Reinhilde Jacobs

Autogenous transalveolar transplantation of maxillary canines: a systematic review and meta-analysis

Summary Background and objectives The objective was to systematically review transalveolar transplantation of maxillary canines and the long-term outcome for an average follow-up period of 2 years or more. Data collection and analysis A systematic review of the currently available literature until December 2017 was conducted, using Medline, Cochrane Central, Web off Science, and PubMed. Articles were screened for 1. indications, 2. contra-indications, 3. surgical planning, 4. surgical technique, 5. associated risk factors, and 6. long-term outcome for transalveolar transplantation of maxillary canines with the following outcome measures: bone-related outcomes, tooth-related outcomes, soft tissue-related outcomes, and aesthetic outcome measures. Descriptive statistics, as well as a quality assessment of included articles, were performed. Following study retrieval and selection, relevant data was extracted and the risk of bias was assessed using the Methodological index for non-randomized studies (MINORS). Results Twelve articles were included in this review. These studies included outcome data for 783 autotransplanted maxillary canines, with long-term studies indicating a clinically acceptable overall outcome. Limitations Since the lack of randomized controlled trials considering this topic, the quality of the evidence in the present review is considered low. However, impacted maxillary canines are a rare anomaly and different aspects, such as position of the impacted canine, patient’s age and patient’s demands, and expectancies must be taken into account, it is practically impossible to randomize treatment. Conclusions There is sufficient evidence to justify the transalveolar transplantation of maxillary canines as a legitimate treatment technique for impacted maxillary canines deemed difficult to treat with surgical exposure and subsequent orthodontic alignment. Long-term studies have shown that a good overall outcome is to be expected. There is no clear agreement in the literature on the indications and contra-indications for transalveolar transplantation of maxillary canines. Implication of key findings It is highly desirable that further research on this issue be undertaken, high-quality observational studies are recommended. Registration PROSPERO (CRD42017056348)

Three-dimensional aesthetic assessment of class II patients before and after orthognathic surgery and its association with quantitative surgical changes

The aim of this study was to compare evaluations of the aesthetic outcome of class II orthognathic patients, as performed by observers with varying expertise using three-dimensional (3D) facial images, and to examine the relationship of aesthetic ratings in relation to quantitative surgical changes. Pre- and postoperative 3D facial images of 20 surgically treated class II patients (13 female, 7 male) were assessed for aesthetics by orthodontists, maxillofacial surgeons, and laypeople. Attractiveness ratings for the lips, chin, and overall facial aesthetics were evaluated on a 5-point Likert scale. Correlation between the aesthetic scores was obtained and quantitative surgical changes were examined. For all groups of observers, significant improvements in attractiveness scores were found, especially for the chin assessment. Orthodontists perceived the greatest improvement and laypeople the smallest. Overall, laypeople scored higher with less variability, but with lower intra- and inter-observer agreement. No significant correlation was found between the aesthetic improvement and soft tissue surgical changes. To avoid patient dissatisfaction, it is important to bear in mind that the demands and perception of aesthetic improvement after orthognathic surgery are higher for clinicians than for the general public.

Estimation of the radiation dose for pediatric CBCT indications: a prospective study on ProMax3D

BACKGROUND An increasing number of CBCT units and a wide variability of radiation doses have been reported in dentistry lately. AIM To estimate the effective, cumulative, and organ absorbed doses in children exposed to CBCT over 2 years. DESIGN A prospective study was conducted in children who underwent CBCT diagnostic imaging with the ProMax3D machine. Organ and effective doses were calculated by Monte Carlo simulation using 5- and 8-year-old pediatric voxel phantoms. Extrapolation procedures were applied to estimate doses for other ages and CBCT protocols used in clinical conditions. RESULTS The median effective dose was 137.9 μSv, and the median cumulative dose was 231.4 μSv. Statistically significant differences in the effective doses and cumulative doses were found for various indications of CBCT in children (P < 0.001). The median absorbed organ dose for brain and thyroid was significantly higher for the clinical condition that required large FOVs (2.5 mGy and 1.05 mGy, respectively) compared to medium (0.19 and 0.51 mGy) and small FOVs (0.07 and 0.24 mGy; P < 0.05). The radiation dose of salivary glands did not vary significantly with FOV. CONCLUSION The results revealed the variation of CBCT doses and the influence of FOV size in pediatric exposure.

Is oestrogen associated with mandibular condylar resorption? A systematic review

A systematic review of the literature was performed regarding the influence of oestrogen on the occurrence of mandibular condylar resorption. Search terms for oestrogen were used in combination with terms related to the effect on condylar remodelling. A search of the PubMed, Embase, and Cochrane Central Register of Controlled Trials databases yielded 419 articles published between October 1993 and March 2017. An additional 48 articles were retrieved through manual searching of the reference lists. After initial abstract selection, 94 eligible articles were screened in detail, resulting in a final number of 33 articles included in the review. From this review, no evidence was found that oestrogen (deficiency) contributes to mandibular condylar resorption. The conclusions are limited by the lack of studies with a high level of evidence. Further investigations on serum oestrogen concentrations in women with condylar resorption are needed. Moreover, future studies should focus on the effects of the different types of medication and diseases influencing oestrogen concentrations, the utility of oestrogen concentrations during preoperative screening, and the policies for managing orthognathic surgery patients with an oestrogen deficiency. Finally, whether the mechanisms and risk factors that lead to idiopathic condylar resorption are the same in condylar resorption following orthognathic surgery remain to be elucidated.

Evaluation of Threshold Values for Root Canal Filling Voids in Micro-CT and Nano-CT Images

While several materials and techniques have been used to assess the quality of root canal fillings in micro-CT images, the lack of standardization in scanning protocols has produced conflicting results. Hence, the aim of this study was to determine a cutoff voxel size value for the assessment of root canal filling voids in micro-CT and nano-CT images. Twenty freshly extracted mandibular central incisors were used. Root canals were prepared with nickel titanium files to an ISO size 40/0.06 taper and then filled with a single cone (40/0.06 taper) and AH Plus sealer. The teeth were scanned with different voxel sizes with either micro-CT (5.2, 8.1, 11.2, and 16.73 μm) or nano-CT (1.5 and 5.0 μm) equipment. Images were reconstructed and analyzed with the NRecon and CTAn software. Void proportion and void volume were calculated for each tooth in the apical, middle, and coronal thirds of the root canal. Kruskal-Wallis and post hoc Mann–Whitney U tests were performed with a significance level of 5%. In micro-CT images, significantly different results were detected among the tested voxel sizes for void proportion and void volume, whereas no such differences were found in nano-CT images (p > 0.05). Micro-CT images showed higher void numbers over the entire root length, with statistically significant differences between the voxel size of 16.73 μm and the other sizes (p < 0.05). The values of the different nano-CT voxel sizes did not significantly differ from those of the micro-CT (5.2, 8.1, and 11.2 μm), except for the voxel size of 16.73 μm (p < 0.05). All tested voxel sizes enabled the detection of root canal filling voids except for the voxel size of 16.73 μm. Bearing in mind the limitations of this study, it seems that a voxel size of 11.2 μm can be used as a reliable cutoff value for the assessment of root canal filling voids in micro-CT imaging.

Three-dimensional planning accuracy and follow-up protocol in orthognathic surgery: a validation study

The purpose of the study was to propose and validate a three-dimensional (3D) tool for the assessment of orthognathic surgery planning accuracy and postoperative follow-up. A total of 15 patients (four male, 11 female; mean age 29.6 years) with skeletal class II and III, who underwent bimaxillary surgery were recruited for the study. All patients had preoperative computed tomography (CT), and cone-beam computerized tomography (CBCT) scans 1-6 weeks and 6 months postoperatively. The data was exported to a customized stepwise module developed in Amira software resulting in the accuracy being presented as translational and rotational differences between the planning and the actual outcome. To evaluate the reliability of the proposed method, intra-class correlation coefficient (ICC) was applied at a 95% confidence interval on the translational and rotational output of two observers. The inter- and intra-observer reliability were found to be high (ICC range: 0.94-0.98) with mean variability of less than 0.4mm and 0.7° for translational and rotational movements for both planning accuracy and follow-up protocols. The study provides a reliable, quantitative and time-efficient method for evaluating the accuracy of virtual surgical planning and postoperative follow-up.

Condylar changes after orthognathic surgery for class III dentofacial deformity: a systematic review

After orthognathic surgery for class II dentofacial deformity, remodelling of the mandibular condyle will take place. In a number of cases, this may evolve towards a phenomenon of condylar resorption. Yet, studies on the occurrence of this complication after the correction of a class III deformity are scarce. A systematic review of the literature was performed with the aim of identifying reports on condylar resorption or remodelling after orthognathic surgery for class III dentofacial deformity. A search of the international databases yielded 12 eligible studies. Eight studies reported some degree of postoperative condylar remodelling, while symptoms of condylar resorption were only described in a limited group of patients. Thus, the literature may show evidence of condylar remodelling after orthognathic treatment of class III patients, and anecdotal reports of condylar resorption exist. The small sample sizes, heterogeneity in methods and outcomes, and use of two-dimensional radiographs indicate the need for updated long-term research. In the future, the use of cone beam computed tomography data for volumetric and morphological condylar analysis in combination with three-dimensional cephalometry may provide the opportunity to further elucidate this phenomenon and better characterize its aetiology.

The clinical outcome of skeletal anchorage in interceptive treatment (in growing patients) for class III malocclusion

A systematic review of the literature was performed regarding the clinical outcome (effectiveness) of bone anchorage devices in interceptive treatment for class III malocclusion. A search of Embase, PubMed and Web of Science databases yielded 285 papers. An additional two articles were retrieved through manual searching of the reference lists. After initial abstract selection, 32 potentially eligible articles were screened in detail, resulting in a final number of eight articles included in this review. Insufficient evidence was found regarding the effects of skeletal anchorage in interceptive class III treatment to support definitive conclusions on long-term skeletal effects and stability. In the short term, it seems that bone anchors can provide more skeletal effect with less dentoalveolar compensations and less unwanted vertical changes. This does not always exclude the use of a face mask. The use of miniscrews as skeletal anchorage device does not seem to provide more skeletal effect, although it could minimize the unwanted dental effects in the upper jaw. No information regarding the need for orthognathic surgery, orthodontic treatment time or patient compliance and complications was found in the selected articles.

Irradiation provided by dental radiological procedures in a pediatric population

BACKGROUND Children are more sensitive to ionizing radiation effects due to their high radiosensitivity. PURPOSE To estimate doses and risks for dental radiological examinations in children. MATERIAL AND METHODS A pediatric population consisting of 7150 children and young adults which underwent 12252 dental radiological examinations (4220 intraoral, 1324 cephalometric, 5284 panoramic radiographs and 1424 CBCTs) within two years were included. Two groups were studied: CBCT group (exposed to CBCT ± conventional radiographs) and 2D group (exposed only to 2D radiological examinations). The effective doses were corrected according to age at exposure and settings parameters (mA;FOV) by using logarithmic fit equations for dose interpolation. The individual cumulative dose, per-caput collective dose and radiation risk were calculated for each group. RESULTS The median effective and cumulative doses for conventional radiographs were lower than 20 μSv and did not vary with age. Children exposed to CBCT had a higher median effective dose (127.2 μSv) and cumulative dose (156.5 μSv) with a significant increased cumulative dose between 11 and 14 years. The CBCT contributed with 70% to the collective dose and per caput collective dose was 184 μSv for CBCT exposures. The Life Attributable Risk (LAR) and Relative Radiation Level (RRL) were significantly higher for children exposed to CBCT under the age of 18. The highest radiation dose for CBCT was equivalent with 34.1 days of natural background radiation and it was found for ages between 11 and 15. CONCLUSION The CBCT doses and radiation risk vary but remain in the lower levels of the relative risk of medical exposures.

CBCT in orthodontics: a systematic review on justification of CBCT in a paediatric population prior to orthodontic treatment

Summary Background Taking into account radiation doses, safety, and protection, we highlighted the features in which cone-beam computed tomography (CBCT) can offer an advantage compared to the conventional two-dimensional imaging in paediatric dentistry before orthodontic treatment. Objective The aim of this article was to conduct a systematic review to assess the diagnostic efficacy of CBCT in the paediatric population at a pre-orthodontic phase. Search methods MEDLINE via PubMed was searched to identify all peer-reviewed articles potentially relevant to the review until 1 July 2018. Relevant publications were selected by two reviewers independently. Selection criteria The literature selection for this systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was based on predetermined inclusion criteria. Data collection and analysis Data were collected on overall study characteristics and examination characteristics of the selected studies. Methodological quality of the selected studies was evaluated. Original studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Thereafter, levels of evidence were obtained according to Grading of Recommendations Assessment, Development and Evaluation criteria. Results As a result of the QUADAS assessment, a total of 37 articles were included in the protocol. Following a proper protocol, CBCT was regarded as a reliable tool for assessment and management of impacted canine and root fracture. It provided a better evaluation of normal and pathological condylar shape and volume. CBCT was a superior choice for pre-surgical diagnostic applications in cleft lip and/or palate over a medical computed tomography based on its lower radiation exposure, shorter investigation time, and low purchase costs. Conclusions CBCT is justified only in those cases where conventional radiography fails to provide a correct diagnosis of pathology. Therefore, it cannot be regarded as a standard method of diagnosis. CBCT imaging may also be justified when it positively affects treatment options or provides treatment optimization. Registration None. Conflict of interest None to declare.