Accuracy of cone beam computed tomography–derived casts: A comparative study

Statement of problemThe accuracy of the external surface and internal trabecular architecture of large cone beam computed tomography (CBCT)–derived dentomaxillofacial anatomic casts has not yet been thoroughly investigated.PurposeThe purpose of this comparative study was to evaluate the quantitative accuracy of CBCT-derived mandibular casts by applying an innovative land-mark free methodology.Material and methodsFollowing inclusion and exclusion criteria, a CBCT scan of an 18-year-old woman was acquired. The mandible was segmented and isolated from the data set. The segmented mandible included depiction of the cortical surface, trabecular architecture, erupted teeth, and impacted third molars with incomplete root formation. Fifteen mandibular casts were fabricated by using multijet (MJ=4), digital light processing (DLP=4), stereolithography (SLA=2), fused deposition modeling (FDM=2), colorjet (CJ=2), and selective laser sintering (LS=1)-based high-quality medical commercial and office printers. Each printed cast was scanned and superimposed onto the original mandible, and the accuracy of the complete mandible and individual surfaces were assessed with a color-coded map.ResultsWhen the overall combined error associated with complete casts based on printing technology were compared, MJ showed the highest accuracy (0.6 ±0.7 mm). FDM technology (2.2 ±3.4 mm) had the highest overall absolute mean difference. No significant difference was observed when both individual surfaces and the complete mandible were compared.ConclusionsOverall, casts replicated the skeletal and dental anatomic surfaces well. However, shortcomings were observed in relation to depicting trabecular architecture.     

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

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

Dental age assessment by the pulp/tooth area proportion in cone beam computed tomography: is medico-legal application for age estimation reliable?

IntroductionForensic dentistry has, as one of its main goals, the identification of living and/or deceased individuals, based on the individual features of the teeth. One of the identification criteria to be established is the chronological age. Several authors, including Kvaal, have developed age estimation methods based on secondary dentine deposition. Nowadays, three-dimensional imaging tests, such as Cone Beam Computed Tomography (CBCT), are used in age estimation.ObjectiveThe aims of this research project were to validate Kvaal’s method and its variables in age estimation and to create new linear regression formulae to better represent the study sample.MethodsWe selected 158 CBCT, with a total of 402 sound teeth (central incisors, lateral incisors and canines). The necessary measurements and ratios were calculated in both coronal and sagittal sections, with XelisDental^®. The formulae developed by Kvaal for age estimation calculation were applied. Subsequently, the results were statistically analyzed.Results and DiscussionThe intraclass correlation coefficients from the two measurements ranged from 0.918 to 0.997. The calculated age estimation had a mean error of -21.4years (coronal section) and -26.3years (sagittal section). The t test revealed statistically significant differences between chronological age and estimated age. The absolute values of Pearson’s correlation coefficient between age and the two Kvaal variables ranged from 0.06 to 0.38 and from 0.06 to 0.55. The coefficients of determination are lower than in the original study (between 0.03 and 0.39). In the linear regression formulae, the coefficients of determination ranged from 0.07 to 0.41.ConclusionThis investigation concludes a non-reproducibility of Kvaal’s method in the Portuguese population when applied in CBCT, with statistically significant differences between the chronological age and the dental age, estimated by the pulp/tooth proportion method, based on the teeth analyzed in this study.     

Imaging characteristics of a Stafne bone cavity—panoramic radiography,computed tomography and magnetic resonance imaging

Introduction

A rare case of Stafne bone cavity (SBC) with salivary gland herniation confirmed by magnetic resonance imaging (MRI) is described.

Results

It was diagnosed in a 72-year-old male patient. Surgical intervention was avoided. The report highlights imaging findings of panoramic radiography, computed tomography, and especially magnetic resonance tomography.

Conclusion

It is demonstrated that employment of MRI for further evaluation of suspicion of SBC on panoramic radiographs can be a helpful diagnostic tool.     

Considerations for placement of mandibular buccal shelf orthodontic anchoring screw in Class III hyperdivergent and normodivergent subjects – A cone beam computed tomography study

Purpose

The study simulated a mandibular buccal shelf (MBS) orthodontic anchoring screw insertion path and determine the effect of vertical skeletal pattern, insertion site, vertical level and insertion angle on the slope, cortical bone thickness and distance from molar root to the insertion path.

Effect of bilateral sagittal split ramus osteotomy on temporomandibular joint symptom and condylar position in patients with skeletal class Ⅲ malocclusion by cone beam computed tomography

目的 探讨双侧下颌骨升支矢状劈开截骨后退术（BSSRO）对行正畸—正颌联合治疗的骨性Ⅲ类错牙合患者颞下颌关节（TMJ）症状及髁突位置的影响。方法 选取24例行正畸-正颌联合治疗的骨性Ⅲ类错牙合患者,分别在BSSRO术前、术后1个月、术后12个月按Helkimo指数整理记录关节症状,并行锥形束CT（CBCT）扫描,在三维方向上测量髁突水平位及冠状截面最大径、髁突短轴径、髁突颈部宽度、髁突高度、不同角度（45°、90°、135°）下关节间隙宽度、双侧髁突间距及髁突角度（水平角、垂直角、受力角）,分析不同时期TMJ症状及骨性结构的变化情况。结果 BSSRO术前与术后的Helkimo指数均为Ai、Di 0级或1级,二者之间无差异。与术前相比,术后1个月时髁突水平角、45°及90°下关节间隙宽度增大,135°下关节间隙宽度减小（P<0.05）;术后12个月时,除髁突水平角增大（P<0.05）外,其余测量项目间差异均无统计学意义（P>0.05）。结论 在正畸—正颌联合治疗中,BSSRO不会对Helkimo指数为Ai、Di 0级或1级的骨性Ⅲ类错牙合患者的TMJ症状及髁突位置产生明显的影响。     

Is the quality of root canal filling obtained by cone-beam computed tomography associated with periapical lesions? A systematic review and meta-analysis

Aim

To evaluate the influence of root canal filling quality on periapical lesion status using cone-beam computed tomography (CBCT).

Materials and Methods

The bibliographic search was conducted in electronic databases of PubMed, Embase, Scopus, and Web of Science without restrictions related to the year of publication and language. Inclusion criteria were prospective or retrospective cohort studies that followed periapical pathosis for, at least, 1 year. Three reviewers independently evaluated the eligibility for inclusion, extracted data, and assessed the risk of bias. The quality of the studies was based on the Newcastle–Ottawa Scale. This meta-analysis was performed to evaluate the quality of treatment by the homogeneity and apical extension of the filling.

Results

Of the 1179 studies initially recovered, six cohort studies were included, out of which four were considered with a low risk of bias. The results showed that the absence of gaps in the filling reduced the chance of unhealed periapical lesions by 2.39 times (RR?=?2.39; 95% CI: 1.62–3.53; p?<?0.00001; I² = 55%). An apical filling extension of 0–2 mm below the apex also contributed significantly to the absence of unhealed periapical lesions (RR?=?1.49; 95% CI: 1.15–1.94; p?=?0.003; I² = 2%).

Conclusion

The homogeneity and apical extension of the filling influenced the presence of unhealed periapical lesions in endodontically treated teeth evaluated using CBCT.

Clinical relevance

Apical extension of the filling ranging between 0 and 2 mm short of the apical foramen and the homogeneity of the filling without gaps are directly related to the success rate of root canal treatment.