Assessment of periodontal bone level revisited: a controlled study on the diagnostic accuracy of clinical evaluation methods and intra-oral radiography

Accuracy of Intra-Oral Radiography and Cone Beam Computed Tomography in the Diagnosis of Buccal Bone Loss

BACKGROUND

The use of cone beam computed tomography (CBCT) in dentistry started in the maxillofacial field, where it was used for complex and comprehensive treatment planning. Due to the use of reduced radiation dose compared to a computed tomography (CT) scan, CBCT has become a frequently used diagnostic tool in dental practice. However, published data on the accuracy of CBCT in the diagnosis of buccal bone level is lacking. The aim of this study was to compare the accuracy of intra-oral radiography (IOR) and CBCT in the diagnosis of the extent of buccal bone loss.

METHODS

A dry skull was used to create a buccal bone defect at the most coronal level of a first premolar; the defect was enlarged apically in steps of 1 mm. After each step, IOR and CBCT were taken. Based on the CBCT data, two observers jointly selected three axial slices at different levels of the buccal bone, as well as one transverse slice. Six dentists participated in the radiographic observations. First, all observers received the 10 intra-oral radiographs, and each observer was asked to rank the intra-oral radiographs on the extent of the buccal bone defect. Afterwards, the procedure was repeated with the CBCT scans based on a combination of axial and transverse information. For the second part of the study, each observer was asked to evaluate the axial and transverse CBCT slices on the presence or absence of a buccal bone defect.

RESULTS

The percentage of buccal bone defect progression rankings that were within 1 of the true rank was 32% for IOR and 42% for CBCT. On average, kappa values increased by 0.384 for CBCT compared to intra-oral radiography. The overall sensitivity and specificity of CBCT in the diagnosis of the presence or absence of a buccal bone defect was 0.89 and 0.85, respectively. The average area under the curve (AUC) of the receiver operating curve (ROC) was 0.892 for all observers.

CONCLUSION

When CBCT images are available for justified indications, other than bone level assessment, such 3D images are more accurate and thus preferred to 2D images to assess periodontal buccal bone. For other clinical applications, intra-oral radiography remains the standard method for radiographic evaluation.

Periodontal disease as a primary cause of surgical site infection in fractures of the mandible: is smoking a confounding variable?

Fractures of the mandible are common in contemporary oral and maxillofacial practice. Wound infection is the most common complication after open reduction and internal fixation, and the management of these is complex and costly in terms of morbidity to the patient, and in fiscal terms. Whilst numerous epidemiological studies implicate smoking, alcohol, drug use, and adverse behaviour, as well as fracture complexity and diabetes, as important risk factors, the role of periodontal disease is only occasionally mentioned and not formally investigated. The aim of this study therefore was to assess the presence of periodontal disease and its severity according to the 2018 EFP/AAP periodontitis case classification in patients with fractured mandibles who presented to a single level 1 trauma centre, and to look for a possible association with surgical site infection. A total of 305 patients were assessed retrospectively following open reduction and internal fixation via transoral incisions with load-sharing osteosynthesis. The postoperative infection rate was 22.95%. Multivariate and multiple logistic regression revealed that there was a strong association between periodontal staging and postoperative surgical site infection. Crucially, the study predicts that patients with severe periodontal disease (periodontal stage III and IV) are over seven times more likely to develop a wound infection than disease-negative individuals. This has implications for risk adjustment, prognostication, treatment planning, and postoperative care. Surprisingly in this study, cigarette smoking, an established risk factor in the pathogenesis of periodontal disease, did not achieve statistical significance, potentially conflicting with the established literature.

Estimation of Alveolar Bone Loss in Periodontitis Using Machine Learning

Aim

The objective of this research was to perform a pilot study to develop an automatic analysis of periapical radiographs from patients with and without periodontitis for the percentage alveolar bone loss (ABL) on the approximal surfaces of teeth using a supervised machine learning model, that is, convolutional neural networks (CNN).

Material and methods

A total of 1546 approximal sites from 54 participants on mandibular periapical radiographs were manually annotated (MA) for a training set (n = 1308 sites), a validation set (n = 98 sites), and a test set (n = 140 sites). The training and validation sets were used for the development of a CNN algorithm. The algorithm recognised the cemento-enamel junction, the most apical extent of the alveolar crest, the apex, and the surrounding alveolar bone.

Results

For the total of 140 images in the test set, the CNN scored a mean of 23.1 ± 11.8 %ABL, whilst the corresponding value for MA was 27.8 ± 13.8 %ABL. The intraclass correlation (ICC) was 0.601 (P < .001), indicating moderate reliability. Further subanalyses for various tooth types and various bone loss patterns showed that ICCs remained significant, although the algorithm performed with excellent reliability for %ABL on nonmolar teeth (incisors, canines, premolars; ICC = 0.763).

Conclusions

A CNN trained algorithm on radiographic images showed a diagnostic performance with moderate to good reliability to detect and quantify %ABL in periapical radiographs.

Observation on the Effect of Bone Grafting Alone and Guided Tissue Regeneration Combined with Bone Grafting to Repair Periodontal Intraosseous Defects

Objective

To investigate the curative effect of guided tissue regeneration (GTR) combined with bone grafting and improve the aesthetic appearance of patients' gingiva.

Methods

A total of 86 patients with periodontal intraosseous defects were selected from February 2019 to February 2021. All the patients were divided into a control group and an observation group according to the random number table, with 43 patients in each group. Bone grafting was performed in the control group, while GTR was additionally used in the observation group on the basis of the control group. The surgical data and follow-up data were collected and organized. The alveolar bone mineral density, the change in the height of the bone defect, plaque index (PLI), sulcus hemorrhage index (SBI), PD, gingival recession (GR), clinical attachment loss (CAL), and other relevant data of the two groups in 6 months before and after surgery were compared. Six months after surgery, the cosmetic morphology of the patient's gums in the soft tissues around her teeth was evaluated.

Results

Six months after surgery, the alveolar bone density of patients in two groups increased compared with that before surgery, and the height of the bone defect decreased compared with that before surgery. The alveolar bone density of the observation group was higher than that of the control group, and the height of the bone defect was lower than that of the control group (P < 0.05). Six months after surgery, the PLI, SBI, PD, and CAL of patients in both groups were lower than those before surgery, while the GR was higher than that before surgery. PD and CAL values in the observation group were lower than those in the control group, and GR was higher than that in the control group (P < 0.05). Six months after surgery, there was no significant difference in PLI and SBI scores between the two groups (P < 0.05). Six months after surgery, the gingival cosmetic scores of the two groups of patients were higher than those before surgery. The observation group was higher than the control group (P < 0.05).

Conclusion

GTR combined with bone grafting has a good effect in the repair of periodontal intraosseous defects and can effectively promote the reconstruction and recovery of periodontal intraosseous defects in patients. At the same time, it can significantly improve the aesthetic appearance of patients' gums, with good clinical application value.

Ultrasonography for noninvasive and real-time evaluation of peri-implant soft and hard tissue: a case series

BACKGROUND

The diagnosis of soft and hard tissue at dental implants will be challenging in the future, as high prevalence of mucositis and peri-implantitis were described in the population. Ultrasonography is a promising non-invasive, inexpensive, painless, and radiation-free method for imaging hard and soft tissue at implants, especially an ultrasound device with a 25-MHz probe demonstrating a high correlation between ultrasound, clinical, and radiological measurements.

CASE PRESENTATION

The following case series demonstrates the use of ultrasonography with high spatial resolution probe in patients with dental implants affected by soft tissue recession and/or crestal bone loss.

CONCLUSION

These ultrasound images can provide valuable additional information for the assessment of peri-implant soft and hard tissue.

Effects of Impacted Lower Third Molar Extraction on Periodontal Tissue of the Adjacent Second Molar

The extraction of impacted lower third molars (ILTM) is one of the most common procedures in oral-maxillofacial surgery. Being adjacent to lower second molars, most impacted lower third molars often lead to distal periodontal defects of adjacent second molars. Several symptoms may occur after extraction, such as periodontal pocket formation, loss of attachment, alveolar bone loss and even looseness of second molar resulting in extraction. The distal periodontal defects of second molars are affected by many factors, including periodontal conditions, age, impacted type of third molars, and intraoperative operations. At present, several studies have suggested that dentists can reduce the risk of periodontal defects of the second molar after ILTM extraction through preoperative evaluation, reasonable selection of flap design, extraction instruments and suture type, and necessary postoperative interventions. This review summarizes the research progress on the influence factors, interventions methods and some limitations of distal periodontal defects of adjacent second molar after extraction of impacted mandibular third molars, with the aim of opening up future directions for studying effects of ILTM extraction on periodontal tissue of the adjacent second molar.

A controlled study on the diagnostic accuracy of panoramic and peri-apical radiography for detecting furcation involvement

BACKGROUND

The aims of this study were (1) to determine the accuracy, sensitivity, and specificity of panoramic and peri-apical radiographs in diagnosing furcation involvement, as well as (2) to evaluate the possible impact of clinical experience on these diagnostic parameters.

METHODS

An existing radiographic dataset of periodontitis patients requiring implant surgery was retrospectively examined for furcation involvement. Criteria for inclusion were the presence of a CBCT, panoramic and peri-apical radiograph of the site of interest within a one-year time frame. All furcation sites were classified using the CBCT, which was considered as the gold standard, according to Hamp's index (1975). Ten experienced examiners and 10 trainees were asked to assess furcation involvement for the same defects using only the corresponding panoramic and peri-apical radiographs. Absolute agreement, Cohen's weighted kappa, sensitivity, specificity and ROC-curves were analyzed.

RESULTS

The study sample included 60 furcation sites in 29 multi-rooted teeth from 17 patients. On average, 20/60 furcations were correctly classified according to the panoramic radiographs, corresponding to a weighted kappa score of 0.209, indicating slight agreement. Similarly, an average of 19/60 furcations were correctly classified according to the peri-apical radiographs, corresponding to a weighted kappa score of 0.211, also indicating slight agreement. No significant difference between panoramic and peri-apical radiography was found (P = 0.903). When recategorizing FI Grades into 'no to limited FI' (FI Grade 0 and I) and 'advanced FI' (FI Grade II and III), the panoramic and peri-apical radiography showed low sensitivity (0.558 and 0.441, respectively), yet high specificity (0.791 and 0.790, respectively) for identifying advanced FI. The ROC-curves for the panoramic and peri-apical radiographs were 0.79 and 0.69 respectively. No significant difference was found between experienced periodontists and trainees (P = 0.257 versus P = 0.880).

CONCLUSION

Panoramic and peri-apical radiography are relevant tools in the diagnosis of FI and provide high specificity. Ideally, they are best used in combination with furcation probing, which shows high sensitivity. Furthermore, clinical experience does not seem to improve the accuracy of a radiological diagnosis of furcation sites.

TRIAL REGISTRATION

Patient radiographic datasets were retrospectively analyzed.

Digital three-dimensional visualization of intrabony periodontal defects for regenerative surgical treatment planning

Background

In the regenerative treatment of intrabony periodontal defects, surgical strategies are primarily determined by defect morphologies. In certain cases, however, direct clinical measurements and intraoral radiographs do not provide sufficient information on defect morphologies. Therefore, the application of cone-beam computed tomography (CBCT) has been proposed in specific cases. 3D virtual models reconstructed with automatic thresholding algorithms have already been used for diagnostic purposes. The aim of this study was to utilize 3D virtual models, generated with a semi-automatic segmentation method, for the treatment planning of minimally invasive periodontal surgeries and to evaluate the accuracy of the virtual models, by comparing digital measurements to direct intrasurgical measurements.

Methods

Four patients with a total of six intrabony periodontal defects were enrolled in the present study. Two months following initial periodontal treatment, a CBCT scan was taken. The novel semi-automatic segmentation method was performed in an open-source medical image processing software (3D Slicer) to acquire virtual 3D models of alveolar and dental structures. Intrasurgical and digital measurements were taken, and results were compared to validate the accuracy of the digital models. Defect characteristics were determined prior to surgery with conventional diagnostic methods and 3D virtual models. Diagnostic assessments were compared to the actual defect morphology during surgery.

Results

Differences between intrasurgical and digital measurements in depth and width of intrabony components of periodontal defects averaged 0.31 ± 0.21 mm and 0.41 ± 0.44 mm, respectively. In five out of six cases, defect characteristics could not be assessed precisely with direct clinical measurements and intraoral radiographs. 3D models generated with the presented semi-automatic segmentation method depicted the defect characteristics correctly in all six cases.

Conclusion

It can be concluded that 3D virtual models acquired with the described semi-automatic segmentation method provide accurate information on intrabony periodontal defect morphologies, thus influencing the treatment strategy. Within the limitations of this study, models were found to be accurate; however, further investigation with a standardized validation process on a large number of participants has to be conducted.

Risk of incident cardiovascular disease in people with periodontal disease: A systematic review and meta-analysis

OBJECTIVES

Cardiovascular disease (CVD) is a major cause of mortality; periodontal disease (PD) affects up to 50% of the world's population. Observational evidence has demonstrated association between CVD and PD. Absent from the literature is a systematic review and meta-analysis of longitudinal cohort studies quantifying CVD risk in PD populations compared to non-PD populations. To examine the risk of incident CVD in people with PD in randomised controlled trials and longitudinal cohort studies.

MATERIAL AND METHODS

We searched Medline, EMBASE and Cochrane databases up to 9th Oct 2019 using keywords and MeSH headings using the following concepts: PD, CVD, longitudinal and RCT study design. CVD outcomes included but were not restricted to any CVD, myocardial infarction, coronary heart disease (CHD) and stroke. Diagnosis method and severity of PD were measured either clinically or by self-report. Studies comparing incident CVD in PD and non-PD populations were included. Meta-analysis and meta-regression was performed to determine risk of CVD in PD populations and examine the effects of PD diagnosis method, PD severity, gender and study region.

RESULTS

Thirty-two longitudinal cohort studies were included after full text screening; 30 were eligible for meta-analysis. The risk of CVD was significantly higher in PD compared to non-PD (relative risk [RR]: 1.20, 95% CI: 1.14-1.26). CVD risk did not differ between clinical or self-reported PD diagnosis (RR = 0.97, 95% CI: 0.87-1.07,). CVD risk was higher in men (RR: 1.16, 95% CI: 1.08-1.25) and severe PD (RR: 1.25, 95% CI: 1.15-1.35). Among all types of CVD, the risk of stroke was highest (RR = 1.24; 95% CI:1.12-1.38), the risk of CHD was also increased (RR = 1.14; 95% CI:1.08-1.21).

CONCLUSION

This study demonstrated modest but consistently increased risk of CVD in PD populations. Higher CVD risk in men and people with severe PD suggests population-targeted interventions could be beneficial.

One- versus two-stage crown lengthening surgical procedure for aesthetic restorative purposes: A randomized controlled trial

AIM

This randomized controlled trial aimed to assess the efficacy of a two-stage crown lengthening intervention (SCL) in the aesthetic zone compared with a one-stage crown lengthening procedure (CCL).

MATERIALS AND METHODS

Thirty subjects were randomly assigned to either SCL (n = 15) or CCL (n = 15) groups. SCL consisted of full-thickness flaps followed by bone recontouring and gingivectomy 4 months postoperatively, if required. In CCL, osseous recontouring after submarginal incisions was performed, followed by flap repositioning. Records were obtained at baseline, 4 months (only in SCL), 6 months and 12 months. Primary outcome was the precision in achieving a pre-determined gingival margin position. Other outcomes considered were changes in the gingival margin position and keratinized tissue width (KTW) at 12 months, and patient-reported outcomes (PROMs).

RESULTS

Surgical precision was comparable between groups (0.2 ± 0.4 mm in the CCL group and -0.2 ± 0.5 mm in the SCL group). Four patients in the SCL group (27.7%) did not require a second-stage surgery. KTW was significantly higher in the SCL group (6.3 ± 1.4 mm versus 5.0 ± 1.4 mm, p = 0.017). SCL resulted in a lower impact on quality of life when compared to the CCL group.

CONCLUSIONS

Both approaches were highly accurate obtaining the desired crown length. SCL was associated with a lower reduction in KTW and more favourable oral health-related quality of life (OHIP-14).

Reliability assessment between clinical attachment loss and alveolar bone level in dental radiographs

Background

The clinical attachment level (CAL) and radiographically assessed bone levels are used to assess the loss of periodontal tissue support in periodontitis, a chronic, multifactorial inflammatory disease of the periodontium. However, few studies have been done to study the relationship between these two parameters. According to our knowledge, this is the first study investigating the relationship between the two measurements using intraclass correlation analysis.

Aim

The aim of the study is to investigate the relationship between CAL and radiographically assessed bone level in teeth affected with periodontitis.

Methods

A retrospective cross‐sectional study was conducted by selecting a sample of 880 periodontal sites in 104 periodontitis patients, aged 25–60 years. CAL and peri‐apical radiographs of the selected sites were obtained from the computerized patient records. The distance from the cemento‐enamel junction (CEJ) to the base of the alveolar bone level (ABL) was measured. The data was analyzed using SPSS.

Results

Intraclass correlation analysis (ICC) revealed a moderate degree of reliability between CAL and CEJ to ABL measurements. The average ICC was 0.68 with a 95% confidence interval of 0.53–0.77 (p < .001) indicating moderate to good reliability. Comparing the types of teeth, the central incisors, particularly the lower central incisors showed the highest ICC values (ICC: 0.822, CI: 0.77–0.86) indicating good reliability while the premolar and molars showed poor to moderate agreement (Maxillary premolars ICC: 0.464, CI: −0.18–0.74; maxillary first molar ICC: 0.516, CI: −0.154–0.772; mandibular first premolar ICC: 0.662, CI: 0.269–0.782; mandibular first molar ICC: 0.625, CI: 0.31–0.82). A moderate correlation existed between the radiographic and the clinical assessments (r = 0.5, p < .001).

Conclusion

Despite the fact that significant varying levels of reliability has been found between CAL and radiographic bone level, both the clinical and radiographic examinations should be performed for the accuracy of diagnosis.

Ultrasonography for noninvasive and real-time evaluation of peri-implant tissue dimensions

AIM

Existing methods for evaluating marginal bone loss and tissue biotype around dental implants present with many limitations. The aim of this study was to examine the accuracy of high-resolution, 3-dimensional ultrasound to measure peri-implant tissue dimensions.

MATERIAL AND METHODS

A 25-MHz ultrasound probe prototype was used to scan peri-implant tissues of 17 implants from seven fresh human cadavers. Four ultrasonic measurements were made as follows: the marginal bone level/thickness, and mucosal level/thickness. The readings were statistically compared to cone beam computed tomography (CBCT) and/or open bone measurements.

RESULTS

The correlations (r) between the ultrasound and direct/CBCT readings of the four parameters ranged from 0.85 to 0.98 (p < 0.0001). The mean absolute difference in the four parameters between ultrasound-direct and ultrasound-CBCT ranged from 0.033 to 0.24 mm.

CONCLUSION

Encouraging evidence is shown that ultrasound can accurately measure peri-implant tissue dimensions. Following clinical trial validations, ultrasound offers potential as a valuable tool to evaluate long-term peri-implant tissue stability without concerns of ionizing radiation and image artefacts around implants.

Quantitative measurement of peri-implant bone defects using optical coherence tomography

Purpose

The purpose of this study was to visualize and identify peri-implant bone defects in optical coherence tomography (OCT) images and to obtain quantitative measurements of the defect depth.

Methods

Dehiscence defects were intentionally formed in porcine mandibles and implants were simultaneously placed without flap elevation. Only the threads of the fixture could be seen at the bone defect site in the OCT images, so the depth of the peri-implant bone defect could be measured through the length of the visible threads. To analyze the reliability of the OCT measurements, the flaps were elevated and the depth of the dehiscence defects was measured with a digital caliper.

Results

The average defect depth measured by a digital caliper was 4.88±1.28 mm, and the corresponding OCT measurement was 5.11±1.33 mm. Very thin bone areas that were sufficiently transparent in the coronal portion were penetrated by the optical beam in OCT imaging and regarded as bone loss. The intraclass correlation coefficient between the 2 methods was high, with a 95% confidence interval (CI) close to 1. In the Bland-Altman analysis, most measured values were within the threshold of the 95% CI, suggesting close agreement of the OCT measurements with the caliper measurements.

Conclusions

OCT images can be used to visualize the peri-implant bone level and to identify bone defects. The potential of quantitative non-invasive measurements of the amount of bone loss was also confirmed.