18,19,20,21], sheep [22, 23], mini pig [24, 25], and non-human primate [26, 27]. To a successful implant, its fixture should be surrounded with cortical bone at cervical part and covered by cancellous bone at rest part of the fixture [28, 29]. Some investigators placed implant out of oral cavity such as the femur [9] and the tibia [12], or not on the ridge of the alveolar bone, i.e., the ramus of mandibular [14] to achieve osseointegration which are able to have samples for osseointegration; however, these models are not closely relevant to clinical implant placement. Implantation at diastema has been reported in mice [30]. However, the pictures showed in the articles, large portion of the implant (0.6 mm × 1.5 mm) are clear projected into the maxillary sinus though some peri-implant bone was observed by the authors. Clinically, it is not a normal practice to let large portion of implant fixture project into maxillary sinus. As the first of the article to place implant at maxillary diastema of rats, Freire and coworker provide informative research results [15]. They not only placed implant at maxillary diastema, but also placed implant at the hard palate midline area in the molar region. Anatomically, hard palate midline is a suture without cancellous bone to support the implant to form osseointegration so that it will not be a suitable place for implantation research.