Detection of Bone Loss With Different X-Ray Techniques in Periodontal Patients

Correlation between the presence of tonsilloliths and the bone defects by periodontitis on imaging analysis: a pilot study

BACKGROUND

Very recently, a significant relationship between tonsilloliths and dental plaque-related pathologies was reported using digital panoramic radiographs. Their dynamics over time suggest that tonsilloliths may be in a permanently active phase that functions to remove foreign matter. The aim of the study was to evaluate the relationship between the occurrence of tonsilloliths and the extent of periodontitis.

METHODS

A total of 608 patients who underwent both CT and panoramic radiographs were included in the study. Both of two imaging were retrospectively and independently assessed with respect to the presence of tonsilloliths detected on CT and panoramic radiographs, and bone defects caused by periodontitis detected on panoramic radiographs. The type of retrospective study is case-control. Then, the differences between age groups were evaluated with respect to the degree of bone resorption and its correlation with the presence of tonsilloliths. The relationships between categorical variables were assessed using Pearson's correlation coefficient or Spearman's correlation coefficient.

RESULTS

There was a significant relationship between tonsilloliths on CT and the extent of the bone defect on panoramic radiographs (Spearman's correlation coefficient, r = 0.648, p = 0.043). In addition, there was a significant difference in the extent of the bone defect caused by periodontitis between subjects with and without tonsilloliths in the 60 to 69-year-old group (Mann-Whitney U test, p = 0.025), 70 to 79-year-old group (Mann-Whitney U test, p = 0.002), and 80 to 89-year-old group (Mann-Whitney U test, p = 0.022), but not in other age groups (Mann-Whitney U test: under 9-year-old group, p = 1.000; 10 to 19-year-old group, p = 1.000; 20 to 29-year-old group, p = 0.854; 30 to 39-year-old group, p = 0.191, 40 to 49-year-old group, p = 0.749; 50 to 59-year-old group, p = 0.627; ≥90-year-old group, p = 1.000).

CONCLUSIONS

The presence of tonsilloliths was related to the extent of periodontitis because the structures were responding dynamically.

The Impetus of Artificial Intelligence on Periodontal Diagnosis: A Brief Synopsis

The current advances in digitized data additions, machine learning and computing framework, lead to the swiftly emerging concept of "Artificial Intelligence" (AI), that are developing into areas that were formerly contemplated for human expertise. AI is a relatively rapid paced mechanics wherein the computer technology is tuned to perform human tasks. An auxiliary domain of AI is machine learning (ML), and Deep learning, a subclass of ML technique comprehends multi-layer mathematical operations. AI-based applications have tremendous potential to improve and systematize patient care thereby alleviating dentists from laborious regular tasks, and facilitate personalized, predictive and preventive dentistry. In the dental clinic, AI can execute a variety of easy tasks with greater accuracy, minimal manpower, and with fewer mistakes over human equivalents. These tasks range from appointment scheduling and coordination to helping with clinical evaluation and therapy. Besides, this could assist in the early diagnosis of dental and maxillofacial abnormalities like periodontal ailments, root caries, bony lesions, and facial malformations in addition to automatically identifying and classifying dental restorations on digital radiographs. This brusque narrative review describes the AI-based systems, their respective applications in periodontal diagnosis, the multifarious studies, possible limitations and the predictable future of AI-based dental diagnostics and treatment planning.

The Detection of Dental Pathologies on Periapical Radiographs—Results from a Reliability Study

(1) Background: Caries, periapical lesions, periodontal bone loss (PBL), and endo-perio lesions are common dental findings that require an accurate diagnostic assessment to allow appropriate disease management. The purpose of this reliability study was to compare the inter- and intra-rater reliability for the detection of the above-mentioned pathologies on periapical radiographs. (2) Methods: Fourteen dentists (three with more than two years and eleven with less than two years of work experience) participated in a training workshop prior to data acquisition. A total of 150 radiographs were assessed by all raters in two rounds. Cohen’s Kappa (CK) values and a binary logistic regression were calculated. (3) Results: The reliability was found in a moderate and substantial range of agreement: caries (mean inter-rater CK value/first round 0.704/mean inter-rater CK value/second round 0.659/mean intra-rater CK value 0.778), periapical lesions (0.643/0.611/0.768), PBL (0.454/0.482/0.739) and endo-perio lesion (0.702/0.689/0.840). The regression model revealed a significant influence of the clinical experience, and furthermore, periapical pathologies and PBL were identified less reliably in comparison to caries and endo-perio lesions. (4) Conclusions: The dentist’s ability to detect the chosen pathologies was linked with significant differences. Periapical lesions and PBL were identified less reliably than caries and endo-perio lesions.

Automated periodontitis bone loss diagnosis in panoramic radiographs using a bespoke two-stage detector

Periodontitis is a serious oral disease that can lead to severe conditions such as bone loss and teeth falling out if left untreated. Diagnosis of radiographic bone loss (RBL) is critical for the staging and treatment of periodontitis. Unfortunately, the RBL diagnosis by examining the panoramic radiographs is time-consuming. The demand for automated image analysis is urgent. However, existing deep learning methods have limited performances in diagnosis accuracy and have certain difficulties in implementation. Hence, we propose a novel two-stage periodontitis detection convolutional neural network (PDCNN), where we optimize the detector with an anchor-free encoding that allows fast and accurate prediction. We also introduce a proposal-connection module in our detector that excludes less relevant regions of interests (ROIs), making the network focus on more relevant ROIs to improve detection accuracy. Furthermore, we introduced a large-scale, high-resolution panoramic radiograph dataset that captures various complex cases with professional periodontitis annotations. Experiments on our panoramic-image dataset show that the proposed approach achieved an RBL classification accuracy of 0.762. This result shows that our approach outperforms state-of-the-art detectors such as Faster R-CNN and YOLO-v4. We can conclude that the proposed method successfully improves the RBL detection performance. The dataset and our code have been released on GitHub. (https://github.com/PuckBlink/PDCNN).

Association between Type 2 Diabetes and Classification of Periodontal Disease Severity in Japanese Men and Women: A Cross-Sectional Study

Background: to evaluate the association between type 2 diabetes and periodontal disease severity using the rate of alveolar bone loss (ABL) and high-sensitivity C-reactive protein (hs-CRP) value as indices. Methods: In this cross-sectional study of 372 patients (mean age ± SD, 53.2 ± 11.8 years) from a Japanese hospital, we measured ABL and number of teeth on either panoramic radiographs or intraoral dental radiographs of all teeth. Periodontal disease severity was classified into nine groups by combining ABL and hs-CRP. Results: 48 subjects had type 2 diabetes; 324 did not. Univariate analysis showed that type 2 diabetes was significantly associated with age, sex, body mass index, number of teeth, ABL, hs-CRP, and periodontal disease severity. Multivariate analysis showed significant associations between type 2 diabetes and the groups with high severity of periodontal disease. In receiver operating characteristic (ROC) curve analysis, predicting the presence of diabetes, area under the ROC curve was 0.762 (95%CI = 0.688–0.835) for ABL, and 0.709 (95%CI = 0.635–0.784) for hs-CRP, which was significant. Conclusions: this study showed that diabetes can be associated with a periodontal disease severity classification using the combination of ABL and hs-CRP.

Association between Carotid Artery Calcification and Periodontal Disease Progression in Japanese Men and Women: A Cross-Sectional Study

Objective: To evaluate the association between alveolar bone loss (ABL) detected on panoramic radiographs and carotid artery calcification (CAC) detected on computed tomography (CT). Methods: The study subjects included 295 patients (mean age ± SD: 64.6 ± 11.8 years) who visited the Matsumoto Dental University Hospital. The rate of ABL and the number of present teeth were measured on panoramic radiographs. Univariate analyses with t-tests and chi-squared tests were performed to evaluate the differences in age, gender, history of diseases, number of present teeth, and the ABL between subjects, with and without CAC. Moreover, multivariate logistic regression analysis, with forward selection and receiver operating characteristic curve (ROC) analysis, was performed. Results: The number of subjects without and with CAC was 174 and 121, respectively. Univariate analyses revealed that CAC was significantly associated with age, hypertension, osteoporosis, number of present teeth, and ABL. Multivariate logistic regression analysis adjusted for covariates revealed that the presence of CAC was significantly associated with ABL (OR = 1.233, 95% CI = 1.167–1.303). In the ROC analysis for predicting the presence of CAC, the the area under the ROC curve was the highest at 0.932 (95% CI = 0.904–0.960) for ABL, which was significant. Conclusions: Our results suggest that the measurement of ABL on panoramic radiographs may be an effective approach to identifying patients with an increased risk of CAC.

Outcome of periodontal–orthodontic treatment in subjects with periodontal disease. Part II: a CBCT study of alveolar bone level changes

Aim

To examine alveolar bone level (ABL) changes before (T1) and after (T2) orthodontic treatment (OT) in subjects with periodontal disease.

Methods

The study included 50 subjects with periodontal disease. All patients received subgingival debridement following baseline examination. Control group patients received final periodontal treatment before the start of OT. For the test group patients final periodontal treatment was performed simultaneous to OT. OT was performed with a straight-wire appliance. Micro-implants or temporary crowns on implants were used for posterior anchorage when needed. ABL measurements of 3821 tooth surfaces were performed on cone beam computed tomography images.

Results

No difference was observed between mean ABL at T1 and T2. ABL remained unchanged on 69 per cent of surfaces. A mean of 15.6 (SD 7.4) per cent of surfaces experienced ABL gain, and a mean of 15.1 (SD 7.5) per cent was found with ABL loss. Small significant median ABL difference was observed on mesial and distal surfaces (P < 0.001). A significant difference was found between median ABL changes on mesial/distal in comparison to buccal/lingual surfaces (P < 0.01). Significantly more buccal (17.9 %) and lingual (18.5 %) surfaces experienced ABL loss when compared with mesial (11.3 %) and distal (12.0 %) surfaces (P < 0.001). Significant difference was found in the median ABL change of intruded (0.5 (IQR 0.94) mm) and non-intruded (−0.4 (IQR 1.07) mm) maxillary incisors (P = 0.04). Significant median ABL gain was found on the lingual surface of maxillary incisors, which were retroclined more than 8.6 degree and intruded more than 1.6 mm.

Conclusions

ABL changes after periodontal–orthodontic treatment in patients with periodontal disease were small. ABL gain was more observed on mesial and distal surfaces and ABL loss on buccal and lingual surfaces. Larger orthodontic movements of maxillary incisors influenced ABL gain.

Comparison of cone-beam computed tomography with bitewing radiography for detection of periodontal bone loss and assessment of effects of different voxel resolutions: an in vitro study

OBJECTIVE

The aim of the study was to compare intraoral radiographs and CBCT images for detection of horizontal periodontal bone loss, and to investigate the diagnostic effect of different voxel resolutions in CBCT imaging.

METHODS

A total of 240 sites with horizontal bone loss were measured on the buccal, lingual, mesial, and distal surfaces of 60 posterior teeth in four maxillary and six mandibular bones obtained from cadavers (dry skulls). Direct measurements on the dry skulls were accepted as the gold standard values. Measurements on CBCT images at two different voxel resolutions (0.250 and 0.160 mm³) and intraoral bitewing radiographs were compared with one another and with the gold standard values.

RESULTS

The measurements on the CBCT images at two voxel resolutions and bitewing radiographs did not differ significantly (p > 0.05) from the direct measurements on the dry skulls. No significant difference was found between the bitewing radiographs and CBCT images for measurements in the mesial and distal regions (p > 0.05). There was no significant difference between the measurements on the buccal and lingual surfaces at the two different voxel resolutions (p > 0.05).

CONCLUSIONS

CBCT scans are recommended for evaluation of buccal and lingual bone loss to avoid intraoral radiographs that exceed routine examination of interproximal alveolar bone loss. Furthermore, instead of basing the voxel size on the required CBCT scans, it is recommended to select the smallest possible field of view to reduce the dose of radiation.

Diagnosis and prediction of periodontally compromised teeth using a deep learning-based convolutional neural network algorithm

Purpose

The aim of the current study was to develop a computer-assisted detection system based on a deep convolutional neural network (CNN) algorithm and to evaluate the potential usefulness and accuracy of this system for the diagnosis and prediction of periodontally compromised teeth (PCT).

Methods

Combining pretrained deep CNN architecture and a self-trained network, periapical radiographic images were used to determine the optimal CNN algorithm and weights. The diagnostic and predictive accuracy, sensitivity, specificity, positive predictive value, negative predictive value, receiver operating characteristic (ROC) curve, area under the ROC curve, confusion matrix, and 95% confidence intervals (CIs) were calculated using our deep CNN algorithm, based on a Keras framework in Python.

Results

The periapical radiographic dataset was split into training (n=1,044), validation (n=348), and test (n=348) datasets. With the deep learning algorithm, the diagnostic accuracy for PCT was 81.0% for premolars and 76.7% for molars. Using 64 premolars and 64 molars that were clinically diagnosed as severe PCT, the accuracy of predicting extraction was 82.8% (95% CI, 70.1%–91.2%) for premolars and 73.4% (95% CI, 59.9%–84.0%) for molars.

Conclusions

We demonstrated that the deep CNN algorithm was useful for assessing the diagnosis and predictability of PCT. Therefore, with further optimization of the PCT dataset and improvements in the algorithm, a computer-aided detection system can be expected to become an effective and efficient method of diagnosing and predicting PCT.

Association of liver enzyme levels and alveolar bone loss: A cross-sectional clinical study in Sado Island

BACKGROUND

The interaction of periodontopathic bacteria with host immune system induces the production of inflammatory mediators which leads to alveolar bone loss (ABL), the essential feature of periodontitis. Concurrently, periodontal diseases cause the elevation of blood cytokine levels, the alteration of gut microbiota and the dissemination of enterobacteria to the liver. Owing to these mechanisms, periodontal disease might be a risk for liver dysfunction. Several epidemiological studies have reported associations between periodontal diseases and liver dysfunction, although the association between ABL and liver dysfunction has not been investigated. This cross-sectional study determined if elevated serum liver enzyme levels were associated with ABL in Japanese adults.

MATERIAL AND METHODS

Japanese adults living on Sado Island who visited Sado General Hospital were invited to participate in the study. Participants over 40 years of age who underwent dental panoramic radiography and blood tests were included. Drinking and smoking habits were self-administered. After excluding patients with edentulous jaw, diagnosed liver diseases, and those on dialysis, data from 44 men and 66 women with a mean age of 73 years were analyzed. The average percentage of ABL for each participant was calculated for mesial and distal sites of all remaining teeth. The levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) were determined. Univariate analyses were performed to select covariates to be put in multivariate analyses. The association between elevated serum liver enzyme levels and the highest quartile of ABL were assessed by multiple logistic regression analysis.

RESULTS

After adjusting for covariates, no significant association was found between elevated serum AST, ALT, or GGT levels as dependent variables and the highest quartile of ABL as an explanatory variable.

CONCLUSIONS

There was no significant association between the elevation of serum liver enzyme levels and ABL in Japanese adults. Key words:Liver enzymes, dental panoramic radiography, alveolar bone loss, Japanese adults.

Comparison of periodontal evaluation by cone-beam computed tomography, and clinical and intraoral radiographic examinations

OBJECTIVES

Cone-beam computed tomography (CBCT) has been widely used in many fields of dentistry. However, little is known about the accuracy of CBCT for evaluation of periodontal status. The objective of this study was to compare and correlate periodontal assessments among CBCT, clinical attachment loss (CAL) measurement, and periapical (PA)/bitewing (BW) radiography.

METHODS

Eighty patients (28 males, 52 females; age range, 19-84 years) from the University of Texas School of Dentistry at Houston were evaluated retrospectively. Measurements were taken on the central incisors, canines, and first molars of the right maxilla and left mandible. CAL was extracted from periodontal charts. The radiographic distance from the cementum-enamel junction (CEJ) to the alveolar crest was measured for tooth mesial and distal sites on PA/BW and CBCT images using MiPacs software and Anatomage Invivo software, respectively. One-way ANOVA and Pearson analysis were performed for statistical analyses.

RESULTS

The CEJ-crest distances for CBCT, PA/BW, and CAL were 2.56 ± 0.12, 2.04 ± 0.12, and 2.08 ± 0.17 mm (mean ± SD), respectively. CBCT exhibited larger values than the other two methods (p < 0.05). There were highly significant positive correlations among CBCT, PA/BW, and CAL measurements at all examined sites (p < 0.001). The Pearson correlation coefficient was higher for CBCT with CAL relative to PA/BW with CAL, but the difference was not significant (r = 0.64 and r = 0.55, respectively, p > 0.05).

CONCLUSIONS

This study validates the suitability of CBCT for periodontal assessment. Further studies are necessary to optimize the measurement methodology with CBCT.

A comparative study of combined periodontal and orthodontic treatment with fixed appliances and clear aligners in patients with periodontitis

Purpose

With the increasing prevalence of orthodontic treatment in adults, clear aligner treatments are becoming more popular. The aim of this study was to evaluate the effect of orthodontic treatment on periodontal tissue and to compare orthodontic treatment with fixed appliances (FA) to clear aligner treatment (CAT) in periodontitis patients.

Methods

A total of 35 patients who underwent orthodontic treatment in the Department of Periodontology were included in this study. After periodontal treatment with meticulous oral hygiene education, patients underwent treatment with FA or CAT, and this study analyzed patient outcomes depending on the treatment strategy. Clinical parameters were assessed at baseline and after orthodontic treatment, and the duration of treatment was compared between these two groups.

Results

The overall plaque index, the gingival index, and probing depth improved after orthodontic treatment (P<0.01). The overall bone level also improved (P=0.045). However, the bone level changes in the FA and CAT groups were not significantly different. Significant differences were found between the FA and CAT groups in probing depth, change in probing depth, and duration of treatment (P<0.05). However, no significant differences were found between the FA and CAT groups regarding the plaque index, changes in the plaque index, the gingival index, changes in the gingival index, or changes in the alveolar bone level. The percentage of females in the CAT group (88%) was significantly greater than in the FA group (37%) (P<0.01).

Conclusions

After orthodontic treatment, clinical parameters were improved in the FA and CAT groups with meticulous oral hygiene education and plaque control. Regarding plaque index and gingival index, no significant differences were found between these two groups. We suggest that combined periodontal and orthodontic treatment can improve patients’ periodontal health irrespective of orthodontic techniques.

Utility of a Newly Designed Film Holder for Premolar Bitewing Radiography

INTRODUCTION

Bitewing radiography is a valuable technique for assessment of proximal caries, alveolar crest and periodontal status. Technical errors during radiography result in erroneous radiographic interpretation, misdiagnosis, possible mistreatment or unnecessary exposure of patient for taking a repeat radiograph.

AIM

In this study, we aimed to evaluate the efficacy of a film holder modified from the conventional one and compared it with that of conventional film holder.

MATERIALS AND METHODS

Our study population comprised of 70 patients who were referred to the Radiology Department for bilateral premolar bitewing radiographs as requested by their attending clinician. Bitewing radiographs in each patient were taken using the newly designed holder in one side and the conventional holder in the other side. The acceptability of the two holders from the perspectives of the technician and patients was determined using a 0-20 point scale. The frequency of overlap and film positioning errors was calculated for each method.

RESULTS

The conventional holder had greater acceptability among patients compared to the newly designed holder (mean score of 16.59 versus 13.37). From the technicians' point of view, the newly designed holder was superior to the conventional holder (mean score of 17.33 versus 16.44). The frequency of overlap was lower using the newly designed holder (p<0.001) and it allowed more accurate film positioning (p=0.005).

CONCLUSION

The newly designed holder may facilitate the process of radiography for technicians and may be associated with less frequency of radiographic errors compared to the conventional holder.

A six-site method for the evaluation of periodontal bone loss in cone-beam CT images

OBJECTIVES

In contrast to two-dimensional planar images, a measuring point is hardly repeatedly determined in a CBCT image when alveolar bone loss is assessed. Thus, the aim of the present study was to propose a six-site measuring method, which is closely related to anatomical structure, for the evaluation of alveolar bone loss in CBCT images.

METHODS

150 measuring points in 11 molars and 14 premolars from 6 patients (2 males and 4 females) were included. CBCT images of the teeth were acquired prior to periodontal surgery. Four observers measured the distances between cemento-enamel junctions and the apical bases of the periodontal bone defect at the mesio-buccal, mid-buccal, disto-buccal, mesio-lingual/palatal, mid-lingual/palatal and disto-lingual/palatal sites in CBCT images. Direct measurements of the six sites were correspondingly obtained in the subsequent periodontal surgeries. Differences between the distances measured in the CBCT images and during the surgery were analysed. Interobserver and intraobserver variances were tested.

RESULTS

No statistically significant difference was found between the surgical and CBCT measurements (p = 0.84). Diagnostic coincidence rates of four observers were 86.7%, 87.3%, 88.7% and 88.0%, respectively. The interobserver (p = 0.95) and intraobserver (p = 0.30) variances were not significant.

CONCLUSIONS

The six-site measuring method validated in the present study may be a useful three-dimensional measuring method for the evaluation of periodontal disease.

Significance of maxillary sinus mucosal thickening in patients with periodontal disease

AIM

To characterise and measure the Schneiderian membranes of individuals with periodontal diseases in China and to analyse the factors impacting maxillary sinus mucosal thickness using cone-beam computed tomography (CBCT).

MATERIAL AND METHOD

A cohort of 221 patients with periodontal disease was subjected to cross-sectional CBCT examination. Various parameters, including age, sex, alveolar bone loss, furcation lesions and vertical infrabony pockets, were analysed as correlates of mucosal thickening (MT). Sinus mucosal thickness ≥ 2 mm qualified as MT.

RESULTS

MT was detected in 103 (48.9%) patients, increasing in frequency as the degree of alveolar bone loss advanced (mild, 14.5%; moderate, 29.5%; severe, 87.9%). The association between MT and vertical infrabony pockets was statistically significant (P < 0.001). The likelihood of MT increased with moderate [odds ratio (OR) = 1.02] and severe (OR = 4.62) periodontal bone loss (P < 0.001), as well as with furcation lesions (OR = 2.76) and vertical infrabony pockets (OR = 13.58).

CONCLUSIONS

Relative to the case in patients with periodontitis and normal mucosa, the probability of MT increased dramatically as alveolar bone loss worsened. Periodontal pathologies (i.e. furcation lesions and vertical infrabony pockets) were also more likely to coincide with MT.

A new digital tool for radiographic bone level measurements in longitudinal studies

Background

The reproducibility of measurements on radiographs is influenced by the techniques by which the images as well as the measurements are obtained. Thus, bias resulting from errors in the image and/or image examinations at two points in time may result in wrongful registrations of true biological or pathological changes. The aim of the present study was to propose and evaluate an indirect radiological examination technique, by which bias, when measuring radiographic bone level, could be substantially reduced as compared to the technique using direct mm measurements.

Methods

A plugin to ImageJ was designed to reduce bias when measuring bone loss on radiographic images. In human dry mandibles, radiographic images of 20 teeth were obtained parallel with the tooth axis (alpha = 0) and at an angle of 30° deviation. The direct technique of measuring radiographic bone level (RBL) and the indirect, length-adjusted RBL were registered by four researchers in a double blinded fashion.

Results

When mean RBL measured at 0° angle was 7.0 mm, the corresponding mean RBL measured at 30° angle was 7.8 mm, signifying an 11.4 % increase (p = 0.032), whereas the mean length-adjusted RBL increased by 0.6 % (p = 0.9).

Conclusions

This study showed that the use of the original, direct technique (ImageJ) resulted in markedly biased radiographic bone level at 30° angle, while the proposed indirect length-adjusted technique (ImageJ plugin) did not.

Physiological adaptations of key oral bacteria

Oral colonising bacteria are highly adapted to the various environmental niches harboured within the mouth, whether that means while contributing to one of the major oral diseases of caries, pulp infections, or gingival/periodontal disease or as part of a commensal lifestyle. Key to these infections is the ability to adhere to surfaces via a range of specialised adhesins targeted at both salivary and epithelial proteins, their glycans and to form biofilm. They must also resist the various physical stressors they are subjected to, including pH and oxidative stress. Possibly most strikingly, they have developed the ability to harvest both nutrient sources provided by the diet and those derived from the host, such as protein and surface glycans. We have attempted to review recent developments that have revealed much about the molecular mechanisms at work in shaping the physiology of oral bacteria and how we might use this information to design and implement new treatment strategies.

Tobacco consumption induces alveolar crest height loss independently of mandibular bone mass and bone density

AIM

To investigate the relationship of tobacco consumption with alveolar crest height (ACH) loss and mandibular bone mass estimated by digital panoramic radiography and cone-beam computed tomography (CBCT).

MATERIAL AND METHODS

We studied 315 patients (43.2% [n = 136] men and 56.8% [n = 179] women) with mean age of 36.6 ± 5.3 (range 21-30 years (16.2%), range 31-46 years (83.8%); 9% (n = 71) were smokers (>10 cig./day). A mean of 13.0 ± 2.0 mandibular teeth were present: 37.5% of patients had 6-12 teeth and 62.5% 13-16 teeth. We analyzed 315 digital panoramic radiographs (2D) and calculated the ACH, mandibular cortical width, and basal and alveolar bone gray level values. ACH and bone density were also measured on CBCT (3D) in the 110 patients scheduled for implantation.

RESULTS

In the univariate analysis, ACH loss was greater in older patients (P = 0.012) and in those with fewer mandibular teeth (P < 0.001) and showed a relationship with tobacco consumption that was close to significant (P = 0.079). In the multivariate analysis, the number of mandibular teeth (P < 0.001) and tobacco consumption (P = 0.048) were significantly associated with ACH. Alveolar and basal bone densities were associated, respectively, with number of mandibular teeth (P = 0.012) and cortical width (P = 0.030).

CONCLUSION

In a Caucasian population aged 21-46 years, tobacco consumption was significantly associated with ACH loss. However, ACH loss showed no significant relationship with mandibular bone mass estimated either as mandibular cortical width index or bone density on digital panoramic radiographs or as bone density on CBCT. ACH loss was a local event independent of mandibular bone mass status.

Is there a role for the use of volumetric cone beam computed tomography in periodontics?

Volumetric computed cone beam tomography offers a number of significant advantages over conventional intraoral and extraoral panoramic radiography, as well as computed tomography. To date, periodontal diagnosis has relied heavily on the assessment of both intraoral radiographs and extraoral panoramic radiographs. With emerging technology in radiology there has been considerable interest in the role that volumetric cone beam computed tomography might play in periodontal diagnostics. This narrative reviews the current evidence and considers whether there is a role for volumetric cone beam computed tomography in periodontics.

Are panoramic radiographs reliable to diagnose mild alveolar bone resorption?

It is extremely important to assess variations between the most used radiographs in dental practice, since minimum distortion on obtained images may change diagnosis, treatment plan, and prognosis for the patient. For this, the distance between the enamel-cementum junction and the alveolar bone crest was measured on conventional and digitized periapical, bitewing, and panoramic radiographs and compared among them. From a total of 1484 records, 39 sets of radiographs that fulfilled the inclusion criteria of the study sample were selected. The measurements were grouped according to the intensity of bone loss. Statistically significant difference was found in the averages of the measurements assessed in radiographs with absence of bone loss between conventional panoramic and periapical radiographs, between digitized panoramic and periapical radiographs and between digitized bitewing and panoramic radiographs. By analyzing the results of this work and considering the research protocol used, one can conclude that small losses in height of alveolar bone crest observed in panoramic radiographs should be cautiously evaluated, as they may be overestimated.

Lipid peroxidation levels, total oxidant status and superoxide dismutase in serum, saliva and gingival crevicular fluid in chronic periodontitis patients before and after periodontal therapy

BACKGROUND

Recent data have demonstrated increased lipid peroxidation (LPO) levels and oxidative stress in periodontitis. Malondialdehyde (MDA) and superoxide dismutase (SOD) are both increased during oxidative stress. Furthermore, this study examined SOD concentration, total oxidative status (TOS) and MDA levels in periodontal patients and investigated the longitudinal effect of periodontal therapy on the index levels of chronic periodontitis (CP) patients.

METHODS

Serum, saliva and gingival crevicular fluid (GCF) samples were obtained from 48 CP patients and 35 healthy control subjects prior to, as well as after 16 weeks following non-surgical post-periodontal therapy. MDA, TOS and SOD and clinical parameters were determined pre- and post-therapy.

RESULTS

The levels of TOS and SOD values were significantly higher in the CP group than in the control group (p < 0.05), but only MDA in GCF. Post-periodontal therapy, serum, saliva and GCF TOS and SOD levels significantly decreased compared to basal levels (p < 0.05), but only MDA in GCF.

CONCLUSIONS

LPO was higher in the periodontal region, with TOS and SOD increasing both locally and peripherally. Non-surgical therapy can restore and control the subject antioxidant capacity by locally and systemically modifying the levels of MDA, TOS and SOD.

Ex vivo radiographic tooth length measurements with the reference sphere method (RSM)

A reference-based radiographic "reference sphere method" (RSM) for accurate length measurements in (dental) projection radiographs for the assessment of tooth length in dry human mandible sections is evaluated. RSM determines the depth coordinates of reference spheres placed in the object plane from the elliptical distortion of their shadows. Two segments (one canine and one molar) of dry human mandibles were exposed 95 times at different angulations (0-40°) on a dental charge-coupled device receptor. Three steel spheres (diameters d (1) = 2.00 mm, d (2) = 3.00 mm) were attached roughly coplanar with the tooth's main axis. Radiographs were assessed once by visual inspection plus manual landmark identification with a mouse-driven cursor. The results were compared to the true tooth length assessed after extraction and to a conventional method (C), i.e., the rule of proportion based on magnification of the sphere shadows. Mean relative length error was 2.28% (d (1)) and 0.46% (d (2)) for RSM and -13.58% (d (1)) and -9.90% (d (2)) for C. For both methods, length errors were significantly (p <  0.0001) correlated with the inclination relative to the receptor. RSM allows for complete a posteriori determination of the imaging geometry under the assumption of a known source-to-receptor distance. One specific application is foreshortening correction of objects coplanar with the reference spheres. Remaining errors are mainly due to incorrect landmark definition. In our setup, these were exaggerated by the visual/manual image-evaluation process. Automated image analysis has been shown for similar tasks to minimize these errors considerably.