GAND classification and volumetric assessment of unilateral cleft lip and palate malformations using cone beam computed tomography

Optimization of orofacial cleft imaging protocols using device-specific low-dose cone-beam computed tomography

OBJECTIVE

The aim of this study was to present optimized device-specific low-dose cone-beam computed tomography (CBCT) protocols with sufficient image quality for pre-surgical diagnostics and three-dimensional (3D) modelling of cleft defects.

METHODS

Six paediatric skulls were acquired, and an artificial bony cleft was created. A high-resolution CBCT scan acted as a reference standard (Accuitomo 170, Morita, Kyoto, Japan) for comparing eight low-dose protocols of Newtom VGi-evo (QR Verona, Cefla, Verona, Italy), which included Eco and Regular protocols with different field of views (FOVs). Delineation of lamina dura, cementoenamel junction (CEJ), trabecular bone and bony bridge were assessed. A 3D model of the defect was also evaluated.

RESULT

The dose area product of low-dose protocols ranged from 31 to 254 mGy*cm2. Despite the dose difference of up to eight times between applied protocols, trabecular bone and CEJ exhibited appropriate image quality in all scans. However, Regular small FOV protocols (5 × 5 and 8 × 5 cm2), for both lamina dura and bony bridge, demonstrated a significant improvement in image quality compared to Eco FOV counterparts. Based on 3D defect analysis, no significant difference existed between low-dose protocols and the reference standard.

CONCLUSION

The findings highlight the possibility of achieving a considerable reduction (up to eight times) in the radiation dose using low-dose CBCT protocols while maintaining sufficient image quality for assessing anatomical structures and 3D modelling in cleft cases.

The use of CBCT in orthodontics with special focus on upper airway analysis in patients with sleep-disordered breathing

Applications of cone-beam CT (CBCT) in orthodontics have been increasingly discussed and evaluated in science and practice over the last two decades. The present work provides a comprehensive summary of current consolidated practice guidelines, cutting-edge innovative applications, and future outlooks about potential use of CBCT in orthodontics with a special focus on upper airway analysis in patients with sleep-disordered breathing. The present scoping review reveals that clinical applications of CBCT in orthodontics are broadly supported by evidence for the diagnosis of dental anomalies, temporomandibular joint disorders, and craniofacial malformations. On the other hand, CBCT imaging for upper airway analysis-including soft tissue diagnosis and airway morphology-needs further validation in order to provide better understanding regarding which diagnostic questions it can be expected to answer. Internationally recognized guidelines for CBCT use in orthodontics are existent, and similar ones should be developed to provide clear indications about the appropriate use of CBCT for upper airway assessment, including a list of specific clinical questions justifying its prescription.

A Comparative Volumetric Assessment of Cancellous and Cortico-Cancellous Bone Graft in the Management of Unilateral Alveolar Cleft Defect using Cone Beam Computed Tomographic Scan-A Randomized Controlled Trial

Introduction

The most commonly preferred procedure for surgical correction of alveolar bone defect and restoration of bony contour is anterior iliac crest graft. Since the ancient time, cancellous bone graft is considered as a gold standard, but it has a high resorption rate and many other disadvantages, and hence we conducted this study to evaluate the efficacy of Cortico-cancellous bone graft harvested from anterior iliac crest to find out whether it can be used as a substitute for cancellous bone graft or not.

Aims & Objectives

The objectives of present study were to compare and evaluate the bone bridge formation rate, resorption rate, and uptake of bone graft at recipient site using cancellous and corticocanellous bone graft harvested from anterior iliac crest for complete unilateral cleft alveolus defects.

Patients and Method

Total 20 patients were divided into two groups by lottery method of randomization. Each group comprises of total 10 patients treated with cancellous bone graft in group 1 and corticocancellous bone graft in group 2 patients harvested from anterior iliac crest. Preoperatively and postoperatively CBCT scans were taken for each patient to calculate the volume of cleft defect and volume of newly formed bone after 6 months, respectively. Grafting fill rate was calculated and mean graft filling rate observed in the patients of group 1 was 1.14 ± 0.03, and in patients of group 2, it was 1.17 ± 0.03. The mean bone bridge formation rate observed in the patients of group 1 was 91.85 ± 0.81 and in patients of group 2 it was 87.89 ± 0.75. The mean bone resorption rate obtained in the patients of group 1 was 18.74 ± 0.42 and in patients of group 2 it was 16.87 ± 0.52.

Conclusion

The present study concluded that accurate estimation of the amount required for bone grafting in the alveolar cleft can be performed by CBCT scan data using Planmeca Romexis viewer version 5.0 software. Even though the corticocancellous bone graft has some drawbacks, it is equally good as cancellous bone graft because of its less resorption than cancellous bone graft and can be considered as a second best option for secondary alveolar bone grafting.Clinical trial registration no (REF/2020/09/031605)/(CTRI/2020/09/028001).

A Three-Dimensional Scale for the Qualitative and Quantitative Assessments of Secondary Alveolar Bone Grafting (SABG) in Unilateral Cleft Lip and Palate Patients Using Cone-Beam Computed Tomography (CBCT)

Background The objective of our study was to derive an objective assessment scale for three-dimensional (3D) qualitative and quantitative evaluation of secondary alveolar bone grafting (SABG) using cone-bone computed tomography (CBCT) in patients with unilateral cleft lip and palate (UCLP).

Methods CBCT scans for pre- and 3-month post-SABG were reviewed for bone volume, height, width, and density of the bony bridge formed in the cleft defect in 20 patients with UCLP. Basic descriptive and principal component analysis was used to extract the various sub-components of the scale. Spearman's correlation was used to check the validity of the scale, and intra-class coefficient (ICC) and Cronbach's α were calculated to establish the reliability and retest applicability of the scale.

Results Each CBCT scan was assessed in five areas: cementoenamel junction (CEJ), root apex, root midpoint, 3 and 6 mm below CEJ, and tabulated in percentiles of 20, 25, 40, 50, 60, and 75 for all the parameters (bone volume, density, and width). These scores were validated when correlated to the scale given by Kamperos et al. Cronbach's α for the domains demonstrated acceptable to excellent internal consistency. The ICC showed good test–retest reliability having a range of scores from 0.89 to 0.94.

Conclusion The proposed scale for the 3D assessment of SABG in patients with UCLP provides gradation for the objective assessment of the bony bridge. This gradation enables the qualitative and quantitative assessments of the bony bridge, thus allowing each clinician to judge SABG more conclusively.

Evaluation of the CBCT imaging accuracy in the volumetric assessment of unilateral alveolar cleft

INTRODUCTION

Appropriate radiographic evaluation is a fundamental step for determining the topography of the defect before the surgical intervention for alveolar bone grafting. Evaluation of cleft volume by CBCT has been done in dry skull samples in previous studies and it was recommended as an effective tool in the volumetric evaluation of the bone defect prior to the surgery. The purpose of this study was to evaluate the accuracy of preoperative clinical use of CBCT¹ imaging in determining the alveolar cleft volume.

MATERIAL AND METHODS

We performed a clinical study. 20 patients with unilateral alveolar cleft underwent preoperative radiographic evaluation using CBCT scan. Volumetric measurement was performed by an oral and maxillofacial radiologist using 0.5, 1, and 2 mm slices and an oral and maxillofacial surgeon using 2 mm slices. After the closure of the nasal floor and palatal mucosa, the alveolar defect was clinically measured with putty impression material. Descriptive and bivariate statistics were computed and the p-value was set at 0.05.

RESULTS

This study showed that there is a statistically significant difference between CBCT-estimated and clinical volumes of the alveolar cleft (paired T-test, p-value < 0.05).

CONCLUSION

Considering the significant difference between clinical and CBCT-estimated volumes of the alveolar cleft, CBCT imaging is not considered an accurate tool for pre-operative volumetric assessment of the alveolar cleft.

Comparison of Two Methods for Presurgical Volumetric Evaluation of Alveolar Cleft Bone Defects Using Computer-Aided Engineering

ABSTRACT

Precise volumetric evaluation of the alveolar cleft facilitates accurate preparation of bone substitutes and reduces donor site morbidity. This study investigates 2 advanced presurgical volumetric assessment methods that use computer-aided engineering (CAE) software. Preoperative computed tomography (CT) scans from 20 unilateral alveolar cleft patients undergoing secondary alveolar bone grafting (SABG) were analyzed by CAE software. Cleft defect volumes were calculated using the mirror-reversed technique and the subtraction method. The mirror-reversed technique determines defect volume by reversing the noncleft side to the cleft side. The subtraction method determines defect volume by subtracting a mask of the preoperative cleft from a mask generated after simulated cleft filling. The mean defect volumes and calculation times of the mirror-reversed technique (1.27 ± 0.35 cm3; 11.80 ± 1.79 seconds) and the subtractive method (1.23 ± 0.32 cm3; 9.43 ± 1.35 seconds) did not differ significantly. In Bland-Altman analysis the 2 methods were equivalent for alveolar cleft defect assessment. Both methods exhibited acceptable interobserver reliability, high precision, clinical convenience, time efficiency, and high reproducibility, and can serve as valuable tools for the planning and execution of SABG. The subtraction method has broader potential applicability and can simulate intraoperative bone grafting more effectively.

3D morphometric quantification of maxillae and defects for patients with unilateral cleft palate via deep learning-based CBCT image auto-segmentation

OBJECTIVE

This study aimed to quantify the 3D asymmetry of the maxilla in patients with unilateral cleft lip and palate (UCP) and investigate the defect factors responsible for the variability of the maxilla on the cleft side using a deep-learning-based CBCT image segmentation protocol.

SETTING AND SAMPLE POPULATION

Cone beam computed tomography (CBCT) images of 60 patients with UCP were acquired. The samples in this study consisted of 39 males and 21 females, with a mean age of 11.52 years (SD = 3.27 years; range of 8-18 years).

MATERIALS AND METHODS

The deep-learning-based protocol was used to segment the maxilla and defect initially, followed by manual refinement. Paired t-tests were performed to characterize the maxillary asymmetry. A multiple linear regression was carried out to investigate the relationship between the defect parameters and those of the cleft side of the maxilla.

RESULTS

The cleft side of the maxilla demonstrated a significant decrease in maxillary volume and length as well as alveolar length, anterior width, posterior width, anterior height and posterior height. A significant increase in maxillary anterior width was demonstrated on the cleft side of the maxilla. There was a close relationship between the defect parameters and those of the cleft side of the maxilla.

CONCLUSIONS

Based on the 3D volumetric segmentations, significant hypoplasia of the maxilla on the cleft side existed in the pyriform aperture and alveolar crest area near the defect. The defect structures appeared to contribute to the variability of the maxilla on the cleft side.

Intra- and Interobserver Reliability of Bone Volume Estimation Using OsiriX Software in Patients with Cleft Lip and Palate Using Cone Beam Computed Tomography

The objective of the current study was to evaluate intra- and interobserver bone volume measurements and effect of orientation on the reliability of bone volume evaluation in as-acquired vis-à-vis oriented cone beam computed tomography scans using Osirix software and possible correlation between gender, age, and bone volume required. For this, 31 cone beam computed tomography (CBCT) scans of 14 girls and 17 boys (aged 9–13) with unilateral cleft lip and/or palate who met the inclusion criteria were analyzed. Efficacy and reliability of third party software Osirix for bone volume calculation was assessed using as acquired and oriented volumes by three specialists (a radiologist, an orthodontist, and an oral maxillofacial surgeon). The dataset and readings were anonymized to prevent any bias. Two-way mixed model analysis on as-acquired and oriented observations exhibited intra-class coefficient (ICC) values ≥ 0.90. Wilcoxon signed rank test (p = 0.10) and Kruskal–Wallis ANOVA (p = 0.46) indicated that although a clinical difference in volume assessment was seen between as-acquired and oriented observations (inter-observer and intra-observer), it was statistically insignificant. Spearman’s bi-variate correlation analysis revealed a significant relation between the type (side) of cleft and bone volume required to fill the defect (p < 0.05). Although there was clinical difference in bone volume measurement by the three observers, it was insignificant statistically. Clefts on the left side in the patients had significantly more bone required than the right side, whereas age and gender had no relation with bone needed to fill the defect. OsiriX software provided good reliability in measurements of bone volume.

Three-dimensional radiological evaluation of secondary alveolar bone grafting in cleft lip and palate patients: a systematic review

OBJECTIVES

To systematically review the existing literature on the three-dimensional (3D) radiological evaluation of secondary alveolar bone grafting (SABG) in cleft lip and palate (CLP) patients, with specific interest in 3D imaging protocols and assessment methods.

METHODS

A comprehensive literature search on PubMed, Embase and the Cochrane Library was conducted. Included publications concerned 3D imaging for evaluation of SABG in CLP patients while articles about primary or tertiary bone grafting or using of two-dimensional images only were excluded. Study quality was evaluated using the Methodological Index for Non-Randomized Studies  or the Cochrane Collaboration tool for assessing risk of bias.

RESULTS

The search yielded 1735 citations, of which 38 met the inclusion criteria. We noticed a large variability in imaging protocols and bone graft evaluation methods between studies. Most articles were observational studies with medium to low methodological quality, except for the one randomised clinical trial having a low risk of bias.

CONCLUSIONS

There is a lack of prospective, controlled trials based on a consistent imaging protocol with a sufficiently long follow-up period. A pressing need exists for the development of a consistent optimized imaging protocol for diagnosis and follow up of SABG in CLP patients. Although 3D evaluation methods seem to be more precise than two-dimensional methods, we should be careful when comparing the outcomes arising from different 3D measuring techniques.

Fetal dental panorama on three-dimensional ultrasound imaging of cleft lip and palate and other facial anomalies

OBJECTIVES

Craniofacial deformities have a high psychosocial impact. The aim of this paper is to improve obstetric ultrasonography and prenatal detection of facial anomalies by providing a new fetal dental panorama.

MATERIAL AND METHODS

The present study describes a new modality to visualize the fetal tooth germs and an easy step-by-step diagnostic approach. Image acquisition was performed between 23 and 32 weeks of gestation using a Voluson E10 GE ultrasound machine with an RM6C transducer (GE Medical Systems, Zipf, Austria). Reconstruction was performed using Omniview from the axial image. Volume contrast imaging (VCI) was used with a thickness of 20 mm, and a render mode that combined "Rx mode" and "surface texture."

RESULTS

The resulting imaging allows a more precise visualization of the fetal dental arch and can be obtained between 14 and 28 weeks of gestation. The presence of dental anomalies can be a clue for the diagnosis of various congenital defects, in particular conditions with a shortage of other physical abnormalities, such as ectodermal dysplasia and Binder syndrome.

CONCLUSIONS

The creation of a precise fetal dental panorama allows an improved detection of facial deformities.

CLINICAL RELEVANCE

With the current paper, we want to increase prenatal diagnostics facial anomalies, and help to establish a tailored multidisciplinary treatment plan. This paper should be of interest to readers who are currently treating patients with craniofacial malformations and readers who are performing diagnostic prenatal sonography.

Cone-beam CT in paediatric dentistry: DIMITRA project position statement

DIMITRA (dentomaxillofacial paediatric imaging: an investigation towards low-dose radiation induced risks) is a European multicenter and multidisciplinary project focused on optimizing cone-beam CT exposures for children and adolescents. With increasing use of cone-beam CT for dentomaxillofacial diagnostics, concern arises regarding radiation risks associated with this imaging modality, especially for children. Research evidence concerning cone-beam CT indications in children remains limited, while reports mention inconsistent recommendations for dose reduction. Furthermore, there is no paper using the combined and integrated information on the required indication-oriented image quality and the related patient dose levels. In this paper, therefore, the authors initiate an integrated approach based on current evidence regarding image quality and dose, together with the expertise of DIMITRA's members searching for a state of the art. The aim of this DIMITRA position statement is to provide indication-oriented and patient-specific recommendations regarding the main cone-beam CT applications in the pediatric field. The authors will review this position statement document when results regarding multidisciplinary approaches evolve, in a period of 5 years or earlier.

Three-dimensional volumetric analysis of ghost cell odontogenic carcinoma using 3-D reconstruction software: a case report

OBJECTIVE

Ghost cell odontogenic carcinoma is a very rare malignant neoplasm. Tumor volume may be a more precise alternative for determining size, which is usually measured by maximum linear dimension. The purpose of this case report is to highlight the importance of obtaining 3-dimensional (3-D) images of the tumor for volumetric analysis to improve the chances of surgical success. This report presents a case of ghost cell odontogenic carcinoma infiltrating the maxillary sinus through the palate. The lesion was surgically treated and subsequently selected for volumetric reconstruction and analysis of the tumor by using InVesalius software. In this case report, we describe the use of a pictorial technique in which the tumor volume was calculated to help predict the surgical results.

RESULTS

The tumor could be visualized in 3-D, with color improving the image of the segmented volume and thus increasing the perception of boundaries and depth.

CONCLUSIONS

Recognition of the lesion shape by volumetric analysis can provide the surgical team with clearer information, thereby helping in surgical planning and consequently increasing the chances of surgical success.