Accuracy of cone-beam computed tomography in detecting alveolar bone dehiscences and fenestrations

Tomographic diagnosis of alveolar bone coverage impact in orthodontic planning: cross-sectional study

INTRODUCTION

Alveolar bone coverage can be diagnosed through cone beam computed tomography (CBCT) and this information can prevent orthodontic tooth movement beyond the biological limit.

OBJECTIVE

This study evaluated the impact of the bone coverage (BC) diagnosis by CBCT in the orthodontists' planning.

METHODS

One hundred fifty-nine Brazilian orthodontists suggested treatment plans for six patients at two different times, using two sequential questionnaires. The first questionnaire consisted of extra and intra-oral photographs, one panoramic radiograph; one lateral cephalometric radiograph with Steiner and Tweed analysis, and the patient chief complaint. The second questionnaire included the same presentations of cases with tomographic images and the radiologist's report. The McNemar test assessed the difference between the first and the second treatment plans.

RESULTS

In all six cases, most participants changed the treatment plan after evaluating the CBCT images and the radiologist's report (93.7% in case 5, 78.6% in case 4, 74.2% in case 3, 69.8% in case 6, 66% in case 2 and 61% in case 1; p≤0.01).

CONCLUSION

The evaluation of bone coverage through CBCT images has a substantial impact on the orthodontic diagnosis and planning of the Brazilian orthodontists.

Accuracy of intraoral ultrasound to evaluate alveolar bone level: an ex vivo study in human cadavers

OBJECTIVES

This study aimed to evaluate the reliability and accuracy of an intraoral ultrasound (US) device to evaluate alveolar bone by comparing it between different raters and to microCT (µCT) measurements.

METHODS

38 teeth distributed across three human cadavers were prepared by placing two notches on the facial enamel surface. The maxillary and mandibular teeth were imaged with a custom-designed intraoral 20 MHz ultrasound and µCT with 0.03 mm voxel size. µCT was considered the reference standard for this study. For each sample, the distance from the inferior border of the most apical notch to the tip of the alveolar bone crest on the facial aspect of the teeth was measured from the US and µCT images. Intraclass correlation coefficient (ICC) and standard deviation were calculated.

RESULTS

The intra-examiner and inter-examiner reliability for both the µCT and US alveolar bone measurements were found to be excellent (intra-examiner ICC was 0.998 for µCT and 0.997 for US, inter-examiner ICC was 0.996 for µCT and between 0.947 and 0.950 for US). The accuracy of the US was found to be good compared to µCT (ICC between 0.885 and 0.894).

CONCLUSION

The study demonstrated that intraoral ultrasound is highly reliable and accurate compared to the µCT reference standard for evaluating facial alveolar bone height.

Mandibular cortical bone remodeling characteristics in patients with extraction: A cone-beam computed tomography study

INTRODUCTION

This study evaluated the labial and lingual cortical bone remodeling characteristics of mandibular central incisors after retraction, which remain controversial among orthodontists.

METHODS

Cortical bone remodeling and central incisor movement of 33 patients (aged 23.64 ± 4.30 years) who underwent mandibular first premolar extraction and incisor retraction at the crestal (S1), midroot (S2), and apical (S3) levels were analyzed using superimposed cone-beam computed tomography images on the basis of voxel-based registration of the mandibular stable region. Multivariate linear regression was used to explore the relationships between labial bone remodeling/tooth movement (BT) ratios and factors such as the ANB angle, mandibular plane angle (Mp-SN), and incisor movement patterns. The patients were divided into 4 groups according to the lingual cortical bone remodeling condition and the relationship between posttreatment incisor roots and the original lingual cortical bone border. At the 3 levels (S1, S2, and S3), the classifications of cortical bone remodeling of the mandibular incisors were calculated; t tests were used to compare the amount of labial and lingual bone remodeling, BT ratios, and lingual bone remodeling/root over the original border (BRo) ratios.

RESULTS

The mean labial BT ratios at all 3 levels were close to 1. Multivariate linear regression indicated that the tooth movement pattern negatively correlated with the BT ratio at the S2 and S3 levels (P <0.05). Lingual bone apposition occurs when the root penetrates the original lingual cortical bone border in most patients. BRo ratios can more accurately reflect the inherent remodeling ability of the lingual cortical bone than BT ratios. The mean lingual BRo ratios were (1) S1 level: mandibular left central incisor (T31), 0.87 ± 0.25 and mandibular right incisor (T41), 0.86 ± 0.25; (2) S2 level: T31, 0.81 ± 0.12 and T41, 0.80 ± 0.22; and (3) S3 level: T31, 0.76 ± 0.20 and T41, 0.83 ± 0.26. There was no significant difference between labial BT ratios and lingual BRo ratios at the S2 and S3 levels.

CONCLUSIONS

The amount of labial cortical bone resorption caused by mandibular incisor retraction showed varied relationships with the amount of tooth movement. Bodily retraction may decrease the labial BT ratios at the S2 and S3 levels. Active lingual cortical bone apposition occurred when the roots penetrated the original lingual border and exhibited strong remodeling ability.

Comparison of near-infrared imaging with cone-beam computed tomography for proximal caries detection in permanent dentition: An in vivo study

OBJECTIVES

This study aimed to evaluate the diagnostic performance of near-infrared imaging (NIRI) and unaided visual examination (UVE) in detecting proximal caries in permanent dentition in comparison with cone-beam computed tomography (CBCT).

METHODS

Patients who underwent NIRI, UVE, and CBCT imaging within 1 week were enrolled. Using CBCT as the reference test, the positive percent agreement (PPA), negative percent agreement (NPA), and overall percent agreement (OPA) of NIRI, UVE, and a combination of the two for detecting proximal caries at different depths and in different tooth locations were assessed. Additionally, the consistency of these diagnostic methods with CBCT was evaluated.

RESULTS

We evaluated 6,084 proximal surfaces and identified 177 CBCT-positive sites. NIRI had a PPA, NPA, and OPA of 68.93 %, 99.09 %, and 98.21 %, respectively, with a substantial agreement with CBCT. When combined with UVE, the PPA increased by approximately 50 % compared with that of UVE alone. Regarding caries at different depths, NIRI outperformed UVE in detecting initial caries (ICDAS 1-2) over moderate-to-advanced caries (ICDAS 3-6). However, the combined use of NIRI and UVE improved the detection of moderate-to-advanced caries. In the anterior teeth region, NIRI exhibited excellent agreement with CBCT, surpassing its performance in the posterior region.

CONCLUSIONS

Although NIRI cannot fully replace radiographic methods, the substantial agreement of NIRI with CBCT in detecting proximal caries highlights its potential as a complementary tool in routine caries screening, especially when combined with UVE.

CLINICAL SIGNIFICANCE

This study highlights the potential of NIRI as a radiation-free method for detecting proximal caries in permanent teeth. Early detection through regular NIRI scanning can lead to timely intervention, improved patient outcomes, and reduced overall disease burden.

Dehiscence and fenestration of skeletal Class III malocclusions with different vertical growth patterns in the anterior region: A cone-beam computed tomography study

INTRODUCTION

This study aimed to evaluate the incidence and distribution of alveolar bone dehiscence and fenestration in skeletal Class III malocclusions with different vertical growth patterns in the anterior region using cone-beam computed tomography (CBCT).

METHODS

In this retrospective study, 84 patients with skeletal Class III malocclusions who underwent CBCT were selected. This study included 28 patients with hypodivergence (mean age, 22.9 ± 3.9 years), 28 with normodivergence (mean age, 21.0 ± 3.0 years), and 28 with hyperdivergence (mean age, 21.0 ± 3.7 years). Teeth in the anterior region were examined using CBCT to detect dehiscence and fenestration. The incidences of dehiscence and fenestration in the anterior teeth region were recorded, and statistical analysis was conducted using SPSS software (version 25.0, IBM, Armonk, NY).

RESULTS

Among the patients with skeletal Class III malocclusions, dehiscence and fenestration were prone to occur in the mandible. Dehiscence and fenestration were more prevalent in patients with hyperdivergence compared with in patients with hypodivergence and normodivergence.

CONCLUSIONS

Dehiscence and fenestration are prevalent among patients with skeletal Class III malocclusion. Furthermore, the occurrence of alveolar bone defects is higher in patients with hyperdivergence.

Multivariate analysis of alveolar bone dehiscence and fenestration in anterior teeth after orthodontic treatment: A retrospective study

OBJECTIVE

To compare the prevalence of fenestration and dehiscence between pre- and post-orthodontic treatment and to explore the factors related to fenestration and dehiscence in the anterior teeth after treatment.

METHODS

This study included 1000 cone-beam computed tomography (CBCT) scans of 500 patients before (T1) and after (T2) orthodontic treatment. These images were imported into Dolphin 11.9 software to detect alveolar fenestration and dehiscence in the anterior teeth area. The chi-square test and Fisher's exact test were performed to compare the prevalence of alveolar bone defects between time points T1 and T2. A total of 499 patients were selected for logistic regression analysis to examine the correlation among age, sex, crowding, sagittal facial type, extraction, miniscrew use and fenestration or dehiscence post-treatment.

RESULTS

Except for the maxillary lingual fenestration and labial fenestration of mandibular canines, a significant change in the prevalence of fenestration and dehiscence was noted between time points T1 and T2 (P < .025). Multinomial logistic regression showed that age, miniscrew use and extraction highly influenced the prevalence of anterior lingual dehiscence (P < .05). Dehiscence of the mandibular labial side (skeletal Class III vs. I, OR = 2.368, P = .000) and fenestration of the mandibular lingual side (skeletal Class II vs. I, OR = 2.344, P = .044) were strongly correlated with the sagittal facial type. Dehiscence of the maxillary labial side (moderate vs. mild, OR = 1.468, P = .017) was significantly associated with crowding.

CONCLUSIONS

Older age, maxillary moderate crowding, skeletal Class III, extraction and miniscrew potentially significantly affect the prevalence of anterior teeth dehiscence. Adult females, skeletal Class III patients on the mandibular labial side and skeletal Class II patients on the mandibular lingual side should be monitored for anterior teeth fenestration.

Characteristics of mandibular anterior alveolar bone in patients with different degrees of periodontitis: a retrospective study based on CBCT

OBJECTIVES

To investigate the alveolar bone characteristics of mandibular anterior teeth in patients with periodontitis.

MATERIALS AND METHODS

100 patients with periodontitis were selected and grouped according to the degrees of alveolar bone resorption, age, gender, and tooth type. The labial thickness of the alveolar bone, the degree of alveolar bone resorption, angulation between the long axis of teeth and alveolar process, alveolar bone height and density of the mandibular anterior teeth were measured.

RESULTS

There were significant differences in alveolar bone morphology between these three groups. Compared with the mild and moderate groups, the severe group showed that the alveolar bone in the half of the root crown was thickened, the alveolar bone height was decreased, the cancellous alveolar bone density was increased, and the cortical alveolar bone density was decreased. The resorption of alveolar bone was characterized by greater resorption of proximal bone than that of labial bone with increased bone loss. There were also differences in alveolar bone characteristics among patients of different ages, genders, and tooth types.

CONCLUSIONS

The morphology of the mandibular anterior alveolar bone changed accordingly with the degree of periodontitis. Labial alveolar bone thickness and cortical alveolar bone density were negatively correlated with the degree of periodontitis, while alveolar bone height and cancellous alveolar bone density were positively correlated with the degree of periodontitis.

CLINICAL RELEVANCE

These results allow clinicians to better understand the alveolar bone morphology of the mandibular anterior teeth in patients with periodontitis, facilitating better treatment design and avoiding complications.

Evaluation of cuspid cortical anchorage with different sagittal patterns using cone-beam computed tomography: a retrospective study

BACKGROUND

No studies have focused on cortical anchorage resistance in cuspids, this study aimed to characterize the cortical anchorage according to sagittal skeletal classes using cone-beam computed tomography (CBCT).

METHODS

CBCT images of 104 men and 104 women were divided into skeletal class I, II, and III malocclusion groups. Skeletal and dental evaluations were performed on the sagittal and axial cross-sections. One-way analysis of variance followed by least significant difference post-hoc tests was used for group differences. Multiple linear regression was performed to evaluate the relationship between influential factors and cuspid cortical anchorage.

RESULTS

All cuspids were close to the labial bone cortex in different sagittal skeletal patterns and had different inclinations. There was a significant difference in the apical root position of cuspids in the alveolar bone; however, no significant difference in the middle or cervical portions of the root was found between different sagittal facial patterns. The middle of the cuspid root was embedded to the greatest extent in the labial bone cortex, with no significant difference between the sagittal patterns. For all sagittal patterns, 6.03 ± 4.41° (men) and 6.08 ± 4.45° (women) may be appropriate root control angles to keep maxillary cuspids' roots detached from the labial bone cortex.

CONCLUSIONS

Comparison of skeletal class I, II, and III malocclusion patients showed that dental compensation alleviated sagittal skeletal discrepancies in the cuspid positions of all patients, regardless of the malocclusion class. Detailed treatment procedures and clear treatment boundaries of cuspids with different skeletal patterns can improve the treatment time, periodontal bone remodeling, and post-treatment long-term stability. Future studies on cuspids with different dentofacial patterns and considering cuspid morphology and periodontal condition may provide more evidence for clinical treatment.

Maxillary cortical bone remodeling characteristics in extraction patients: A cone-beam computed tomography study

INTRODUCTION

This study aimed to evaluate labial and palatal cortical bone remodeling (BR) characteristics and related aspects of maxillary incisors after retraction, as these aspects are still controversial among orthodontists.

METHODS

Cortical BR and incisor movement of 44 patients (aged 26.18 ± 4.71 years) who underwent maxillary first premolar extraction and incisor retraction were analyzed using superimposed cone-beam computed tomography images. Labial BR/tooth movement (BT) ratios at the crestal, midroot (S2), and apical (S3) levels were compared using the Friedman test and pairwise comparisons. Multivariate linear regressions were used to explore the relationships between the labial BT ratio and several factors, including age, ANB angle, mandibular plane angle, and incisor movement patterns. According to the type of palatal cortical BR observed, the patients were divided into 3 groups: type I (no BR without root penetration of the original palatal border [RPB]), type II (BR with RPB), and type III (no BR with RPB). Student's t test was used to compare the type II and III groups.

RESULTS

The mean labial BT ratios at all levels were <1.00 (0.68-0.89). This value at the S3 level was significantly smaller than that at the crestal and S2 levels (P <0.01). Multivariate linear regression indicated that the tooth movement pattern negatively correlates with the BT ratio at S2 and S3 levels (P <0.01). Type I was noted in 40.9% of the patients, and similar proportions exhibited type II (29.5%, 25.0%) or type III remodeling (29.5%, 34.1%). The retraction distance of the incisors in type III patients was significantly larger than in type II patients (P <0.05).

CONCLUSIONS

The amount of cortical BR secondary to maxillary incisor retraction is less than the tooth movement. Bodily retraction may lead to lower labial BT ratios at the S3 and S2 levels. Roots penetrating the original border of the cortical plate are necessary for palatal cortical BR initiation.

Assessment of thin bony structures using cone-beam computed tomography

OBJECTIVES

To investigate the validity and reliability of marginal bone level measurements on cone-beam computed tomography (CBCT) images of thin bony structures using various reconstruction techniques, two image resolutions, and two viewing modes.

MATERIALS AND METHODS

CBCT and histologic measurements of the buccal and lingual aspects of 16 anterior mandibular teeth from 6 human specimens were compared. Multiplanar (MPR) and three-dimensional (3D) reconstructions, standard and high resolutions, and gray scale and inverted gray scale viewing modes were assessed.

RESULTS

Validity of radiologic and histologic comparisons were highest using the standard protocol, MPR, and the inverted gray scale viewing mode (mean difference = 0.02 mm) and lowest using a high-resolution protocol and 3D-rendered images (mean difference = 1.10 mm). Mean differences were significant (P < .05) at the lingual surfaces for both reconstructions, viewing modes (MPR windows), and resolutions.

CONCLUSIONS

Varying the reconstruction technique and viewing mode does not improve the observer's ability to visualize thin bony structures in the anterior mandibular region. The use of 3D-reconstructed images should be avoided when thin cortical borders are suspected. The small difference when using a high-resolution protocol is unjustified due to the higher radiation dose required. Previous studies have focused on technical parameters; the present study explores the next link in the imaging chain.

Silk-Inorganic Nanoparticle Hybrid Hydrogel as an Injectable Bone Repairing Biomaterial

Silk fibroin is regarded as a promising biomaterial in various areas, including bone tissue regeneration. Herein, Laponite^® (LAP), which can promote osteogenic differentiation, was introduced into regenerated silk fibroin (RSF) to prepare an RSF/LAP hybrid hydrogel. This thixotropic hydrogel is injectable during the operation process, which is favorable for repairing bone defects. Our previous work demonstrated that the RSF/LAP hydrogel greatly promoted the osteogenic differentiation of osteoblasts in vitro. In the present study, the RSF/LAP hydrogel was found to have excellent biocompatibility and significantly improved new bone formation in a standard rat calvarial defect model in vivo. Additionally, the underlying biological mechanism of the RSF/LAP hydrogel in promoting osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was extensively explored. The results indicate that the RSF/LAP hydrogels provide suitable conditions for the adhesion and proliferation of BMSCs, showing good biocompatibility in vitro. With the increase in LAP content, the alkaline phosphatase (ALP) activity and mRNA and protein expression of the osteogenic markers of BMSCs improved significantly. Protein kinase B (AKT) pathway activation was found to be responsible for the inherent osteogenic properties of the RSF/LAP hybrid hydrogel. Therefore, the results shown in this study firmly suggest such an injectable RSF/LAP hydrogel with good biocompatibility (both in vitro and in vivo) would have good application prospects in the field of bone regeneration.

Association between nonextraction clear aligner therapy and alveolar bone dehiscences and fenestrations in adults with mild-to-moderate crowding

INTRODUCTION

This study aimed to assess the association between nonextraction clear aligner therapy (CAT) and the presence of alveolar bone dehiscences (ABDs) and fenestrations (ABFs) in adults with mild-to-moderate crowding.

METHODS

Cone-beam computed tomography images from 29 adults were obtained before and immediately after nonextraction CAT. Total root lengths were evaluated in axial and cross-sectional slices. Linear measurement for dehiscence (LM-D) was defined as the distance between the alveolar crest to the cementoenamel junction of each root (critical point set at 2 mm). Linear measurement for fenestration (LM-F) was recorded when the defect involved only the apical one-third of a root (critical point set at 2.2 mm). Counts of ABDs/ABFs and magnitudes of LM-Ds/LM-Fs were recorded before and immediately after nonextraction CAT at buccal and lingual root surfaces. Binary logistic regression analyses and repeated measures analyses of variance were performed.

RESULTS

Counts of ABDs/ABFs and magnitudes of LM-Ds/LM-Fs increased at most jaw locations and root surfaces. Nonextraction CAT was associated with an increased presence of ABDs and ABFs. Nonextraction CAT was associated with a higher magnitude of LM-Ds but not LM-Fs.

CONCLUSIONS

Immediate posttreatment cone-beam computed tomography scans showed that nonextraction CAT is associated with increased ABDs and ABFs in adults with mild-to-moderate crowding.

Ex vivo assessment of the buccal and oral bone by CBCT

PURPOSE

Identifying buccal and oral bone as an important supporting periodontal structure for teeth provides important information for treatment planning in periodontics and orthodontics. This study aims to add evidence to the knowledge of preciseness of cone beam computed tomography (CBCT) measurements of the vertical dimension of buccal and oral bone. The hypothesis is that CBCT is an accurate and reliable method to measure vertical vestibular and oral bone loss.

METHODS

The amount of vertical buccal and oral bone loss (bl) of 260 sites of 10 human cadavers was investigated clinically and radiographically by CBCT. Radiographic measurements were rated by two blinded raters. Measurements and the corresponding differences between clinical and radiological findings are described by medians and quartiles (Q1-Q3). For statistical analysis, Lin's concordance correlation coefficient (CCC) and Bland-Altman plots were calculated.

RESULTS

The CCC between the raters was 0.994 (95% confidence interval 0.992-0.995). The median bone loss (bl) distance from the cementoenamel junction (CEJ) to the bony defect (BD) was 3.5 mm (range 3-5 mm). The median bl measured in the CBCT was 3.8 mm (range 3.1-4.8 mm). The median difference of the 2 measurements for all sites included in the study (N = 260) was -0.2 mm (-0.7 to 0.3 mm).

CONCLUSIONS

CBCT seems to be an accurate and highly reliable method to detect and describe vertical buccal and oral bone loss. It could improve planning and prediction for successful combined periodontal and orthodontic therapies.

Evaluation of facial alveolar bone thickness and fenestration of the maxillary premolars

OBJECTIVE

The objective of this study was to retrospectively investigate the facial alveolar bone (FAB) thickness and fenestration rate of maxillary first and second premolars using cone-beam computed tomography (CBCT).

DESIGN

A total of CBCT images of 66 patients were selected and 200 maxillary premolar (100 first and 100 second premolar) were included. The FAB thicknesses were measured at 1,3 and 5 mm apical to the alveolar bone peak. The prevalence of fenestration in maxillary premolars was recorded. The statistical analyses were performed.

RESULTS

The FAB thicknesses of the second premolars (1.39 mm at 1 mm, 1.42 mm at 3 mm, and 1.22 mm at 5 mm) were significantly higher than the first premolars (1.11 mm at 1 mm, 0.70 mm at 3 mm, and 0.48 mm at 5 mm) at 1, 3, and 5 mm levels (p < 0.05). The lowest prevalence (1 %) of the thickness of FAB ≥ 2 mm was in the first premolar has at 5 mm apical of the alveolar bone peak. The overall prevalence of fenestration in maxillary premolars was found as 30.5 %. There was a statistically significant difference between first and second premolars (p < 0.05).

CONCLUSION

The FAB thicknesses are lower in the first premolar than the second premolar. The lowest FAB thickness was in the first premolar at 5 mm apical of the bone crest as 0.42 mm. The prevalence of fenestration in maxillary premolars was higher in the Turkish subpopulation than in other populations. Fenestration was more common in the maxillary first premolar.

Alveolar defects before and after surgically assisted rapid palatal expansion (SARPE): a CBCT assessment

INTRODUCTION

Surgically Assisted Rapid Palatal Expansion (SARPE) promote maxillary expansion in skeletally mature patients. This technique is effective; however, some side effects are still unknown.

OBJECTIVES

evaluate the presence of alveolar defects (dehiscences and fenestrations) in patients submitted to the SARPE. The null hypothesis tested was: SARPE does not influence the number of dehiscences and fenestrationss.

METHODS

A retrospective quasi-experiment study of a convenience sample of 279 maxillary teeth, in 29 patients evaluated with Cone Beam Computed Tomography (CBCT) at T1 (before SARPE), T2 (after expansion) and T3 (after retention), was performed. The examined teeth were: canines, first and second premolars, first and second molars. in axial, coronal, and cross-sectional views. The evaluations involved viewing slices from mesial to distal of the buccal roots.

RESULTS

All statistical analyses were performed using SAS 9.3 and SUDAAN softwares. Alpha used in the study was 0.05. Alveolar defects increased statistically from T1 (69.0%) to T2 (96.5%) and T3 (100%). Dehiscences increased 195% (Relative Risk 2.95) at the end of expansion (T2). After retention (T3), individuals were on average 4.34 times more likely to develop dehiscences (334% increase). Fenestrations did not increase from T1 to T2 (p = 0.0162, 7.9%) and decreased from T2 to T3 (p = 0.0259, 4.3%). Presence of fenestrations at T1 was a significant predictor for the development of dehiscences in T2 and T3. Dehiscences increased significantly in all teeth, except second molars.

CONCLUSION

The null hypothesis was rejected. After SARPE the number of dehiscences increased and fenestrations decreased. Previous alveolar defects were predictor for dehiscences after SARPE.

Symphysis morphology and mandibular alveolar bone thickness in patients with β-thalassemia major and different growth patterns

Objective:

The present study aimed to assess the morphology of symphysis and alveolar bone thickness (ABT) surrounding mandibular incisors in thalassemic patients, as compared to unaffected individuals.

Methods:

This case-control study was conducted on lateral cephalograms of 60 thalassemic and 60 unaffected patients with Class II malocclusion seeking orthodontic treatment at Dental School, Shiraz University of Medical Sciences. The sample was divided into three subgroups including hyperdivergent, normodivergent, and hypodivergent, according to the Jarabak index. Symphysis dimensions and alveolar bone thickness surrounding mandibular incisors were measured using AutoCad software. Finally, the correlation between alveolar bone thickness and symphysis morphology was assessed.

Results:

In general, chin dimensions and bone thickness at different levels of mandibular incisor roots (cervical, middle, apical) were smaller in thalassemic adolescents than controls. Concerning the total sample as well as the normodivergent subgroup, significantly lower values were observed in thalassemic patients for symphysis width, total ABT at the cervical, and lingual ABT at the apical root area compared to controls (p < 0.05). The hypodivergent growth pattern was not associated with any statistical differences between the groups (p> 0.05). In both thalassemic and control subjects, symphysis width showed a weak to moderate positive correlation with ABT of lower incisors (p< 0.05), whereas symphysis height showed a moderate positive correlation with cervical ABT in only ß‐thalassemia patients (p< 0.05).

Conclusions:

Compared to controls, ß-thalassemia patients showed thinner alveolar bone at different levels of lower incisor roots and smaller symphysis dimensions. There were significant correlations between symphysis dimensions and alveolar bone thickness of mandibular incisors in the sample.

Effect of voxel size in cone-beam computed tomography on surface area measurements of dehiscences and fenestrations in the lower anterior buccal region

Objectives

This study aims to assess whether different voxel sizes in cone-beam computed tomography (CBCT) affected surface area measurements of dehiscences and fenestrations in the mandibular anterior buccal region.

Materials and methods

Nineteen dry human mandibles were scanned with a surface scanner (SS). Wax was attached to the mandibles as a soft tissue equivalent. Three-dimensional digital models were generated with a CBCT unit, with voxel sizes of 0.200 mm (VS200), 0.400 mm (VS400), and 0.600 mm (VS600). The buccal surface areas of the six anterior teeth were measured (in mm²) to evaluate areas of dehiscences and fenestrations. Differences between the CBCT and SS measurements were determined in a linear mixed model analysis.

Results

The mean surface area per tooth was 88.3 ± 24.0 mm², with the SS, and 94.6 ± 26.5 (VS200), 95.1 ± 27.3 (VS400), and 96.0 ± 26.5 (VS600), with CBCT scans. Larger surface areas resulted in larger differences between CBCT and SS measurements (− 0.1 β, SE = 0.02, p < 0.001). Deviations from SS measurements were larger with VS600, compared to VS200 (1.3 β, SE = 0.05, P = 0.009). Fenestrations were undetectable with CBCT.

Conclusions

CBCT imaging magnified the surface area of dehiscences in the anterior buccal region of the mandible by 7 to 9%. The larger the voxel size, the larger the deviation from SS measurements. Fenestrations were not detectable with CBCT.

Clinical relevance

CBCT is an acceptable tool for measuring dehiscences but not fenestrations. However, CBCT overestimates the size of dehiscences, and the degree of overestimation depends on the actual dehiscence size and CBCT voxel size employed.

Dehiscence and fenestration of Class I individuals with normality patterns in the anterior region: a CBCT study

OBJECTIVES

The purpose of this study was to investigate the prevalence of alveolar bone dehiscence and fenestration of Class I individuals with normality patterns in the anterior region using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

A total of 4715 retrospective cases from January 2018 to December 2020 in the Orthodontic Department of xxx Hospital were screened. Sixty-one cases were Class I individuals with normality patterns in the anterior region. Their incidence of dehiscence and fenestration in the anterior teeth region was studied and statistically analyzed.

RESULTS

Dehiscence was found in 27.46% of the evaluated anterior teeth and fenestration was found in 26.91% of anterior teeth. Severe dehiscences and fenestrations mainly occurred in mandibular canines and maxillary canines, respectively. Alveolar bone defects were present in 100% of patients, while one patient had alveolar bone defects in 91.67% of the anterior teeth.

CONCLUSIONS

Dehiscence was found in 27.46% of the anterior teeth of Class I individuals with normality patterns, while fenestration was found in 26.91% of them. Alveolar bone defects were present in 100% of patients.

CLINICAL RELEVANCE

Alveolar bone dehiscence and fenestration were normal and common in our sample, indicating that they are more likely to be physiological rather than pathological defects. Orthodontists should be aware of the presence and severity of these defects before treatment in order to avoid both possible complications and overtreatment.

The Diagnostic Accuracy of Cone-Beam Computed Tomography (CBCT) Imaging in Detecting and Measuring Dehiscence and Fenestration in Patients With Class I Malocclusion: A Surgical-Exposure-Based Validation Study

Background No study has evaluated the diagnostic accuracy of cone-beam computed tomography (CBCT) imaging in detecting bone defects in orthodontic patients with Class I malocclusions. This study aimed to evaluate the accuracy of CBCT in detecting dehiscences and fenestrations before orthodontic treatment compared to the gold standard i.e., the actual clinical detection of bone defects on surgical exposure. Methods A validation study was undertaken at the Department of Orthodontics, University of Damascus between 29 August 2018 and 1 November 2020. The sample included 16 patients who had Class I malocclusion with moderate crowding on the lower anterior teeth. Results The proportion of dehiscence diagnosed on CBCT images was approximately two-and-a-half times greater than that found on direct examination i.e., 42.7% versus 17.7%, respectively. The proportion of fenestrations was almost three times greater when diagnosed on CBCT images compared to the gold standard i.e., 39.5% versus 13.5%, respectively. The sensitivity of CBCT imaging in detecting dehiscence and fenestration was 100%. The specificity of CBCT imaging ranged from 45.5% to 86.7% and from 50% to 86.7% for dehiscence and fenestration detection, respectively. Also, the diagnostic accuracy of CBCT imaging ranged from 44% to 87.5% and from 56% to 87.5% for dehiscence and fenestration detection, respectively. Conclusions The proportion of dehiscence diagnosed on CBCT images was approximately two-and-a-half times greater than that found on direct examination, and the proportion of fenestrations was almost three times greater when diagnosed on CBCT images compared to the gold standard. The CBCT overestimates the dimensions of the linear measurements compared to those measured by the gold standard.

Low-dose CBCT imaging of alveolar buccal bone adjacent to mandibular anterior teeth- a pilot study

Objectives

Accurate description of buccal bone adjacent to mandibular anterior teeth is helpful for planning and monitoring periodontal and orthodontic treatment. Low-dose cone beam computed tomography (LD-CBCT) imaging has shown promising results for very small dental structures in animals. This study asserts that LD-CBCT is sufficiently accurate to measure buccal alveolar bone adjacent to human mandibular anterior teeth.

Materials and methods

Buccal bone level adjacent to 16 mandibular anterior teeth from four human cadavers was measured radiographically using one high-dose (HD) CBCT protocol and two LD-CBCT protocols. The resulting radiographic measurements of buccal bone height (bl) and thickness (bt) were compared with reference probe and reflected-light microscopy measurements. Measurement medians and Bland–Altman plots were calculated, and a linear mixed model was used to compare raters and imaging modalities.

Results

All regression coefficients were approximately 0, indicating high interrater, intrarater, and intermodality agreement. No significant differences were found between reference measurements and CBCT protocols. The mean differences for bl measurements were 0.07 mm (rater 1 [r1]) and 0.12 mm (rater 2 [r2]) for HD-CBCT; 0.07 mm (r1) and 0.13 mm (r2) for LD-CBCT-1; and 0.02 mm (r1) and 0.01 mm (r2) for LD-CBCT-2. For bt measurements, mean differences were 0.02 mm (r1) and 0.02 mm (r2) for HD-CBCT; 0.01 mm (r1) and 0.01 mm (r2) for LD-CBCT-1; and 0.00 mm (r1) and 0.01 mm (r2) for LD-CBCT-2.

Conclusions

Within the limitations of the present study, LD-CBCT seems to be a precise method for describing buccal bone and its thickness adjacent to mandibular anterior teeth in this experimental setting.

Clinical relevance

For the first time, this study showed LD-CBCT produces excellent results and is a reliable modality for imaging buccal bone in vitro. If clinical studies confirm these results, LD-CBCT could enable better treatment planning and monitoring at a radiation dose that is far lower than that of conventional HD-CBCT but similar to that of panoramic views.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-022-04389-x.

Reliability of an indirect bone-probing method for diagnosis of labial bone crest level of the mandibular anterior teeth

OBJECTIVES

To evaluate the null hypothesis that there would be no difference between the labial bone crest level of the mandibular anterior teeth evaluated with an indirect bone-probing method (IBP) and cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

Twenty-nine adult patients with a mean age of 32.15 ± 8.75 years were enrolled. An IBP based on indirect tactile perception was used to determine the labial bone crest level of the mandibular anterior teeth clinically. Bone crest perception degree, gingival thickness, and patient discomfort during IBP were also recorded. CBCT scans were used to evaluate the level and thickness of the labial bone crest. IBP and CBCT methods were compared statistically. The significance level was set at 5%.

RESULTS

There was a significant difference between the labial bone crest level diagnosed by IBP and CBCT. However, the difference was not clinically significant. IBP and CBCT measurements were significantly and strongly correlated (R = 0.74). Thinner gingival tissue was associated with a higher perception of bone crest. Only two patients reported mild to moderate discomfort during IBP.

CONCLUSIONS

IBP allowed the labial bone crest level to be determined with acceptable clinical accuracy, especially in patients with thinner gingival tissue.

Ex-vivo imaging of buccal and oral periodontal bone with low-dose CBCT in porcine jaws

OBJECTIVES

New CBCT devices have been developed which can provide "low-dose CBCTs (LD-CBCT)". Aim of this study is to investigate the suitability of LD-CBCT for measurement of alveolar buccal/oral bone.

METHODS AND MATERIALS

Vestibular and oral bone loss of the teeth of seven porcine mandibles free of soft tissues were investigated by Micro-CT and three CBCT-modes: high-dose (HD), standard-dose (SD) and low-dose (LD). Radiographic measurements of bone loss (bl) and vestibular and oral bone thickness (bt) were made by two raters at 69 sites. Measurement means and differences, Intraclass correlation (ICC) and Bland-Altman plots were calculated.

RESULTS

ICCs between raters(r) concerning bl were 0.954 for HD, 0.949 for SD and 0.945 for LD; concerning bt they were 0.872 for HD, 0.845 for SD and 0.783 for LD. Means of differences of bt measurements were -0.01 mm(r1)/0.00 mm(r2) for HD, 0.04 mm(r1)/0.02 mm(r2) for SD and 0.02 mm(r1)/0.04 mm(r2) for LD; for bl measurements they were 0.06 mm(r1)/0.05 mm(r2) for HD, -0.01 mm(r1)/0.13 mm(r2) for SD and 0.07 mm(r1)/0.16 mm(r2) for LD.Linear regression indicates no noticeable differences between methods and the raters with respect to bl and bt.

CONCLUSIONS

Relating to the CBCT-device used in this study, LD-CBCT is a promising method to detect and describe buccal and oral periodontal bl and bt. Further studies with human anatomic structures must confirm these results.

Accuracy of static digital surgical guides for dental implants based on the guide system: A systematic review

In the present study, we tried to review the current literature, focusing on the effect of different guide systems on the accuracy of the digital surgical guides. A search in PubMed's database, without any date restriction, was performed using keywords based on the PICO question. 54 of the 2378 articles' were chosen for full-text assessment. Articles were screened using predetermined inclusion and exclusion criteria. 21 articles were included in the qualitative assessment. Descriptive analysis was performed for numeric parameters using mean ± standard deviation. Six types of guide systems were used in the included articles. The commonest guide system was SimPlant (45.64%) followed by NobleGuide (23.00%). The pooled mean angle deviation, global coronal deviation, and global apical deviation were 3.43 mm (95% CI = 2.96, 3.90), 1.16 mm (95% CI = 0.98, 1.24) and 1.35 mm (95% CI = 1.11, 1.59), respectively. The maximum mean(SD) of angle deviation, global coronal deviation, and global apical deviation happened in Stent Cad 4.1(1.86) degrees, NobleGuide 1.86(0.56) mm, and OnDemend3d 1.56(1.48) mm, respectively. Although a final statement could not be made on which system is better, it is certain that the software affects the deviation and could be as important as the implant itself. CLINICAL SIGNIFICANCE: The choice of guide systems used for the production of static guide systems which was studied in this article could affect the accuracy of the implant placement procedure.

Long-term changes in the anterior alveolar bone after orthodontic treatment with premolar extraction: A retrospective study

OBJECTIVES

To evaluate the morphometric changes in maxillary and mandibular anterior alveolar bone after orthodontic treatment and retention for 18-24 months by cone-beam computed tomography (CBCT).

SETTING AND SAMPLE POPULATION

Thirty-four adolescent patients (12 males and 22 females; mean age: 14.29 ± 1.24 years) diagnosed with bimaxillary dentoalveolar protrusion and with extractions of the 4 first premolars were included.

MATERIALS AND METHODS

The labial and lingual (palatal) alveolar bone thickness, height and root length of the maxillary and mandibular anterior teeth were assessed using CBCT imaging at the pre-treatment (T1), post-treatment (T2) and retention phases (T3). Voxel-based superimpositions of the T2 and T3 images were performed, and the distances of incisal and apical movement between T2 and T3 were measured to determine whether relapses occurred.

RESULTS

After orthodontic treatment, the labial and lingual (palatal) bone height decreased significantly (P < .05) and the labial thickness at the crestal (L1), midroot (L2), and apical levels (L3) had no significant change, while the lingual (palatal) bone thickness at all three levels decreased significantly (P < .05). After 18-24 months of retention, the lingual (palatal) height and the lingual (palatal) thickness at the crestal (L1) level increased significantly (P < .05). There were no obvious incisal and apical movements of the anterior teeth between T2 and T3 (P > .05), indicating that no relapses occurred.

CONCLUSIONS

Even though lingual (palatal) alveolar loss occurred due to the orthodontic treatment, the cervical alveolar bone seemed to recover over time. Therefore, appropriate camouflage treatment can be used in patients with bimaxillary dentoalveolar protrusion, and this treatment will not irreversibly deteriorate periodontal health and affect the orthodontic treatment stability.

Correlation between alveolar cleft volume and alveolar bone quality in patients with unilateral cleft lip and palate: A cone-beam computed tomography study

OBJECTIVES

This study aimed to determine the correlation between alveolar cleft volume and fenestration and dehiscence in the adjacent alveolar bone in patients with unilateral cleft lip and palate (UCLP) using cone-beam computed tomography (CBCT) sections.

MATERIALS AND METHODS

In this descriptive, cross-sectional study, CBCT scans of 68 non-syndromic patients with UCLP aged between 6 and14 years were selected. All patients were treated in Iran and had undergone lip and palate repair surgery within the first 3 to 18 months after birth. CBCT scans had been taken after orthodontic expansion and prior to alveolar bone grafting surgery. Cleft volume, fenestration and dehiscence were assessed using Mimics software. Data were analyzed using independent t-test, Kruskal-Wallis test, Spearman's correlation coefficient and logistic regression model.

RESULTS

The mean alveolar cleft volume was 628.66±172.84 mm³. There was a significant negative correlation between cleft volume and fenestration (P<0.001). Also, there was a significant positive correlation between cleft volume and dehiscence (P<0.001) in the adjacent bone.

CONCLUSION

The Mimics software can be successfully used to estimate the cleft volume prior to surgical procedures in UCLP patients. The results suggest that the alveolar cleft volume can be used as an aid to assess the periodontal condition of adjacent teeth. The cleft volume has a negative and positive correlation with fenestration and dehiscence respectively.

Morphologic analysis of alveolar bone in maxillary and mandibular incisors on sagittal views

PURPOSE

The aim of this study was to analyze the morphologic features of alveolus in relatively healthy maxillary and mandibular incisors using cone-beam-computed tomography (CBCT).

METHODS

CBCT images of 318 patients were retrospectively acquired. Alveolar bone in incisive area was divided into: type 1 (thick), type 2 (relatively thick with mono-plate concavity), type 3 (thin with double-plate concavities), and type 4 (vulnerably thin). Alveolus prevalence and widths were analyzed statistically relative to age, gender, and molar relationship.

RESULTS

Prevalence of type 1 alveolus was 78.9% in maxillary central incisors, 15.1% in maxillary lateral incisors, 24.1% in mandibular central incisors, and 5.0% in mandibular lateral incisors. Type 2 alveolus was commonly observed in the maxillary lateral incisors (82.2%), mandibular central incisors (66.2%), and mandibular lateral incisors (87.9%). Prevalence of type 3 and 4 alveoli ranged from 0.0 to 9.4%. As for maxillary central incisors, type 1 was the widest both at the alveolar crest (7.77 ± 0.58 mm) and apical area (9.05 ± 1.86 mm), while type 3 had the lowest width at the apical region (4.08 ± 0.51 mm). Among maxillary central incisors, prevalence of type 1 tended to decrease with age. At all maxillary and mandibular incisor sites, alveolus widths were significantly thicker in males than in females. At maxillary lateral incisor and mandibular incisor sites, prevalence of alveolus type was significantly different among three molar relationships.

CONCLUSION

A 4-type classification system was suggested for alveolus morphology in incisive region. Identification of alveolus type might aid in the corresponding treatment.

A comparison of voxel- and surface-based cone-beam computed tomography mandibular superimposition in adult orthodontic patients

OBJECTIVE

To evaluate the accuracy, reliability, and efficiency of voxel- and surface-based registrations for cone-beam computed tomography (CBCT) mandibular superimposition in adult orthodontic patients.

METHODS

Pre- and post-orthodontic treatment CBCT scans of 27 adult patients were obtained. Voxel- and surface-based CBCT mandibular superimpositions were performed using the mandibular basal bone as a reference. The accuracy of the two methods was evaluated using the absolute mean distance measured. The time that was required to perform the measurements using these methods was also compared. Statistical differences were determined using paired t-tests, and inter-observer reliability was assessed by intraclass correlation coefficients (ICCs).

RESULTS

The absolute mean distance on seven mandible surface areas between voxel- and surface-based registrations was similar but not significantly different. ICC values of the surface-based registration were 0.918 to 0.990, which were slightly lower than those of voxel-based registration that ranged from 0.984 to 0.996. The time required for voxel-based registration and surface-based registration was 44.6 ± 2.5 s and 252.3 ± 7.1 s, respectively.

CONCLUSIONS

Both methods are accurate and reliable and not significantly different from each other. However, voxel-based registration is more efficient than surface-based registration for CBCT mandibular superimposition.

Buccal alveolar bone changes following rapid maxillary expansion and fixed appliance therapy

OBJECTIVES

To assess factors that may be associated with buccal bone changes adjacent to maxillary first molars after rapid maxillary expansion (RME) and fixed appliance therapy.

MATERIALS AND METHODS

Pretreatment (T1) and posttreatment (T2) cone-beam computed tomography scans were obtained from 45 patients treated with RME and preadjusted edgewise appliances. Buccal alveolar bone thickness was measured adjacent to the mesiobuccal root of the maxillary first molar 4 mm, 6 mm, and 8 mm apical to the cementoenamel junction, and anatomic defects were recorded. Paired and unpaired t-tests were used to compare alveolar bone thickness at T1 and T2 and to determine whether teeth with posttreatment anatomic defects had thinner initial bone. Correlation analyses were used to examine relationships between buccal alveolar bone thickness changes and amount of expansion, initial bone thickness, age at T1, postexpansion retention time, and treatment time.

RESULTS

There was a statistically significant reduction in buccal alveolar bone thickness from T1 to T2. Approximately half (47.7%) of the teeth developed anatomic defects from T1 to T2. These teeth had significantly thinner buccal bone at T1. Reduction in alveolar bone thickness was correlated with only one tested variable: initial bone thickness.

CONCLUSIONS

RME and fixed-appliance therapy can be associated with significant reduction in buccal alveolar bone thickness and an increase in anatomic defects adjacent to the expander anchor teeth. Anchor teeth with greater initial buccal bone thickness have less reduction in buccal bone thickness and are less likely to develop posttreatment anatomic defects of buccal bone.

Buccal bone defects and transversal tooth movement of mandibular lateral segments in patients after orthodontic treatment with and without piezocision: A case-control retrospective study

INTRODUCTION

This study aimed to compare the extent of buccal bone defects (dehiscences and fenestrations) and transversal tooth movement of mandibular lateral segments in patients after orthodontic treatment with and without piezocision in cone-beam computed tomography and digital dental models.

METHODS

The study sample of this study consisted of cone-beam computed tomography scans and digital dental models taken before (T0) and after (T1) orthodontic treatment of 36 patients with moderate mandibular anterior crowding. The experimental group consisted of 17 patients that had piezocision performed at the beginning of treatment with the goal of accelerating tooth movement, which was compared with 19 patients who did not receive piezocision. The measurement of bone defects, buccolingual inclination, and transversal distances of the tooth in the mandibular lateral segments (mandibular canines, premolars, and first molars) were evaluated at baseline and at the end of the orthodontic treatment.

RESULTS

Overall, an increase in dehiscences, buccal inclination, and arch width from T0 to T1 was observed in both groups, but no statistically significant difference was found between groups. A significant increase in fenestrations from T0 to T1 was observed only for the canines in the experimental group. No statistically significant association was found between the increase of dehiscences and the amount of buccolingual inclination or transversal width changes. However, the changes in transversal width were statistically significantly associated with the increase in buccal inclination at the canines, first and second premolars.

CONCLUSIONS

No significant differences were found in buccal dehiscences and transversal tooth movement (buccolingual inclination and arch width) of mandibular lateral segments between patients after orthodontic treatment with and without piezocision. Dehiscences, buccal inclination, and arch width significantly increased from T0 to T1 in both groups.

Tomographic evaluation of buccal bone in different skeletal patterns and incisors inclination

OBJECTIVE

The aim of this study was to correlate the absence of BB with skeletal patterns and incisor inclination using cone-beam computed tomography (CBCT).

METHODS

The sample comprised CBCT images of 45 patients undergoing orthodontic treatment. BB was classified in each third of the anterior teeth as critical, slender, regular, and thick. The skeletal pattern was determined by the ANB (A point, nasion, B point) angle and the incisor inclination using the 1.NA and 1.NB measurements and the interincisal angle (1:1).

RESULTS

In both analyses, the skeletal pattern of class II revealed better BB in the cervical and middle thirds than classes I and III. A higher proportion of critical BB was found in the middle thirds, and the apical third presented the best regular and thick BB conditions, mainly class I. Less BB was observed in middle and apical thirds in the upper incisors and in cervical thirds in lower incisors, mostly when they were more upright.

CONCLUSIONS

Knowledge of alveolar bone height and thickness can alter the treatment plan in orthodontics. During orthodontic treatment, more attention should be paid to the lower incisors and vertical teeth because of poor BB conditions, especially in class III skeletal patterns.

Effect of Attapulgite-Doped Electrospun Fibrous PLGA Scaffold on Pro-Osteogenesis and Barrier Function in the Application of Guided Bone Regeneration

PURPOSE

Guided bone regeneration (GBR) therapy, which is a widely used technique in clinical practice and is effective in improving the repair of alveolar bone defects or bone mass deficiency regeneration, requires the use of membrane materials with good biocompatibility, barrier function, rigidity matching the space maintenance ability, economic benefits and excellent clinical applicability. The aim of this study was to develop an electrospun attapulgite (ATT)-doped poly (lactic-co-glycolic acid) (PLGA) scaffold (PLGA/ATT scaffold) as a novel material for GBR applications.

METHODS AND RESULTS

Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to determine the morphology and the crystalline structure of the PLGA/ATT scaffolds, respectively. Porosity and contact-angle measurements were also carried out to further characterize the physical properties of the PLGA/ATT scaffolds. The results of in vitro studies showed that bone marrow mesenchymal stem cells (BMSCs) attached more readily to and spread better over the PLGA/ATT scaffolds than the Bio-Gide membrane. Furthermore, in the in vitro osteoinductive experiments with BMSCs, the PLGA/ATT scaffolds were found to enhance the activity of alkaline phosphatase (ALP), promote the formation of mineralized bone nodules, and up-regulate the expression of several osteogenic markers-namely, runt-related transcription factor 2, alkaline phosphatase, osteopontin, and osteocalcin-which are similar to the effects of the Bio-Gide membrane. Further, in in vivo studies, the results of sequential fluorescent labeling, micro-computed tomography, and histological analysis suggest that using the PLGA/ATT scaffolds for repairing V-shaped buccal dehiscence on a dog's tooth root improved bone regeneration, which is not only similar to the result obtained using the Bio-Gide membrane but also much better than that obtained using PLGA scaffolds and the negative control.

CONCLUSION

To achieve satisfactory therapeutic results and to lower the cost of GBR treatment, this study provided a promising alternative material of bio-degradable membrane in clinical treatment.

Quantitative Comparison of Cephalogram and Cone-Beam Computed Tomography in the Evaluation of Alveolar Bone Thickness of Maxillary Incisors

Objective

This study aims to quantitatively compare cephalogram and cone-beam computed tomography (CBCT) when evaluating maxillary central incisor alveolar bone thickness.

Methods

We used 30 sets of lateral cephalograms and CBCT images that were recorded at the same time. Labial, buccal, and overall alveolar bone thicknesses were measured on three measurement lines of the forward-most incisor in lateral cephalograms and four maxillary incisors in CBCT images. Paired t-test, interclass correlation coefficient analysis, one-way analysis of variance (ANOVA), and Bland-Altman analysis were used to assess cephalometrically measured alveolar bone thickness of maxillary incisors and compare these measurements with those made using CBCT images.

Results

Significant differences were observed between cephalometric and CBCT-based measurements of maxillary incisor alveolar bone thickness; most values showed mild or moderate correlation between the two methods. In most cases, cephalometric measurements were greater than CBCT-based measurements. Bland-Altman plots and ANOVA revealed that measurement bias increased when measurement lines moved apically. Alveolar bone thickness was always overestimated on cephalograms.

Conclusion

Maxillary incisor alveolar bone thickness is always overestimated on cephalograms compared with CBCT-based measurements, with the overestimations ranging from 0.3 to 1.3 mm. Cephalometric measurement bias increases when measurement lines move apically. Thus, CBCT should be recommended when the accurate evaluation of alveolar bone thickness is warranted.

Cone beam computed tomography (CBCT) in periodontal diseases: a Systematic review based on the efficacy model

BACKGROUND

Periodontal diseases are prevalent among adult populations. Its diagnosis depends mainly on clinical findings supported by radiographic examinations. In previous decades, cone beam computed tomography has been introduced to the dental field. The aim of this study was to address the diagnostic efficacy of cone-beam computed tomographic (CBCT) imaging in periodontics based on a systematic search and analysis of the literature using the hierarchical efficacy model.

METHODS

A systematic search of electronic databases such as PubMed, Scopus, Web of Science, and Cochrane was conducted in February 2019 to identify studies addressing the efficacy of CBCT imaging in Periodontics. The identified studies were subjected to pre-identified inclusion criteria followed by an analysis using a hierarchical model of efficacy (model) designed for an appraisal of the literature on diagnostic imaging modality. Four examiners performed the eligibility and quality assessment of relevant studies and consensus was reached in cases where disagreement occurred.

RESULTS

The search resulted in 64 studies. Of these, 34 publications were allocated to the relevant level of efficacy and quality assessments wherever applicable. The overall diagnostic accuracy of the included studies showed a low or moderate risk of bias and applicability concerns in the use of CBCT. In addition, CBCT is accurate in identifying periodontal defects when compared to other modalities. The studies on the level of patient outcomes agreed that CBCT is a reliable tool for the assessment of outcomes after the treatment of periodontal defects.

CONCLUSION

CBCT was found to be beneficial and accurate in cases of infra-bony defects and furcation involvements.

Differences in the corono-apical location of sinus tracts and buccal cortical bone defects between vertically root-fractured and non-root-fractured teeth based on periradicular microsurgery

This retrospective study aimed to investigate whether the corono-apical location of sinus tracts differs according to the presence/location of vertical root fracture (VRF) in microsurgically treated root-filled teeth. The cases included were (1) anterior and premolar teeth without a preoperative diagnosis of VRF, (2) those with a periodontal probing depth of ≤3 mm, and (3) those for which preoperative cone-beam computed tomography (CBCT) scans and intraoperative video records were available. VRF was diagnosed intraoperatively. The locations of buccal cortical bone defects and fracture lines were categorized on video images, and the corono-apical sinus tract locations were determined by superimposing video images onto volume-rendered CBCT images. Eleven of the 78 teeth investigated had VRF, and there was no significant difference in the incidence of sinus tracts between vertically fractured and non-fractured teeth (Mann-Whitney U-test, P > 0.05). The location of the sinus tract was significantly more coronal in vertically fractured than in non-fractured teeth (Mann-Whitney U-test, P < 0.0001). The location of sinus tracts was high correlated with cortical bone defects (Spearman's correlation, P < 0.0001). In microsurgically treated anterior and premolar teeth with a normal probing depth, sinus tracts were located more coronally in vertically fractured than in non-fractured teeth, and were highly correlated with the location of cortical bone defects.

A cone-beam computed tomographic evaluation of alveolar bone dimensional changes and the periodontal limits of mandibular incisor advancement in skeletal Class II patients

OBJECTIVES

To evaluate the presence of dehiscences and changes in alveolar bone height and width in the area of the mandibular central incisors pre- and post-orthodontic treatment.

MATERIALS AND METHODS

In 60 skeletal Class II patients, cone-beam computed tomographic (CBCT) images were obtained and the patients were divided into four groups based on the presence of dehiscences at pre- and post-orthodontic treatment. The alveolar bone height and width were measured on CBCT in cross section along the long axis of the teeth. Lateral cephalograms were analyzed.

RESULTS

The changes in L1-NB and IMPA appeared to be correlated with vertical bone loss and dehiscence. Alveolar bone height appeared to follow a segmented relationship with these two variables, with changes below a threshold (L1-NB = 0.71 mm, IMPA = 3.02°) having relatively minimal or no effect on bone loss but with changes beyond the threshold correlated with extensive bone loss. Similarly, increases in L1-NB or IMPA correlated with decreases in alveolar bone width (L1-NB: -0.25 mm/mm, IMPA: -0.07 mm/°) and increased the probability of developing dehiscences, with an estimated 50% probability of vertical bone loss at a L1-NB change of 2.00 mm or, equivalently, an IMPA change of 8.02° was estimated.

CONCLUSIONS

When treating skeletal Class II patients, the limits of incisor proclination/protraction are less than previously thought. To prevent undesired periodontal outcomes, careful three-dimensional diagnosis is advisable. Furthermore, when excessive protrusion and/or proclination is planned, additional treatment modalities, including orthognathic surgery, tooth extraction, and corticotomy with bone graft, should be considered.

Bone dehiscence formation during orthodontic tooth movement through atrophic alveolar ridges

OBJECTIVES

To test the null hypothesis that there is no difference in bone dehiscence formation before and after orthodontic tooth movement through an atrophic alveolar ridge.

MATERIAL AND METHODS

This longitudinal retrospective study evaluated pretreatment and posttreatment cone-beam computed tomography imaging of 15 adult patients. Twenty-five teeth were moved through the atrophic alveolar bone, whereas 25 teeth not subjected to translational movement were considered controls. The distances between the cementoenamel junction and the alveolar bone crest were assessed at the mesial, distal, buccal, and lingual surfaces of all of these teeth. Data were compared using the Wilcoxon test. The Spearman correlation test and multivariate linear regression analysis were also performed.

RESULTS

In general, crestal bone height was reduced around 0.5 mm in all groups in every direction. Median buccal dehiscence increased significantly (+2.25 mm) (P < .05) in teeth moved through the atrophic ridge. Control teeth also had buccal crest loss (+0.83 mm), but this was not statistically different from that of the experimental teeth. Lingual dehiscence increased significantly for the experimental (+0.17 mm) and control (+0.65 mm) groups. Mesial bone height decreased more in the control group (-0.44mm) than in the experimental group (-0.14mm). There was moderate correlation between amount of tooth movement and alveolar bone loss.

CONCLUSIONS

The null hypothesis was rejected as dehiscence increased after tooth movement through an atrophic alveolar ridge, mainly in the buccal plate.

Prevalence of posterior alveolar bony dehiscence and fenestration in adults with posterior crossbite: a CBCT study

Background

Correcting posterior crossbite in adult patients using nonsurgical methods may involve buccolingual tooth movement. Knowing the extent of the pretreatment alveolar bony dehiscences and fenestrations in the posterior area will aid orthodontists in planning posterior crossbite patients accordingly to minimize posttreatment bony defects. Before the advent of cone beam computed tomography (CBCT), observing buccal and lingual bony defects was not possible unless other treatment needs allowed for an open-flap procedure. With CBCT technology, we can now detect posterior defects with some accuracy. The aim of the present study was to determine the prevalence of posterior alveolar bony dehiscence and fenestration in adults with posterior crossbite compared with noncrossbite adults.

Methods

The study group consisted of pretreatment CBCTs of 28 samples with at least one or more teeth in posterior crossbite or edgebite. The comparison group consisted of pretreatment CBCTs of 28 samples with no posterior crossbite or edgebite. All buccal and lingual sides of the upper and lower posterior segments were measured for the presence of dehiscence, fenestration, and combined total bony defects.

Results

The prevalence of total bony defects was higher in the study group (61.6%) than in the comparison group (52.1%) (p < 0.05). While there was no difference in prevalence between crossbite teeth in the study group and noncrossbite teeth in the comparison group, the noncrossbite teeth in the study group showed a higher prevalence of total bony defects, dehiscence, and fenestration than the noncrossbite teeth in the comparison group (p < 0.05). The prevalence of dehiscence was higher in the study group (41.2%) than in the comparison group (33.3%) (p < 0.05). Neither the prevalence of fenestration nor the mean bony defect size showed statistical significance between the two groups. First premolars showed a higher prevalence of dehiscence than other posterior teeth, and maxillary posterior teeth had a higher prevalence of fenestration than mandibular posterior teeth. Among the maxillary posterior teeth, second premolars had the least amount of fenestration.

Conclusions

Adult subjects with posterior crossbite had a higher prevalence of total bony defects and dehiscence, especially buccal dehiscence, in the posterior region than subjects with no posterior crossbite. This was due to the high prevalence observed in the noncrossbite teeth in posterior crossbite subjects.

The efficacy of metal artifact reduction (MAR) algorithm in cone-beam computed tomography on the diagnostic accuracy of fenestration and dehiscence around dental implants

BACKGROUND

The aim of the present study was to investigate the impact of metal artifact reduction (MAR) algorithm of cone-beam computed tomography (CBCT) on the diagnostic accuracy of fenestration and dehiscence around dental implants.

METHODS

Twenty-three dental implants were placed adjacent to the dehiscence and 23 adjacent to the fenestration defects on bovine bone blocks. The blocks were scanned with CBCT unit in two modes, with and without MAR algorithm. The area under the receiver operator characteristic (ROC) curves (Az value), specificity, sensitivity, positive predictive value, negative predictive value, and accuracy were determined for all modes.

RESULTS

For both defects, the Az values were higher in off MAR condition. The values of sensitivity, positive predictive value, negative predictive value, and accuracy, were higher in off MAR condition for both defects. However, the specificity in both defects in the two modes was equal.

CONCLUSION

The MAR algorithm in CBCT unit may not be helpful in increasing the diagnostic accuracy of fenestration and dehiscence around dental implants.

Changes of alveolar bone dehiscence and fenestration after augmented corticotomy-assisted orthodontic treatment: a CBCT evaluation

Background

To evaluate the changes of alveolar dehiscence and fenestration after augmented corticotomy-assisted orthodontic treatment on cone-beam computed tomography (CBCT) compared with traditional pre-surgical orthodontics, both quantitatively and qualitatively.

Methods

Two hundred and four anterior teeth from 17 skeletal class III malocclusions were divided into four groups. Groups G1 (upper teeth) and G3 (lower teeth), comprising 120 teeth, accepted traditional pre-surgical orthodontics; groups G2 (upper teeth) and G4(lower teeth), comprising 84 teeth, accepted augmented corticotomy-assisted pre-surgical orthodontics. The changes of alveolar bone dehiscence and fenestration of each tooth in all groups were evaluated with the help of CBCT.

Results

Quantitative analysis for comparing both groups: For the upper teeth, d₁ − d₀ was different between both groups while f₁ − f₀ was not statistically different. For the lower teeth, d₁ − d₀ was statistically different between both groups while f₁ − f₀ was not statistically different. Qualitative analysis: For the teeth that had no dehiscence before treatment, G2 and G4 had a better transition than did G1 and G3. For those having dehiscence before treatment, G4 had a better transition than did G3. For teeth having no fenestration before treatment, there was no statistically significant difference in transition between the control and treatment groups. For those having fenestration before treatment, G4 had a better transition than did G3.

Conclusions

For skeletal class III patients, augmented corticotomy-assisted orthodontic treatment is a promising method of improving alveolar bone dehiscence and fenestration for lower anterior teeth, and it also has the potential to protect both lower and upper anterior teeth against dehiscence.

Dentoalveolar Evaluation of Lower Incisors by CBCT after Treatment with Herbst Appliance

Abstract This study aimed to evaluate the effects of the Herbst appliance on the proclination and protrusion of the lower incisors, and to verify if the device causes alveolar bone loss in the anterior region of the mandible. This is a retrospective study. The sample consisted of 35 individuals. The treatment group consisted of 22 individuals (8 girls and 14 boys; initial mean age of 8.2 years) who used the Cantilever Herbst appliance for a period of 12 months. The control group consisted of 13 individuals (3 girls and 10 boys; initial mean age of 8.9 years) who received no treatment and were followed up for a period of approximately 18 months. Cone-beam computed tomography scans were performed at the beginning and at the end of the observational period. The medullary bone thickness (MT), buccal cortical bone thickness (BCT), lingual cortical bone thickness (LCT), and lower incisors proclination and protrusion were evaluated. Data were submitted to statistical analysis (ANCOVA and Student’s t-test) with a significance level of 5%. There was no significant difference in MT, BCT, LCT and incisor proclination between groups. Incisor proclination increased in the treated group with no statistical significance. The treatment group showed a significant increase in the protrusion of the incisors (p = 0.02). The Herbst appliance promoted a small proclination and protrusion of the lower incisors, without relevant clinical implications. The Herbst appliance did not cause bone loss in the anterior region of the mandible during Class II treatment.

Cone-beam computed tomography evaluation of bone plate and root length after maxillary expansion using tooth-borne and tooth-tissue-borne banded expanders

INTRODUCTION

The objective of this research was to evaluate the buccal bone plate and root length of maxillary permanent first molars using cone-beam computed tomography after maxillary expansion with different activation protocols.

METHODS

Cone-beam computed tomography images of growing patients were obtained from the orthodontic department of Pontifical Catholic University of Rio Grande do Sul in Brazil. The groups were Haas-type 2/4 turns, Haas-type 4/4 turns, hyrax-type 2/4 turns, and hyrax-type with alternate rapid maxillary expansions and constrictions (alt-RAMEC) 4/4 turns a day. Tooth length, periodontal insertion, alveolar bone thickness, and intermolar distances were evaluated. The data at the start of treatment and 6 months later were compared using generalized linear models. The intergroup differences were determined by univariate analysis of variance with the Bonferroni adjustment.

RESULTS

Tooth length was significantly shortened after expansion in all groups (-0.28 to -0.51 mm), except for the alt-RAMEC group. Bone level variables (bone level and bone level at the tooth tip) changed statistically in all groups, except for the Haas 4/4 turns group. There was significant periodontal attachment loss after rapid maxillary expansion with the hyrax/alt-RAMEC (5.09 mm). The hyrax/alt-RAMEC and hyrax groups had more dehiscences, fenestrations, and exposures of the root.

CONCLUSIONS

The consequence of rapid maxillary expansion using the hyrax was alveolar bone resorption, especially in the hyrax/alt-RAMEC group, whereas the Haas expander caused mild root resorption.

Comparison of ultrasound imaging and cone-beam computed tomography for examination of the alveolar bone level: A systematic review

Background and objective

The current methods to image alveolar bone in humans include intraoral 2D radiography and cone-beam computed tomography (CBCT). However, these methods expose the subject to ionizing radiation. Therefore, ultrasound imaging has been investigated as an alternative technique, as it is both non-invasive and free from ionizing radiation. In order to assess the validity and reliability of ultrasonography in visualizing alveolar bone, a systematic review was conducted comparing ultrasound imaging to CBCT for examination of the alveolar bone level.

Study design

Seven databases were searched. Studies addressing examination of alveolar bone level via CBCT and ultrasound were selected. Risk of bias under Cochrane guidelines was used as a methodological quality assessment tool.

Results

All the four included studies were ex vivo studies that used porcine or human cadaver samples. The alveolar bone level was measured by the distance from the alveolar bone crest to certain landmarks such as cemento-enamel junction or gingival margin. The risk of bias was found as low. The mean difference between ultrasound and CBCT measurements ranged from 0.07 mm to 0.68 mm, equivalent to 1.6% - 8.8%.

Conclusions

There is currently preliminary evidence to support the use of ultrasonography as compared to CBCT for the examination of alveolar bone level. Further studies comparing ultrasound to gold standard methods would be necessary to help validate the accuracy of ultrasonography as a diagnostic technique in periodontal imaging.

Alveolar bone morphology of maxillary central incisors near grafted alveolar clefts after orthodontic treatment

INTRODUCTION

The aim of this study was to evaluate the thickness and the height of the maxillary central incisors' alveolar bone near the grafted alveolar cleft area, after comprehensive orthodontic treatment.

METHODS

The sample comprised 30 patients with unilateral alveolar cleft with a mean age of 20.5 years (range, 17-25.8 years). High-resolution cone-beam computed tomography images of the maxilla were obtained 6 to 24 months after the comprehensive orthodontic treatment. The contralateral maxillary central incisor was used as a comparison group. Axial sections at the level of the central incisor root were used to measure the labial and lingual alveolar bone thicknesses. Cross sections were used to measure the bone crest heights using the cementoenamel junction as the reference. Paired t and Wilcoxon tests were used to compare the cleft and noncleft sides.

RESULTS

The labial and lingual bone thicknesses of the maxillary central incisors' alveolar bone were significantly thinner (0.16 and 0.39 mm, respectively), and the labial alveolar crest height distance was significantly greater on the cleft side compared with the noncleft side (-1.2 mm).

CONCLUSIONS

In patients with unilateral cleft lip and palate, the maxillary central incisors adjacent to the grafted alveolar cleft had thinner labial and lingual alveolar bones and an apically displaced labial alveolar crest level than the controls.

Associations between mandibular symphysis form and craniofacial structures

OBJECTIVES

This study aimed to (1) analyze the relationships between mandibular symphysis characteristics (height, prominence, inclination, concavity, and convexity) and facial pattern, skeletal class, lower incisor position, and sex, and (2) determine the associations between the symphysis soft tissue dimensions and the underlying osseous structures.

METHODS

Cone-beam computed tomography (CBCT) images were selected for 385 patients (206 women and 179 men). The patients were classified according to their skeletal class and vertical pattern. The lower incisor inclination (IMPA) was recorded. Twelve measurements were taken for each mandibular symphysis using Invivo5 software (Anatomage, San Jose, CA, USA).

RESULTS

Symphyseal measurements were larger in males than in females. Skeletal Class II and III hyperdivergent patients showed the highest symphysis height values. Hypodivergent individuals showed lower symphysis convexity angles. Concavity of the symphysis was greater for Class II hyperdivergent patients. Lower incisor inclination showed a positive correlation with symphysis concavity and inclination. Moderate and weak correlations were found between hard tissue and soft tissue parameters.

CONCLUSIONS

Only a few characteristics of symphysis morphology depend on sex, incisor position, skeletal class, and vertical pattern. More significant relationships are found when the vertical pattern and skeletal class are analyzed in combination. The shape of the symphysis soft tissue is not directly correlated with the underlying skeletal structures.