Senior Member of the Staff
Department of Microbiology
Associate Professor, Department of Oral Medicine Infection and Immunity,
Harvard School of Dental Medicine
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 children, dental caries is the most frequent problem leading to tooth loss whereas In adults, most teeth are lost because of gum disease, or periodontitis. Furthermore, both advanced dental caries and periodontal diseases have been associated with systemic complications. Children with high sugar diets are at increased risk for tooth decay. Unsightly teeth may lead to low self 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. Periodontitis in pregnancy has been associated with complications including increased risk of premature and underweight babies. 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.
Dental Caries (Decay)-associated infection in Children: Dental caries is a major childhood infection, and the most frequent reason for emergency room visits in children. Our comprehensive microbiological assessment of severe-early childhood caries involves clinicians and investigators at Boston and Tufts Universities, with analyses involving the University of Umea, Sweden. Our studies 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, and the new species Scardovia wiggsiae as significantly associated with severe early childhood caries. Our studies have examined the association of foods coded by cariogenic potential with early childhood caries, and evaluated the oral microbiota before and after comprehensive restorative therapy. In a study funded by Harvard Catalyst, we examined 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.
Periodontal species in children: One important question is how frequently periodontal pathogens can be detected in children, so that the age when interventions to prevent colonization can be established. In a study as part of the Northeast Center to Reduce Oral Health Disparities in children we 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 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 within a population already at high risk for dental disease.
Initial Periodontitis: Several bacteria have been associated with moderate to advanced periodontitis particularly Porphyromonas gingivalis, and Tannerella forsythia. In a collaborative study between The Forsyth Institute, Boston and Harvard Universities we reported adults with initial (slight) periodontitis were characterized clinically by increased gingival inflammation, 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.
Periodontal and vaginal infection as a risk factor for prematurity: 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. Findings suggest that signs of vaginal infection played a greater role in prematurity than level of periodontitis and periodontal pathogens.
Infant microbiota and birth delivery route: A major source of bacteria in infants is from their mother and differences in gut microbiota have been observed depending on whether infantes delivered vaginally or by Caesarian (C)-section. Our recent study using the HOMIM microarray indicated differences in the oral microbiota depending on mode of infant delivery with a more diverse microbiota in children delivered vaginally compared with C-section. Ongoing studies are examining the influence of diet on the infant oral microbiota.
Periodontal species: Two periodontal bacteria have been named for Anne Tanner: Prevotella tannerae (Lillian Moore and co-workers, 1994), and Tannerella forsythia (Sakamoto and co-workers, 2002) for the reclassified Bacteroides forsythus.
1. Tanner A, Kent RL Jr, Lif Holgerson PL, Hughes CV, Loo CY, Kanasi E, Chalmers NI, Johansson I. 2011. Microbiota of severe early childhood caries before and after therapy. J. Dent. Res. (In press) NIHMSID: NIHMS315708
2. Lif Holgerson P, Harnevik L, Hernell O, Tanner ACR, Johansson I. 2011. Mode of birth delivery affects oral microbiota in infants. J. Dent. Res. (In press) NIHMSID: NIHMS315934
3. Stashenko P, Van Dyke T, Tully P, Kent R, Sonis S, Tanner AC. 2011. Inflammation and genetic risk indicators for early periodontitis in adults. J. Periodontol. 82(4):588-596.
4. Tanner A, Mathney JM, Kent RL Jr, Chalmers NI, Hughes CV, Loo CY, Pradhan N, Kanasi E, Hwang J, Dahlan MA, Papadopolou L, Dewhirst FE. 2011. Cultivable anaerobic microbiota of severe early childhood caries. J. Clin. Microbiol. 49(4):1464-1474. PMCID: PMC3122858
5. Downes J, Tanner AC, Dewhirst FE, Wade WG. 2010. Prevotella saccharolytica sp. nov., isolated from the human oral cavity. Int. J. Syst. Evol. Microbiol. 60(Pt. 10):2458-2461. PMC Journal – In Process
6. Palmer CA, Kent R Jr, Loo CY, Hughes CV, Stutius E, Pradhan N, Dahlan M, Kanasi E, Arevalo Vasquez SS, Tanner ACR. 2010. Diet and caries-associated bacteria in severe early childhood caries. J. Dent. Res. 89 (11):1224-1249. PMCID: PMC2954266 [Available on 2011/11/01]
7. Kanasi E, Dewhirst FE, Chalmers NI, Kent R, Moore A, Hughes CV, Pradhan N, Loo CY, Tanner ACR. 2010. Clonal analysis of the microbiota of severe early childhood caries. Caries Res. 44(5):485-497. PMCID: PMC2975730
8. 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. 89(4):378-383. PMCID: PMC2880172
9. Johansson I, Lif Holgerson P, Kressin NR, Nunn ME, Tanner AC. 2010. Snacking habits and caries in young children. Caries Res. 44(5):421-4230. PMCID: PMC2969163
10. Soncini JA, Kanasi E, Lu SC, Nunn ME, Henshaw MM, Tanner AC. 2010. Oral microbiota of children in a school-based dental clinic. Anaerobe 16(3):278-282. PMCID: PMC2881591
11. Dewhirst FE, Chen T, Izard J, Paster BJ, Tanner ACR, Yu W-H, Lakshmanan A, Wade WG. 2010. The human oral microbiome. J. Bacteriol. 192(19):5002-5017. PMCID: PMC2944498
12. Sakamoto M, Tanner ACR, Benno Y. 2010. Genus VIII. Tannerella. In: Hedlund B, Krieg NR, Paster BJ, Schleifer K-H, Staley JT, Ward N, Whitman WB, eds. Bergey’s Manual of Systematic Bacteriology, 2nd ed., Vol. 4. The Planctomycetes, Spirochaetes, Fibrobacteres, Bacteriodetes and Fusobacteria. Springer, New York.
13. Pagonis TC, Chen J, Fontana CR, Devalapally H, Ruggiero K, Song X, Foschi F, Dunham J, Skobe Z, Yamazaki H, Kent R, Tanner ACR, Amiji MM, Soukos NS. 2010. Nanoparticle-based endodontic anti-microbial photodynamic therapy. J. Endod. 36(2):322-328. PMCID: PMC2818330
14. 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. PMCID: PMC2561333
Post-Doctoral Fellows: Pernilla Lif Holgerson, DDS, PhD.
Interns: Carol A. Patel (NU), Yansel Nunez (Harvard HC-LITT)