Three-dimensional measurement of periodontal surface area for quantifying inflammatory burden

Evaluating Factors Influencing Periodontal Bone Loss Using Cone Beam Computed Tomography: A Retrospective Study

BACKGROUND The assessment of alveolar bone loss and determining patterns of disease progression with respect to different etiologic or contributing factors plays a vital role in the diagnosis of periodontitis, prognosis of the disease, and better treatment planning. This study aimed to determine periodontal bone loss using cone beam computed tomography images obtained from various age groups and evaluate the effects of age, sex, jaw type, tooth type, and tooth surface width on periodontal destruction. MATERIAL AND METHODS In total, 200 cone beam computed tomography images obtained for any indication were randomly selected and analyzed. The distance between the alveolar crest and cemento-enamel junction was measured, and values exceeding 2 mm were considered as bone loss. Furthermore, the buccolingual and mesiodistal widths of all teeth at the cemento-enamel junction were measured to determine tooth surface width. RESULTS Among the patients included in the study, bone loss increased with age. The highest bone loss was observed in the maxillary molars, followed by the mandibular incisors. Although there was no significant difference in mean bone loss values between the jaws, distal surfaces in the maxilla showed greater bone loss than that in the mandible. Furthermore, the relationship between tooth surface width at the cemento-enamel junction and bone loss varied by tooth type. In mandibular incisors and premolars, bone loss increased as the buccolingual and mesiodistal widths decreased. CONCLUSIONS These findings indicate that periodontal bone loss is influenced by age, sex, tooth type, and tooth surface width.

Automatic tooth periodontal ligament segmentation of cone beam computed tomography based on instance segmentation network

Objective

The three-dimensional morphological structures of periodontal ligaments (PDLs) are important data for periodontal, orthodontic, prosthodontic, and implant interventions. This study aimed to employ a deep learning (DL) algorithm to segment the PDL automatically in cone-beam computed tomography (CBCT).

Method

This was a retrospective study. We randomly selected 389 patients and 1734 axial CBCT images from the CBCT database, and designed a fully automatic PDL segmentation computer-aided model based on instance segmentation Mask R-CNN network. The labels of the model training were 'teeth' and 'alveolar bone', and the 'PDL' is defined as the region where the 'teeth' and 'alveolar bone' overlap. The model's segmentation performance was evaluated using CBCT data from eight patients outside the database.

Results

Qualitative evaluation indicates that the PDL segmentation accuracy of incisors, canines, premolars, wisdom teeth, and implants reached 100%. The segmentation accuracy of molars was 96.4%. Quantitative evaluation indicates that the mIoU and mDSC of PDL segmentation were 0.667 ± 0.015 (>0.6) and 0.799 ± 0.015 (>0.7) respectively.

Conclusion

This study analysed a unique approach to AI-driven automatic segmentation of PDLs on CBCT imaging, possibly enabling chair-side measurements of PDLs to facilitate periodontists, orthodontists, prosthodontists, and implantologists in more efficient and accurate diagnosis and treatment planning.

Effects of the cone-beam computed tomography protocol on the accuracy and image quality of root surface area measurements: An in vitro study

Purpose

The objective of this study was to evaluate and compare the accuracy and image quality of root surface area (RSA) measurements obtained with various cone-beam computed tomography (CBCT) protocols, relative to the gold standard of micro-computed tomography (CT), in an in vitro setting.

Materials and Methods

Four dry human skulls were scanned using 8 different protocols, with voxel sizes of 0.15 mm, 0.3 mm, and 0.4 mm. Three-dimensional models of the selected teeth were constructed using CBCT and micro-CT protocols, and the RSA was automatically measured by the image-processing software. The absolute difference in the percentage of the RSA (%ΔRSA) was calculated and compared across the 8 CBCT protocols using repeated-measures analysis of variance. Finally, image quality scores of the RSA measurements were computed and reported in terms of percent distribution.

Results

No significant differences were observed in the %ΔRSA across the 8 protocols (P>0.05). The deviation in %ΔRSA ranged from 1.51% to 4.30%, with an increase corresponding to voxel size. As the voxel size increased, the image quality deteriorated. This decline in quality was particularly noticeable at the apical level of the root, where the distribution of poorer scores was most concentrated.

Conclusion

Relative to CBCT protocols with voxel sizes of 0.15 mm and 0.3 mm, the protocols with a voxel size of 0.4 mm demonstrated inferior image quality at the apical levels. In spite of this, no significant discrepancies were observed in RSA measurements across the different CBCT protocols.

Association between periodontal inflamed surface area and systemic inflammatory biomarkers among pre-dialysis chronic kidney disease patients

Background

Several studies have shown an association between chronic kidney disease (CKD) and periodontitis. However, only few studies have quantified the burden of periodontal inflammation in pre-dialysis CKD patients. The aim of this study was to determine the association between periodontal inflamed surface area (PISA) and systemic inflammatory biomarkers among pre-dialysis CKD patients.

Materials and Methods

120 pre-dialysis CKD participants were recruited into this study. 60 participants constituted Group A (those with periodontitis) while 60 participants constituted Group B (those without periodontitis). Full periodontal examination was carried out in the participants for the estimation of PISA. Blood samples also collected to determine levels of high sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) in all participants. Independent t-test was used to compare means of PISA, hsCRP and IL-6 levels in the two groups. Pearson correlation analysis was used to determine association between PISA and (hsCRP and IL-6).

Results

The mean value of hsCRP was significantly higher in Group A compared to Group B (3.41 mg/L vs. 2.18 mg/L). PISA moderately correlated with hsCRP (r = 0.4, P < 0.01) in both groups. hsCRP also moderately correlated with IL-6 (r = 0.6, P < 0.001) in both groups.

Conclusion

This study demonstrates that there was an association between PISA and hsCRP. Increased hsCRP level in Group A revealed the inflammatory burden imposed by periodontitis.

Three-dimensional measurement of periodontal support during surgical orthodontic treatment of high-angle skeletal Class III malocclusion: A retrospective study

INTRODUCTION

This study aimed to quantify the periodontal health of incisors during surgical orthodontic treatment in patients with high-angle Class III malocclusion using a cone-beam computed tomography (CBCT) 3-dimensional (3D) reconstruction technique.

METHODS

The sample consisted of 30 patients with high-angle Class III malocclusion (mean age, 20.53 ± 2.86 years). CBCT images were taken before treatment (T0), after presurgical orthodontic treatment, and after treatment (T2). In addition, 3D tooth and alveolar bone models were generated. The root surface area, periodontal ligament (PDL)_Area, and vertical bone level (VBL) around the maxillary and mandibular central incisors were measured.

RESULTS

The root surface area and PDL_Area of maxillary and mandibular central incisors decreased continuously between T0 and T2 (P <0.01). At T2, mandibular central incisors showed 38.64 ± 13.39% PDL_Area loss, and maxillary central incisors exhibited 21.13 ± 16.48% PDL_Area loss. For mandibular central incisors, the PDL_Area loss caused by VBL loss was significantly greater than that for maxillary central incisors (P <0.01) and significantly greater than the PDL_Area loss caused by root resorption (P <0.01). From T0 to T2, the lingual surface of maxillary central incisors exhibited greater VBL loss than the other 3 surfaces (P <0.01), and the labial and lingual surfaces of mandibular central incisors demonstrated greater VBL loss than proximal surfaces (P <0.01).

CONCLUSIONS

The 3D CBCT reconstruction method provides useful information regarding the periodontal defects of incisors in patients with high-angle skeletal Class III malocclusion. The PDL_Area of maxillary and mandibular central incisors decreased continuously during the treatment. Vertical alveolar bone levels at proximal surfaces appeared to be relatively stable.

The Effect of Diabetes Mellitus on IGF Axis and Stem Cell Mediated Regeneration of the Periodontium

Periodontitis and diabetes mellitus (DM) are two of the most common and challenging health problems worldwide and they affect each other mutually and adversely. Current periodontal therapies have unpredictable outcome in diabetic patients. Periodontal tissue engineering is a challenging but promising approach that aims at restoring periodontal tissues using one or all of the following: stem cells, signalling molecules and scaffolds. Mesenchymal stem cells (MSCs) and insulin-like growth factor (IGF) represent ideal examples of stem cells and signalling molecules. This review outlines the most recent updates in characterizing MSCs isolated from diabetics to fully understand why diabetics are more prone to periodontitis that theoretically reflect the impaired regenerative capabilities of their native stem cells. This characterisation is of utmost importance to enhance autologous stem cells based tissue regeneration in diabetic patients using both MSCs and members of IGF axis.

Relationships between jaw deformity and the occlusal plane in cone beam computed tomography scans

STATEMENT OF PROBLEM

Consistent findings about the relationships between jaw deformity and the occlusal plane are lacking.

PURPOSE

The purpose of this clinical study was to explore the relationships between the occlusal plane and jaw deformity by measuring data obtained from cone beam computed tomography (CBCT) scans.

MATERIAL AND METHODS

Reconstructed images simulated by using the Materialise Interactive Medical Image Control System (Mimics) software program of CBCT data of 80 participants with facial asymmetry and 42 participants from the normal control group were measured with a new 3-dimensional geometric morphologic measurement system. Fifteen craniofacial surfaces were marked at a point, line, or plane, measuring correlation distances and angles to analyze the relationship between jaw deformity and the inclination of the occlusal plane and other relevant facial features. The Student t test was used to analyze whether the difference in the occlusal plane between the jaw deformity group and the normal group was statistically significant (α=.05). The Pearson correlation was used to analyze the correlation among the jaw deformity, the occlusal plane, and other landmarks, and linear regression was used to analyze the relationships among them.

RESULTS

A significant difference was found between the occlusal plane of the jaw deformity and that of the normal group (P<.001) and a significant positive correlation between the degree of mandibular deformity and the inclination of occlusal plane (P<.001). A linear relationship was found between the linear regression equation of the angle of the left occlusal plane and the midsagittal sagittal plane Y and the distance between the mental apex of chin and the midsagittal plane X (the mandibular deflection to the right was defined as positive) as Y=90.646+0.388X. Statistically significant differences were found in the deviation of the chin vertex from the midsagittal plane and the distance between the midlines of the maxillary and mandibular central incisors by more than 2 mm (P<.001).

CONCLUSIONS

A positive correlation was found between the inclination of the occlusal plane and the degree of jaw deformity, with a linear relationship between them. These findings provide a theoretical basis for the clinical reconstruction of occlusal relationships with jaw deformity.

Morphology of the patellar tendon and its insertion sites using three-dimensional computed tomography: A cadaveric study

BACKGROUND

To clarify, with three-dimensional (3D) images, the morphological properties of the patellar tendon and both of its insertion sites.

METHODS

Thirty-two human cadaveric left knees were evaluated, and 3D computed tomography images were created. These images were used to analyse the morphology of both insertion sites of the patellar tendon, and the width, length and thickness of each region of the patellar tendon.

RESULTS

The insertion sites of the patellar tendon on the patellar and tibial sides were V-shaped and crescent-shaped, respectively, with the respective bony apexes located at 44.5 ± 2.2% (standard deviation) and 35.5 ± 2.8% of the tendon width from its medial edge. The proximal, central and distal widths of the patellar tendon were 29.9 ± 2.7 mm, 27.3 ± 2.5 mm and 25.0 ± 2.4 mm, respectively. The length of the patellar tendon was shortest at 40.6% ± 6.7% of the central width and gradually became longer toward both edges. The patellar tendon was thickest in the central portion of 40-75% and gradually became thinner toward both edges.

CONCLUSIONS

The morphological properties of the patellar tendon and its insertion sites on both the patellar and tibial sides were consistent. These findings indicate that the characteristics of the bone-patellar tendon-bone graft markedly depend on the location from which it is harvested, and that these characteristics contribute to predicting the length, width and shapes of the bone plugs of the graft when performing bone-patellar tendon-bone surgery.