Ichiro Nakajima

By Ichiro Nakajima, Mitsuyo Shinohara and Hiroiku Ohba

Oral cancer is first treated with surgery for the patients. In most cases, it becomes difficult for these patients to perform smooth jaw movements postoperatively, causing masticatory dysfunctions, due to the mandible excision including muscles and peripheral nerves. However, it is still unknown whether the surgery affects the brain function for jaw movement in the patients. In this study, therefore, we investigated a significance of the movement-related cortical potential (MRCP) for jaw movements in the patients after the cancer surgery, to clarify the motor preparation process in the brain, as compared with healthy subjects. Eight normal subjects and seven patients with oral cancers were enrolled in the study. Experiment 1: The normal subjects were instructed to perform jaw-biting movement and hand movement, respectively. The MRCPs appeared bilaterally over the scalp approximately 1 to 2 s before the onset of muscle discharge in both movements. Experiment 2: The MRCPs appeared preoperatively in the jaw biting movement in all patients. However, the amplitudes of the MRCP decreased significantly after than before the surgery (p < 0.05). Our data indicated the dysfunction of the motor preparation process for jaw movements in the patient after the surgery, suggesting impairment of feed-forward system in the maxillofacial area.

Part of the book: Cerebral and Cerebellar Cortex

By Ichiro Nakajima, Ken-ichiro Ejima, Yoshinori Arai, Kunihito Matsumoto, Kazuya Honda, Hirofumi Aboshi, Marina Hamaguchi, Akao Lyvongsa, Bounnhong Sidaphone, Somphone Phanthavong, Chanthavisao Phanthanalay and Souksavanh Vongsa

In the field of dentistry, diagnoses based on data obtained using medical imaging modalities such as digital panoramic radiography and cone beam computed tomography (CBCT) have been widely recommended for advanced dental care. In Lao People’s Democratic Republic (Laos), there are place where advanced dental imaging devices are available in only one university dental hospital. The establishment of an information and communication technology (ICT) system has been expected as telemedicine system, for sharing medical imaging data among medical institutions in Laos. Recently, regional medical cooperation using telemedicine has been developed in Japan, and medical imaging data have been provided and shared among medical institutions, by using a mobile tablet terminal application. Therefore, we have carried out the empirical research on the telemedicine system with the university in Laos. The technologies and research results from our project will be presented in this chapter.

Part of the book: Oral Health Care

By Ichiro Nakajima, Ryosuke Koshi, Atsushi Uchida and Taketo Yamaguchi

In most countries that have reached an aging society, the feeding function among the elderly population has declined and become a serious problem. Therefore, understanding the development of human oral function is required to address this problem. However, only a few research studies have reported oral motor functions and dysfunctions in children. Our chapter describes the relationship between oral motor functions (chewing, swallowing, and breathing) and maxillofacial morphology in children. In addition, case studies on children with cerebral palsy and sleep aspiration disorders will also be introduced. This study would also like to clarify the significance of human oral function development from infancy in pediatric dentistry.

Part of the book: Pediatric Dentistry