Senior Member of the Staff
Department of Molecular Genetics
Associate Professor, Department of Oral Medicine Infection and Immunity,
Harvard School of Dental Medicine
email:
University of London, UK, B.D.S., 1968, Dentistry
Royal College of Surgeons, UK, L.D.S, 1967, Dentistry
The Forsyth Institute, Certificate, 1975, Microbiology
University of London, UK, Ph.D., 1981, Dental Microbiology
University of Umea, Sweden, Honorary M.D., 2008
In adults, most teeth are lost because of gum disease, or periodontitis, whereas in children, dental caries is the most frequent problem leading to tooth loss. Furthermore, periodontal diseases have been associated with extra-oral clinical infections, including increased risk of premature and underweight babies. Children with high sugar diets are at increased risk for tooth decay. Unsightly teeth may lead to low esteem, affecting children's social development. Severe early childhood caries can be the underlying cause for poor general health, loss of school days from dental pain and abscesses and other significant issues. Dental caries and periodontitis are infections caused by bacteria. The Tanner group's goal is to learn which bacteria can indicate risk of dental diseases and need to be controlled to treat and prevent dental infections.
Several bacteria have been associated with moderate to advanced periodontitis particularily Porphyromonas gingivalis and Tannerella forsythia. Our recent collaborative study between the periodontal clinic at Forsyth, the clinical research center at Boston University, and at Brigham and Women’s Hospital indicated that adults with initial (slight) periodontitis were characterized clinically by increased gingival inflammation and increased gingival crevice fluid and immunological markers of infection. Initial periodontitis adults harbored Porphyromonas gingivalis and Tannerella forsythia more frequently than periodontally healthy subjects, confirming the association of these periodontal pathogens with initial or slight periodontitis. Knowledge of risk markers and/or factors involved in initial periodontitis and an appropriate diagnostic sampling protocol will be invaluable for identifying individuals at risk for periodontitis and developing effective interventions.
Infection is a major risk factor for preterm birth and prematurity of infants. In collaboration with investigators at New York School of Dentistry we examined the subgingival, vaginal and cervical microbiota of pregnant women at high risk for preterm birth. We adapted the whole genomic probe checkerboard assay to detect extra-oral vaginal bacteria, and used PCR assays including the Human Oral Microbe Identification Microarray at Forsyth. Findings suggest that signs of vaginal infection played a greater role in prematurity than level of periodontitis and periodontal pathogens. Ongoing analyses further examine interactions between oral and vaginal infection as risk factors from premature infants.
Periodontal species in children
One important questions is how frequently periodontal pathogens can be detected in children, so that the age when interventions to prevent colonization can be established. We assayed periodontal species in studies in the NIDCR-funded Northeast Center to Reduce Oral Health Disparities in children, a center that complements Forsyth's intitiative in children's health. Our findings confirmed detection of periodontal pathogens in preschool children from studies in pediatrician's offices at Boston Medical Center and the Tufts University-based Floating Hospital for Children. In a new dental school clinic, serving a low-income community at high risk for dental diseases, we detected subgingival, periodontal pathogens in children, but there was no difference in species detection based on ethnicity or immigration status. This suggested that while it is beneficial to target preventive and treatment programs to disadvantaged populations, there is likely no additional benefit to focus on subgroups with a population already at high risk for dental disease.
Periodontal species
Two periodontal bacteria have been named for Dr. Tanner: Prevotella tannerae (Lillian Moore and co-workers, 1994), and Tannerella forsythia (Sakamoto and co-workers, 2002) for the reclassified Bacteroides forsythus.
Dental caries is a major childhood infection, and the most frequent reason for emergency room visits in children. Our comprehensive extensive microbiological assessment of severe-early childhood caries involves clinicians at Boston and Tufts Universities Departments of Pediatric Dentistry and Pediatric Medicine. Findings, with analysis involving the University of Umea, Sweden, confirm the strong association of mutans streptococci with early childhood caries, and further link different Lactobacillus species with either caries, or for the probiotic Lactobacillus species with health. A combined genetic and cultural approach has detected several new, including previously uncultivated, bacterial species. Current analyses link caries-associated species with dental decay and the diet of young children to better understand the dynamics of this devastating infection. In a new study, funded by Harvard Catalyst, we examine very early signs of dental caries visible only as “white spot lesions”. Finding similar species in early and later stages of dental caries would indicate major species to target in preventive and treatment programs, and provide new tools for risk assessment for childhood caries.
Sakamoto M, Tanner ACR, Benno Y. (2010) Genus Tannerella. In: Krieg, Holt, eds. Bergey's Manual of Systematic Bacteriology. Baltimore: The Williams and Wilkins Co. (In press)
Soncini JA, Kanasi E, Lu SC, Nunn ME, Henshaw MM, Tanner AC. (2010) Oral microbiota of children in a school- based dental clinic. Anaerobe (In press)
Kanasi E, Johansson I, Lu SC, Kressin NR, Nunn Me, Kent R Jr, Tanner ACR. (2010) Microbial risk markers for childhood caries in pediatricians offices. J. Dent. Res.(In press)
Fimple JL, Fontana CR, Foschi F, Ruggiero K, Song X, Pagonis TC, Tanner AC, Kent R, Doukas AG, Stashenko PP, Soukos NS. (2008) Photodynamic treatment of endodontic polymicrobial infection in vitro. J. Endod. 34(6):728-734.
Fontana CR, Abernethy AD, Som S, Ruggiero K, Doucette S, Marcantonio RAC, Boussios CI, Doukas AG, Kent R,
Goodson JM, Tanner AC, Soukos NS. (2009) The antibacterial effect of photodynamic therapy in dental plaque- derived biofilms. J. Periodontal Res. 44(6):751-759.
Dasanayake AP, Chhun N, Tanner ACR, Craig RG, Lee MJ, Moore AF, Norman RG. (2008) Periodontal pathogens and gestational diabetes mellitus. J. Dent. Res. 87(4):328-333.
Tanner ACR, Izard J. (2006) Tannerella forsythia, a periodontal pathogen entering the genomic era. Periodontol. 2000. 42(1): 88-113.
Tanner ACR, Paster BJ, Lu SC, Kanasi E, Kent R, Van Dyke T, Sonis ST. (2006) Subgingival and tongue microbiota of adults with early periodontitis. J. Dent. Res. 85(4) :318-323.
Tanner ACR, Kent RL Jr, Van Dyke T, Sonis ST, Murray LA. (2005) Clinical and other risk indicators for early periodontitis in adults. J. Periodontol. 76(4):573-581.
Tanner ACR, Izard J. (2005) Etiology of oral disease in view of microbial complexity. Oral Biosci. Med. 2(2/3):209-213.
Downes J, Sutchliffe I, Tanner ACR, Wade WG. (2005) Prevotella marshii sp. nov. and Prevotella baroniae sp. nov., isolated from the human oral cavity. Int. J. Syst. Evol. Microbiol. 55(Pt. 4):1551-1555.
Jennifer M. Jolivet, B.A., M.A.
Pernilla Lif Holgerson, D.D.S., Ph.D.
Deema Farsi, D.D.S.
Kevin Oh, BS
Sonia S. Arevalo Vasquez, BS
