Jop090532 982.99
Volume 81 • Number 7
Periodontal Disease Activity Measuredby the Benzoyl-DL-Arginine-Naphthylamide Test Is AssociatedWith Preterm BirthsHui-Chen Chan,* Chen-Tsai Wu,† Kathleen B. Welch,‡ and Walter J. Loesche§
Background: Infection is a risk factor for preterm birth. This
study was conducted in the field and addressed the link be-tween periodontal pathogens measured with the benzoyl-DL-arginine-naphthylamide (BANA) test and preterm birth.
Methods: This prospective study was performed in Chan-
ghua, Taiwan. Periodontal examinations included the plaqueindex, papillary bleeding scores, and measurement of theBANA enzyme in plaque samples at the second and third tri-
The prevalence of preterm birth
(PB) is often associated with in-
mesters. Independent variables included maternal demo-
graphic characteristics, previous pregnancy histories, risk
because of the activation of the immune
factors, plaque and gingivitis scores, and current pregnancy
system, by microorganisms that trigger
the release of inflammatory cytokines
Results: There were 19 (7%) preterm deliveries among the
such as interleukin-8, interleukin-1, and
268 subjects. A history of a previous preterm birth and low
tumor necrosis factor-alpha.1 This in-
birth weight, frequency of prenatal visits, preterm uterine con-
flammatory cascade and microbial en-
tractions, antepartum hemorrhages, placenta previae, and
dotoxins derived from invading bacteria
preterm premature rupture of membranes were significantly
stimulate the production of prostaglan-
related to preterm birth (P = 0.035, 0.027, <0.001, 0.025,
dins,2 which can increase uterine con-
0.006, 0.014, and <0.001, respectively). Maternal weight
tractions that result in preterm labor
gain was higher with a normal term delivery (P = 0.003). Mul-
causing a PB.3 Among the infections
tivariable logistic regression analyses showed that the number
that have been associated with PBs is
of BANA-infected sites in the third trimester (odds ratio [OR]:
periodontal disease.1
5.89; 95% confidence interval [CI]: 1.5 to 31.6), maternal
Periodontal disease is an inflamma-
weight gain (OR: 0.78; 95% CI: 0.65 to 0.91), antepartum
tory process in the periodontal tissue that
hemorrhages (OR: 10.0; 95% CI: 2.2 to 46.9), and preterm
is initiated by the microorganisms in the
premature rupture of membranes (OR: 12.6; 95% CI: 3.97 to
subgingival plaque.4 Although the mi-
42.71) had significant influences on preterm-birth outcomes.
crobiota of the subgingival plaque is
Conclusions: BANA-positive plaque in the third trimester
complex, there appears to be a selection
was associated with preterm births after controlling for other
for anaerobes when there is an active
risk factors. The BANA test can be used to screen pregnant
disease process, especially for the
women at chairside and/or bedside to apply suitable interven-
Gram-negative, proteolytic species Por-
tion tactics. J Periodontol 2010;81:982-991.
phyromonas gingivalis, Tannerella for-sythia (previously T. forsythensis), and
Treponema denticola.5 P. gingivalis, T.
BANA; periodontal disease; preterm birth.
forsythia, and T. denticola were foundin higher levels in subgingival plaques
* Department of Orthodontic and Pediatric Dentistry, School of Dentistry, University of
of women who delivered PB or low–birth
Michigan, Ann Arbor, MI.
† Dental Department, Show Chawn Memorial Hospital, Changhua, Taiwan.
‡ Center for Statistical Consultation and Research, University of Michigan.
women who delivered normal term
§ Marcus Ward Professor Emeritus School of Dentistry, Professor Emeritus of Microbiology &
Immunology, School of Medicine, University of Michigan.
(NT) babies.6,7 This association was con-comitant with an increase in maternal
J Periodontol • July 2010
Chan, Wu, Welch, Loesche
serum inflammatory mediators and antibodies.6-8 P.
of the University of Michigan (Hum00000327) and
gingivalis was also detected in the amniotic cavity
Hospital Institutional Research Board of the Show
of pregnant women with threatened premature la-
Chawn Memorial Hospital (940607). Subjects were
bor7-9 and along with other periodontal species in
recruited between September 2005 and June 2006
the placentas of women with preeclampsia.10
during their second-trimester visit to the OBGYN clinic.
Efforts to detect these periodontal pathogens in
Experimental Protocol
dental plaque have included DNA probes, cultural
Pregnant women with a singleton gestation in the sec-
procedures, microscopic measures, and immuno-
ond trimester (gestational age: 13 to 28 weeks) were
logic reagents. P. gingivalis, T. forsythia, and T. den-
recruited, whereas subjects with multiple gestations
ticola possess a trypsin-like enzyme that can
who were undergoing fertility treatment were ex-
hydrolyze the synthetic trypsin substrate benzoyl-
cluded. The subjects signed consent forms after the
DL-arginine-naphthylamide (BANA).11 The presence
format, purpose, and nature of the study were pre-
of these organisms in subgingival plaque can be de-
sented to them. Information regarding maternal char-
termined by the ability of the plaque to hydrolyze
acteristics, which included demographic information
BANA12 using a 5-minute chairside assay. In the de-
data, previous pregnancy histories, and risk factors
tection of P. gingivalis, T. forsythia, and T. denticola,
(history of smoking and alcohol consumption), was
the BANA test had a 92% sensitivity and a 70% spec-
collected via a written questionnaire. At the second-
ificity compared to DNA probes and polyclonal im-
trimester appointment, dental measurements, in-
munologic reagents.13 When the BANA test was
cluding the plaque index score (PI)20 and papillary
compared to checkerboard DNA–DNA hybridization
bleeding score (PBS)21 were made, and measurement
using highly specific, whole-genomic DNA probes
of the BANA enzyme in plaque samples using the
to P. gingivalis, T. forsythia, and T. denticola, it had
BANA testi was performed. The PI, PBS, and BANA
a sensitivity of 95% and was most effective for the de-
test were repeated when the subjects returned for their
tection of these organisms when their levels in subgin-
third-trimester visit (gestational age: 25 to 40 weeks).
gival plaque were high, i.e., in the initial diagnosis of
Pregnancy outcomes, which were collected from hos-
chronic periodontitis.14 The results suggest that the
pital records, included the patient's status during
BANA test could be used as a surrogate for DNA
pregnancy (gestational age at first prenatal visit, fre-
probes in the detection of these bacterial species in
quency of prenatal visits, prepregnancy weight and
plaque samples.
height, and weight and height at the last prenatal
Probing measurement of pocket depth and attach-
visit), complications during pregnancy, type of deliv-
ment often require a separate visit to a dental clinic.
ery, gender of the infant, gestational age, and birth
The BANA test can be obtained at chairside and/or
weight at delivery. The participants did not have to
bedside15 and was shown to be significantly associ-
make any visits other than their regularly scheduled
ated with probing depth16,17 and to predict future at-
prenatal visits.
tachment loss after initial treatment.18 The BANA testwas used in epidemiologic studies where it was found
Dental Measurements
to be an important explanatory variable for attach-
Because periodontal disease frequently begins sub-
ment loss in seniors19 and to correlate with the Com-
gingivally in the interdental papilla around the poste-
munity Periodontal Index of Treatment Needs index.16
rior teeth, plaque samples from the four interdental
This suggested that the BANA test could be used
sites between the first and second molars of each
under field conditions, such as the waiting room of
quadrant were collected. If teeth were missing, the
a hospital, to obtain information concerning the peri-
plaque sample was removed from the mesial or distal
odontal status of the patient. The purpose of this pro-
side of the remaining tooth.
spective study was to investigate the relationship
The PI score was recorded on a scale of 0 to 3 at the
between the presence of BANA-positive species in
interdental site from which the plaque sample would
subgingival plaque during the second and third tri-
be obtained for the BANA test. No plaque disclosing
mesters with the subsequent development of PB un-
solution was used. After the PI was measured, the
der field conditions.
supragingival plaque was removed from the site,and a soft wooden toothpick¶ was inserted between
MATERIALS AND METHODS
the first and second molars in each quadrant. When
the toothpick was removed, the PBS21 was recorded
This study was conducted in the Obstetric and Gyne-
at the interdental papilla on a scale from 0 to 5. The
cological (OBGYN) clinics in Show Chawn Memorial
subgingival plaque adherent to the toothpick was
Hospital and San Ann Hospital in Changhua, Taiwan,after all procedures were reviewed and approved
i BANAMet LLC, Ann Arbor, MI.
by the Health Sciences Institutional Research Board
¶ STIM-U-DENT, Johnson & Johnson, New Brunswick, NJ.
Periodontal BANA Scores and Preterm Births
Volume 81 • Number 7
used for the BANA test. A separate toothpick was
categoric variable (e.g., educational level and ethnic-
used to obtain each plaque sample, and both sides
ity). Chi-square tests were calculated to assess the
of each toothpick were wiped onto the lower strip of
relationship of categoric variables (e.g., ethnicity)
the BANA card. The upper strip of the BANA card
with PB (yes or no). Independent samples t tests were
was moistened with distilled water, and the card was
carried out to determine whether there was a signifi-
folded at the perforation mark so that the lower and
cant difference in the means of continuous variables
upper reagent strips met. The folded card was incu-
(e.g., time of dental measurement) for PB versus NT
bated in a special BANA test–designed heater at
outcomes. The potential independent variables for
55C for 5 minutes. After incubation, the lower re-
PB included in the multivariable logistic regression
agent strip containing plaque was discarded in a man-
model were antepartum hemorrhage, a preterm pre-
ner appropriate for contaminated material. The color
mature rupture of the membrane, infected second
on the upper strip was recorded by the consensus
and third BANA plaque samples, ethnicity, and weight
of two examiners (HC and Natalie Grossman,
gain during pregnancy. The statistical significance of
BANAMet, Ann Arbor, MI) with no blue = negative,
each variable and odds ratio (OR) were calculated us-
faint blue = weakly positive, and blue = positive. The
ing the Firth bias correction25 for a small sample size.
intraexaminer k agreement was 0.92, and the interexa-
The various predictors were entered in different com-
miner k agreement was 0.90. For statistical analyses,
binations into the models, and the model with the
weakly positive and positive results were recorded
highest Nagelkerke maximum rescaled R2 value26
as positive. A woman was defined as being BANA in-
and lowest Akaike's information criterion (AIC)27
fected when plaques from ‡2 of the four sample sites
value was selected. An a level of 0.05 was used for
were either weakly or strongly BANA positive.
all statistical tests. Statistical analyses were carriedout using a software package.**
Definition of Pregnancy OutcomesThe primary outcome was PB, which was defined as
a birth occurring <37 weeks (<259 days) of gestation
There were 317 women who consented to participate
and referred to the time that elapsed between the first
in this study, of whom 13 were seen in the Show
day of the last menstrual period and the day of deliv-
Chawn Memorial Hospital and 304 were seen in the
ery.22 The obstetricians (Hong-Chen Chang, Jinn-
San Ann Hospital. Eighteen subjects were excluded
Fa Bai, and Biau Hsiung Chen, San Ann Hospital;
for the following reasons: multiple gestations (n = 1),
and Hui-Yin Chiu, Show Chawn Memorial Hospital,
early pregnancy termination (n = 2), and no informa-
Changhua, Taiwan) were masked to the subjects par-
tion on the pregnancy outcome (n = 15). As a result,
ticipating in the study and had no knowledge of the
299 subjects had BANA test results obtained in the
women's periodontal data.
second and/or third trimesters. To address the effect
Statistical Analyses
of BANA-infected plaque on pregnancy outcomes,
Power calculations were made prior to initiation of the
the 268 subjects who had BANA test results in the
study, assuming that the total PB rate in Taiwan is
second and third trimesters and pregnancy out-
;7%23 and that 60% of our participants would be
comes were included in the statistical analysis. Of
BANA positive.24 We expected to be able to recruit
these 268 subjects, 194 (72.4%) subjects had >10
300 patients in the time frame of the study and calcu-
prenatal appointments. A total of 207 women
lated that a two-group x2 test with a 0.05 one-sided
(77.2%) delivered their babies vaginally, and 61 sub-
significance level would have 76% power to detect
jects (22.8%) underwent cesarean section deliveries.
the difference between a 10% incidence of PB babies
Nineteen women had a PB outcome (7%). There was
in the BANA-positive group and 3% PB babies in the
no significant difference in gender between PB and NT
BANA-negative group, assuming sample sizes in
infants (P >0.999).
the two groups of 180 and 120, respectively. Power
Maternal Demographic Characteristics
calculations were performed using statistic software.#
The ages of subjects ranged from 16 to 43 years with
Independent variables included maternal demo-
a mean – SD of 27.2 – 4.3 years. Sixty-seven women
graphic characteristics (age, occupational level, edu-
were ‡30 years of age. There was no significant differ-
cational level, ethnicity, and previous medical
ence in maternal age, occupational level, educational
history), pregnancy history (previous pregnancies,
level, and previous medical history among subjects
previous PBs, previous LBW infants, and abortion his-
who had PBs and subjects who had NT births (Table
tory), risk factors for PB (prepregnancy body mass
1). Thirteen of 268 subjects were non-Taiwanese,
index [BMI], smoking, and alcohol consumption),complications during pregnancy, second- and third-trimester dental measurements (the PI, PBS, and
# nQuery Advisor version 7.0, Statistical Solutions, Cork, Ireland.
** PASW Statistics 18, SPSS Inc, Chicago, IL; SAS for Windows, release
BANA test). Frequency data were generated for each
9.2, 2002-2008, SAS Institute, Cary, NC.
J Periodontol • July 2010
Chan, Wu, Welch, Loesche
Relationship of Maternal Characteristics to PB for 268 Subjects
Pregnancy Outcome
Normal (n = 249) (n [%])
PB (n = 19) (n [%])
Less than senior high school
Senior high school or further
Previous medical history
Medical condition
Previous pregnancy history
First-time pregnancy
Number of previous pregnancies
Previous spontaneous abortion
Previous artificial abortion
Prepregnancy BMI (kg/m2)
First prenatal care
Periodontal BANA Scores and Preterm Births
Volume 81 • Number 7
Table 1. (continued )
Relationship of Maternal Characteristics to PB for 268 Subjects
Pregnancy Outcome
Normal (n = 249) (n [%])
PB (n = 19) (n [%])
* Fisher exact test.
and these women had a higher proportion of PBs
the second and third trimesters (P <0.001 and
than the Taiwanese women (P = 0.055). None of these
P <0.001, respectively) than women who were BANA
non-Taiwanese women had graduated from senior
negative (fewer than two of the four sampling sites)
high school, whereas ;50% of the Taiwanese women
(data not shown). There was a tendency for the prev-
had schooling beyond high school.
alence of a BANA infection to increase from the sec-ond to third trimesters (Table 3).
Previous Pregnancy History (Table 1)
There were no significant differences in the gesta-
A total of 119 women (44.4%) were pregnant for the
tional age at the time of the examination among the
first time, and they were no more likely than the multi-
women destined to have an NT birth or a PB (Table
parious women to have a PB (>0.999; Table 1). Preg-
4). In the second and third trimesters, there was no
nant women who had a previous PB and previous LBW
significant difference among women who had PBs
infants were more likely to have a PB (P = 0.035 and
and women who had NT births in the adequacy of oral
hygiene procedures or in the presence of gingivitis, al-
Risk Factors and Pregnancy Complications
though there was a slight tendency for the prevalence
There was no significant relationship between a PB
of gingivitis to be higher in the second trimester in
and prepregnancy BMI, smoking, alcohol consump-
women destined to have a PB (Table 4). In the third
tion during pregnancy, and time of the first prenatal
trimester, but not the second trimester, there was
visit (P >0.05 for all comparisons; Table 1). The BMI
a tendency for women with ‡2 BANA-positive sites
at the first prenatal visit for the women destined to
to be in the PB group compared to women with <2
be in the NT group (mean: 21.04; SD: 3.57) and
BANA-positive sites (P = 0.08) (Table 4). Although
women destined to be in the PB group (mean:
the BANA results for each individual did not change
20.61; SD: 2.33) was comparable (P = 0.604). There-
between the second and third trimesters for the major-
after, women in the NT group gained significantly
ity of the subjects, there was a tendency for a BANA
more weight than the women in the PB group (P =
infection to decrease in the NT subjects compared
0.003) (data not shown). Ninety-eight percent of
to the PB subjects in the third trimester. Twelve per-
the women never smoked and the four women who
cent of the NT subjects had a decrease in BANA infec-
were current smokers were in the NT group. Only
tions, whereas only 5% of PB subjects had a decrease.
two women reported consuming alcoholic beverages
Twenty-six percent of the PB subjects showed an in-
(Table 1). There was a highly significant increase in
crease in BANA infections, whereas 17% of the NT
PB for women who had a preterm uterine contraction,
subjects showed an increase in BANA infections (data
antepartum hemorrhage, placenta previa, and pre-
not shown). The sample size was too small to show
term premature rupture of membrane (P = 0.025,
0.006, 0.014, and <0.001, respectively) (Table 2).
Logistic regression analysis was used to model the
occurrence of PBs based on the values of the various
Dental Measurements
explanatory variables. The following variables were
Approximately 80% of the women had good or fair oral
not significant in any of the models: age, education
hygiene, and there was no change in oral hygiene as
and occupation, smoking status, alcohol consumption,
they progressed from the second to third trimesters
oral hygiene status, presence of gingivitis, second-
(Table 3). Sixty-six percent of the women had gingi-
trimester BANA results, prepregnancy BMI, number
vitis in the second trimester, and this prevalence in-
of previous pregnancies, and whether the pregnancy
creased significantly to 78% in the third trimester.
was the subject's first pregnancy. The model with
Women who were BANA positive (i.e., ‡2 sites of
the highest maximum square value and lowest AIC
the four sampling sites were positive or weakly posi-
is shown in Table 5. BANA-infected plaque samples
tive) were more likely to have gingival bleeding in
in the third trimester (OR: 5.9), ethnicity (OR: 5.6),
J Periodontol • July 2010
Chan, Wu, Welch, Loesche
Relationship of Pregnancy Complications to PB for 268 Subjects
Normal (n = 249) (n [%])
PB (n = 19) (n [%])
Genitourinary infection
Hemorrhage at <28 weeks
Preterm uterine contraction
Antepartum hemorrhage
PPROM = Preterm premature rupture of membrane; PIH = pregnancy-induced hypertension; PGD = pregnancy gestational diabetes.
* Fisher exact test.
antepartum hemorrhage (OR: 10.0), and the preterm
periodontal disease with PB and/or LBW infants.28
premature rupture of membranes (OR: 12.6) were sig-
This variability in disease definition has lead to contra-
nificantly positive predictors of PBs, whereas maternal
dictory results with regard to the role of periodontal dis-
weight gain (OR: 0.78) was a significantly negative
ease in adverse pregnancy outcomes.28 Although
predictor of PBs, after adjusting for other potential risk
periodontal disease is regarded as an infection, only
factors. Although BANA-infected plaque samples in
occasionally are markers of infection used to recognize
the second trimester were not significantly related to
this infection, and then it is usually the host response,
PBs, this variable was kept in the model because of
as noted by bleeding, the visual appearance of tissue
its contrast with the third-trimester BANA results.
inflammation, and the presence of inflammatorymarkers. This current prospective study analyzed peri-
odontal pathogens in dental plaque, albeit indirectly by
Periodontal disease is traditionally defined on the basis
an enzyme test, to address the association between
of clinical morbidity about the teeth, such as probing
periodontal disease and adverse pregnancy outcomes.
depth, clinical attachment loss, and radiographic bone
Our population-based study demonstrated a link be-
loss. There is no consensus as to what constitutes the
tween BANA-positive dental plaques in the third tri-
threshold for periodontal disease as documented by
mester and PBs.
the fact that at least 14 different definitions and 50
Periodontal disease, as a source of persistent infec-
different measurements have been used to associate
tion, has been indicated by increased serum C-reactive
Periodontal BANA Scores and Preterm Births
Volume 81 • Number 7
protein (CRP) levels.29 In pregnant women, elevated
with an increased risk for preterm delivery7 and were
CRP levels were associated with periodontal disease
detected at higher levels in women who delivered pre-
in African American women30 and with an increased
term LBW infants6 and in the placentas of women
risk of preeclampsia.31 In this regard, the value of mi-
with preeclampsis.10
crobial tests to diagnose a periodontal infection would
DNA probes were used to establish the connection
seem worthwhile. Although the subgingival plaque
among P. gingivalis, T. denticola, and T. forsythia with
flora is bacteriologically complex, P. gingivalis, T. for-
adverse pregnancy outcomes in the cited studies.7,32
sythia, and T. denticola have emerged as major peri-
They were also used to show that periodontal treat-
odontal pathogens.5 These species were associated
ment in the second trimester could significantly reducethe levels of these species in plaque samples.32 The
use of DNA probes is a laboratory-based procedurethat requires equipment and resources that were not
Comparison of Categoric Variables for
available for the present study, whereas the BANA test
Dental Measurements Between the
could be performed at chairside and lended itself to
Second and Third Trimesters
the type of field study described. The BANA test ap-pears to be a reliable surrogate for the use of DNA
probes in the detection of P. gingivalis, T. denticola,
and T. forsythia in plaque samples.14 Bayingana33
showed that the BANA test was more reflective of gin-gival conditions during pregnancy than were DNA
Periodontal disease, as a response to a chronic in-
fection, shares risk factors with a PB.1 The logistic re-
gression model with the Firth correction for a small
sample size was performed to control for the possible
confounding effects of other predictors. This model in-
dicated that the odds of having a PB were 5.9 times
higher for women in the third trimester with ‡ 2 infected
BANA-positive or weakly BANA-positive sites com-
pared to women with fewer than two BANA-positive
* McNemar test.
or weakly BANA-positive sites after controlling for
† PI score ‡2 in <50% of sites.
other variables. Other investigators6,7 obtained bacte-
‡ Two or more sites bled after measurement by the toothpicks.
§ Two or more sites that were BANA positive or weakly positive.
riologic data from women in the second trimester and
Relationship of Dental Measurements to PB
Second Trimester (n = 268)
Third Trimester (n = 268)
Gestational age at sampling (n [mean days])*
Oral hygiene (n [%])†
Gingivitis (n [%])†
BANA-infected plaque samples (n [%])†
* Independent samples t test.
† Fisher exact test.
‡ PI score ‡2 in <50% of sites.
§ Two or more sites bled after measurement by the toothpicks.
i Two or more sites were BANA positive or weakly positive.
J Periodontol • July 2010
Chan, Wu, Welch, Loesche
Relationships of Predictors to PB Based on Logistic Regression Analysis for 268 SubjectsWho Had Plaque Sampled for the BANA Test in the Second and Third Trimesters*
Explanatory Variables
Antepartum hemorrhage
Premature rupture of membranes
Second-trimester BANA infection§
Third-trimester BANA infection§
df = degrees of freedom; CI = confidence interval.
* All variables were included in the model simultaneously. Age, gender, oral hygiene, gingivitis, history of PBs, history of LBW, and premature contraction
were not significant in the model. Firth bias correction was used for the analysis Nagelkerke R2 = 0.412; AIC = 94.87.
§ BANA-infection mean plaque removed from ‡2 sites were BANA positive or weakly positive.
found that the levels of eight plaque bacteria, including
In one intervention study,35 an average of 1.3 ses-
P. gingivalis, T. forsythia, and T. denticola, tended to be
sions of scaling and root planing was associated with
higher in the second trimester in mothers who deliv-
a ‡2-mm loss of attachment at ‡4 sites in 41% of the
ered preterm babies than in mothers who delivered
women. Scaling and root planing often causes bac-
term babies.7 Our results show that 58% of the women
teremia, the intensity of which increases with the se-
in the second trimester had a BANA infection, but that
verity of periodontal disease,38-40 and increases the
no connection between a BANA infection and PB could
level of interleukin-6,41,42 which has been indicated
be shown until the third trimester. This could have im-
as a risk for PB.43 It is possible that mechanical de-
portant implications for the timing of treatment.
bridement without a concurrent usage of an antimi-
Because periodontal disease is preventable and
crobial agent may cause a bacteremia or incite an
treatable, treating periodontal disease during preg-
acute inflammatory response.44 In this regard, the
nancy should improve pregnancy outcomes. Two
strategy for reducing PBs by periodontal intervention
large, well controlled, intervention studies34,35 that
might consider restricting the treatments to women
used debridement procedures (i.e., scaling and root
who have a periodontal infection in the early third tri-
planing was delivered in the second trimester) were
mester, include the use of antimicrobial agents, and
unsuccessful in reducing PBs. A study36 that began
provide intervention at the gestational age of 28 to
in the second trimester and continued into the third
trimester and included an antimicrobial agent (i.e.,
There is evidence that suggests that ethnicity might
a 0.12% chlorhexidine rinse) in addition to debride-
play a role in PBs.1 In our study, 4.9% of the subjects
ment was successful in reducing PBs. This difference
were non-Taiwanese and they were more likely to
in outcomes suggests that scaling and root planing in
have a higher rate of an adverse pregnancy outcome
the second trimester was not enough to reduce PBs.
compared to the Taiwanese women (P = 0.055). The
The importance of timing of the treatment was shown
non-Taiwanese women tended to have a lower social
by a study37 in which women who had periodontal
economic status as indicated by the educational level
disease and were hospitalized with a threatening PB
compared to the Taiwanese women (Table 1). Also,
were randomly assigned to a treatment group or to
married immigrants faced problems of adaptation,
a non-treatment group.37 The treatment was pro-
communication difficulties, a lack of family support
vided in the third trimester, at ;32 weeks, and con-
from their home town, and barriers to healthcare sys-
sisted of oral hygiene instructions, scaling and root
tem use at the beginning of their lives in Taiwan.45
planning, and polishing of teeth with a fluoride paste.
Smoking exhibits a dose-dependent relationship
The babies of the treated women were delivered at
with PBs, as does a very high consumption of alco-
37.5 weeks and weighed 3,079 g, which was signifi-
hol.1,46 In Taiwan, women rarely smoke or use alco-
cantly more than the 2,602-g infants who were born
hol or drugs, and especially do not do so during
at 36.1 weeks to the women in the comparable con-
pregnancy. The self-reported data regarding smoking
and alcohol consumption were only 1.5% and 0.7%,
Periodontal BANA Scores and Preterm Births
Volume 81 • Number 7
respectively. As a result, our study provided informa-
School of Dentistry, University of Michigan, for advice
tion on the association between periodontal disease
and guidance, and to BANAMet, Ann Arbor, Michigan,
and PBs without these confounding factors. In Taiwan,
for their BANA tests and incubators. This research was
the National Health Insurance provides for 10 paid
funded by a gift from Oralife, Toronto, Ontario, to the
prenatal examinations during pregnancy. Almost all
School of Dentistry, University of Michigan. Dr. Loesche
(i.e., 98%) of our participants had their first prenatal
has received financial support from BANAMet and is
consultation at <12 weeks gestational age, which
a partner of BANAMet, the manufacturer of the BANA
would eliminate inadequate prenatal care as a risk
test. Drs. Chan, Wu, and Welch report no conflicts of
factor for a PB.47,48
interest related to this study.
A history of a PB or a history of LBW was not signif-
icant in the adjusted models. Both histories are usually
risk factors for PBs.1 Possible reasons for the lack of
1. Goldenberg RL, Culhane JF, Iams JD, Romero R.
significance include the small number of PBs or that
Epidemiology and causes of preterm birth. Lancet2008;371:75-84.
the association of these factors with PBs is through
2. Romero R, Hobbins JC, Mitchell MD. Endotoxin stim-
an underlying BANA infection so that adjusting for
ulates prostaglandin E2 production by human amnion.
BANA infection removes the association. We tested
Obstet Gynecol 1988;71:227-228.
for the latter possibility by removing the BANA data
3. Goldenberg RL, Hauth JC, Andrews WW. Intrauterine
from the models and still found no association of a his-
infection and preterm delivery. N Engl J Med 2000;
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In our population, women with £10 prenatal visits
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had more PBs compared to women who had >10 pre-
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natal visits (P <0.001). This result is consistent with
a specific, albeit chronic, infection: diagnosis and
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Persistently high levels of periodontal pathogens as-
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obic bacterial burden and the inflammatory response
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To our knowledge, our study provides a new insight
pregnant women with a diagnosis of threatened pre-
by addressing the infectivity progression with BANA-
mature labor. J Periodontol 2003;74:1764-1770.
associated periodontal pathogens and suggests that
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the third-trimester bacterial status of the subgingival
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plaque may be an important predictor of PBs. The abil-
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ity of the BANA test to detect anaerobic periodontal
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This research was performed by Dr. Hui-Chen Chan in
matic methods. Oral Microbiol Immunol 1986;1:65-72.
partial fulfillment of the requirements for a master's
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Dr. Jinn-Fa Bai, Dr. Hong-Chen Chang and Dr. Biau
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to clinic patients and clinical facilities. Also, thanks to
naphthylamide (BANA) test, DNA probes, and immu-
Mrs. Natalie Grossman, consultant for BANAMet, for
nological reagents for ability to detect anaerobic
her participation in helping to read BANA results, and
periodontal infections due to Porphyromonas gingiva-
to all of the subjects for participating in this research.
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Correspondence: Dr. Hui-Chen Chan, North University
Avenue, Department of Orthodontic and Pediatric Dentistry,
32. Novak MJ, Novak KF, Hodges JS, et al. Periodontal
School of Dentistry, University of Michigan, Ann Arbor, MI
bacterial profiles in pregnant women: response to
48109-1078. E-mail:
[email protected].
treatment and associations with birth outcomes inthe obstetrics and periodontal therapy (OPT) study.
Submitted September 13, 2009; accepted for publication
J Periodontol 2008;79:1870-1879.
February 25, 2010.
Source: http://www.hakusui-trading.co.jp/common/download.php?Tb=0&Tp=12&oid=34567
Table 10. MIC and zone diameter breakpoints for staphylococci Comments 1-3 relate to urinary tract infections (UTI) only. 1 These recommendations are for organisms associated with uncomplicated urinary tract infections only. For complicated infections and infections caused by Staphylococcus aureus and Staphylococcus epidermidis, which are associated with more serious infections, systemic recommendations should be used.
Target cell availability and the successful suppression of HIV by hydroxyurea and didanosine Rob J. De Boer AIDS 1998, 12:1567–1570 Keywords: Hydroxyurea, immunosuppression, target cell availability, 72 weeks of ddI–HU treatment, three out of sixpatients had no detectable plasma virus, and that there