Antibody response to actinomyces antigen and dental caries experience: implications for caries susceptibility.

Fluoridated dentifrices reduce dental caries in subjects who perform effective oral hygiene. Actinomyces naeslundii increases in teeth-adherent microbial biofilms (plaques) in these subjects, and a well-characterized serum immunoglobulin G (IgG) antibody response (Actinomyces antibody [A-Ab]) is also increased. Other studies suggest that a serum IgG antibody response to streptococcal d-alanyl poly(glycerophosphate) (S-Ab) may indicate caries experience associated strongly with gingival health and exposure to fluoridated water. The aim of this study was to investigate relationships between A-Ab response, oral hygiene, S-Ab response, and caries experience. Measurements were made of A-Ab and S-Ab concentrations, caries experience (number of decayed, missing, and filled teeth [DMFT], number of teeth surfaces [DMFS], and number of decayed teeth needing treated [DT]), exposure to fluoridated water (Flu), mean clinical pocket depth (PD; in millimeters), and extent of plaque (PL) and gingival bleeding on probing (BOP). A-Ab concentration, the dependent variable in a multiple regression analysis, increased with S-Ab concentration and decreased with PL and DMFT adjusted for Flu (R(2) = 0.51, P < 0.002). Residual associations with age, DMFS, DT, and BOP were not significant. In addition, an elevated A-Ab response, defined from immunoprecipitation and immunoassay measurements, indicated a significant, 30% reduction in DMFT after adjustment for significant age and Flu covariance (analysis of variance with covariance F statistic = 10.6, P < 0.003; S-Ab response and interactions not significant). Thus, an elevated A-Ab response indicates less caries in subjects performing effective oral hygiene using fluoridated dentifrices. Conversely, a low A-Ab response is suggestive of decreased A. naeslundii binding to saliva-coated apatite and greater caries experience, as reported by others.

Risk factors for injury in high school football players.

BACKGROUND: Many studies have reported the frequency and types of injuries in high school football players. However, few have assessed the relationship between player characteristics and risk of injury. PURPOSE: To describe the epidemiologic characteristics of and risk factors for injury in high school football players and to determine whether players' characteristics could be used to predict subsequent injury. STUDY DESIGN: Prospective cohort study. METHODS: This study was part of a 2-year prospective investigation (1998 to 1999) of risk factors for injury in 717 (343 in the 1998 season and 374 in the 1999 season) high school football players in the Oklahoma City, Oklahoma, School District. Player characteristics (playing experience, position, injury history) and physical parameters (body mass index, weight, height, grip strength) were measured at the beginning of each season. Logistic regression analysis was used to determine whether any of the baseline variables were associated with the odds of subsequent injury. RESULTS: The physical characteristics of players, such as body mass index and strength, were not associated with risk of injury. More playing experience and a history of injury in the previous season were significantly related to increased risk. Linemen were at the highest risk of injury, particularly knee injuries and season-ending injuries. CONCLUSIONS: Future research should focus on decreasing the risk of injury to linemen.

Risk factors for injury in middle school football players.

BACKGROUND: Little is known about the frequency of or risk factors for injuries in middle school or junior high school football players. PURPOSE: To examine the associations of player characteristics (injury history, conditioning, player position, special equipment) and physical parameters (body mass index, weight, height, grip strength) with risk of injury. STUDY DESIGN: Prospective cohort study. METHODS: We documented risk factors for injury in 646 middle school football players, 10 to 15 years of age, in the Oklahoma City, Oklahoma, school district during the 1998 and 1999 seasons. Player characteristics and physical parameters were measured at the beginning of both seasons. Logistic regression methods were used to determine whether baseline variables were associated with the odds of subsequent injury. RESULTS: More playing experience was the only variable significantly associated with the risk of injury in multivariate analyses. This association was observed regardless of the type of injury and even after indirectly controlling for time at risk of injury by restricting analyses to first-string players. Increasing age was significantly associated with the risk of fractures. CONCLUSIONS: Results suggest that physical characteristics play a minor role in risk of injury from football in this age group.

Elevated antibody to D-alanyl lipoteichoic acid indicates caries experience associated with fluoride and gingival health.

: BACKGROUND: Acidogenic, acid-tolerant bacteria induce dental caries and require D-alanyl glycerol lipoteichoic acid (D-alanyl LTA) on their cell surface. Because fluoride inhibits acid-mediated enamel demineralization, an elevated antibody response to D-alanyl LTA may indicate subjects with more acidogenic bacteria and, therefore, an association of DMFT with fluoride exposure and gingival health not apparent in low responders. METHODS: Cluster analysis was used to identify low antibody content. Within low and high responders (control and test subjects), the number of teeth that were decayed missing and filled (DMFT), or decayed only (DT) were regressed against fluoride exposure in the water supply and from dentrifice use. The latter was determined from gingival health: prevalences of plaque (PL) and bleeding on probing (BOP), and mean pocket depth (PD). Age was measured as a possible confounding cofactor. RESULTS: In 35 high responders, DMFT associated with length of exposure to fluoridated water (F score), PL and BOP (R2 = 0.51, p < 0.001), whereas in 67 low D-ala-IgG responders, DMFT associated with PL, age, and PD (R2 = 0.26, p < 0.001). BOP correlated strongly with number of 7 7 decayed teeth (DT) in 54 high responders (R2 = 0.57, p < 0.001), but poorly in 97 low responders (R2 = 0.12, p < 0.001). The strength of the PD association with DMFT, or of BOP with DT, in high responders significantly differed from that in low responders (p < 0.05). CONCLUSION: Caries associates with gingival health and fluoridated water exposure in high D-alanyl LTA antibody responders.