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Purpose To determine the prevalence of third molars in the US population and to report the differences in prevalence of visible third molars in the most recent National Health and Nutrition Examination Survey (NHANES) population of 2011 through 2012 by participant, jaw, and demographics. Materials and Methods The number of visible third molars in the NHANES data was assessed in nonclinical settings by trained, calibrated dental hygienists by decade of age beginning in the 20- to 29-year-old cohort through the 70- to 79-year-old cohort. Cross-sectional analyses of third molar data were conducted by the authors from the NHANES databases of 2001 through 2002, 2009 through 2010, and 2011 through 2012 to compare data for similarity of outcomes on third molar prevalence in the US population. Outcomes on third molar prevalence also were assessed from the NHANES of 2011 through 2012 by participant, jaw, and demographics: gender, race or ethnicity (Caucasian, African American, other), and education (less than high school, high school graduate, some college, college graduate). Results Data on the mean number of third molars from NHANES of 2001 through 2002, 2009 through 2010, and 2011 through 2012 were similar. The number of visible third molars in the NHANES of 2011 through 2012 decreased progressively from a mean of 1.48 in the 20- to 29-year-old cohort to 0.81 in the 60- to 69-year-old cohort, No visible third molars were observed in 47% of the 20- to 29-year-old cohort compared with 53% in the 50- to 59-year-old cohort. Participants who were male, non-Caucasian, and had less than a high school education were more likely to have a visible third molar in all age cohorts. No data were collected by NHANES examiners to determine why third molars were absent. Conclusion Third molar prevalence did not appear to differ in the US population during the first decade of the 21st century. Numbers of visible third molars, prevalent in young adults, decreased progressively through each successive age cohort. Demographic differences exist for prevalence of third molars in the US population.

To assess the impact of third molar removal on the periodontal status of adjacent second molars and teeth more anterior in the mouth in patients with mild symptoms of pericoronitis.Healthy patients with mild symptoms of pericoronitis affecting at least 1 mandibular third molar were recruited for a study approved by the institutional review board. The subset analyzed in this study had all 4 third molars removed. Data were collected at enrollment and at least 3 months after surgery. Full-mouth periodontal probing was conducted at 6 sites per tooth. A probing depth of at least 4 mm (PD4+) was considered an indicator for periodontal pathology. The presence of a PD4+ on the distal of second molars (D2Ms) or anterior to the D2Ms, the number of PD4+s, and extent scores (percentage of PD4+s of all possible probing sites) were assessed at the patient and jaw levels. The association between patients' pre- and postsurgical periodontal status was assessed using the McNemar exact test. The level of significance was set at .05.The median age of the 69 patients was 21.8 years (interquartile range, 20.2 to 25.2 yr). Forty-five percent were men, and 57% were Caucasian. Significantly more patients (88%) had at least 1 D2M PD4+ at enrollment compared with after surgery (46%; P.01). D2M extent scores decreased from 31.5 at enrollment to 11 after surgery. Significantly more patients (61%) had at least 1 PD4+ anterior to the D2M at enrollment compared with after surgery (29%; P.01). Extent scores anterior to the D2M decreased from 2.0 at enrollment to 0.6 after surgery.Removal of third molars in patients with mild pericoronitis symptoms improved the periodontal status of the D2Ms and teeth more anterior in the mouth.

To assess the relationship between the presence or absence of visible third molars and outcomes for periodontal inflammatory disease.Obstetric subjects, at enrollment in an institutional review board-approved, multisite study, Maternal Oral Therapy to Reduce Obstetric Risk (N = 1,798), were divided into 2 groups, those with no visible third molars (n = 692) and those with at least 1 visible third molar (n = 1,106), the predictor variables for this study. The principal outcome variables were the patient-level periodontal status of the first/second molars: mean periodontal probing depths, mean attachment levels, and mean extent scores. Periodontal disease severity also was assessed by criteria from the Oral Conditions and Pregnancy trial and the Centers for Disease Control and Prevention/American Academy of Periodontology. Outcomes according to the presence or absence of third molars were compared with χ(2) statistics and multivariable analyses. Significance was set at P.05.Significantly more subjects had at least 1 third molar (62%) as compared with subjects with no visible third molar (38%) (P.01). Ethnic characteristics of the 2 groups were similar. Overall, more subjects were white (61%), with most identifying their ethnicity as Latino. African-American subjects were well represented (37%). Subjects with a visible third molar were more likely to be significantly older, to be receiving medical assistance, and to have used tobacco before pregnancy. If subjects had at least 1 visible third molar, the mean first/second molar probing depths, attachment levels, and scores for bleeding on probing were significantly greater even after adjustment for covariates. On the basis of either Oral Conditions and Pregnancy criteria or Centers for Disease Control and Prevention/American Academy of Periodontology criteria, subjects were significantly more likely to have moderate or severe periodontal disease if a third molar was detected.If at least 1 visible third molar was detected in subjects in the Maternal Oral Therapy to Reduce Obstetric Risk study at enrollment as compared with no detected third molars, periodontal outcomes were significantly worse.

Purpose To establish a relationship between visible third molars (M3s) and increased periodontal probing depths on teeth other than M3s and to examine the hypothesis that the presence of M3s and/or increased probing depths and local inflammation associated with M3s was associated with increased levels of serum inflammatory markers. Patients and Methods The data from three previous population studies (Dental Atherosclerosis Risk In Communities [DARIC], Oral Conditions and Pregnancy [OCAP], and National Health and Nutrition Estimates Study [NHANES III]) and the third molar clinical trials of young adults (White et al) are summarized. A secondary analysis determined whether the presence or absence of visible M3s was associated with an increased prevalence of clinical signs of periodontal disease using adjusted logistic regression models. In addition, serum samples collected from the OCAP, DARIC, and White studies were used to measure the markers of systemic inflammation, C-reactive protein, interleukin-6, and soluble intracellular adhesion molecule-1. Results In young adults, asymptomatic M3s were associated with an increase in periodontal probing depths of at least 4 mm on second molars and an increase in probing depth of at least 2 mm in 24% of subjects after 2 years. Retention of asymptomatic M3s for 6 years led to a significant increase in the number of subjects with a probing depth of 4 mm or more in non-M3 regions of the mouth. Findings from the DARIC, OCAP, and NHANES III further confirmed the association between the M3 probing depth and periodontal inflammation on non–M3s. Retention of M3s in the presence of periodontal inflammation was associated with significant increases in the serum interleukin-6, soluble intracellular adhesion molecule-1, and C-reactive protein levels. Conclusion Patients deciding to retain M3s should consider the potential long-term effects on their periodontal status and the potential for the retained M3s to serve as a chronic source of inflammation that stresses their systemic health.

Purpose To assess the prevalence of caries experience and periodontal pathology on third molar teeth compared with first and second molars and teeth more anterior from subjects who had data collected over time in a longitudinal clinical study. Patients and Methods Healthy subjects with 4 asymptomatic third molars and data for at least 4 years after enrollment were included in these analyses. The presence or absence of caries experience on the occlusal surface of the third molars and any surface of the first or second molars was assessed using a visual-tactile caries examination. Full mouth periodontal probing, 6 sites per tooth, was conducted as a measure of clinical periodontal status. The primary outcome measures were at least 1 periodontal probing depth of at least 4 mm versus none, and caries experience versus no caries experience. The prevalence of caries experience and periodontal pathologic findings at follow-up and the relationship of the occurrence between the third molars and teeth more anterior in the mouth were examined using McNemar's statistics. Results The follow-up was a median of 6.9 years (interquartile range 4.6 to 7.7 years) for 179 subjects, with a mean age of 29 years. More subjects were female (54%) and white (80%). At follow-up, 85% of the subjects had caries experience detected on the first or second molars, and only 50% had a third molar affected. In contrast, at follow-up, the presence of at least 1 periodontal probing depth of at least 4 mm was marginally more prevalent on the third molars than on the first or second molars (56% and 50%, respectively). Fewer subjects had third molars free of caries experience and periodontal pathology at follow-up compared with at enrollment (28% versus 38%, respectively). Conclusions The prevalence of both third molar caries experience and third molar periodontal pathology increased from baseline to the follow-up examination. At follow-up, the prevalence of caries experience was greater on the first or second molars than on the third molars, and periodontal pathology were greater on the third molars than on the more anterior teeth.

Purpose To assess the relationship between visible third molars and the periodontal status of teeth more anterior in the mouth from reports that included periodontal probing data for all teeth. Materials and Methods Each of 4 reports that included periodontal probing data, 6 probing sites for all teeth, including third molars collected by trained, clinician examiners, were briefly summarized. The design, strengths, and weaknesses of each of the 4 studies were compared and summarized. A Forest plot was used to combine the findings from the 4 studies comparing the mean second molar probing depth differences in mm by the presence of at least 1 visible third molar or no visible third molar. Results A review of the data from 4 reports, 1 from middle-age adults and 3 from young adults, suggested an association between the visible presence of a third molar and increased periodontal probing depths on teeth more anterior in the mouth, predominately the first and second molars. Coupled with the probing depth around the third molars, the result was an expanded surface area at the biofilm–gingival interface. Conclusions Although all those with retained third molars are not at increased risk, the summary data we have reported suggest that those with a visible third molar are more likely to have greater periodontal probing depths overall, particularly on second molars, and a greater surface area of the biofilm–gingival interface compared with those with no visible third molar.

Purpose To assess the prevalence of periodontal inflammatory disease on the distal side of second molars after third molar removal and the association between presurgical and surgical variables and postsurgical periodontal outcomes. Patients and Methods Data before and after surgery from 2 studies approved by an institutional review board were used. In 1 study, 26 subjects had 4 asymptomatic third molars and in the other 49 subjects had at least 1 mandibular third molar with symptoms of pericoronitis. Full-mouth periodontal probing data, 6 sites per tooth, were obtained as a measurement of periodontal status before and after surgery. A probing depth (PD) ≥4 mm on either of the 2 possible probing sites on the distal side of any second molar (D2M) served as an indicator of periodontal inflammatory disease; periodontal health was defined as all D2M PD

Purpose To assess the association between the visible presence of third molars and the severity of periodontal pathologic findings on teeth more anterior in the mouth. Patients and Methods The present analysis included dentate participants, 52 to 74 years old, from the Dental Atherosclerosis Risk in Communities study who had undergone an oral examination that included periodontal probing depths (PDs) on all visible teeth, including any third molars. A PD of 4 mm or more and a clinical attachment level of 3 mm or greater were indicator variables for periodontal pathologic features. Explanatory variables were the presence or absence of visible third molars. The covariates included gender, ethnicity, age, income level, education, and smoking status. The outcome variables for periodontal pathologic features were the mean PD, extent (percentage of probing sites) of PDs of 4 mm or more, and the extent (percentage of probing sites) of a clinical attachment level of 3 mm or more. The outcomes between those with and without visible third molars were compared using descriptive statistics and chi-square tests, with significance set at P = .05. Multivariate modeling was performed using Statistical Analysis Systems SAS Proc GLM (SAS Institute, Cary, NC) to calculate the least squared means, adjusting for the study outcome variables and covariates. Results The Dental Atherosclerosis Risk in Communities study sample included 6,793 subjects; 80% were white and 19% were black. Most (53%) were 62 to 74 years old and female (54%). Of the 6,793 participants, 2,035 (30%) had at least 1 visible third molar. The presence of a visible third molar was significantly associated with male gender, black race, age younger than the mean of 62.4 years, greater income, and never smoking (all P < .01). A greater mean PD for the first and second molars, the extent of PD of 4 mm or more at the first and second molars, and the extent of a clinical attachment level of 3 mm or more at the first and second molars were all significantly associated with the presence of a visible third molar in the unadjusted and adjusted models. Conclusions In these middle-age and older Americans, the presence of a visible third molar was significantly associated with more severe periodontal disease on teeth more anterior in the mouth compared with those subjects with no visible third molars.

To compare the prevalence and severity of periodontal inflammatory disease in subjects with pericoronitis involving a mandibular third molar and those without pericoronitis.Data obtained from healthy adults consecutively enrolled in an institutional review board-approved trial with pericoronitis affecting at least 1 mandibular third molar (study group) were compared with data obtained during the same time frame from subjects without pericoronitis enrolled in a longitudinal third molar monitoring study (comparison group). The periodontal status of each subject was classified based on periodontal probing depths (PD): all PD4 mm, no disease; 1 to 3 PDor=4 mm, incipient disease; at least 4 PDor=4 mm, early disease. Full mouth periodontal probing data were obtained as clinical measures of periodontal status. Data were aggregated to the subject level for the third molar region, the 6 third molar probing sites and the 2 second molar distal probing sites, the non-third molar region, and all remaining probing sites. The prevalence of disease in the study and comparison groups were compared with the Fisher's exact test. As an indicator of disease severity, the number of PDor=4 mm in the 2 groups were compared by the Kruskal-Wallis test. Level of significance was set at P values less than .05.Median age of the 56 subjects with pericoronitis was 23.3 years (IQR 21.3-26.0 years). Fifty-five percent were Caucasian, 16% African American, and 22% Asian. Males and females were almost equally represented in the study group and in the comparison group. The 194 subjects enrolled without pericoronitis were significantly older (32.8 years; IQR 27.2-40.0 years; P.001). Eighty-four percent were Caucasian, 10% African American, and 4% Asian. The proportion of subjects with periodontal inflammatory disease in the third molar region was significantly different between the study and comparison groups. Thirty-one percent of the subjects with pericoronitis had incipient and 55% early disease in the third molar region compared with 25% with incipient and 38% with early disease among subjects without pericoronitis (P = .003). The pattern was similar, but the proportion of subjects was not significantly different between the groups for the non-third molar region. In the study group, 32% had incipient disease and 32% early disease compared with 27% with incipient disease and 22% with early disease in the comparison group (P = .09). The median number of PDor=4 mm for all teeth differed significantly for subjects with and without pericoronitis (median 5 [IQR 3-9] vs 3 [IQR 0-8], respectively; P = .03).Pericoronitis involving mandibular third molars may reflect more underlying periodontal inflammatory disease in affected young adults than might be found in young adults with retained third molars and no pericoronitis.

Purpose To assess the impact of mechanical debridement (scaling and root planing), without adjunctive therapy, on reducing the numbers of periodontal pathogens detected in pregnant subjects with and without visible third molars. Patients and Methods Sixty-seven subjects in the second trimester of pregnancy were enrolled in an institutional review board-approved study. Full mouth periodontal exams of all teeth were conducted at baseline and postpartum. Presence or absence of third molars was noted. Subgingival biofilm samples were obtained from the mesiobuccal of all first molars at enrollment and postpartum. Subjects' total counts for periodontal pathogens in biofilm samples were determined by DNA-DNA checkerboard hybridization. We analyzed data from a subsample of 26 subjects. All subjects in the study were treated at enrollment by mechanical debridement of all teeth, including third molars. Differences between subjects' baseline and postpartum demographic and clinical characteristics were analyzed by χ2 and t tests by presence or absence of third molars. Statistical significance for differences in pathogen levels was determined by Rank analysis of covariance. Significance was set at 0.05 without correction for multiple comparisons. Results Most of the 26 subjects were African American (61%), on Medicaid (92%), and did not smoke during pregnancy (88%). The 15 subjects with visible third molars were significantly older (28.0 years [SD 6.4] vs 23.7 years [SD 3.9]). In the 11 subjects with no third molars noted, all pathogen counts were reduced postpartum. In the 15 subjects with visible third molars, total counts for each pathogen analyzed were higher postpartum as compared with subjects with no visible third molars, and their bacterial counts were increased for 5 of the 8 pathogens, including all “red cluster” pathogens. Differences between study groups were observed by the presence or absence of third molars for T. forsythia and P. nigrescens (P = .04), and for P. gingivalis, F. nucleatum, total “orange cluster” bacteria, and total pathogens (P Conclusion The efficacy of mechanical debridement to lower periodontal pathogen counts during pregnancy was limited by the presence of visible third molars and should be analyzed further in larger scale trials.

The purpose of this study was to assess changes in periodontal probing depth (PD) over time for third molar and nonthird molar regions in young adults.The data were obtained from healthy subjects with 4 asymptomatic third molars, enrolled in an IRB-approved longitudinal trial. Demographic and oral health data were collected at baseline. Full-mouth PD, 6 sites per tooth, was conducted to determine periodontal status at baseline and at longest follow-up. The third molar region was defined as the PD for 6 sites around the third molars and the 2 sites on the distal of the second molars. The nonthird molar region was defined as the remainder of the PD sites in the mouth. The primary outcome measures for this study were the occurrence of a PD greater than or equal to 4 mm and the increase in PD of at least 2 mm in the third molar and nonthird molar regions. Changes from enrollment to longest follow-up were compared by the binomial or McNemar's test. Level of significance was .05.Data from 195 subjects were available, and the median follow-up was 5.9 years (interquartile range [IQ], 4.6 to 6.9 years). Median age at enrollment was 26.2 years (IQ, 22.0 to 34.0 years); 52% were female, 84% were Caucasian, and 10% were African American. The proportion of subjects with at least 1 involved site in nonthird molars increased significantly from baseline to follow-up, 36% to 49% (P.01), reflecting mostly changes in mandibular nonthird molars, 33% to 48% (P.01). Of the 122 subjects who presented at baseline with at least 1 PD greater than or equal to 4 mm in the third molar region, the proportion of subjects with at least 1 involved site in nonthird molars increased significantly from baseline to follow-up, 48% to 59% (P = .05), also reflecting mostly changes in mandibular nonthird molars, 44% to 59% (P = .05).In this unique longitudinal clinical study of early periodontal disease in young adults, periodontal pathology worsened over time for nonthird molars. This was more likely if PD greater than or equal to 4 mm was detected in the third molar region.

This study was designed to identify risk indicators for the prevalence at enrollment and incidence over 36 months of periodontal pathology and coronal caries experience affecting third molars in a community-based study of people over 65 years of age.Data from a subsample of 810 dentate subjects from the Piedmont 65+ Study were available for analyses. All visible teeth were examined. Periodontal probing measures were taken at 2 sites, mesiobuccal and buccal/facial. Clinical data on caries experience were collected by visual-tactile examination. At enrollment, 340 subjects had at least 1 visible third molar; all were examined for caries experience. Periodontal probing measures were available for 277 of these same subjects. The significance of the possible risk indicators for periodontal pathology and caries affecting third molars was determined by chi(2) tests. Statistical significance was set at .05. Logistic multivariable models were used to derive odds ratios and 95% confidence intervals.African-American subjects were more likely to have visible third molars (P.01). Caucasian subjects were more likely to have third molar coronal caries experience (P.01), as were subjects with greater than a high school education and those with a dental visit within 3 years (both P.01). However, African American subjects were more likely to have periodontal pathology, CALs/= 3 mm on third molars (P.01), as were those who used tobacco (P.01). None of the other risk indicators we studied were associated with progression of periodontal pathology or coronal caries experience on visible third molars.In this population study of senior adults, Caucasians and African Americans appear to have different levels of risk for caries experience and periodontal pathology affecting retained third molars.

This study was designed to assess the prevalence at enrollment and incidence over 36 months of periodontal pathology and caries affecting third molars in a community-based study of people over the age of 65 years in North Carolina.A sub-sample of 818 subjects with dental examinations taken from the Piedmont 65+ Study was available for analysis. All visible teeth were examined. Periodontal probing (PD) measures were taken at 2 sites, mesiobuccal and buccal/facial. Clinical data on caries experience were collected by visual-tactile examination. At enrollment, 342 subjects had at least 1 visible third molar that could be examined. PD measures were available for 276 of these same subjects. The significance of comparisons between third molars and nonthird molars were determined by chi(2) tests and the statistical significance was set at .05.Most of the 342 subjects with at least 1 visible third molar were female (57%) or African American (63%). Mean age was 73 years (SD 5.5 years). Of the 197 subjects with caries experience, third molars were affected in 49% of subjects, less than the 87% in nonthird molars. Third molar caries experience was associated with caries experience on nonthird molar teeth (P.01). Clinical attachment level (CAL) greater than 3 mm was detected at enrollment in third molars in 68% of subjects, and in nonthird molars in 96%. With one exception, CAL greater than 3 mm in third molars was associated with CAL greater than 3 mm elsewhere in the mouth. Few subjects (17%) had clinical evidence of both caries and periodontal pathology affecting third molars. In this older population of individuals with third molars, 21% were free of periodontal pathology or caries experience.Data on the prevalence of third molar periodontal pathology and third molar caries experience in an elderly population should be useful to both clinicians and their younger patients when considering the merits of retaining or removing third molars with no evidence of pathology.

Purpose: To assess the association between risk markers of chronic oral inflammation and changes over time in periodontal probing depth (PD) in the third molar region, the distal of a second molar, or around a third molar. Subjects and Methods: The data from these analyses are part of a study of subjects enrolled with 4 asymptomatic third molars with adjacent second molars in an institutional review board-approved longitudinal trial. Full-mouth periodontal probing was conducted at enrollment and follow-up. Enrollment levels of periodontal pathogens and gingival crevicular fluid inflammatory mediators were assayed as indicators of the degree of oral inflammation. Subjects were categorized as those who had at least a 2 mm change in periodontal PD between baseline and follow-up in the third molar region and those who did not. The relationship between aggregated subject baseline PD, levels of periodontal pathogens, and gingival crevicular fluid IL-1β, and the proportion of subjects with changes in PD ≥2 mm versus those with PD

Purpose This study was designed to assess changes in third molar position and angulation in young adults and the resulting third molar periodontal probing (PD) status. Patients and Methods Data derived from patients with 4 asymptomatic third molars with adjacent second molars enrolled in an institutional review board approved longitudinal trial. Inclusion criteria for the trial dictated that patients be healthy and 14 to 45 years of age. Panoramic radiographs were analyzed for third molar angulation as compared with the long axis of the second molar (mesial/horizontal ≥25°) and eruption to the occlusal plane. Full mouth PD including third molars was conducted at follow-up. At follow-up, PD ≥4 mm distal of second molars or around third molars was considered important clinically. Results Data from 237 patients were available. Median age was 25.9 years (interquartile range [IQ], 22.1 years, 32.8 years). With a median follow-up of 2.2 years (IQ, 2.0 years, 3.7 years), 44% of impacted maxillary third and 26% of impacted mandibular third molars changed angulation or position. One third of vertical/distal impacted third molars in both jaws and 11% mesial/horizontal mandibular third molars erupted to the occlusal plane during follow-up from baseline. If mandibular third molar angulation as compared with the long axis of the second molar was mesial/horizontal ≥35°, only 3% erupted to the occlusal plane. At follow-up, 11% of the 125 impacted maxillary third and 29% of the 133 impacted mandibular third molars had PD ≥4 mm. Similarly, 11% of the 307 maxillary third molars at the occlusal plane had PD ≥4 mm, but 51% of the 312 erupted mandibular third molars were affected. Conclusion A change in third molar position or angulation was common. Erupted mandibular third molars were more likely to have PD ≥4 mm.

Purpose The study goal was to assess the association between the presence of visible third molars and periodontal pathology in a community-dwelling sample of middle-aged and older adults. Materials and methods Data were obtained between 1996 and 1999 on 6,793 persons aged 52 to 74 from the Dental ARIC Study, a substudy of the Atherosclerosis Risk in Communities Study. The main independent variable was presence or absence of third molars assessed visually, and the dependent variable was assessment of periodontal disease as measured by pocket depth of 5 mm or greater (PD5+). Periodontal measures included pocket depth, gingival recession, and attachment level on 6 sites per tooth on all remaining teeth. Second molars were compared for periodontal pathology based on the presence or absence of a visible third molar in the same quadrant. Associations were determined using odds ratios and 95% confidence intervals. Weighted multivariable models were fit using logistic regression, and variances were adjusted to account for the clustering of quadrants within persons with the use of SUDAAN (Research Triangle Institute, Research Triangle Park, NC). Results A visible third molar was associated with 1.5 times the odds of PD5+ on the adjacent second molar, while controlling for other factors associated with the presence of third molars and periodontal disease. Other factors positively associated with PD5+ in the model were male gender, older age, smoking, and irregular and episodic dental visits. Conclusions The finding of more severe periodontal conditions associated with visible third molars in these middle-aged and older adults indicates that third molars may continue to have a negative impact on periodontal health well into later life. The relationship between third molars and periodontal disease pathogenesis deserves further study using longitudinal data.

Purpose: Our goal was to report the detection and levels of pathogenic bacteria in subgingival plaque samples taken from the distal of all second molars in 295 patients with asymptomatic third molars. Patients and Methods: Data assessing oral health were collected from each of these healthy patients (ASA Classes I and II). Probing depth (PD), at 6 sites per tooth, including third molars, was obtained to determine periodontal status. Subgingival plaque samples were taken from the distal of all second molars before periodontal probing. The presence and levels of 11 bacterial species were determined using whole chromosomal DNA probes and checkerboard DNA-DNA hybridization. Detected bacterial species were grouped into clusters of periodontal pathogens designated as “red” or “orange” complex microorganisms as described by Socransky et al (J Clin Periodontal 25:134, 1998) who found an association of these specific microorganisms with periodontitis. Results: As a group these relatively young patients were periodontally healthy. “Orange and red” complex microorganisms were detected at levels equal to or greater than 105 more often if patients had a PD equal to or greater than 5 mm with periodontal attachment loss at the distal of second molars or around third molars at their entry examination. In patients with no PD equal to or greater than 5 mm in the third molar region, “orange and red” complex microorganisms were detected at levels equal to or greater than 105 more frequently than would be anticipated in patients with little clinical evidence of periodontal disease. Conclusions: The clinical findings of increased periodontal PDs and periodontal attachment loss coupled with colonization of periodontal pathogens support the concept that clinical and microbial changes associated with the initiation of periodontitis may present first in the third molar region in young adults. © 2002 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 60:1234-1240, 2002

Purpose: We report the prevalence of periodontal probing depth (PD) as a clinical measure of the extent of periodontitis associated with asymptomatic third molars at the initial examination in a cohort of patients enrolled in an institutional review board–approved longitudinal clinical trial. Patients and Methods: Three hundred twenty-nine healthy patients were enrolled during a 30-month period. Full mouth periodontal probing that included third molars was conducted to determine periodontal status. Panoramic radiographs were taken to assess the degree of eruption of the third molars and the angulation of third molars compared with the adjacent second molar. Vertical bitewing radiographs were analyzed to detect alveolar bone levels relative to the cementoenamel junction on the distal of second molars. Results: Twenty-five percent (82 of 329) of all enrolled patients, and 34% (14 of 41) of black patients, had at least one PD equal to or greater than 5 mm on the distal of a second molar or around a third molar. PD equal to or greater than 5 mm was associated with periodontal attachment loss of at least 1 mm in every patient; PD equal to or greater than 5 mm was associated with attachment loss equal to or greater than 2 mm in 80 of 82 patients. A higher proportion of patients 25 years old or older had a PD equal to or greater than 5 mm on the distal of second molars or around third molars compared with patients younger than 25 years (33% vs 17%, P =.002). The distals of second molars and third molars in the mandible were affected more often than in the maxilla (25% vs 5%, P =.0001). Conclusions: Our data indicating that 25% of patients with retained asymptomatic third molars have considerable periodontal pathology in the third molar region were unexpected. National epidemiologic surveys indicate a much lower rate of periodontitis in the population younger than 35 years. © 2002 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 60:1227-1233, 2002

Purpose : This prospective clinical study was designed to determine the clinical and biologic outcomes of treatment for minor signs and symptoms of pericoronitis. Patients and Methods : Patients (n = 20) with all third molars, presenting consecutively to an academic clinical center for treatment of minor signs and symptoms of pericoronitis, were enrolled in the study. At the initial visit, gingival crevicular fluid (GCF) samples to assess levels of the cytokines interleukin-1b (IL-1b) IL-1b and prostaglandin E2 (PGE2) as a measure of the host inflammatory response, and plaque samples to identify microorganisms, were collected from the distal of all second molars and the mesial of first molars. Standardized vertical bite wing radiographs were taken to assess alveolar bone height on the distal of the second molars and the inclination and the degree of eruption of the third molar. Full-mouth periodontal probing was conducted to determine probing depths and relative clinical attachment levels (CAL). Pain levels were assessed with Gracely verbal descriptor scales for sensory intensity and unpleasantness and 10-cm visual analog scales. Symptomatic third molar sites were treated with local debridement and irrigation after baseline data collection. One week after entry, data were collected again. Subsequently, the patients were scheduled for removal of all third molars. Data collection was repeated 3 months postsurgery. As controls, data were collected from 12 subjects who had asymptomatic third molars removed previously. Results : At entry, symptomatic mandibular third molars (n = 21) were mostly vertical (n = 18) and at or above the occlusal plane (n = 19). No maxillary teeth had symptoms. Microbial counts were elevated for specific anaerobic microorganisms. GCF IL-1 b levels were elevated at the distal of second molars adjacent to symptomatic third molars, as compared with asymptomatic third molars and second molars in control patients. Alveolar bone levels and CAL-on the distal of second molars were normal. At 1 week, patients' pain symptoms and IL-1b levels were reduced, but microbial counts remained high. Three months after surgery, patients had no pain symptoms, and alveolar bone levels and CAL were similar to entry levels. IL-1b levels were elevated at both the distal of second molars and the mesial of first molars for all patients; microbial counts decreased, although not to levels of control patients. No increase in microbial counts for Porphyromonas gingivalis or Bacteroides forsythus, or GCF PGE2 levels, risk factors for progressive periodontal disease, was detected in samples taken from the study patients. Conclusion : Pericoronitis expressed by minor signs/symptoms in these patients was associated with considerable discomfort. Symptomatic mandibular third molars were vertical and at or near the occlusal plane. Additionally, this condition was characterized by microbial flora and GCF inflammatory mediator levels that are more consistent with gingivitis than periodontitis. Removal of third molars eliminated symptoms, but the microbial burden and an affected patient's inflammatory response, as measured by IL-1b levels, remained elevated as compared with controls. Further study is needed to determine which of these factors can be used to identify patients at risk for pericoronitis before symptoms arise.