Marginal alveolar bone height in an adult Swedish population

The purpose of the present cross-sectional epidemiologic study was to assess the interproximal alveolar bone level within the dentition of 732 randomly selected adult individuals, stratified according to gender and age. Full mouth series of periapical radiographs were used for the assessments of the relation alveolar bone height/root length (B/R). A computer/digitizer recording method was utilized for the assessments. The results were presented as (i) mean values per age group and gender, (ii) mean frequency of subjects with sites exceeding certain thresholds of bone loss and (iii) cumulative frequencies of subjects with various number and percentual proportion of sites in relation to different B/R-ratio intervals. The results showed a reduction in mean alveolar bone/root ratio with age. The women had a significantly more favourable mean B/R-ratio than men in the ages above 40 years; the women had, however, more missing sites above age 60 years. By older age, there was observed an increased variation between individual mean B/R-ratios. Only a few subjects had a mean B/R-ratio less than or equal to 50%. A subfraction of the subjects in the different age groups had greater than 20% of their sites below a B/R-ratio of 60%. This fraction increased with age.     

Periodontal bone loss in the aging beagle dog A radiographic study

Studies in the beagle dog have clearly established the usefulness of this breed in periodontal disease research. However, little is known about the progressive nature of the disease with advancing age. It is the purpose of this paper to describe frequency and distribution of radiographically detectable lesions in an aging population of 166 colony dogs. 3 grades of alveolar bone loss were determined on high-quality postmortem radiographs. The number of teeth involved was similar in male and female and was age-dependent. Disease was more frequent in the maxillary arcades, with the 2nd upper premolar most frequently involved. Most extensive bone loss was noted around the 3rd and 4th upper premolars, and 1st and 2nd lower molars. It is felt that by the study of such a large group of older colony dogs, a better understanding can be gained of the expected alveolar bone loss with age as determined radiographically.     

Assessment of alveolar bone loss with high resolution computed tomography

In this in vitro study we compared high resolution computed tomography (HR-CT) with dental radiographs regarding the interpretation of horizontal and vertical alveolar bone loss. After removal of the soft tissue and metallic restorations of 20 dentate upper and lower jaw segments 40 infra-alveolar bony defects of different dimensions were experimentally produced. The specimens were examined radiographically with standardized dental radiographs and 1.0 mm thick contiguous axial CT-scans. On the specimens, radiographs and CT-scans the bone loss was measured between the cemento-enamel junction and the adjacent alveolar bone level of 472 mesial and distal tooth surfaces; the identification, classification and vertical depth of the infra-alveolar bony defects were also compared. An average underestimation of 0.6 mm of horizontal alveolar bone loss in the dental radiographs and an overestimation of 0.2 mm in CT-scanning was shown. No significant differences between the imaging accuracy of horizontal alveolar bone loss between dental radiographs and CT-scanning could be evaluated. In the dental radiographs 24 (60%) of the infra-alveolar bony defects could be identified and the vertical depth was underestimated by a mean of 2.2 mm. In comparison, all 40 (100%) infra-alveolar defects could be identified in the CT-scans and the vertical depth was underestimated by an average of 0.2 mm. The HR-CT-technique offers a three-dimensional interpretation of the alveolar morpholoy without overlying structures. This permits a high identification rate and classification of infra-alveolar bone loss according to the number of surrounding bone walls into one-, two or three-walled bony pockets.     

Impact of Porphyromonas gingivalis inoculation on ligature-induced alveolar bone loss. A pilot study in rats

Meulman T, Peruzzo DC, Stipp RN, Gonçalves PF, Sallum EA, Casati MZ, Goncalves RB, Nociti FH Jr. Impact of Porphyromonas gingivalis inoculation on ligature‐induced alveolar bone loss. A pilot study in rats. J Periodont Res 2011; 46: 629–636.©2011 John Wiley & Sons A/S Background and Objective: Periodontitis is a polymicrobial infection characterized by the loss of connective tissue attachment, periodontal ligament and alveolar bone. The aim of this study was to evaluate the impact of Porphyromonas gingivalis inoculation on the ligature‐induced alveolar bone loss (ABL) model in rats. Material and Methods: Forty male Wistar rats were randomly assigned to the following groups: G1, control (n = 10); G2, ligature‐induced ABL (n = 15); and G3, ligature‐induced ABL + P. gingivalis inoculation (n = 15). Rats in G2 and G3 were killed 15, 21 and 30 d after ligature placement, and the following parameters were assessed: microbiological load; ABL; and interleukin (IL)‐1β (Il1beta)/Il1ra, Il6/Il10 and Rankl/osteoprotegerin (Opg) mRNA ratios in the gingival tissues, as determined by quantitative PCR. Results: Microbiological analyses demonstrated that rats in G1, G2 and G3 were positive for the presence of bacteria (determined using PCR amplification of the 16S gene), but that only the treatment sites of rats in G3 were positive for P. gingivalis at all time‐points investigated. Histometrically, significant bone loss (p < 0.001) was observed for both ligated groups (G2 and G3) compared with the nonligated group (G1), with higher ABL observed for G2 at all the experimental time‐points. Furthermore, gene‐expression analysis demonstrated that the presence of P. gingivalis in the dentogingival area significantly decreased the Il1β/Il1ra, Il6/Il10 and Rankl/Opg mRNA ratios compared with ligature alone. Conclusion: Within the limits of this pilot study, it was concluded that inoculation of P. gingivalis affected the ligature‐induced ABL model by the induction of an anti‐inflammatory and antiresorptive host response.     

Comparison between standardized periapical and bitewing radiographs in assessing alveolar bone loss

Readability and alveolar bone level were compared in 455 sets of standardized radiographs each consisting of four periapical (PA) and two bitewing (BW) films. BW radiographs showed significantly higher proportions of unreadable sites in the canines and the mesial surface of first premolars (P less than 0.0001), while PA radiographs exhibited significantly higher proportions of unreadable sites in the distal surface of second molars (P less than 0.0001). Alveolar bone level was assessable in a total of 10016 sites, and the comparison showed identical readings in 82% of the sites. In the maxilla, a significantly higher proportion of sites exhibited larger bone loss measurements (P less than 0.0001) and more sites with significantly higher mean values (P less than 0.005) in BW than in PA films. Mandibular sites showed the opposite trend. The majority of the sites revealed a Pearson's correlation coefficient (r) ranging between 0.60 and 0.82. No significant difference between mean bone loss measurements in the two types of radiographs for all the sites was found. It was concluded that the two radiographic techniques may be used interchangeably in epidemiologic studies.     

Cytomegalovirus periodontal presence is associated with subgingival Dialister pneumosintes and alveolar bone loss

Destructive periodontal disease is associated with human cytomegalovirus (HCMV), Epstein-Barr type 1 virus (EBV-1) and other members of the Herpesviridae family as well as with various gram-negative anaerobic bacteria, including the Dialister pneumosintes species. This study aimed to determine possible interrelationships between periodontal HCMV, EBV-1, herpes simplex virus and D. pneumosintes, and relate the microbiological findings to periodontitis clinical status. Sixteen subjects each contributed paper point samples from two progressing and two stable periodontitis lesions, as determined by ongoing loss of probing attachment. Polymerase chain reaction methodology was used to identify the study herpesviruses and D. pneumosintes. Chi-squared tests, Fisher exact tests and multivariate logistic regression were employed to identify statistical associations among herpesviruses, bacteria and clinical variables. HCMV, and no other virus or combination of viruses, was positively associated with the presence of D. pneumosintes, and the relationship was specific for individual periodontitis sites with no detectable subject effect. D. pneumosintes was in turn positively associated with periodontal pocket depth and disease-active periodontitis. When the average percentage of alveolar bone loss in all teeth was treated as a response, HCMV remained significant even after D. pneumosintes was included in the model, suggesting that both HCMV and D. pneumosintes affected bone loss or, alternatively, HCMV affected factors not studied that themselves can induce bone loss. We hypothesize that periodontal HCMV sets the stage for subgingival proliferation of D. pneumosintes and subsequent periodontal disease progression. Studies on herpesviral-bacterial interactions may hold great promise for delineating important etio-pathogenic aspects of destructive periodontal disease.     

Accelerated alveolar bone loss in male HLA-B27 transgenic rats: adult onset

OBJECTIVE AND BACKGROUND: HLA-B27 transgenic (TG) rats exhibit severe colitis, arthritis and other inflammatory lesions. Previous studies in female TG rats indicate that they develop severe alveolar bone loss (ABL). Lack of data on male TG rats has left open the question of possible hormonal/sex dependence for the observed ABL. The purpose of the present study was to assess the natural history of ABL in male HLA-B27 rats, compared to age- and sex-matched wild-type Fischer 344 (WT) rats. MATERIALS AND METHODS: Fourteen WT and 11 TG male rats, aged 7-8 weeks, were used. Sacrifice times occurred at 10, 22 and 35 weeks. Animal heads were defleshed and treated to remove organic material, and skulls were stained to locate the cemento-enamel junction. ABL was measured as exposed molar root surface area (mm2) on the right maxilla and right mandible. Blinded measurements were performed using a computer-assisted image analysis system. RESULTS: ABL for the entire TG group was significantly different from the WT group (p < 0.05). There was no significant difference in ABL between WT and TG rats at 10 weeks of age. At 22 and 35 weeks of age TG rats experienced 23% and 37% greater ABL than WT rats, respectively; these differences were statistically significant (p < 0.015). For both TG and WT animals, ABL was significantly different between the three age groups. CONCLUSIONS: These results, consistent with previous findings in female TG rats, suggest that the accelerated ABL found in TG rats is an adult-onset, age-dependent, and sex-independent process.     

The relationship between attachment level loss and alveolar bone loss

Standardized radiographs and repeated periodontal probe measurements were made on 22 untreated subjects with destructive periodontal disease monitored for 1 year. Radiographs of selected sites were taken at 0, 6 and 12 months. Measurements of attachment level were made monthly. Radiographic measurements were made on 7X magnified projected images. Alveolar bone height from the CEJ was computed by multiplying the average length of the root times the measured ratio of CEJ to alveolar bone over CEJ to root tip. Each radiograph was measured twice by 2 investigators. Sites were excluded as having indistinct anatomical landmarks in which the standard deviation of the 4 measurements exceeded 0.16 mm, the measurement error for repeat determination of bone height on high quality radiographic images. A 3 sigma critical value for significant bone loss was selected as 0.48 mm. Changes in attachment level were computed for the intervals preceding and during the 6-12 month radiographic measurement period. Based on these critical values, 6.1% of the 231 radiographed sites showed significant bone loss. Similarly, 5.7% of the 1155 probed sites showed significant attachment loss. However, none of the sites with significant bone loss exhibited significant attachment loss over the same time period. In general, significant attachment loss preceded bone loss by 6 to 8 months. At 4 mm, attachment loss was found to predict subsequent bone loss with a true positive ratio of 60% and a false positive ratio of 5%, indicating a high degree of predictive discrimination. These observations indicate that attachment loss precedes radiographic evidence of crestal alveolar bone loss during periods of periodontal disease activity.     

Involvement of toll‐like receptor 4 in alveolar bone loss and glucose homeostasis in experimental periodontitis

Watanabe K, Iizuka T, Adeleke A, Pham L, Shlimon AE, Yasin M, Horvath P, Unterman TG. Involvement of toll‐like receptor 4 in alveolar bone loss and glucose homeostasis in experimental periodontitis. J Periodont Res 2011; 46: 21–30. © 2010 John Wiley & Sons A/S Background and Objective: There is general agreement that certain fatty acids and lipopolysaccharides (LPS) promote inflammation through toll‐like receptor 4 (TLR4), and that inflammation promotes insulin resistance. We therefore hypothesized that mice with periodontitis and a TLR4 loss‐of‐function (LOF) mutation fed a high‐fat (HF) diet would develop improved glucose homeostasis compared with wild‐type (WT) animals with periodontitis fed a HF diet. Material and Methods: Wild‐type and TLR4 mutant mice fed a HF diet were divided into four groups (n = 6/group): WT; WT with periodontitis (WT/P); mutant (Mut); and mutant with periodontitis (Mut/P). Periodontitis was induced by placing LPS soaked ligatures around maxillary second molars. Fasting insulin and glucose levels were measured weekly for 10 wk. Glucose tolerance was evaluated at baseline (week 1) and at 9 wk. Insulin signaling (phosphorylation of Akt) and tumor necrosis factor‐α (TNF‐α) mRNA levels in liver were determined when the mice were killed at week 10. Results: Mut/P mice developed less alveolar bone loss compared with WT/P mice (p < 0.05). Fasting glucose levels were improved after 8 wk of feeding a HF diet (weeks 9 and 10) in Mut/P mice compared with Mut, WT and WT/P mice (p < 0.05). Glucose tolerance was impaired in all groups compared with baseline (p < 0.05), except for the Mut/P group. Insulin signaling was improved (p < 0.05), and expression of TNF‐α was decreased (p < 0.05) in the liver of Mut/P mice compared with the liver of WT/P mice. Conclusion: The TLR4 LOF mutation partially protects against alveolar bone loss and improves glucose homeostasis in mice with periodontitis fed a HF diet.     

Digital radiography of interproximal bone loss; validity of different filters

The aim of the present study was to compare linear measurements of interproximal bone loss on digitized radiographic images after application of different filters to the gold standard of intrasurgical measurements. Immediately before surgery, 50 radiographs of 50 periodontally-diseased teeth exhibiting interproximal bone loss, were obtained by a standardized technique in 33 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 with 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 interproximal lesions from the digitized but unchanged radiographic images and also after use of 7 different basic image-processing modes (enhancement of contrast [dynamics], inversion, high-pass, enhancement of gray-level differences, mean value, histogram correction, spreading of grey values) with 11-fold magnification. Neither the measurement of the distance CEJ to AC on the unchanged images nor assessments with any of the filters revealed significant differences from the gold standard. Multivariate analysis of variance showed the respective filter (p=0.009), intrasurgical and radiographic assessments (p<0.0001), to statistically significantly, influence the difference between intrasurgical and radiographic measurements of the distance CEJ to BD. The underestimation of the intra-surgically assessed distance CEJ to BD by radiographic measurements ranged from 0.3+/-2.0 to 0.8+/-1.9 mm. The filter "mean value" underestimated interproximal bone loss statistically significantly more than the digitized but unchanged radiograph (p=0.05). In this study, basic digital manipulations (filters) of radiographic images failed to result in statistically significantly more valid measurements of interproximal bone loss when compared to the unchanged but digitized images. All radiographic assessments on the digitized images except for use of one filter (mean value) came close to the intrasurgical gold standard.     

Radiological evaluation of marginal bone loss at tooth surfaces facing single Brånemark implants

A radiologic evaluation of marginal bone loss around single implants ad modum Brånemark and their adjacent teeth was performed: 58 adults with 71 fixtures were followed up to 3 years after crown installation. The following factors were considered: age, cause of tooth loss, vertical relation between fixture and teeth, distance between adjacent teeth, distance between fixture and natural tooth, jaw region. Specified distance were measured as well as marginal bone levels around fixtures and tooth surfaces in magnified standardized intraoral radiographs. The results show a loss of marginal bone support at tooth surfaces adjacent to inserted implants during the interval between preoperative examination and crown installation that exceeds the loss during subsequent years. The largest bone loss was observed when implants were placed next to lateral upper incisors. A strong correlation was found between bone loss at adjacent teeth and the horizontal distance fixture‐tooth. With decreasing distance the bone loss increased, especially in the upper incisor region. At present it seems difficult to predict which individual or individual condition may have a higher risk for bone loss, due to large intra‐ and 1 interindividual variation.     

Alpha 2-macroglobulin in gingival fluid: correlation with alveolar bone loss in periodontal disease

The concentration of total, free and bound (complexed forms) of alpha 2-macroglobulin was measured by crossimmunoelectrophoresis in patients with different degrees of periodontal disease as indicated by the gingival index (GI) and the proportion of alveolar bone loss (ABL). The concentration of total alpha 2-M (bound and free forms) is lower in gingival fluid taken from sites with more inflamed gingivae. Its concentration decreases with an increase in the pocket depth and the alveolar bone loss at the sites of fluid collection. The concentration of alpha 2-M bound form, i.e., the presence of alpha 2-M: protease complexes, in gingival fluid is low or absent at the sites with more pronounced bone loss (above 15%). Our results support the hypothesis that unbalanced protease activity damages the periodontal tissue. Not only the proteolytic but also inhibitory activities are altered and correspond to the severity of the disease.     

The significance of alveolar bone in periodontal disease

The periodontal conditions in 19 patients with unilateral cleft lip, alveolus and palate (CLAP) and in 6 patients with bilateral CLAP, were evaluated in 1979 and re-examined in 1987. During these 8 years, these patients were not subjected to any professionally supervised maintenance care program. Pronounced plaque accumulation and high frequency of gingival units exhibiting bleeding on probing were noted in the majority of the patients both in 1979 and 1987, documenting inadequate oral hygiene standards with resulting inflammatory reactions of the periodontal tissues. Progression of periodontal disease over time was assessed as loss of clinical attachment and loss of alveolar bone height. The periodontal destruction was not found to be more severe at cleft sites with a long connective tissue attachment than at control sites not affected by cleft defects. It was concluded that sites with a long supracrestal connective tissue attachment do not seem to be more prone to periodontal destruction, induced by bacterial infection, than sites with a normal length of the supraalveolar fibrous attachment. The results also show that the alveolar bone height, as visualized in radiographs at sites with alveolar defects, is of limited value for the diagnosis of the degree of periodontal destruction at such sites.     

Longitudinal study of dental caries, tooth mortality and interproximal bone loss in adults with intellectual disability

The investigation focused on longitudinal changes of oral health in a group of adults with intellectual disability. A number of 124 individuals, aged 21-40 yr in 1990, were followed during 8.5 yr. The incidence and prevalence of caries, incidence of tooth mortality, and interproximal bone loss were registered from clinical examinations and bite-wing radiographs. The subjects visited the dental clinic for preventive dental care on average every third month during the period. The caries incidence was low, on average 0.51 new lesions per yr. Persons with mild intellectual disability experienced more caries than other subjects. During the 8.5 yr, the subjects had lost on average 1.82 teeth, with periodontitis dominating as the reason for tooth mortality. Individuals who cooperated poorly with dental treatment had lost the most teeth. The average annual bone loss in all subjects was 0.03 mm. Subjects with Down syndrome had a higher bone loss compared to those with other diagnoses of intellectual disability. Thus, the major part of the persons with intellectual disability showed satisfactory oral health. However, subjects with poor ability to cooperate with dental treatment and subjects with Down syndrome showed an increased risk for impaired oral health.     

Color conversion of alveolar bone density changes in digital subtraction images

This study evaluated the influence of image processing of digital subtraction images on inter- and intra-examiner agreement relative to the detection of alveolar bone change on radiographs. 62 sites on digital subtraction images from standardized radiographs from patients requiring periodontal surgery were included in this study. The images were displayed as digital subtraction images, contrast enhanced subtraction images and as color-converted digital subtraction images. The images were projected in random order, analyzed by 4 interpreters and 1 of 8 possible diagnostic decisions was noted for each one of 62 sites. 2 months after the first evaluation, the slides were re-analyzed. 3 different computations (overall agreement, specific agreement and kappa-value) were calculated. The results indicated that image processing of subtraction images using pseudocolor display of the density changes might improve the intra- and inter-examiner agreement.     

The angular bony defect in the maintenance of the periodontal patient

The present retrospective study was performed to evaluate some long-term alterations of the alveolar bone level at periodontal sites with angular and even ("horizontal") patterns of bone loss. The investigation included 48 patients who, following treatment for advanced periodontal disease, were placed in a maintenance care program which included recall appointments every 3-6 months for a period of 5 to 16 years. The material of the study comprised all teeth at which angular osseous defects (test sites) could be detected in a full-mouth series of radiographs obtained at the end of the active treatment phase. Alterations in the position of the marginal alveolar bone crest and the base of the osseous defect which took place during the maintenance period were assessed by comparing the post-treatment radiographs with a 2nd set of radiographs obtained at the final examination. In the same patients, an equal number of contralateral or neighboring teeth at which bone loss in the radiographs had an even or "horizontal" character were included as controls. The results from the assessments demonstrated that periodontal sites which, following active therapy displayed either angular or "horizontal" patterns of alveolar bone loss underwent, during a 5-16 year period of maintenance, only minor bone level alterations. Additional loss of supporting bone occurred equally frequently at sites with "horizontal" and angular patterns of bone loss. Thus, the findings reported failed to show up sites with angular bony defects as being particularly susceptible to recurrent destructive periodontitis.