Aesthetic assessment of maxillary lateral and canine implant-supported crowns by laypersons and orthodontists

INTRODUCTION

The objectives of this study were to evaluate how laypersons and orthodontists evaluate and rank aesthetic parameters of an implant-supported crown (ISC) on the canine position (ISC-C) and lateral position (ISC-L).

METHODS

A digital survey of 11 cases, 5 ISC-C, 5 ISC-L and 1 control case without ISC, was distributed to 207 laypersons and 296 orthodontists. All cases included one extraoral photograph and three intraoral photographs. The respondents were asked to identify the ISC and to evaluate the aesthetic parameters regarding colour of the implant (CI), shape of the implant (SI) and gingival colour around ISC (GCI). Differences within and between the groups were tested using Chi-2-test and Independent-Samples t-test.

RESULTS

All invited laypersons and 184 orthodontists (62% response rate) answered the survey. Orthodontists (89%) more correctly identified the ISC, regardless of its position, than laypersons (50%) (p < 0.001). Both laypersons (54%) and orthodontists (23%) rated higher proportions of acceptance of CI, SI and GCI in favour for the ISC-L than ISC-C (laypersons: 40%, orthodontists: 10%) (p < 0.001). Assessing each parameter separately, orthodontists rated higher for ISC-L, compared to the ISC-C (p < 0.001). In general, laypersons and orthodontist ranked tooth colour (mean, standard deviation [SD]:8.0,1.5 and 9.0, 1.0) and tooth shape (mean, SD: 8.0, 1.7 and 8.8, 1.2) as aesthetically higher than the gingival colour (mean, SD: 7.2, 2.2 and 8.0, 1.7) (p > 0.001).  Conclusion: Laypersons and orthodontists consider the ISC-L as aesthetically more preferable, compared to the ISC-C.

Cone beam computed tomography indications for interdisciplinary therapy planning of impacted canines

OBJECTIVE

To investigate how cone beam computed tomography (CBCT) affects the therapeutic planning of impacted maxillary canines.

STUDY DESIGN

A total of 132 impacted canines from 89 pediatric patients were collected from 3 specialist clinics in Stockholm, Sweden. An interdisciplinary therapy planning team consisting of 5 dental specialists evaluated each case and chose their preferred treatment alternative, initially without and later with CBCT images, to decide whether CBCT was justified for therapy planning. Predefined variables measurable using only 2-dimensional (2D) assessments were analyzed using stepwise logistic regression analyses.

RESULTS

The CBCT was considered indicated in 47% of the cases. Additional information from CBCT led to a treatment decision change in 9.8%. Significant 2D predictors for CBCT justification were horizontal canine angulation compared with vertical angulation (odds ratio [OR] = 10.9), extraction strategy involvement (OR = 6.7), and buccally positioned canines compared with palatal (OR = 5.3), central (OR = 25.0), and distal or uncertain positions (OR = 7.7).

CONCLUSIONS

The benefit-risk assessment of CBCT for impacted canines may be reinforced by performing and applying justification decisions for CBCT acquisition at the therapeutic thinking level. If preliminary treatment planning motivates further in-depth investigation of either root status or tooth location, a CBCT is indicated.

Image quality assessment of low-dose protocols in cone beam computed tomography of the anterior maxilla

OBJECTIVES

To evaluate overall image quality and visibility of anatomic structures on low-dose cone beam computed tomography (CBCT) scans and the effect of a noise reduction filter for assessment of the anterior maxilla.

METHODS

We obtained 48 CBCT volumes on 8 skull-phantoms using 6 protocols: 2 clinical default protocols [standard definition (SD) and high definition (HD)] and 4 low-dose protocols, 2 with a noise reduction filter [ultra-low-dose with high definition (ULDHD) and ultra-low-dose (ULD)] and 2 without [low-dose with high definition (LDHD) and low-dose (LD)]. Overall image quality and visibility of 8 anatomic structures were assessed by 5 observers and statistically analyzed using the Wilcoxon signed rank test. Intra- and interobserver agreement was measured using Cohen's weighted kappa.

RESULTS

HD provided higher overall image quality than diagnostically required; LD scored lower than diagnostically acceptable. ULDHD, ULD, and LDHD were acceptable. For anatomic structures, ULDHD and ULD were acceptable. LDHD and LD showed significantly inferior visibility for 1 and 4 structures, respectively. Mean values of intra- and interobserver agreement were 0.395 to 0.547 and 0.350 to 0.370, respectively.

CONCLUSIONS

ULDHD, ULD, and LDHD may be recommended for assessment of impacted maxillary canines. The noise reduction filter affects image quality positively only at low exposure.

Three-Dimensional Leeds Orthodontic Root Resorption Target Scale (3D-LORTS): A new structured pictographic tool for reporting root resorption caused by impacted maxillary canines detected on CBCT images and its impact on orthodontic treatment planning

OBJECTIVES

The objective of this study was to determine whether use of a root resorption pictogram, the Three-Dimensional Leeds Orthodontic Root Resorption Target Scale (3D-LORTS), in addition to cone beam computed tomography reports was associated with a change in orthodontic extraction decisions in cases with impacted maxillary canines and associated root resorption of adjacent teeth and to assess orthodontists' experiences using the pictogram.

STUDY DESIGN

Orthodontists completed a web-based survey in which they selected their preferred treatment plan for 6 cases. Each case was randomly presented twice, initially without and then subsequently with the pictogram. Statistical analysis was conducted to assess differences in extraction decisions with and without the pictogram and the participants' experiences using the 3D-LORTS.

RESULTS

A total of 194 orthodontists completed the survey. Significant differences in treatment decisions were found for 3 individual cases (P < .05) and for the 6 cases overall (P < .05). The majority of participants had positive perceptions of the pictogram, particularly with respect to ease of use, effect on understanding of root resorption location and severity, and usefulness as a communication aid.

CONCLUSIONS

Inclusion of the pictogram in cone beam computed tomography reports was associated with an overall change in orthodontists' extraction decisions. The majority of orthodontists reported positive experiences using the 3D-LORTS.

Two-Dimensional Analysis of Digital Images through Vector Graphic Editors in Dentistry: New Calibration and Analysis Protocol Based on a Scoping Review

This review was carried out to analyse the functions of three Vector Graphic Editor applications (VGEs) applicable to clinical or research practice, and through this we propose a two-dimensional image analysis protocol in a VGE. We adapted the review method from the PRISMA-ScR protocol. Pubmed, Embase, Web of Science, and Scopus were searched until June 2020 with the following keywords: Vector Graphics Editor, Vector Graphics Editor Dentistry, Adobe Illustrator, Adobe Illustrator Dentistry, Coreldraw, Coreldraw Dentistry, Inkscape, Inkscape Dentistry. The publications found described the functions of the following VGEs: Adobe Illustrator, CorelDRAW, and Inkscape. The possibility of replicating the procedures to perform the VGE functions was analysed using each study’s data. The search yielded 1032 publications. After the selection, 21 articles met the eligibility criteria. They described eight VGE functions: line tracing, landmarks tracing, linear measurement recording, angular measurement recording, image calibration, image overlay, file transfer, and vector graphics development. The features offered by the VGEs bring great precision and objectivity to two-dimensional image analysis. The image analysis and editing procedures are currently not protocolised. Thus, a protocol for image calibration and measurement recording is proposed in order to guarantee the protocol’s replication.

Comparative analysis of panoramic radiography and cone-beam computed tomography in treatment planning of palatally displaced canines

INTRODUCTION

The objective of this research was to compare the predictive value of panoramic radiographs (PRs) and cone-beam computed tomography (CBCT) scans for the estimation of root resorption, spontaneous eruption of a canine, and time for orthodontic traction.

METHODS

CBCT scans and PR images of 88 patients (27 male and 61 female; aged between 11 and 44 years) with 106 palatally displaced maxillary canines were retrieved from a database. Predictive values of several radiographic parameters, including the 3-dimensional angle of the canine, were analyzed using the area under the curve and multiple regression analysis.

RESULTS

The angle to the midline and canine position category had a discriminative ability for root resorption of the central incisors with area under the curve values of 0.63 (95% confidence interval, 0.56-0.79) and 0.83 (95% confidence interval, 0.75-0.91), respectively. PR measurements were not reliable predictors of resorptions, except severe resorptions, of the lateral incisors and the premolars. The measurements describing the position of the canine in relation to the midline could predict spontaneous eruption of the canine, regardless of the imaging method. The canine angle to the midline assessed on CBCT was significantly associated with traction time of the canine, producing the following equation: canine traction time = 49.6 - 0.24 × canine angle to the midline (r² = 0.360).

CONCLUSIONS

Only severe resorptions of roots can be predicted with PRs. The use of CBCT is indicated in cases of impacted canines.

CBCT of Swedish children and adolescents at an oral and maxillofacial radiology department. A survey of requests and indications

Objectives: This retrospective study investigated requests and indications for cone-beam computed tomography (CBCT) in children and adolescents over a 3-year period at one oral and maxillofacial radiology department. Specific aims were to determine what technical settings were used, which caregivers write the referrals, and how often and for what reasons re-exposure was necessary.Materials and methods: Patients <19 years of age who had been referred to the department and undergone a CBCT scan during 2015-2017 were included in the study.Results: CBCT were made in 617 of the 3847 eligible referrals. The most common referral was from general practice dentists (GPD) (43%). Mean age of the patients was 12.5 years (range: 6-18). Nineteen different types of requests were identified. The most common request was assessment of an ectopic canine with a question about potential resorption of adjacent teeth (38.6%). Forty (6.5%) of the CBCT needed to be re-taken due to patient motion artefacts.Conclusions: The most common request and indication for CBCT examination of children and young adults were to assess an ectopic canine and determine the presence of resorption of adjacent teeth. Referrals from GPDs were the most frequent and the largest age group was the 11- to 15-year olds. The reason for re-exposures was motion artefacts. High scanning speed to reduce motion artefacts and a half rotation (180°) to reduce the radiation dose to the patient should be preferred. The need for continuous work with quality and systematic monitoring of radiographic procedures at any radiology department should be given high priority.

Evaluation of orthodontically induced external root resorption following orthodontic treatment using cone beam computed tomography (CBCT): a systematic review and meta-analysis

Background

Orthodontically induced external root resorption (OIRR) is a pathologic consequence of orthodontic tooth movement. However, the limitations of two-dimensional radiography suggest that cone beam computed tomography (CBCT) with its three-dimensional capabilities might be more suitable to assess OIRR.

Objective

The aim of this study was to assess in an evidence-based manner data on linear or volumetric OIRR measurements of permanent teeth by means of CBCT, during and/or after the end of orthodontic treatment.

Search methods

Unrestricted electronic and hand searches were performed up to January 2017 in 15 databases.

Selection criteria methods

Randomized clinical trials, prospective, and retrospective non-randomized studies assessing OIRR during and/or after orthodontic treatment using CBCT in human patients were included.

Data collection and analysis

After duplicate study selection, data extraction, and risk-of-bias assessment according to the Cochrane guidelines, random-effects meta-analyses, followed by subgroup, meta-regression, and sensitivity analyses were also performed in order to evaluate factors that affect OIRR.

Results

A total of 33 studies (30 datasets) were included in the qualitative analysis while data from 27 of them were included in the quantitative analysis. Direct comparisons from randomized trials found little to no influence of appliance-related factors on OIRR. Explorative analyses including non-randomized studies found a pooled OIRR of 0.79 mm based on all included studies and 0.86 mm when OIRR was assessed at the end of orthodontic treatment. Statistically significant differences in OIRR were found according to tooth type or jaw, inclusion of extractions, treatment duration, and diagnostic accuracy of the CBCT.

Conclusions

Based on the results of this study, CBCT seems to be a reliable tool to examine OIRR during or at the end of orthodontic treatment. Although the average OIRR measured with CBCT seems to lack clinical relevance, there are certain factors that may affect OIRR following orthodontic treatment. Nevertheless, due to data heterogeneity and low quality of the included studies, the corresponding results should be interpreted with some caution.

Registration

PROSPERO (CRD42016030131).

Comparisons of the Computed Tomographic Scan and Panoramic Radiography Before Mandibular Third Molar Extraction Surgery

BACKGROUND Mandibular third molar extraction surgery has a postoperative complication of hypoesthesia of the lower lip and/or chin. The objective of the study was to determine if preoperative radiographic examination by panoramic radiography and computed tomography (CT) scan can predict postoperative complications of mandibular third molar extraction surgery. MATERIAL AND METHODS In total, 479 patients who had mandibular third molar extraction surgery were included in this cross-sectional study. Patients had panoramic radiographies and CT scans to determine the relationship of the tooth, the canal, and the buccolingual position. Inferior alveolar nerve sensory impairment was detected using a two-point discrimination method. Wilcoxon test and Tukey's test were used to compare diagnostic modalities at a 99% confidence level. RESULTS Inferior alveolar nerve was more successfully quantified by CT scan compared to panoramic radiography (p<0.0001, q=8.062). Orthopantomography was better than the CT scan in detecting a close relationship of the tooth and the canal (p<0.0001, q=25.609), but the CT scan was better in detecting the buccolingual position of the teeth (p<0.0001, q=36.757). The age of patients (p<0.0001, q=36.757), postoperative bleeding (p<0.0001, q=15.981), and experience of the surgeon (p<0.0001, q=10.99) had an affected on inferior alveolar nerve sensory impairment. CONCLUSIONS Preoperative panoramic radiography, CT scan, age, the experience of the surgeon, and postoperative bleeding can predict postoperative complications for extraction of a mandibular third molar.

Radiation dose from X-ray examinations of impacted canines: cone beam CT vs two-dimensional imaging

OBJECTIVES

To compare the radiation dose to children examined for impacted canines, using two-dimensional (2D) examinations (panoramic and periapical radiographs) and cone beam CT (CBCT).

METHODS

Organ doses were determined using an anthropomorphic 10-year-old child phantom. Two CBCT devices, a ProMax3D and a NewTom5G, were examined using thermoluminescent dosimeters. For the panoramic radiograph, a Promax device was used and for periapical radiographs, a Prostyle device with a ProSensor digital sensor was used. Both the panoramic and the intraoral devices were examined using Gafchromic-QR2 dosimetric film placed between the phantom slices.

RESULTS

ProMax3D and NewTom5G resulted in an effective dose of 88 µSv and 170 µSv respectively. A panoramic radiograph resulted in an effective dose of 4.1 µSv, while a periapical radiograph resulted in an effective dose of 0.6 µSv and 0.7 µSv using a maxillary lateral projection and central maxillary incisor projection respectively.

CONCLUSIONS

The effective dose from CBCT ranged from 140 times higher dose (NewTom5G compared to two periapical radiographs) to 15 times higher dose (ProMax3D compared to three periapical and one panoramic radiograph) than a 2D examination.