A reliable computerized method to determine the level of the radiographic alveolar crest

Artificial intelligence models for diagnosing gingivitis and periodontal disease: A systematic review

STATEMENT OF PROBLEM

Artificial intelligence (AI) models have been developed for periodontal applications, including diagnosing gingivitis and periodontal disease, but their accuracy and maturity of the technology remain unclear.

PURPOSE

The purpose of this systematic review was to evaluate the performance of the AI models for detecting dental plaque and diagnosing gingivitis and periodontal disease.

MATERIAL AND METHODS

A review was performed in 4 databases: MEDLINE/PubMed, World of Science, Cochrane, and Scopus. A manual search was also conducted. Studies were classified into 4 groups: detecting dental plaque, diagnosis of gingivitis, diagnosis of periodontal disease from intraoral images, and diagnosis of alveolar bone loss from periapical, bitewing, and panoramic radiographs. Two investigators evaluated the studies independently by applying the Joanna Briggs Institute critical appraisal. A third examiner was consulted to resolve any lack of consensus.

RESULTS

Twenty-four articles were included: 2 studies developed AI models for detecting plaque, resulting in accuracy ranging from 73.6% to 99%; 7 studies assessed the ability to diagnose gingivitis from intraoral photographs reporting an accuracy between 74% and 78.20%; 1 study used fluorescent intraoral images to diagnose gingivitis reporting 67.7% to 73.72% accuracy; 3 studies assessed the ability to diagnose periodontal disease from intraoral photographs with an accuracy between 47% and 81%, and 11 studies evaluated the performance of AI models for detecting alveolar bone loss from radiographic images reporting an accuracy between 73.4% and 99%.

CONCLUSIONS

AI models for periodontology applications are still in development but might provide a powerful diagnostic tool.

Development of a Computational Tool for the Estimation of Alveolar Bone Loss in Oral Radiographic Images

The present study evaluated a newly developed computational tool (CT) to assess the alveolar bone space and the alveolar crest angle and compares it to dentist assessment (GT). The novel tool consisted of a set of processes initiated with image enhancement, points localization, and angle and area calculations. In total, we analyzed 148 sites in 39 radiographic images, and among these, 42 sites were selected and divided into two groups of non-periodontitis and periodontitis. The alveolar space area (ASA) and alveolar crest angle (ACA) were estimated. The agreement between the computer software and the ground truth was analyzed using the Bland–Altman plot. The sensitivity and specificity of the computer tool were measured using the ROC curve. The Bland–Altman plot showed an agreement between the ground truth and the computational tool in all of the parameters assessed. The ROC curve showed 100% sensitivity and 100% specificity for 12.67 mm of the alveolar space area. The maximum percentage of sensitivity and specificity were 80.95% for 13.63 degrees of the alveolar crest angle. Computer tool assessment provides accurate disease severity and treatment monitoring for evaluating the alveolar space area (ASA) and the alveolar crest angle (ACA).

The Buffalo OsteoPerio Studies: Summary of our findings and the unique contributions of Robert J. Genco, DDS, PhD

PURPOSE

Robert ("Bob") Genco was a member of the research team that established the Buffalo Osteoporosis and Periodontal Disease (OsteoPerio) study. Here we detail the scientific discoveries emanating from this enduring collaboration.

STUDY COHORTS

OsteoPerio is ancillary to the Women's Health Initiative Observational Study (WHI-OS). WHI-OS is a longitudinal study of 93,000 postmenopausal women aged 50-79 enrolled at 40 U.S. centers (enrolled 1993-1998). OsteoPerio enrolled 1342 women 3 years later (1997-2001) from the Buffalo WHI-OS participants to study the association of osteoporosis and periodontal disease. OsteoPerio has 5-year (N=1026) and 17-year (N=518) follow-up examinations.

PARTICIPANTS

In addition to information on health status from the WHI-OS, OsteoPerio further included comprehensive oral examinations assessing probing pocket depth, clinical attachment loss, gingival bleeding, alveolar crestal height, and DMFT. Systemic bone density (measured by DXA), blood, saliva and plaque also were collected at all three visits.

SUMMARY

Findings from these studies are summarized here.

Association of clinical measures of periodontal disease with blood pressure and hypertension among postmenopausal women

BACKGROUND

Hypertension and periodontal disease are common conditions among postmenopausal women. Periodontal disease has been found associated with hypertension in previous studies, but data in postmenopausal women is limited.

METHODS

We assessed the cross-sectional associations of clinically measured periodontal disease with prevalent hypertension and measured systolic blood pressure (SBP) among 1341 postmenopausal women enrolled in the Buffalo Osteoporosis and Periodontal Disease (OsteoPerio) study, an ancillary study of the Women's Health Initiative-Observational Study.

RESULTS

Clinical attachment level (CAL) and number of teeth missing were positively associated with SBP among those not taking antihypertensive medication in crude and multivariable adjusted linear regression models (both P < 0.05). Alveolar crestal height (ACH) and gingival bleeding on probing were associated with higher SBP in crude but not multivariable adjusted models. Neither probing pocket depth (PPD) nor severity categories of periodontitis were associated with SBP. Number of teeth missing was significantly associated with prevalent hypertension in crude and multivariable adjusted models (OR = 1.14, per 5 teeth; P = 0.04). ACH was associated with prevalent hypertension in crude but not adjusted models. CAL, PPD, gingival bleeding, and severity of periodontitis were not significantly associated with prevalent hypertension.

CONCLUSIONS

These results suggest that measures of oral health including CAL and number of teeth missing are associated with blood pressure in postmenopausal women. Prospective studies are needed to further investigate these associations and the potential underlying mechanisms for these relationships.

Tomographic late evaluation of xenogeneic bone grafts in sockets of impacted third molars

It is necessary to preserve height and thickness of the alveolar bone to facilitate rehabilitation with osteointegratable implants or simply to maintain bone integrity after extraction. Biomaterials associated with resorbable or non-resorbable membranes, when placed in the region of the socket, may contribute to avoid this unwanted reabsorption.

Age-related periodontitis and alveolar bone loss in rice rats

OBJECTIVE

To characterize in rice rats: (a) periodontitis (PD) progress with feeding of standard laboratory rat chow (STD) during ages 4-80 weeks; and (b) PD progress with feeding of a high sucrose-casein (H-SC) diet during young adulthood.

METHODS

One group (N=12) was euthanized at age 4 weeks (Baseline). Four groups (N=8-16) consumed a STD diet from baseline and were necropsied at ages 22, 30, 52, and 80 weeks. Three groups (N=10-16) consumed an H-SC diet from baseline. Two were necropsied at ages 22 and 30 weeks, respectively. The third switched to the STD diet at age 22 weeks and was necropsied at age 30 weeks. All mandibles/maxillae were assessed by histometry for degree of periodontal inflammation (PD Score), alveolar crest height (ACH, mm), and horizontal alveolar bone height (hABH, mm²).

RESULTS

In STD diet rats aged ≥30 weeks, all endpoints were worse (P<0.05) than at Baseline. In H-SC diet rats aged ≥22 weeks, all endpoints were worse than at Baseline (P<0.05). At age 22 weeks, all endpoints were worse in the H-SC group than in the STD group (P<0.05). By age 30 weeks, the STD and H-SC groups did not differ.

CONCLUSIONS

1) STD diet fed rice rats develop moderate/severe PD by age 30 weeks; 2) an H-SC diet accelerates moderate/severe PD development; and 3) switching to a STD diet does not halt/reverse PD that was accelerated by an H-SC diet. These data further clarify use of the rice rat as a PD model.

Periodontal disease severity and cancer risk in postmenopausal women: the Buffalo OsteoPerio Study

PURPOSE

Few prospective studies have reported on relationships between objective periodontal disease (PD) measures and cancer risk. This association was examined in 1,337 postmenopausal women participating in the Buffalo OsteoPerio Study.

METHODS

Oral alveolar crestal height (ACH) was measured using oral radiographs. Incident cancers were adjudicated with medical records. Hazard ratios (HRs) and 95 % confidence intervals (CIs) for associations between ACH and incident cancer outcomes were estimated using Cox proportional hazards models.

RESULTS

There were 203 confirmed total incident cancer cases during follow-up (12.2 ± 4.2 years). After adjusting for age and smoking, there were no statistically significant associations between ACH-defined PD categories and total cancer risk (mild/moderate vs. none: HR 1.33, 95 % CI 0.91-1.94; severe vs. none: HR 1.20, 95 % CI 0.77-1.86). ACH-defined PD categories were not associated with common site-specific cancers. Whole-mouth mean and worst-site ACH (per 1 mm loss) were significantly associated with increased risk of lung (adjusted HR 1.81, 95 % CI 1.30-2.54; adjusted HR 1.34, 95 % CI 1.08-1.66, respectively), but not total or other site-specific cancer. Smoking status modified the associations between continuous ACH variables and total cancer risk; measures of PD were associated with total cancer among smokers but not never smokers (interaction p = 0.02 and p < 0.01 for whole-mouth mean and worst-site ACH, respectively).

CONCLUSIONS

ACH-defined PD was associated with total cancer risk in ever but not never smoking postmenopausal women. Whole-mouth mean and worst-site ACH were associated with increased lung cancer risk. However, these results need to be interpreted cautiously given the small number of lung cancer cases (n = 18). Further research utilizing a larger sample is warranted to confirm the relationships among oral bone loss, site-specific cancers, and total cancer.

Is Radiologic Assessment of Alveolar Crest Height Useful to Monitor Periodontal Disease Activity?

The mainstay of periodontal assessment is clinical probing. Radiographic assessment provides quantitative information on the status of tooth-supporting bone. This article reviews methods to assess periodontal structures, including basic radiograph acquisition, assessment of alveolar crest levels, and typical patterns of bone loss. Computer technology to objectively assess loss of alveolar crest from radiographs is reviewed. Developments in computer-assisted quantitation of alveolar crest height are described. Although probing measurements continue to be viewed as more practical than radiographic measurements, radiographic assessment can be made quantitative and is likely easier and more precise than probing for routine assessment of periodontal disease activity.

Association of serum 17β-estradiol concentration, hormone therapy, and alveolar crest height in postmenopausal women

BACKGROUND

Declines in endogenous estrogen levels after menopause can lead to systemic bone loss, including loss of oral bone and alveolar crest height (ACH). However, few studies have assessed both serum 17β-estradiol (E2) and exogenous hormone therapy (HT) use in relation to oral bone loss.

METHODS

This study examines the associations among serum E2, HT use, and ACH in 613 postmenopausal women from the Buffalo OsteoPerio study. Baseline ACH levels and 5-year ACH were assessed for groups according to E2 level (undetectable, >5.00 to ≤18.00, >18.00 to ≤46.07, and >46.07 pg/mL) and among HT use (never, ever) using analysis of variance and analysis of covariance. Logistic regression was used to analyze the association of ACH loss with serum E2 and HT use.

RESULTS

In cross-sectional analyses, no association was found of serum E2 with whole-mouth mean or worst-site ACH. However, history of HT use was associated with ACH. Women who had never used HT had more ACH loss assessed as a whole-mouth mean ACH (P = 0.01) and as worst-site ACH loss (P = 0.03). In logistic regression analyses of baseline ACH loss severity, HT never-users had two-fold higher odds of being in the severe ACH loss category compared to ever-users (odds ratio, 2.00; 95% confidence interval, 1.11 to 3.62). No association was observed of 5-year change in ACH with baseline serum E2 or HT use.

CONCLUSION

Although this study did not detect an association with current serum E2 level and ACH, HT use was found to be associated with less ACH loss in postmenopausal women.

Accuracy of self-reported periodontal disease in the Women's Health Initiative Observational Study

BACKGROUND

This study examines the accuracy of self-reported periodontal disease in a cohort of older females.

METHODS

The study comprised 972 postmenopausal females aged 53 to 83 years who completed baseline (1997 to 2001) and follow-up (2002 to 2006) whole-mouth oral examinations. Examinations included: 1) probing depth, 2) clinical attachment level, and 3) oral radiographs for alveolar crestal height in a study ancillary to the Women's Health Initiative Observational Study (WHI-OS) conducted in Buffalo, New York, called the OsteoPerio study. Participants also self-reported any history of diagnosis of periodontal/gum disease on a WHI-OS study-wide questionnaire administered during the time interval between the two OsteoPerio examinations.

RESULTS

Participants reporting diagnosis of periodontal/gum disease on the WHI-OS questionnaire (n = 259; 26.6%) had worse oral hygiene habits, periodontal disease risk factors, and clinical periodontal measures compared with those not reporting periodontal/gum disease. Frequency of reported periodontal/gum disease was 13.5%, 24.7%, and 56.2% across OsteoPerio baseline examination categories of none/mild, moderate, and severe periodontal disease, respectively (trend: P <0.001), defined by criteria of the Centers for Disease Control and Prevention/American Academy of Periodontology (CDC/AAP). Sensitivity, specificity, and positive and negative predictive values for reported periodontal disease status were 56.2%, 78.8%, 32.8%, and 90.7%, respectively, when CDC/AAP-defined severe periodontal disease at baseline was the criterion measure (prevalence of 15%) and were 76.0%, 77.4%, 22.0%, and 97.4%, respectively, when tooth loss to periodontitis (prevalence of 7%) was the criterion.

CONCLUSION

A simple question for self-reported periodontal disease characterizes periodontal disease prevalence with moderate accuracy in postmenopausal females who regularly visit their dentist, particularly in those with more severe disease.

Association between metabolic syndrome and periodontal disease measures in postmenopausal women: the Buffalo OsteoPerio study

BACKGROUND

The objective of this study is to characterize the association between metabolic syndrome (MetS) and periodontitis in women, for which there is limited evidence.

METHODS

Cross-sectional associations between MetS and periodontitis were examined in 657 postmenopausal women aged 50 to 79 years enrolled in a periodontal disease study ancillary to the Women's Health Initiative Observational Study. Whole-mouth measures of alveolar crest height (ACH), clinical attachment level (CAL), probing depth (PD), gingival bleeding, and supragingival plaque and measures to define MetS using National Cholesterol Education Program criteria were from a clinical examination. Study outcomes were defined as: 1) mean ACH ≥3 mm, two sites ≥5 mm, or tooth loss to periodontitis; 2) ≥2 sites with CAL ≥6 mm and ≥1 site with PD ≥5 mm; 3) gingival bleeding at ≥50% of sites; and 4) supragingival plaque at ≥50% of sites. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

In unadjusted analyses, MetS (prevalence: 25.6%) was significantly associated with supragingival plaque (OR = 1.74; 95% CI: 1.22 to 2.50) and non-significantly associated with periodontitis defined by ACH (OR = 1.23; 95% CI: 0.81 to 1.85) and gingival bleeding (OR = 1.20; 95% CI: 0.81 to 1.77). Adjustment for age, smoking, and other confounders attenuated observed associations, though supragingival plaque remained significant (OR = 1.47; 95% CI: 1.00 to 2.16; P = 0.049). MetS was not associated with periodontitis defined by CAL and PD.

CONCLUSIONS

A consistent association between MetS and measures of periodontitis was not seen in this cohort of postmenopausal women. An association between MetS and supragingival plaque requires further investigation.

Chronic periodontitis and its possible association with oral squamous cell carcinoma - a retrospective case control study

Introduction

Different inflammatory processes may trigger the development of malignancies. Therefore, the aim of the present study was to evaluate a potential association between radiological determined chronic periodontitis (CPA) and oral squamous cell carcinoma (OSCC).

Methods

In a retrospective study, OSCC-patients and a control group without malignant tumors were radiographically examined for bone loss. Via telephone survey and questionnaire, general clinical data on the individual oral hygiene and concomitant diseases together with tobacco and alcohol use were assessed and data were compared between the groups.

Results

178 OSCC-patients and 123 controls were included. In univariate analysis, a statistically relevant higher mean bone loss was seen in the OSCC group (4.3 mm (SD: 1.8; 95% confidence interval (CI): 4-4.6) vs. 2.9 mm (SD: 0.7; 95% CI: 2.8-3); p < 0.001)). This was confirmed in a multivariate regression model (OR: 2.4, 95% CI: 1.5-3.8; p < 0.001). A history of periodontal treatment was associated with significantly reduced OSCC risk (p < 0.001; OR: 0.2, CI: 0.1-0.5).

Conclusions

CPA is a common disease and the monitoring as well as the treatment of such a chronic oral inflammation may be beneficial in reducing one potential cause of OSCC. Therefore, further clinical studies on oral neoplasms should consider clinical periodontal parameters as well.

Association of bone mineral density with periodontal status in postmenopausal women

AIM

Menopausal changes expose an individual towards risk of various pathologies during midlife transition. This study aimed to investigate the possible association of bone mineral density (BMD) with periodontal parameters in early postmenopausal Indian women.

METHODS

In 78 dentate postmenopausal female patients periodontal examination was performed including clinical attachment loss, pocket depth, plaque index and sulcular bleeding index. Alveolar crestal height was measured on proximal surfaces of all posterior teeth except third molars with the help of bitewing radiographs. Patient's BMD was assessed with dual energy X-ray absorptiometry. Statistical analysis was performed to assess the correlation between BMD and periodontal parameters.

RESULTS

Pocket depth, clinical attachment loss and alveolar crestal height were found to have negative and statistically significant (P = -0.000 each) correlation with T-score, with the value of Pearson's correlation coefficient being -0.474, -0.426, and -0.419 respectively. Number of teeth lost due to periodontitis was not significantly correlated with T-score (P > 0.05). Results of anova and the post-hoc Tukey test revealed a statistically significant difference of mean clinical attachment loss, pocket depth and alveolar crestal height for the osteoporotic versus osteopenic group and the osteoporotic versus normal group. However, between the osteopenic and normal group, the differences of mean were statistically nonsignificant (P > 0.05). Body mass index was found to have a weakly positive (r = 0.376) and statistically significant (P = 0.001) correlation with T-score.

CONCLUSIONS

Bone mineral density is an important risk indicator for periodontitis in postmenopausal women. Number of teeth lost due to periodontitis is not significantly affected by the BMD of the early postmenopausal phase.

Local inflammation and human papillomavirus status of head and neck cancers

OBJECTIVE

To determine whether periodontitis is associated with human papillomavirus (HPV) status of head and neck squamous cell carcinoma (HNSCC).

DESIGN AND SETTING

Hospital-based case-control study in a comprehensive cancer center.

PATIENTS

Evaluation included all patients diagnosed with incident primary squamous cell carcinoma of the oral cavity, oropharynx, and larynx between 1999 and 2007 for whom tissue samples and dental records were available (N = 124). Patients younger than 21 years and those with a history of cancer were excluded. Periodontitis history was assessed by alveolar bone loss in millimeters from panoramic radiographs by one examiner blinded to cancer status.

MAIN OUTCOME MEASURE

The presence of HPV-16 DNA in paraffin-embedded tumor samples was identified by polymerase chain reaction.

RESULTS

The prevalence of HPV-positive HNSCC was 50 of 124 patients (40.3%). A higher proportion of oropharyngeal cancers were HPV-positive (32 of 49 [65.3%]) compared with oral cavity (9 of 31 [29.0%]) and laryngeal (9 of 44 [20.5%]) cancers. Each millimeter of alveolar bone loss was associated with 2.6 times increased odds (odds ratio [OR], 2.61; 95% CI, 1.58-4.30) of HPV-positive tumor status after adjustment for age at diagnosis, sex, and smoking status. The strength of the association was greater among patients with oropharyngeal SCC (OR, 11.70; 95% CI, 2.09-65.53) compared with those with oral cavity SCC (OR, 2.32; 95% CI, 0.65-8.27) and laryngeal SCC (OR, 3.89; 95% CI, 0.95-15.99).

CONCLUSIONS

A history of chronic inflammatory disease in the oral cavity may be associated with tumor HPV status in patients with HNSCC. This association seems to be stronger among patients with oropharyngeal cancer compared with those who have oral cavity or laryngeal SCC.

Five-year changes in periodontal disease measures among postmenopausal females: the Buffalo OsteoPerio study

BACKGROUND

Understanding of longitudinal characteristics of periodontal disease in older females is limited. This study examined 5-year changes in periodontal disease measures among postmenopausal females.

METHODS

Participants were 1,025 postmenopausal, 53- to 83-year-old females who completed baseline (1997 to 2001) and 5-year follow-up (2002 to 2006) whole-mouth oral examinations in a study ancillary to the Women's Health Initiative. Periodontal disease was characterized using probing depth (PD), clinical attachment level (CAL), alveolar crest height (ACH), and tooth loss. Differences in measures between examinations were used to characterize patterns of change.

RESULTS

Baseline prevalence of none/mild, moderate, and severe periodontal disease defined using criteria of the Centers for Disease Control and Prevention was 27%, 58%, and 15%, respectively. Tooth loss attributable to periodontitis occurred in 13% of females. Mean ± SD changes in whole-mouth mean measures showed progression when based on ACH (-0.19 ± 0.49 mm) yet relatively stable disease when based on PD (0.11 ± 0.42 mm) and CAL (0.06 ± 0.58 mm). Mean change in worst-site ACH was greater (P <0.001) in females with severe periodontitis and osteoporosis at baseline and with tooth loss during follow-up. Periodontal changes did not differ according to baseline age, hormone therapy use, smoking status, or age at menopause.

CONCLUSIONS

Five-year changes in periodontal measures among generally healthy postmenopausal females were, on average, small and did not suggest a consistent pattern of disease progression. Females with history of severe periodontitis or osteoporosis may experience accelerated oral bone loss despite stability or small improvement in routine probing measures.

A paralleling technique modification to determine the bone crest level around dental implants

The aim of this report is two-fold. First it analyses the precision of a modification of the parallel technique that can be used in those cases with anatomical limitations. Second, it checks the influence of the reference points' definition of objects to be measured by using both the original and the modified radiographic techniques. 2 intraoral radiographs were taken of 28 implants with 2 different methods: a standard paralleling technique and a modified technique that used a smaller film and a silicone spacer to ensure parallelism. Measurements of peri-implant bone levels and implant width were made in triplicate on digitized film radiographs. The results of the peri-implant bone levels were that with the parallel method the mean was 0.44 mm and the precision was 0.43 mm, and with the modified method the mean was 0.73 mm and the precision was 0.66 mm. In addition to the correct localization of the point of reference in this study, the precision with the parallel method was 0.08 mm and with the modified method was 0.13 mm. Although it was greater with the gold standard technique than with the modified technique, precision was very high for both methods and accurate enough for clinical use.

Clinical and community risk models of incident tooth loss in postmenopausal women from the Buffalo Osteo Perio Study

 

OBJECTIVE

While risk factors for tooth loss in adults have been identified, limited studies describing factors associated with incident tooth loss in postmenopausal women exist. This study assessed both clinical and non-clinical risk factors for incident tooth loss.

METHODS

Postmenopausal women (N = 1341) were recruited between 1997 and 2000 from 1847 eligible Observational Study participants of the Buffalo, NY center of the Women's Health Initiative who had complete dental examinations to assess alveolar bone height, soft tissue attachment and general oral health, and completed questionnaires concerning demographics, general health, lifestyle and oral health (72.6% participation rate). Five years later (2002-2005), 1021 women (76.1%) repeated these examinations and questionnaires. Incident tooth loss was determined by oral examination.

RESULTS

After an average 5.1 years of follow-up (SD, 0.38), a total of 323 teeth were lost in 293 women, resulting in 28.7% of women with incident loss of at least one tooth. In multivariable models, diabetes history, gum disease history, smoking, previous tooth loss, BMI and plaque index, baseline clinical measures including alveolar crestal height (ACH) (OR = 1.22 per mm loss, 95% CI 1.11, 1.35), clinical attachment loss (CAL) (OR = 1.13 per mm loss, 95% CI 1.05, 1.23), and pocket depth (PD) (OR = 1.26 per mm loss, 95% CI 1.13, 1.41) were significant risk factors of incident tooth loss. In a community model that included no clinical measures, diabetes history (OR = 2.45, 95% CI 1.26, 4.77), prior gum disease (OR = 1.97, 95% CI 1.43, 2.70), ever smoking (OR = 1.42, 95% CI 1.06, 1.89), number of teeth lost at baseline (OR = 1.05 per tooth, 95% CI 1.02, 1.08), and BMI (OR = 1.15 per 5 km/m(2) increase, 95% CI 1.01, 1.33) were associated with an increased risk of incident tooth loss.

CONCLUSIONS

Clinical and questionnaire-based models were found to provide similar risk estimates for incident tooth loss in postmenopausal women. These models identified high-risk postmenopausal women where preventive strategies may be targeted.

Chronic periodontitis and the incidence of head and neck squamous cell carcinoma

Substantial evidence supports an association between chronic infections/inflammation, and cancer. The aim of this study was to assess the effect of chronic periodontitis on head and neck squamous cell carcinoma (HNSCC). The study population consisted of new patients at the Department of Dentistry and Maxillofacial Prosthetics, Roswell Park Cancer Institute between 1999 and 2005. Cases were patients diagnosed with primary HNSCC. Controls were all patients seen during the same time period but negative for malignancy. Patients age <21 years, edentulous, immunocompromised, and those with history of cancer were excluded. Periodontitis was measured by alveolar bone loss (ABL) from panoramic radiographs by one examiner blind to cancer status. A total of 473 patients (266 cases and 207 controls) were included in the study. Each millimeter of ABL was associated with >4-fold increased risk of HNSCC (odds ratio, 4.36; 95% confidence interval, 3.16-6.01) after adjustment for age, gender, race/ethnicity, marital status, smoking status, alcohol use, and missing teeth. The strength of the association was greatest in the oral cavity, followed by oropharynx and larynx. The association persisted in subjects who never used tobacco and alcohol. There was a significant interaction between smoking and ABL (P = 0.03). Patients with periodontitis were more likely to have poorly differentiated oral cavity SCC than those without periodontitis (32.8% versus 11.5%; P = 0.038). This study suggests that chronic periodontitis is an independent risk factor for HNSCC and smoking modifies this association. These results have implications for practical and safe strategies for prevention, diagnosis, and treatment of HNSCC.

Alveolar bone measurement precision for phosphor-plate images

OBJECTIVES

The aim was to demonstrate methods for determining measurement precision and to determine the precision of alveolar bone measurements made with a vacuum-coupled positioning device and phosphor plate images.

STUDY DESIGN

Subjects were rigidly attached to the x-ray tube by means of a vacuum coupling device and custom cross-arch bite plates. Original and repeat radiographs (taken within minutes of each other) were obtained of the mandibular posterior teeth of 51 subjects, and cementoenamel junction-alveolar crest (CEJ-AC) distances were measured on both sets of images. In addition, x-ray transmission (radiodensity) and AC height differences were determined by subtracting one image from the other. Image subtractions and measurements were performed twice. Based on duplicate measurements, the root mean square standard deviation (precision) and least significant change (LSC) were calculated. LSC is the magnitude of change in a measurement needed to indicate that a true biologic change has occurred.

RESULTS

The LSCs were 4% for x-ray transmission, 0.49 mm for CEJ-AC distance, and 0.06 mm for crest height.

CONCLUSION

The LSCs for our CEJ-AC and x-ray transmission measurements were similar to what has been previously reported. The LSC for AC height (determined with image subtraction) was <0.1 mm. Compared with findings from earlier studies, this represents a highly precise measurement of AC height. The methods demonstrated for calculating LSC can be used by investigators to determine how large changes in radiographic measurements need to be before the changes can be considered to be (with 95% confidence) true biologic changes and not noise (i.e., equipment/observer error).

Osteoporosis and Oral Infection: Independent Risk Factors for Oral Bone Loss

Studies have suggested that oral bone loss is independently influenced by local and systemic factors, including osteoporosis. This cross-sectional study of 1256 post-menopausal women, recruited from the Buffalo center of the Women’s Health Initiative Observational Study, evaluated the influence of oral infection and age on the associations between osteoporosis and oral bone loss. Systemic bone density was measured by dual-energy x-ray absorptiometry. Alveolar crestal height was measured from standardized dental radiographs. Oral infection was assessed from subgingival plaque samples. Total forearm density [β (SE) = −0.931 (0.447), p = 0.038] and presence of Tannerella forsythensis [β (SE) = 0.125 (0.051), p = 0.015] were independently associated with mean alveolar height among women aged < 70 years after confounder adjustment. Women aged 70+ years had worse oral bone loss, in general, but neither bone density nor oral infection was significantly associated with mean alveolar height in this age group. Systemic bone density and oral infection independently influenced oral bone loss in post-menopausal women aged < 70 years.

Orthodontic movement in bone defects filled with xenogenic graft: An experimental study in minipigs

INTRODUCTION

In this study, we investigated whether it is possible to orthodontically move a tooth into an adjacent bone defect previously filled with xenogenic grafting material, with emphasis on the reactions of the tooth roots and adjacent tissues.

METHODS

Six minipigs were used. In each animal, 4 defects were created at the mesial aspects of the maxillary and mandibular first permanent molars; the defects on the right were filled with the xenograft (test side), and the opposite defects (control side) were filled with blood clots and allowed to heal spontaneously. Three months later, orthodontic appliances were placed in each quadrant to allow mesial bodily movement of the first permanent molars. When the teeth were moved about halfway into the defect spaces, the animals were killed, and the areas of interest were harvested. The mesial roots of the first molars and adjacent tissues were histologically and morphometrically evaluated. The volume density of bone tissue, the percentage of root resorption, and the bone height were evaluated with image analysis software.

RESULTS

Data analysis showed that (1) the percentage of root resorption was smaller (P = .0359) for the test group (4.16%) compared with the control (6.52%); (2) there was no statistically significant differences between groups concerning the volume density of neoformed bone (P >.05); (3) the bovine bone matrix was almost totally replaced by structured bone tissue; (4) the test group had a statistically significant smaller bone height loss (2.18 mm, P = .0018) than the control group (3.26 mm).

CONCLUSIONS

Based on these results, it was concluded that teeth can be moved into areas of bone defects previously filled with xenograft.

The infrabony defect and its determinants

BACKGROUND AND OBJECTIVE

The purpose of this study was to assess the defect width of infrabony defects in a cross-sectional study and to evaluate whether the defect width is a function of defect depth.

MATERIAL AND METHODS

Complete sets of intra-oral radiographs of patients with severe periodontitis, which exhibited at least one infrabony defect, were digitised and evaluated. The following parameters were measured: depth and width of the infrabony defect, defect angle, and width of the interdental spaces.

RESULTS

Fifty-one patients (26 women), ranging from 21 to 73 yr of age (48.5 +/- 13.4 yr), contributed a total of 1272 teeth with 135 infrabony defects (10.6%). Seventeen infrabony defects were located at sites without a neighboring tooth. Infrabony defects were statistically more prevalent in the mandible (n = 82) than in the maxilla (p = 0.013), and more prevalent at mesial sites (n = 92) than at distal sites (p < 0.001). At infrabony defects, the width of interdental spaces at the most coronal extension of the alveolar crest could be measured only at sites with neigboring teeth 2.67 +/- 0.78 mm (range: 1.19-5.70 mm). Analysis failed to reveal a statistically significant difference between defect width at sites with (2.64 +/- 0.82 mm) and sites without (2.76 +/- 0.70 mm) a neighboring tooth. Multilevel regression analysis revealed narrow defect angles to be related to deep infrabony defects, whereas width of the interdental space and distal location were related to wide defects.

CONCLUSION

Defect angle depended on defect depth and defect width was not different at sites with or without a neighboring tooth. Even in severe periodontitis, infrabony defects are found only at a minority of teeth.

Radiographic assessment of impacted mandibular third molar sockets filled with composite xenogenic bone graft

OBJECTIVES

The main purpose of this study was to evaluate the radiographic aspect of the healing of extraction sockets filled with a xenogenic graft material (Gent-tech).

METHODS

Thirty-nine patients ranging in age from 15 years to 25 years with bilateral impacted mandibular molars were chosen based on bilateral mandibular similarities. After tooth extraction, the socket was filled with the graft. The opposite site was left to heal naturally and served as a control. The experimental and control sites were chosen randomly. Bone density and crest healing were evaluated on digital radiographs taken immediately, 2 months and 6 months after surgery. The respective pixels values obtained with the Digora software were compared statistically.

RESULTS

The results showed a significant decrease in the distance from the cemento-enamel junction to the alveolar bone crest, but no difference was found between the control and experimental groups. Bone density increased significantly, and there was difference between experimental and control groups.

CONCLUSION

The analysed parameters observed by the authors were similar to those of the control group, suggesting xenogenic graft being an acceptable material and a graft option.

The Association Between Osteoporosis and Alveolar Crestal Height in Postmenopausal Women

BACKGROUND

Evidence supporting an association between osteoporosis and loss of alveolar crestal bone is limited. This study investigated that association in a large cohort of postmenopausal women.

METHODS

A cohort of 1,341 postmenopausal women aged 53 to 85 were assessed for alveolar crestal height (ACH) and bone density. ACH was determined from oral radiographs with subjects dichotomized by disease severity. Bone density was assessed by dual energy x-ray absorptiometry, with severity determined by worst T score measured (normal >-1.00; low -1.00 to -2.00; moderate -2.01 to -2.49; osteoporotic <-2.5).

RESULTS

Compared to subjects in the normal T-score group, the odds of worse ACH increased by 39%, 59%, and 230% for those in the low, moderate, and osteoporotic groups, respectively. Adjustment for weight, education, hormone use, calcium or vitamin D supplementation, and smoking did not appreciably change the findings. Further adjustment for age attenuated the association, with osteoporotic subjects having a 1.9-fold increase of being in the worst ACH group (95% confidence interval [CI] 1.19 to 3.05). After age stratification, in women younger than 70 there was a significant trend by decreasing T-score category (P <0.02). Osteoporotic subjects had worse ACH (odds ratio [OR] = 1.95; 95% CI 1.20 to 3.17). In women aged 70 and older, worse ACH was 2.5- to 4.6-fold increased for decreasing T-score category. After adjustment, the OR (95% CI) for the low, moderate, and osteoporotic groups were 2.66 (1.12 to 6.29), 2.31 (0.89 to 6.01), and 3.57 (1.42 to 8.97), respectively (P trend = 0.026).

CONCLUSIONS

This study found a strong and consistent association between T score and ACH in postmenopausal women. Increasing age is an important modifier of that association.

Periodontal disease and the incidence of tooth loss in postmenopausal women

BACKGROUND

The role of periodontal disease as a predictor of incident tooth loss in postmenopausal women has not been determined. The aim of this cohort study was to determine the extent of the association between baseline periodontal status and incident tooth loss in a population of postmenopausal women.

METHODS

The study population included 106 dentate white postmenopausal women who participated in a cross-sectional study between 1989 and 1991 who were willing and eligible to have a repeat examination after 10 to 13 years. At baseline, full-mouth assessment of periodontal status was performed clinically and radiographically. Assessment of tooth loss during follow- up was assessed clinically by a periodontist. Odds ratio (OR) and its 95% confidence interval (CI) for each periodontal variable was obtained from separate multiple logistic regression analyses adjusting for the effect of age, household income, smoking, hormone therapy, snack consumption, and number of decayed teeth.

RESULTS

Sixty-one (57.5%) subjects lost at least one tooth during follow-up. Mean tooth loss per person was 1.81 +/- 2.77. After adjusting for confounders, each millimeter of alveolar bone loss at baseline increased the risk of tooth loss 3-fold (OR = 3.26; 95% CI: 1.60 to 6.64). The risk of tooth loss also increased 2.5 times for each millimeter of clinical attachment loss (OR = 2.50; 95% CI: 1.24 to 5.07). Probing depth (OR = 2.53; 95% CI: 0.98 to 6.53), gingival bleeding (OR = 1.99; 95% CI: 0.21 to 18.94), calculus (OR = 2.05; 95% CI: 0.91 to 4.61), and plaque (OR = 0.70; 95% CI: 0.13 to 3.34) were not significantly associated with incident tooth loss.

CONCLUSION

Periodontal disease, especially measured by alveolar bone loss, is a strong and independent predictor for incident tooth loss in postmenopausal women.

Implant-supported fixed cantilever prostheses in partially edentulous arches. A seven-year prospective study

The purpose of the following study was to evaluate the medium- to long-term prognosis of implant-supported cantilever fixed prostheses, and to establish to what degree this is influenced by factors such as length, type of cantilever (mesial or distal), and opposite dentition versus cantilever prostheses. This study was performed on a sample of 38 partially edentulous patients treated between January 1994 and March 2001 with 49 partial cantilever fixed prostheses supported by 100 implants. Marginal bone resorption (MBL) has been studied and used as a reference parameter to define therapeutic success. The MBL measurement was made possible by transposing X-ray images of patients selected on a PC and then using a software program. Statistical analysis was carried out for possible correlation between peri-implant bone resorption and the parameters considered in this study: length and type (mesial or distal) of cantilever and opposite dentition to cantilever prostheses. Seven years after loading cantilever prostheses, the overall cumulative implant survival rate (OCSR) was 97%, and the prostheses success rate is 98%. Mesial cantilever prostheses registered a lower success rate (97.1%) than distal cantilever prostheses (100%). Furthermore, a better prognosis was not observed when the opposite dentition of the prostheses comprised natural teeth, or fixed prostheses on natural teeth, when compared with the cases in which opposite teeth were implant-supported fixed prostheses. The authors concluded that medium-term prognosis of implant-supported cantilever fixed prostheses and traditional implant-supported fixed prostheses was comparable. However, a thorough pre-treatment analysis of risk factors regarding implant-supported prosthesis survival is important.

The pattern of alveolar crest height change in healthy postmenopausal women after 3 years of hormone/estrogen replacement therapy

BACKGROUND

The loss of ovarian function at menopause is associated with loss of postcranial and oral bone. Hormone/estrogen replacement therapy (HRT/ERT) has a positive effect on both postcranial and oral bone. The objective of the study was to determine if the positive effect of HRT/ERT on alveolar crest height (ACH) is generalized or site specific.

METHODS

The sample consisted of 49 women who completed a 3-year, HRT/ERT prospective study. Cemento-enamel junction distances (ACH) were measured on digitized images of bitewing radiographs. Lumbar spine and proximal femur bone mineral densities (BMDs) were determined with dual-energy x-ray absorptiometric scans. Measurements were made at baseline and at the end of year 3. For the 3-year study period, mean change in ACH was determined for each patient. In addition, the sites with the greatest, second and third greatest ACH changes were determined for each patient. Correlations between changes in ACH (as determined by the various methods) and postcranial BMD were determined.

RESULTS

Mean ACH changes had an average correlation (r) of -0.24 with femoral and lumbar spine BMDs. Although the largest site-specific change in ACH resulted in a mean correlation of -0.21, the correlations for the second and third largest changes in ACH dropped to -0.15 and -0.12. Overall, the correlations for site-specific changes were substantively smaller than those for generalized change.

CONCLUSIONS

The data of this study indicate that ACH change attributable to HRT/ERT is generalized rather than site specific. Studies of the effect of HRT/ERT on ACH should employ multiple measurements to minimize measurement errors associated with site-specific measurements.

Comparison of conventional periodontal maintenance versus scaling and root planing with subgingival minocycline

BACKGROUND

Alternative regimens using subgingival antimicrobials compared to conventional periodontal maintenance (PM) may lead to more efficient protocols. The purpose of this study was to evaluate treatment time and clinical and radiographic outcomes in 2 periodontitis cohorts, one receiving conventional PM and the other receiving scaling and root planing (SRP) and multiple doses of subgingival minocycline.

METHODS

Moderate to advanced chronic periodontitis patients were concurrently treated with either: 1) scaling and root planing and 4 subgingival doses of minocycline microspheres in all > or = 5 mm pockets over a 6-month period (RP/M; n = 24 patients); or 2) conventional 3-month periodontal maintenance (PM; n = 24 patients). Clinical and radiographic measurements, including probing depth (PD), clinical attachment level (CAL), and interproximal bone height (BH), were analyzed in 2 premolar/molar interproximal > or = 5 mm pockets at baseline and 1 year using paired t tests, analysis of variance, chi-square analysis, and correlation coefficients.

RESULTS

Baseline clinical and radiographic data were similar between RP/M and PM patients. Probing depths showed greater mean improvement in RP/M (0.9 +/- 0.1 versus 0.4 +/- 0.1 mm, P = 0.02), with 25% of subjects in RP/M gaining > or = 2 mm compared to 4.2% in PM (differences were statistically significant). The mean loss in bone height and percent subjects losing bone height were less in RP/M (0.05 +/- 0.05 mm; 12.5%) than PM (0.09 +/- 0.08 mm; 16.7%), but bone height differences were not statistically significant. A subset of RP/M molar furcation sites responded with similar PD reduction and no BH loss over 1 year. While cross-sectional RP/M data between CAL and BH, or PD and CAL were highly correlated, changes over 1 year were not correlated among any of these parameters.

CONCLUSIONS

Scaling and root planing and subgingival minocycline in experimental sites took little time (<5 minutes/appointment), but resulted in more probing depth reduction and less frequent bone height loss than conventional periodontal maintenance.

Reliability of assessing interproximal bone loss by digital radiography: intrabony defects

AIM

The aim of the present study was to assess the reproducibility and validity of linear measurements of interproximal bone loss in intrabony defects on digitized radiographic images after application of different filters and magnifications.

METHODS

Immediately before surgery 50 radiographs of 50 periodontally diseased teeth exhibiting interproximal intrabony defects were obtained by a standardized technique in 50 patients. Intrasurgically the distances from the cementoenamel-junction (CEJ) to the alveolar crest (AC) and from the CEJ to the deepest extension of the bony defect (BD) were assessed. All radiographs were digitized by a flatbed scanner (resolution: 600x1200 dpi). Using the FRIACOM-soft ware, the linear distances CEJ to AC and CEJ to BD were measured at 50 intrabony defects on digitized but unchanged radiographic images and also after use of 2 different basic image processing modes (filters: enhancement of grey level differences, spreading of grey values) with 7-fold and 14-fold magnification by 2 different examiners.

RESULTS

Repeated measures MANOVA revealed reproducibility of the measurement of the distance CEJ to AC to be significantly influenced by examiner (p=0.027) and filter in combination with the height of 2 wall component of the intrabony defect (p=0.066). For the distance CEJ to BD filters had significant influence on reproducibility in correlation with vertical angulation difference (p=0.001). On the average in this study radiographic measurements tended to overestimate the amount of bone loss as assessed by intrasurgical measurements (CEJ-AC: 0.74-1.91 mm; CEJ-DB: -0.04-0.77 mm). Validity of measurement of the distance CEJ-AC was shown to be significantly influenced by the depth of the intrabony defect (p<0.003). Validity of the distance CEJ-BD was significantly influenced by intrasurgically assessed bone loss (p=0.029), horizontal angulation (p=0.066). Filters influenced the validity only in combination with examiner (p<0.001).

CONCLUSIONS

In this study, the chosen digital manipulations (filters: spreading, structure) of radiographic images failed to result in statistically significantly more reproducible or valid measurements of interproximal bone loss within intrabony defects when compared to the digitized but unchanged images. All radiographic assessments on the digitized images except for use of enhancement of grey level differences (structure) came close to the intrasurgical gold standard.

Radiographic and digital imaging in periodontal practice

This review defines terms such as accuracy, validity, and reliability, which are used to describe the quality of methods for taking x-rays and for analyzing digital images. Values for these parameters are described for techniques of taking standardized x-rays such as ear-rod fixation and fixation by use of teeth with a dental impression. In addition, values are given for linear measurements on digitized images and for quantitative image subtraction. Differences are addressed between quantitative subtraction with a reference ramp and relative subtraction using the computer-assisted densitometric image analysis (CADIA) system. The relationship between radiographic bone height and clinical attachment level is also discussed. Finally, present and future use in the periodontal office of linear radiographic measurements on digital images and digital subtraction is discussed.

Reliability of linear alveolar bone loss measurements of mandibular posterior teeth from digitized bitewing radiographs

Observer reliability in performing linear measurements between the cementoenamel junction and alveolar crest was determined for mandibular posterior teeth from digitized clinical bitewing radiographs acquired during recall examinations. 6 measurements (corresponding to traditional probing measurements) were made per tooth by 3 observers. Mesial and distal measurements made to the most coronal aspects of the alveolar crest were the most reliable and least biased. As was anticipated, intra-observer reliability was better than inter-observer reliability although the 3 observers of our study were able to detect a significant mean change (0.1 mm, p<0.0001) in alveolar bone height over a 1-year period for 10 patients. For our most reliable and unbiased measurements (mesial measurements to the alveolar crest), a change of 0.54 mm (90th percentile) would be required to indicate change at a site from one time to the next. Based on the reliability of our digital radiographic measurements, with the alpha error rate set at 0.05 and beta at 0.20, a difference in alveolar bone height of 0.3 mm could be detected with a patient sample size of between 13 (best case) and 54 (worst case).

Acceptance Program Guidelines. Products and methods for the diagnosis and/or management of periodontitis. Council on Scientific Affairs. American Dental Association

SCOPE

These Guidelines apply to the design of clinical trials to evaluate products and methods which are intended to be used for the detection and diagnosis of periodontitis. The general purpose for such products and methods would be to assist in the identification of sites or subjects with existing periodontitis or, at increased risk of periodontitis, or for the development or progression of periodontitis. Clinical use of such diagnostics might occur: 1) during initial evaluation (screening, pre-treatment risk assessment, diagnosis, treatment-planning); 2) during treatment or management (monitoring therapeutic endpoints, identifying therapeutic targets); and 3) post-treatment (establishment of recall intervals, early detection of recurrent disease). The specifics of clinical trial design for each of these related, but separate, clinical functions may differ depending on a variety of circumstances.

Horizontal alveolar bone loss and vertical bone defects in an adult patient population

The objectives of the present investigation were to analyze intraoral radiographs and to study 1) the distribution of the distance between the cemento-enamel junction (CEJ) and the alveolar bone level (BL) and 2) the prevalence and severity of vertical defects, and furcation lesions in 416 individuals seeking dental care. Full mouth radiographs were enlarged 7.5 times and the mesial and distal distances between CEJ and bone level were measured. The extent of interradicular molar radiolucencies was also measured. Images of 10,282 teeth were studied. Subjects were between 15 to 94 years (mean age: 47.2, S.D.+/-15.2). On average they had 24.8 teeth (S.D.+/-5.5). The mean distance CEJ-BL increased significantly up to age 45 (r2=0.07; beta=0.29; P < 0.0001) and remained stable thereafter r2=0.09, beta=-0.02, N.S.). The mean distance CEJ-bone level was 1.4 mm (S.D.+/-0.7) in the 15 to 24 age group; 3.0 (S.D.+/-1.5) in the 45 to 54 age group; and 3.02 (S.D.+/-1.4) in the 75 to 94 age group. No vertical defects were found in 163 participants (39.3%); vertical defects > or = 3.0 mm were found in 30.2% (126). Mesial defects were significantly more common that distal defects (P < 0.001). The extent of horizontal bone loss was correlated to extent of vertical defects (r2=0.88; P < 0.0001). The number of remaining teeth was not associated with horizontal or vertical bone loss. In conclusion, the study indicated that few of the individuals had extensive horizontal bone loss. Vertical defects suitable for guided tissue regeneration procedures however, were found in many patients.

Crestal bone changes around titanium implants. A radiographic evaluation of unloaded nonsubmerged and submerged implants in the canine mandible

Current implant placement utilizes both nonsubmerged and submerged techniques. However, the implications of the location of a rough/smooth implant interface as well as the location of a microgap between implant and abutment on crestal bone changes are not well understood. The purpose of this study was to radiographically evaluate crestal bone changes around unloaded nonsubmerged and submerged titanium implants in a side-by-side comparison. Fifty-nine (59) implants were placed at different levels to the alveolar crest in 5 foxhounds. Standardized radiographs were taken at baseline and at monthly intervals until sacrifice at 6 months. Radiographic assessment was carried out by measuring the distance between the top of the implant/abutment and the most coronal bone-to-implant contact (DIB), and by evaluation of bone density changes using computer-assisted densitometric image analysis (CADIA). DIB measurements revealed that in 1-part, nonsubmerged implants, the most coronal bone-to-implant contact followed at all time points the rough/smooth implant interface. In all 2-part implants, nonsubmerged and submerged, the most coronal bone-to-implant contact was consistently located approximately 2 mm below the microgap. In addition, CADIA values for all 2-part implants were decreased in the most coronal area-of-interest (AOI). All bone changes were statistically significant and detectable 1 month after implant placement in nonsubmerged implants or 1 month after abutment connection in submerged implants. Neither implant position nor individual dog effects were statistically significant. These results demonstrate that the rough/smooth implant interface as well as the location of the microgap have a significant effect on marginal bone formation as evaluated by standardized longitudinal radiography. Bone remodeling occurs rapidly during the early healing phase after implant placement for non-submerged implants and after abutment connection for submerged implants.

Reproducibility of bone height measurements made on serial radiographs

The objective of this study was to determine the reproducibility of alveolar bone height measurements made on digitized images of serial radiographs using 3 different alignment systems for taking serial radiographs: 1) XCP Rinn System, 2) XCP Rinn System modified to include an alignment pin, and 3) I/EGAD system (impression based-electronically guided alignment device). Eighty duplicate films taken 1 hour apart of randomly selected anterior or posterior sites for alignment systems 1 and 2 were taken on 40 subjects. Thirty-eight duplicate films were taken of posterior and anterior sites on 19 subjects with alignment system 3. Cemento-enamel junction alveolar crest measurements were made on digital images using the side-by-side technique. Image pairs of serial radiographs were dichotomized into well-matched and poorly matched groups based on subjective evaluation of the geometric likeness. Of those taken with system 1, 47% were well matched; with system 2, 62%; and with system 3, 98%. The measurement error of change in radiographic bone height, defined as twice the standard deviation of difference (mm), was determined. This varied between 1.03 mm for poorly matched radiographic pairs taken with alignment system 1 and 0.52 mm for all radiographic pairs taken with alignment system 3. These results can be used together with power calculations to select an alignment system for a particular study. For example, power calculations indicate that detecting a bone change of 0.5 mm using the I/EGAD system would require one-third of the subjects needed when using the XCP Rinn method.

Prevalence of periodontal disease in patients with Sjögren's syndrome

The periodontal status of 25 patients with Sjögren's syndrome was compared with that of an age-, sex-, and race-matched healthy controls. Clinical evaluation included determination of number of teeth, decayed/missing/filled surfaces, probing pocket depth, clinical attachment level, plaque index, gingival index, bleeding on probing, and measurement of alveolar bone level (examined with radiography). Results of the study suggest that patients with Sjögren's syndrome have a significantly higher plaque index score (p < 0.005), higher decayed/missing/filled surfaces scores (p < 0.05), increased alveolar bone loss (p < 0.05), deeper clinical attachment level (p < 0.05), and increased cementoenamel junction-alveolar bone crest distance (p < 0.005). Although no significant difference was found in the number of cases of "established periodontitis" between the Sjögren's syndrome and controls, odds ratio analysis suggests that patients with Sjögren's syndrome are at 2.2 times higher risk of having adult periodontitis than healthy controls.

The use of periodontal probes and radiographs in clinical trials of diagnostic tests

Periodontal probing attachment level measurements and intraoral radiographs are used to assess the level of the clinical attachment and bone support in the diagnosis of periodontitis. Together these physical measurements of tooth support comprise the standard against which new diagnostic tests are compared. Since probing and radiographs provide a measure of the severity of attachment or bone loss at one point in time, serial measurements must be compared to determine whether periodontitis is progressive. Periodontal probing may be performed manually or by using controlled force electronic instruments. The resolution, depending on the instrument, will vary from 1.0 mm to 0.1 mm. Variations in probing force, size and shape of tip, location of tip placement, detection or reference landmarks for attachment level probing, degree of gingival inflammation, and transcription may adversely influence accuracy. Electronic probes offer the advantage of improved resolution, force control, and automatic recording, but the literature is inconsistent about the advantages in terms of repeatability and accuracy. Radiographic assessment of alveolar bone loss may be achieved by visual interpretation, measurement, or digital image analysis. While visual interpretation of unstandardized radiographs is insensitive to changes in bone, standardized radiographs can permit measurement of changes on the order of 0.2 mm when computerized methods are used. Newer techniques such as digital subtraction radiography permit detection of bony changes too small to be seen by the unaided eye and are over 95% sensitive and specific in detecting bony changes less than 10 mg.

Serum cotinine levels, smoking, and periodontal attachment loss

Cigarette smoking and tobacco use have been the subjects of numerous studies for many years. Smoking has also been associated with periodontal disease. However, no relationship between a reliable biochemical marker and increased severity of the periodontal condition has yet been described. It was thus the aim of this study to apply the measurement of cotinine, the major metabolite of nicotine, as a quantitative method to assess levels of smoking, and to correlate serum levels of cotinine with severity of periodontal disease. The degree of association between smoking and periodontal attachment loss was investigated in a study including 79 patients 25 to 64 years old suffering from periodontitis. Patients were examined and the following parameters recorded: Gingival Assessment (GA), Probing Pocket Depth (PPD), Clinical Attachment Level (CAL), and Bone Crest Height (BCH). In addition, self-reported histories of tobacco use as well as blood samples for quantitative analysis of serum levels of cotinine were taken. The serum samples were analyzed for cotinine content by means of a competitive-inhibition ELISA technique. The differences in mean cotinine levels were statistically significant (p = 0.0001) between smokers and non-smokers, showing no overlap between the groups. Severity of periodontal attachment loss was positively correlated with serum levels of cotinine for both measures of periodontal disease (CAL p = 0.005; BCH p = 0.008). Results from the present study indicate that serum cotinine levels used as a biochemical marker of smoking status are correlated with severity of periodontal attachment loss.

The use of radiographic techniques in the diagnosis and management of periodontal diseases

Radiographs continue to play an important role in the diagnosis and management of periodontal disease although opinions as to the most appropriate form of assessment vary. It is important to recognize the limitations of each technique in terms of resolution, repeatability and accuracy so that radiographs can be correctly interpreted to the benefit of the patient. The value of intra-oral and panoramic radiography is reviewed, with particular reference to articles published over the past five years, followed by a consideration of developing computer-aided techniques which may, in time, prove of value to the dental practitioner in the diagnosis and management of periodontal disease.

Development of automated registration algorithms for subtraction radiography

An algorithm is described which provides necessary information for automated registration and computation of alveolar height for subtraction radiographic analysis. This procedure involves identification of the cemento-enamel junctions from radiographic images by incrementally comparing a characteristic image signature along computed tooth boundaries. The identification of these anatomically invariant structures provides information necessary to warp images and create automatic superimposition, correcting for geometric misalignment. The present report describes and demonstrates the feasibility of utilizing automated CEJ, edge finding and image warping algorithms to align automatically sequential radiographs and permit their subtraction.

Severe overjet and overbite reduced alveolar bone height in 19-year-old men

Few investigations have reported convincing evidence of an association between malocclusion and loss of periodontal tooth support. The contradictory findings may in part be explained by the selection of material and by method differences. In many studies not-very-severe malocclusion was compared with not-very-correct occlusion. Only recently have measuring methods been developed that calculate the distance between the cementoenamel junction (CEJ) and the interproximal alveolar bone crest (AC) to the nearest 0.01 mm with acceptable accuracy. The association between overjet > or = 8 mm and the reduction of the bone support as expressed by the distance between CEJ and AC in 21 military recruits was compared with a peer group of 50 recruits with nearly ideal occlusion. The results showed a significant reduction of bone height (mean = 0.96 mm) of the four upper front teeth and of the four lower incisors (mean = 0.35 mm) in the malocclusion group. Similarly, a group of 31 army recruits with overbite > or = 6 mm revealed a significant reduction of bone height of 0.71 mm of the upper front teeth and 0.49 mm of the lower front teeth. Overjet and overbite did not appear in combination in this material. In conclusion, alveolar bone height was reduced in regions with severe malocclusion when compared with corresponding regions in healthy men with near ideal occlusion. The material was military recruits (age 19 years).

Alternative methods for screening periodontal disease in adults

Clinical measurements of periodontal attachment loss, while not always representing the histological changes, are used to establish the diagnosis of adult periodontitis. Such measurements are difficult to perform accurately and are labor intensive. To counter these problems, index teeth and index sites have been employed in an attempt to estimate the severity of the periodontal condition without the need to resort to elaborate attachment measurements. Unfortunately, such indices usually tend to underestimate prevalence while often overestimating severity. The purpose of the present study was to examine the correlation of alternative clinical, radiographic and microbiological parameters, with periodontal disease using the diagnostic criteria of established periodontitis. 508 adults included in this study received thorough periodontal examination which included probing pocket depth, clinical attachment level, plaque, gingival and calculus scores, together with radiographic analysis and assays of subgingival periopathogenic microorganisms. Radiographic alveolar bone loss and probing pocket depth had the highest correlation with clinical attachment loss (phi = 0.72 and phi = 0.75 respectively). Plaque scores (phi = 0.17), like gingival scores (phi = 0.06) and calculus scores (phi = 0.42) had poor correlation with established periodontitis. Periodontopathogenic species demonstrated high specificity and negative predictive values; but low sensitivity and positive predictive values make for an overall low correlation of these species with established periodontitis. However, when used in a logistic regression model, the presence of P. gingivalis (odds ratio = 6.25) has shown to contribute significantly to the estimate of probability for established periodontitis. The use of these various alternative parameters for screening of periodontal disease is discussed in light of their sensitivity, specificity and predictive value.