My original research in the neuorphysiological parameters underlying the brain stem reflex of swallowing established, professionally, a life long development. This work started as a thesis while a trainee of the Brain Research Institute at UCLA in 1970, led to several papers, a review in Physiological Reviews in 1982, a book on the Neurophysiological Principles Underlying Swallowing and Dysphagia in 1999, and the cooperation with several investigators at Johns Hopkins and the Medical College of Wisconsin in the development of a new society, the Dysphagia Research Society. I have been on the executive board for several years and was President in 2007-2008 organizing our annual meeting which took place in Vancouver. This annual meeting provides the basis for international investigators around the world to come and present their research. Part of our function has been to expand our ties with investigators in Europe and Japan to develop more research presentations and joint meetings. This has involved working with several groups in Europe and Japan to bring our different research groups closer together and has involved more traveling to German and Japan. Many of the new concepts on rehabilitation in dysphagia are using principles established in neuroscience including electrical stimulation and transmagnetic cortical stimulation.
My interest in the brain stem and the neuromuscular system led to my research expanding to the craniomandibular region and its muscles, which brought me to UCSF over 35 years ago in 1975. This interest in the craniofacial region has focused on the jaw muscles and their interaction with bone. This has led to 15 years of research using the rhesus monkey as well as interacting with clinicians and researchers in craniofacial anomalies, temporomandibular disorders, and other dental fields. Some of this collaboration has been with a good friend and colleague, Dr. Kuotaro Maki, from Showa University in Tokyo, in which we have worked for over 17 years together. He spent a year at UCSF where we worked together, and then he returned and became chair of his Department of Orthodontics at Showa University. This has been a long-term interaction which culminated in expanding our original studies using CT to evaluate cortical bone mineralization, to bringing a new system to USCF using volumetric three-dimensional analysis with cone beam computed tomography (CBCT). We were the first institution in the United States to use a CBCT system, and we have developed a variety of joint projects that incorporate our orthodontic residents. The cone beam CT system at UCSF has now become the standard for our Division of Orthodontics, which purchased the Hitachi MercuRay unit in 2004, and is rapidly becoming a standard for other advanced postgraduate programs at UCSF. This work has developed a long-term collaboration with Dr. Janice Lee and Dr. John Huang. Two of our residents, which I helped, co-mentor, Dr. Chad Sears, and Dr. Eric Haney, won the Thomas M. Graber Research Award for Special Merit in 2007 from the American Association of Orthodontists. We are in the forefront of developing how CBCT can be used, and how craniofacial development can be followed with highly accurate and three-dimensional volumes that render the skeleton, the airway, and facial profile. We are also dedicated to expanding the use of CBCT in the dental school curriculum, and are working with Dr. Linda Angin to incorporate CBCT in the dental curriculum. Cone beam CT will become the standard for radiographic and 3-D analysis in dentistry in the next generation of dentists.
2000 Maki K, Miller AJ, Okano, T, Shibasaki, Y. Changes in cortical bone mineralization in the developing mandible: A three-dimensional QCT study. Journal of Bone and Mineral Research 15; 700-709.
This paper is one of the first in a series that we are writing that focuses on evaluation of the mineralization in cortical bone of the craniomandibular skeleton. This study is conducted in humans but has a complementary study in both the monkey and rabbit. The approach of using a calibrated phantom with computed tomography in assessing bone allows determination of different levels of cortical bone mineralization. The advent of sophisticated three-dimensional reconstruction on microcomputers has provided a method to evaluate the pattern of mineralization during development in the human mandible. Our data indicate that the highest mineralization occurs always within the body of the mandible and along the anterior border of the ramus. This pattern then expands through the ramus during development. We are testing the concept that the pattern of mineralization within the cortical bone depends upon the vector of force and level of force developed by the jaw-closing muscles. Our approach of defining the pattern of distribution of different levels of mineralization as assessed by QCT has not been done in the field of bone. My role has been in the development of the concept, conducting the animal studies, analyzing all of the data, and writing the paper.
2002 Usui T, Maki K, Toki Y, Shibasaki Y, Takanobu H, Takanishi, Hatcher D, Miller AJ. Measurement of mechanical strain on mandibular surface with mastication robot: influence of muscle loading direction and magnitude. Orthodontics and Craniofacial Research 6 (Suppl 1): 163-167.
This paper provides one of the first approaches to using a skull as a robot in which motors are attached through wires to simulate jaw muscles, and make the mandible and clench on the dentition. Strain is measure in multiple sites both buccally and lingually during clenching at different force levels. The distribution of strain is shown directly under the dentition, through the ramus, and under the condyle with joint loading. My role has been in collaborating with investigators in Japan both at the Orthodontic Department of Showa University and the Tokyo Institute of Technology to develop the idea, to analyze the data, and to write the paper.
2008 Stratemann S, Huang JC, Maki K, Miller AJ, Hatcher D. Comparison of cone beam computed tomography (CBCT) imaging to physical measures. Dentomaxillofacial Radiology 37: 1-14.
This paper is the first of a series of five papers from this work which is analyzing and developing methods on how to evaluate three-dimensional volumetric data to determine change on craniofacial growth using cone beam CT extracted data. My role has been as a mentor to the postgraduate orthodontic student, guide in the design of the project, oversee and assist in the data analysis, and assist in the writing of the five papers of which this is the first.
2009 Aboudara C, Hatcher DC, Maki K, Miller AJ. Comparison of evaluating the human airway using conventional two-dimensional cephalography and three-dimensional volumetric data. American Journal of Orthodontics and Dentofacial Orthopedics 135: 468-479. 2009
This paper establishes the concept that volumetric three-dimensional analysis, particularly or the airway, can provide much more valuable data on how its shape and size impact on function and relate to potential problems in developing mouth breathing and obstructive sleep apnea. My role has been as a mentor to the postgraduate orthodontic student, guide in the design of the project, oversee and assist in the data analysis, and assist in the writing of this paper.
2009 Stratemann S, Huang JC, Maki K, Hatcher DC, Miller AJ. Methods for evaluating the human mandible using cone beam computed tomography (CBCT). American Journal of Orthodontics and Dentofacial Orthopedics 137: S58-S70, 2010
This paper was designated as the lead paper in a special edition of this journal to highlight the new research in CBCT. This paper provided the first detailed approach to evaluating the three-dimensionally developed human mandible using cone-beam CT data in which a quantitative ranking of the mandibles was achieved and compared to the average mandibular shape. This paper provided the basis for using 3-D data in comparing subjects and in following mandibular growth. My role was as a mentor to the postgraduate orthodontic resident, helping to design and guide the three-year project, assist in the data analysis and interpretation, and assist in writing the final paper.