The Mathews Acquisition Group

The Mathews sample is the first long-term U.S. study of growing children with metallic implants of the Bjork type. The sample was collected by Dr. J. Rodney Mathews in the Section on Orthodontics, School of Dentistry, University of California San Francisco between the years of 1967 and 1979. Using open surgical methods, Dr. W. H. Ware, an associate of Dr. Mathews, placed 3 to 5 implants unilaterally in the mandible and a simlar number arrayed transversely in the maxilla. Subjects were recalled at annual intervals between the ages of 7 and 18 years although few have records at more than 8 time points. Lateral Cephs, Posterior-Anterior Cephs, left and right 45-degree obliques were collected at each time point, but not all films have been digitized and traced at this time. Dr. Mathews' original publication appeared in the Angle Orthodontist. (See reference 1.)

Investigations of these records and data set at CRIL have resulted in a number of publications on dental and skeletal changes during preadolescent and adolescent growth (references 2 through 10). Among the most interesting observations from this data set has been the first documentation of systematic spontaneous post-natal widening of the core structures of the human mandible (references 9 and 10). This observation has since been corroborated in two other longitudinal studies using subjects with implants.

About Dr. Mathews

Dr. Mathews Dr. J. Rodney Mathews (1911-1988) was a 1948 graduate of the University of California San Francisco's "Curriculum II" specialty program in orthodontics. He had earlier pursued graduate studies in microbiology and had been involved in bacteriological research for the US Navy during World War II. At the UCSF School of Dentistry, studying under the mentorship of Wendell Wylie, his interest in the biology of growth and development deepened. For the next thirty-five years, Dr. Mathews divided his time between teaching and research at the UCSF Division of Orthodontics and Department of Growth and Development, and the private practice of orthodontics in Berkeley, California.

In his private orthodontic practice, he focused particularly on the early treatment of developing malocclusions, and in this area he collaborated closely with George Hahn. At the UCSF School of Dentistry, the main focus of his research was on the longitudinal study of human craniofacial growth with the aid of roengenographic cephalometrics.

Dr. Mathews Dr. Mathews was among the first investigators in the U.S. to recognize the seminal importance of Arne Bjork's implant method to the study of craniofacial development. Between 1967 and 1985, he became the first and only American investigator to conduct a replication of the studies of Bjork for a sample of treated and untreated children observed longitudinally. Illness prevented his carrying these studies to completion but he graciously facilitated their continuation by CRIL. Through the continued kindness and support of the Mathews family, uniquely valuable images and data from these studies are being made available to the orthodontic specialty and the craniofacial research community on this web site.

Dr. Mathews was widely respected as a clinician and lecturer. He was featured in more than 100 presentations to local and national orthodontic groups, many in collaboration with his friend and colleague, Eugene E. West. As a teacher, he was always stimulating and patient. His publications were clear and concise. A hallmark of his presentations was his desire to stimulate information exchange among participants at all levels of academic sophistication.

Dr. Mathews was an early Diplomate of the American Board of Orthodontics and served as President of the Northern California Component of the Edward H. Angle Society. He was a member of Omicron Kappa Upsilon, the National Dental Honor Society, and of the Sigma Xi National Honorary Scientific Society.

Among his most widely known students are James A. McNamara, George S. Payne, Donald R. Poulton and Wayne Watson. His family continues his interest in craniofacial research by generous ongoing support of CRIL.


  1. JR Mathews, GS Payne: Quantitative analysis of lower incisorchanges: A longitudinal implant study in man. Angle Orthod. 50:218-29, 1980.
  2. S Baumrind, EL Korn, Y Ben-Bassat, EE West: The Quantitation of Maxillary Remodeling: 1. A description of osseous changes relative to superimposition on metallic implants. Am. J. Orthod. 91:29-45, 1987.
  3. S Baumrind, EL Korn, Y Ben-Bassat, EE West: The Quantitation of Maxillary Remodeling: 2. Masking of remodeling effects when an "Anatomical" method of superimposition is used in the absence of metallic implants. Am. J. Orthod. 91:463-474, 1987.
  4. S Baumrind, Y Ben-Bassat, EL Korn, LA Bravo and S Curry: Mandibular Remodeling Measured on Cephalograms: 1. Osseous changes relative to superimposition on metallic implants. Am. J. Orthod. Dentof. Orthop. 102:134-42, 1992.
  5. S Baumrind, Y Ben-Bassat, EL Korn, LA Bravo and S Curry: Mandibular Remodeling Measured of Cephalograms: 2. A comparison of information from implant and anatomical best fit superimpositions. Am. J. Orthod. Dentof Orthop. 102:227-38, 1992.
  6. LA Bravo, S Baumrind, EL Korn, Y Ben-Bassat, S Curry: Efectos ortodóncicos y ortopédicos en la dentición del maxilar superior: diferencias observadas entre una superposición anatómica convencional y la superposición en implantes. Rev. Esp. Ortod. 24:139-51, 1994.
  7. S Baumrind, LA Bravo, Y Ben-Bassat, S Curry, EL Korn: Lower incisor and molar displacement associated with mandibular remodeling. Angle Orthodontist 67: 93-102. [Reprinted in translation in: German (Informationen aus Orthodontie & Kieferorthopadie 29:35-50,1997), Italian (Orthognatodonzia Italiana 6:223-237,1997), Spanish (Rev Esp Ortod. 27:29-44,1997) and French (Rev Orthop Dento Faciale 31:61-78, 1997).]
  8. S Baumrind, Y Ben-Bassat, LA Bravo, EL Korn, S Curry: Partitioning the Components of Tooth Displacement in the Maxilla by the Comparison of Data from Three Cephalometric Superimpositions. Angle Orthodontist 66: 117-130, 1996.
  9. EL Korn and S Baumrind: Transverse development of the human jaws between the ages of 8.5 and 15.5 years studied longitudinally with use of implants. Journal of Dental Research 69:1298-1306, 1990.
  10. S Baumrind and EL Korn: Post-natal width changes in the internal structures of the human mandible: A longitudinal three-dimensional cephalometric study using implants. J. European Orthodontic Society 14:417-426, 1992.