Classification, reproducibility and prevalence of root proximity in periodontal patients

Furcation area and root proximity of molars as a risk indicator of periodontitis: a cone‑beam computed tomography-based study

OBJECTIVES

This study assessed the root proximity in molars and the furcation area (FA) in the first root separation point (RSP) using cone‑beam computed tomography (CBCT) and evaluated the association between the furcation area of molars and periodontal status of the patients.

METHODS

A total of 264 molar teeth in 66 participants were included in the study. The control group consisted of 110 molar teeth of participants, and 154 molar teeth were included in periodontitis group, which consisted of only stage II and III periodontitis patients. FA, RSP, and root proximities were measured in axial slices, and bone resorption rates were measured in sagittal slices.

RESULTS

Both maxillary and mandibular molar groups had significantly less FA in periodontitis group than in controls (p < 0.005), and there were significant relationships between the degree of bone resorption in molars and FA and furcation grades (p < 0.001). According to regression analysis, the risk of periodontitis increased by 1.011 times as total FA decreased (p < 0.001), and periodontitis risk of maxillary molar was 1.693 times higher than mandibular molars but not found to be statistically significant (p = 0.152). When assessing the root proximity between molar teeth, maxillary molars showed significantly higher root proximity in CEJs than mandibular molars in both periodontitis and control groups (p < 0.05).

CONCLUSIONS

The results indicate that the association between FA and the degree of bone resorption and root proximity of maxillary molars might be considered as a risk indicator for bone resorption in molars and might play a role during disease progression.

Three-dimensional evaluation of a virtual setup considering the roots and alveolar bone in molar distalization cases

We aimed to evaluate root parallelism and the dehiscence or fenestrations of virtual teeth setup using roots isolated from cone beam computed tomography (CBCT) images. Sixteen patients undergoing non-extraction orthodontic treatment with molar distalization were selected. Composite teeth were created by merging CBCT-isolated roots with intraoral scan-derived crowns. Three setups were performed sequentially: crown setup considering only the crowns, root setup-1 considering root alignment, and root setup-2 considering the roots and surrounding alveolar bone. We evaluated the parallelism and exposure of the roots and compared the American Board of Orthodontics Objective Grading System (ABO-OGS) scores using three-dimensionally printed models among the setups. The mean angulation differences between adjacent teeth in root setups-1 and -2 were significantly smaller than in the crown setup, except for some posterior teeth (p < 0.05). The amount of root exposure was significantly smaller in root setup-2 compared to crown setup and root setup-1 except when the mean exposure was less than 0.6 mm (p < 0.05). There was no significant difference in ABO-OGS scores among the setups. Thus, virtual setup considering the roots and alveolar bone can improve root parallelism and reduce the risk of root exposure without compromising occlusion quality.

Effects of Low-Level Laser Therapy on Orthodontic Tooth Movement: Evaluation of Bony Changes via 3DCBCT

OBJECTIVE

The prime objective of this research was to study the effect of low-level laser therapy (LLLT) with an evaluation of bony changes via pre- and post-treatment 3DCBCT in orthodontic malocclusion cases treated with fixed orthodontic appliances.

MATERIALS AND METHODS

Subjects who attended the Orthodontic Clinic, were diagnosed with orthodontic malocclusion, treated with fixed orthodontic appliances, and had pre- and post-management CBCT were included in the study. Patients aged 14 to 25 years who met the inclusion criteria were assigned to two groups, group A (LLLT) and group B (non-LLLT). Group A participants were treated with LLLT therapy as per standard protocol after explaining the nature of the treatment. Group B (non-LLLT) participants were not treated with LLLT therapy and therefore served as the control. LLLT was used in the experimental group after placing each archwire. Interradicular bony changes at depth levels of 1 to 4 (2, 5, 8, and 11 mm) using 3DCBCT were measured as outcome parameters.

RESULTS

The information collected was analyzed using SPSS computer software. Mostly insignificant differences were noted among groups for the different parameters (p < 0.05). Student's t-tests and paired t-tests were used to investigate the differences. Experimental Hypothesis: There will be significant differences in the interradicular width (IRW) measurements between the LLLT and non-LLLT groups.

CONCLUSIONS

The hypothesis was rejected. Upon investigation of prospective changes, most of the measured parameters showed insignificant differences.

Accuracy of a Method to Monitor Root Position Using a 3D Digital Crown/Root Model during Orthodontic Treatments

This study aimed to assess the accuracy of a method of predicting post-movement root position during orthodontic treatment using a 3D digital crown/root model (3DCRM) created with pre-movement records of both cone-beam computed tomography (CBCT) and dental arch digital scans. Pre- and post-movement CBCT scans and dental arch digital scans of five patients who had completed orthodontic treatments were used in this study. The 3DCRM was superimposed onto the post-movement scanned dental arch to identify the post-movement root position (test method). Post-movement CBCT (referenced as the current method) served as the control to identify the actual post-movement root position. 3D-coordinate analysis revealed no significant differences between the test and current methods along the X and Y axes. However, the discrepancy on the Z axis (especially in cases of intrusion) was greater than that in all other directions for all three tooth types examined (p < 0.05). A strong positive correlation between the degree of discrepancy and the distance of tooth movement was observed on the Z axis (r = 0.71). The 3DCRM method showed promising potential to accurately predict root position during orthodontic treatments without the need for a second CBCT. However, root resorption, which affected the Z axis prediction, needs to be closely monitored using periapical radiographs to complement this method.

Association between root taper and root proximity of single-rooted teeth with periodontitis: a cone-beam computed tomography based study

This study aimed to determine the association between the root taper and proximity of single-rooted teeth with periodontitis using cone-beam computed tomography (CBCT). CBCT images of 362 single-rooted teeth from 37 patients were evaluated. This case-control study analyzed 17 participants with stage II and III periodontitis, (n = 161 teeth, periodontitis group) and 20 participants with healthy periodontium (n = 201 teeth, control group). Multiplanar reconstructions were used for proximity measurements, and cross-sectional images for calculating the angle of the root tapers. Root proximity, root length, and root taper were measured. Multivariate binary logistic regression analysis was used to determine association with periodontitis. In the periodontitis group, the upper lateral root-taper was 18.33° ± 3.25° and was significantly higher when compared to the control group (p = 0.001). The root taper of the lateral incisor was associated with the diagnosis of periodontitis (p = 0.01) with an odds ratio of 1.541 according to regression analysis. Root length was also identified as a potential protective parameter. The risk of being diagnosed with periodontitis decreases when root length increases by 0.785 times (p = 0.043). Upper canines in the periodontitis group presented shorter root lengths (p = 0.039) and higher root tapers (p = 0.01). Also, mandibular canines were closer form adjacent teeth in the periodontitis group (p = 0.042). This study indicated that short-root and increased root-taper at specific teeth could be considered as risk indicators for periodontitis.

Dental long axes using digital dental models compared to cone-beam computed tomography

OBJECTIVE

Standard methods of evaluating tooth long axes are not comparable (digital dental models [DDMs], panoramic and cephalometric radiographs) or expose patients to more radiation (cone-beam computed tomography [CBCT]). This study aimed to compare angular changes in tooth long axes using DDMs vs using CBCTs.

SETTINGS AND SAMPLE POPULATION

Secondary data analysis of DDMs and CBCTs, taken before and after orthodontic treatment with piezocision of 24 patients.

METHODS

Angular changes in tooth long axes were evaluated using landmarks on first molars (centre of the occlusal surface and centre of the furcation), canines and incisors (cusp tip and centre of the root at the cementoenamel junction). Wilcoxon test, intraclass correlation coefficient (ICC) and Bland-Altman plots were used to test intra- and inter-rater agreement and compare DDM and CBCT measurements.

RESULTS

The mesiodistal angulation and buccolingual inclination DDM measurements were reproducible. Overall mean differences between DDM and CBCT measurements of mesiodistal angulation, 1.9°±1.5°, and buccolingual inclination, 2.2 ± 2.2°, were not significant for all teeth. ICC between DDM and CBCT measurements ranged from good (0.85 molars) to excellent (0.94 canines; 0.96 incisors). The percentages of measurements outside the range of ±5 were 17.4% for molars, 13.8% for canines and 4.5% for incisors.

CONCLUSIONS

DDM assessment of changes in tooth long axes has good reproducibility and yields comparable measurements to those obtained from CBCT within a 5° range. These findings lay the groundwork for machine learning approaches that synthesize crown and root canal information towards planning tooth movement without the need for ionizing radiation scans.

Dental prostheses and tooth-related factors

OBJECTIVES

This narrative review summarizes the current evidence about the role that the fabrication and presence of dental prostheses and tooth-related factors have on the initiation and progression of gingivitis and periodontitis.

FINDINGS

Placement of restoration margins within the junctional epithelium and supracrestal connective tissue attachment can be associated with gingival inflammation and, potentially, recession. The presence of fixed prostheses finish lines within the gingival sulcus or the wearing of partial, removable dental prostheses does not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. However, hypersensitivity reactions to the prosthesis dental material can be present. Procedures adopted for the fabrication of dental restorations and fixed prostheses have the potential to cause traumatic loss of periodontal supporting tissues. Tooth anatomic factors, root abnormalities, and fractures can act as plaque-retentive factors and increase the likelihood of gingivitis and periodontitis.

CONCLUSIONS

Tooth anatomic factors, such as root abnormalities and fractures, and tooth relationships in the dental arch and with the opposing dentition can enhance plaque retention. Restoration margins located within the gingival sulcus do not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. Tooth-supported and/or tooth-retained restorations and their design, fabrication, delivery, and materials have often been associated with plaque retention and loss of attachment. Hypersensitivity reactions can occur to dental materials. Restoration margins placed within the junctional epithelium and supracrestal connective tissue attachment can be associated with inflammation and, potentially, recession. However, the evidence in several of the reviewed areas, especially related to the biologic mechanisms by which these factors affect the periodontium, is not conclusive. This highlights the need for additional well-controlled animal studies to elucidate biologic mechanisms, as well as longitudinal prospective human trials. Adequate periodontal assessment and treatment, appropriate instructions, and motivation in self-performed plaque control and compliance to maintenance protocols appear to be the most important factors to limit or avoid potential negative effects on the periodontium caused by fixed and removable prostheses.

Dental prostheses and tooth-related factors

OBJECTIVES

This narrative review summarizes the current evidence about the role that the fabrication and presence of dental prostheses and tooth-related factors have on the initiation and progression of gingivitis and periodontitis.

FINDINGS

Placement of restoration margins within the junctional epithelium and supracrestal connective tissue attachment can be associated with gingival inflammation and, potentially, recession. The presence of fixed prostheses finish lines within the gingival sulcus or the wearing of partial, removable dental prostheses does not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. However, hypersensitivity reactions to the prosthesis dental material can be present. Procedures adopted for the fabrication of dental restorations and fixed prostheses have the potential to cause traumatic loss of periodontal supporting tissues. Tooth anatomic factors, root abnormalities, and fractures can act as plaque-retentive factors and increase the likelihood of gingivitis and periodontitis.

CONCLUSIONS

Tooth anatomic factors, such as root abnormalities and fractures, and tooth relationships in the dental arch and with the opposing dentition can enhance plaque retention. Restoration margins located within the gingival sulcus do not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. Tooth-supported and/or tooth-retained restorations and their design, fabrication, delivery, and materials have often been associated with plaque retention and loss of attachment. Hypersensitivity reactions can occur to dental materials. Restoration margins placed within the junctional epithelium and supracrestal connective tissue attachment can be associated with inflammation and, potentially, recession. However, the evidence in several of the reviewed areas, especially related to the biologic mechanisms by which these factors affect the periodontium, is not conclusive. This highlights the need for additional well-controlled animal studies to elucidate biologic mechanisms, as well as longitudinal prospective human trials. Adequate periodontal assessment and treatment, appropriate instructions, and motivation in self-performed plaque control and compliance to maintenance protocols appear to be the most important factors to limit or avoid potential negative effects on the periodontium caused by fixed and removable prostheses.

Accuracy and reliability of the expected root position setup on clinical decision making of root position at midtreatment

INTRODUCTION

Accurate root position is imperative for successful orthodontic treatment that is stable and functional. Current methods to monitor root position are either inaccurate or use relatively high levels of radiation. A method to generate an expected root position (ERP) setup has been reported to have the potential to accurately evaluate root position with minimal radiation. The purpose of this study was to determine the accuracy and reliability of the clinical decisions made on root position using the ERP setup.

METHODS

This retrospective study included 10 subjects who had pretreatment and midtreatment cone-beam computed tomography (CBCT) scans and study models. An ERP setup was generated for all patients at midtreatment. Four examiners assessed both the CBCT scan and ERP setup and made clinical decisions regarding the root position with each method. Cohen's kappa was determined to assess intraoperator and intermethod reliability. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated to determine the accuracy of the ERP setup.

RESULTS

The kappa values for intraoperator reliability for both the CBCT scan and ERP setup fell within the 0.61-0.80 range. The kappa values for intermethod reliability between the CBCT scan and ERP setup fell within the 0.61-0.80 range for all tooth groups. The sensitivity of the ERP setup ranged from 0.72 to 0.90, specificity ranged from 0.89 to 0.97, positive predictive value ranged from 0.57 to 0.85, and negative predictive value ranged from 0.93 to 0.99.

CONCLUSIONS

This study demonstrated that the ERP setup, when compared with the gold standard CBCT scan, was accurate and reliable in making clinical decisions regarding root position at midtreatment.

Comparison of Two-Dimensional and Three-Dimensional Radiographs Using Clinically Relevant Parameters

This work compared the assessment of clinically relevant parameters by two-dimensional, that is, full-mouth intraoral radiograph (I-O) and panoramic radiograph (OPT), and three-dimensional, that is, cone beam computed tomography (CBCT), imaging methods. Different radiographic images (CBCT, I-O and OPT) were available for a 53-year-old female patient with dental and periodontal problems. A total of 14 dental and periodontal parameters were assessed by two independent examiners and compared among the three radiographic imaging modalities. For 10 parameters (71%), the CBCT images were superior to both I-O and OPT images. In contrast, CBCT demonstrated an inferior performance compared to I-O and OPT in the assessment of caries and dental restorations. Compared to OPT, I-O provided more clinically relevant findings for 10 out of 14 parameters (71%). Agreement between I-O and OPT was found with respect to dehiscence, fenestration, the number of bone walls and the root canal cross-section. Differences between the radiographic images were more likely to be detected when maxillary teeth rather than mandibular teeth were assessed with regard to furcation involvement, root proximity and root fusion.

Accuracy and reliability of the expected root position setup methodology to evaluate root position during orthodontic treatment

INTRODUCTION

Current methods to evaluate root position either are inaccurate (panoramic radiograph) or expose patients to relatively large amounts of radiation (cone-beam computed tomography [CBCT]). A method to evaluate root position by generating an expected root position (ERP) setup was recently reported but has not been validated. The purpose of this study was to quantitatively assess the accuracy and reliability of the ERP setup with adequate statistical power.

METHODS

This retrospective study included 15 subjects who had completed phase 2 orthodontic treatment. An ERP setup was generated for all patients after treatment. The ERP setup was compared with the posttreatment CBCT scan, which served as the control. The mesiodistal angulation and buccolingual inclination of all teeth in both the ERP setup and the posttreatment CBCT scan were measured and compared. Bland-Altman analysis was used to assess interoperator reliability, intraoperator reliability, and agreement between the ERP setup and the posttreatment CBCT scan.

RESULTS

Bland-Altman plots showed high interoperator and intraoperator reliabilities. These plots also showed strong agreement between the ERP setup and the posttreatment CBCT scan; 11.8% of teeth measured for mesiodistal angulation and 9.6% of teeth measured for buccolingual inclination were outside the ±2.5° range of clinical acceptability.

CONCLUSIONS

We validated that the method to generate an ERP setup to evaluate root position for posttreatment orthodontic assessment is accurate and reliable.

Enamel matrix derivative for the treatment of partially contained intrabony defects: 12-month results

BACKGROUND

The aim of the study was to evaluate the use of enamel matrix derivative (EMD) alone or in association with deproteinized bovine bone mineral (DBBM) for the treatment of partially contained intrabony defects.

METHODS

A total of 20 two-walled intrabony defects belonging to nine patients were included. Ten defects were treated with EMD alone (test group 1) and the other 10 were treated with EMD and DBBM (test group 2), applying either modified papilla preservation technique or simplified papilla preservation technique.

RESULTS

Twelve months after surgery, in the test group 1, PD was 2.8 ± 0.8 mm, REC was 2.3 ± 2.4 mm and CAL was 5.0 ± 2.8 mm, significantly reduced from baseline values (P < 0.05). Likewise, in test group 2, PD, REC and CAL reduced to 3.0 ± 0.7 mm, 3.9 ± 1.5 mm and 6.9 ± 1.1 mm respectively, from baseline values at 12 months (P < 0.05). No significant differences between groups were found.

CONCLUSIONS

The results showed that the use of EMD alone and the use of a combination of EMD and DBBM for the treatment of partially contained defects showed comparable clinical and radiographic outcomes after 12 months.

Influence on interradicular bone volume of Invisalign treatment for adult crowding with interproximal enamel reduction: a retrospective three-dimensional cone-beam computed tomography study

BACKGROUND

The aim of this study was to use three-dimensional datasets to identify associations between treatment for adult crowding, using Invisalign aligner and interproximal enamel reduction (IER), and changes in the volume of interradicular bone.

METHODS

A total of 60 cone-beam computed tomography (CBCT) scans from 30 adult patients (28 women, two men; 30 CBCTs pre-treatment, 30 post-treatment) were examined retrospectively in order to measure bone volume three-dimensionally. The patients' average age was 36.03 ± 9.7 years. The interradicular bone volume was measured with OsiriX at four levels in the anterior tooth areas of the maxilla and mandible. Differences in bone between T0 and T1 were analyzed with IBM SPSS 21.0 using the Wilcoxon test for paired samples.

RESULTS

Overall, a slight increase in the quantity of bone was found (0.12 ± 0.73 mm). There was a highly significant increase in bone in the mandible (0.40 ± 0.62 mm; P <  0.001), while in the maxilla there was a slight loss of bone, which was highly significant in the apical third (- 0.16 ± 0.77 mm; P = 0.001).

CONCLUSIONS

Overall, treatment for adult crowding using an aligner and IER appears to have a positive effect on interradicular bone volume, particularly in patients with severe grades of the condition (periodontally high-risk dentition). This effect is apparently independent of IER. This is extremely important with regard to the treatment outcome, since IER and root proximity have been matters of debate in the literature and teeth should remain firmly embedded in their alveolar sockets.

Three-dimensional evaluation of root position at the reset appointment without radiographs: a proof-of-concept study

Background

Accurate root position is integral for successful orthodontic treatment. Current methods of monitoring root position are either inaccurate, exhibit poor resolution, or use relatively large amount of radiation relative to the benefits for the patient. The purpose of this study was to present an approach that can monitor root position during orthodontic treatment with minimal radiation.

Methods

Cone-beam computed tomography (CBCT) scans were taken for a patient at pre-treatment and at a dedicated reset appointment. An extra-oral laser scan of a poured up cast was taken at the reset appointment. An expected root position (ERP) setup, an approximation of the root position at the reset appointment, was generated using the pre-treatment CBCT scan and reset appointment cast. The ERP setup was compared to the CBCT scan taken at the reset appointment which served as the control. Color displacement maps were generated to measure any differences between the expected and true root positions.

Results

Color map displacement analysis after indirect superimposition found displacement differences of 0.021 mm ± 0.396 mm for the maxillary roots and 0.079 mm ± 0.499 mm for the mandibular roots.

Conclusions

This approach was demonstrated in a patient at the reset appointment to have the potential to accurately monitor root positions during treatment in three dimensions without the need for additional radiographs.

Imaging an adapted dentoalveolar complex

Adaptation of a rat dentoalveolar complex was illustrated using various imaging modalities. Micro-X-ray computed tomography for 3D modeling, combined with complementary techniques, including image processing, scanning electron microscopy, fluorochrome labeling, conventional histology (H&E, TRAP), and immunohistochemistry (RANKL, OPN) elucidated the dynamic nature of bone, the periodontal ligament-space, and cementum in the rat periodontium. Tomography and electron microscopy illustrated structural adaptation of calcified tissues at a higher resolution. Ongoing biomineralization was analyzed using fluorochrome labeling, and by evaluating attenuation profiles using virtual sections from 3D tomographies. Osteoclastic distribution as a function of anatomical location was illustrated by combining histology, immunohistochemistry, and tomography. While tomography and SEM provided past resorption-related events, future adaptive changes were deduced by identifying matrix biomolecules using immunohistochemistry. Thus, a dynamic picture of the dentoalveolar complex in rats was illustrated.

The effectiveness of a single osteointegrated implant combined with pendulum springs for molar distalization

The aim of this report was to present the clinical efficiency of a single osteointegrated implant combined with pendulum springs for molar distalization. A 15-year-old girl sought treatment for irregular anterior teeth and poor smile esthetics. A novel appliance was designed that combined osteointegrated implants with 0.032-in beta-titanium wire and pendulum springs. The treatment results were evaluated from lateral cephalometric radiographs. Distalization of the maxillary first molars was achieved in 6 months. Total treatment time was 21 months. Facial esthetics improved as a consequence of treatment. This appliance design offers reliable molar distalization, even when absolute anchorage is required.

Dental health assessed more than 10 years after interproximal enamel reduction of mandibular anterior teeth

INTRODUCTION

We investigated whether interdental enamel reduction using fine diamond disks with air cooling, followed by polishing, leads to iatrogenic damage or reduced interradicular distances.

METHODS

Our subjects were 61 consecutive patients who had received mesiodistal enamel reduction of all 6 mandibular anterior teeth more than 10 years previously. Dental caries, bleeding on probing, probing depths, and gingival recessions were assessed with standard techniques. Incisor irregularities and tooth width/thickness ratios were measured on models, and the patients were asked about any increased tooth sensitivity. The reference group comprised 16 students.

RESULTS

No new caries lesions were detected. Three mature adults had some minor labial gingival recessions. There was no evidence of root pathology. The distance between the roots of the mandibular incisors was statistically significantly greater in the patients who had received stripping than in those who had not; 59 of 61 patients reported no increased sensitivity to temperature variations. The overall irregularity index at follow-up was only 0.67 (SD, 0.64).

CONCLUSIONS

Interdental enamel reduction according to this protocol did not result in iatrogenic damage. Dental caries, gingival problems, or alveolar bone loss did not increase, and the distances between the roots of the teeth in the mandibular anterior region were not reduced. The overall incisor irregularity at the follow-up examination was small.

Root proximity as a risk marker for periodontal disease: a case-control study

AIM

The aim of this study is first, to examine the prevalence, symmetry and spread of root proximity using the measurement tools and classification as described in part I of the study, and second to examine whether root proximity is a risk marker for periodontal disease.

MATERIAL AND METHODS

The radiographs of 227 patients were examined. The study consisted of a study group of 197 patients with advanced periodontal disease with at least one site with bone loss more than one third of the root length and 30 controls without periodontal disease. Every inter-proximal space was assessed on the full-mouth radiographs and a score was assigned according to severity and location. Consequently prevalence of severity and location, symmetry, spread and an odds ratio and relative risk for periodontal disease was calculated.

RESULTS

Root proximity is a symmetrical and localized but widespread phenomenon in periodontal patients and to lesser extend in the non-periodontal control group. In periodontal patients root proximity was most often encountered in the coronal and intervening part whereas subjects without periodontal disease had more root proximity in the apical and intervening part where it is less critical. Subjects with bilateral root proximity had a 3.6 times higher chance to have periodontitis.

CONCLUSION

Root proximity must be taken into consideration as a risk marker for periodontal disease.