A new method of volumetric assessment of alveolar bone grafting for cleft patients using cone beam computed tomography

New Assessment Method of Alveolar Bone Grafting Using Automatic Registration and AI-based Segmentation

OBJECTIVE

The aim of this Technical note is to present a new assessment method of alveolar bone grafts after secondary alveolar bone grafting using automatic registration and artificial intelligence (AI)-based segmentation.

METHODS

A total of 7 Japanese patients (4 men and 3 women) with a unilateral cleft lip, alveolus, and/or palate, who underwent secondary alveolar bone grafting between March 2021 and August 2022 were evaluated. Computed tomography (CT) analyses were performed about 1 month before the surgery, and 1 day and 6 months after the surgery. All CT images were imported into a 3-dimensional analysis workstation. CT images from after the surgery were superimposed onto CT images from before the surgery, by automatic rigid image registration. The segmentation of bone tissues was automatically performed by the AI-based function. Grafted bone was extracted by subtraction of the bone tissue after the surgery from the bone tissue before the surgery. The volumes and Hounsfield units (HUs) of the grafted bones were calculated. The intraclass correlation coefficient (ICC) was reviewed to assess inter-rater reliability.

RESULTS

The ICCs (2,1) of the volumes and HUs measured by the observers immediately after the surgery were 0.95 and 0.99, respectively. On the other hand, the ICCs (2,1) of the volumes and HUs measured by the observers 6 months after the surgery were 0.81 and 0.57, respectively.

CONCLUSIONS

Our new assessment method enables simple and quick evaluation of residual grafted bone after secondary alveolar bone grafting and demonstrated relatively high inter-rater reliability.

Adaptable cascaded registration for personalized maxilla completion and cleft defect volume estimation

BACKGROUND

Cone-beam computed tomography (CBCT) images provide high-resolution insights into the underlying craniofacial anomaly in patients with cleft lip and palate (CLP), requiring non-negligible annotation costs to measure the cleft defect for the guidance of the clinical secondary alveolar bone graft procedures. Considering the cumbersome volumetric image acquisition, there is a lack of paired CLP CBCTs and normal CBCTs for learning-based anatomical structure restoration models. Nowadays, the registration-based method relieves the annotation burden, though one-shot registration and the regular mask are limited to handling fine-grained shape variations and harmony between restored bony tissues and the defected maxilla.

PURPOSE

This study aimed to design and evaluate a novel method for deformable partial registration of the CLP CBCTs and normal CBCTs, enabling personalized maxilla completion and cleft defect volume prediction from CLP CBCTs.

METHODS

We proposed an adaptable deep registration framework for personalized maxilla completion and cleft defect volume prediction from CLP CBCTs. The key ingredient was a cascaded partial registration to exploit the maxillary morphology prior and attribute transfer. Cascaded registration with coarse-to-fine registration fields handled morphological variations of cleft defects and fine-grained maxillary restoration. We designed an adaptable cleft defect mask and volumetric Boolean operators for reliable voxel filling of the defected maxilla. A total of 36 clinically obtained CLP CBCTs were used to train and validate the proposed model, among which 22 CLP CBCTs were used to generate a training dataset with 440 synthetic CBCTs by B-spline deformation-based data augmentation and the remaining for testing. The proposed model was evaluated on maxilla completion and cleft defect volume prediction from clinically obtained unilateral and bilateral CLP CBCTs.

RESULTS

Extensive experiments demonstrated the effectiveness of the adaptable cleft defect mask and the cascaded partial registration on maxilla completion and cleft defect volume prediction. The proposed method achieved state-of-the-art performances with the Dice similarity coefficient of 0.90 ± $\pm$ 0.02 on the restored maxilla and 0.84 ± $\pm$ 0.04 on the estimated cleft defect, respectively. The average Hausdorff distance between the estimated cleft defect and the manually annotated ground truth was 0.30 ± $\pm$ 0.08 mm. The relative volume error of the cleft defect was0.09 ± $0.09\pm$ 0.08. The proposed model allowed for the prediction of cleft defect maps that were in line with the ground truth in the challenging unilateral and bilateral CLP CBCTs.

CONCLUSIONS

The results suggest that the proposed adaptable deep registration model enables patient-specific maxilla completion and automatic annotation of cleft defects, relieving tedious voxel-wise annotation and image acquisition burdens.

Evaluation of Secondary Alveolar Bone Grafting for Unilateral Complete Cleft Alveolus: A Retrospective Cone Beam Computed Tomography-Based Study

Background: In patients with cleft lip and palate (CLP), secondary alveolar bone grafting (SABG) with particulate cancellous bone marrow (PCBM) is recommended. Objective: To compare bone graft outcomes in patients with unilateral CLP, when SABG is completed before or after canine tooth eruption (ACE or BCE), as measured by cone beam computed tomography (CBCT). Methods: Patients were allocated into two cohorts, ACE and BCE. The outcomes were evaluated using CBCT, followed by univariate and multifactorial analyses. Results: A total of 468 patients (age 11.61 ± 4.03 years; male/female 288/180) were analyzed, including 282 in the BCE group (9.41 ± 1.59 years, 175/107) and 186 in the ACE group (14.95 ± 4.31 years, 113/73). Although 5-level assessment revealed no significant difference in clinical success rate (>4 points) between the BCE and ACE groups (53.90% vs. 47.85%, p = 0.20), BCE group showed significantly higher rate of bone bridges formation (73.05% vs. 62.90%, p = 0.02), which can be attributed to variations in orthodontic participation and follow-up time. Independent predictors of graft failure were wide cleft, severe oronasal fistula, no palatal bone wall, and insufficient PCBM filling (p < 0.01). Conclusions: SABG should be performed before canine eruption with more aggressive PCBM filling and oral fistula management.

Bioglass 45S5, a relevant alternative to autogenous harvesting for secondary alveolar bone grafts in clefts? Retrospective study of one hundred surgeries

The secondary alveolar bone grafting (SABG) step restores the continuity of the alveolar bone necessary for dentition. Faced with the complications of autografts, synthetic biomaterials such as Bioglass (BG) 45S5 have been proposed. The objective was to evaluate the success rate of SABG with the addition of BG 45S5 and to highlight the prognostic factors. Patients who underwent operation between 2015 and 2021 and had follow-up cone-beam computed tomography (CBCT) were analyzed. Multivariate analysis was performed to determine factors influencing radiographic success. A total of 102 SABG were analyzed. They were unilateral total cleft lip and palate (49, 48.0%). The mean age at surgery was 9.32 ± 3.09 years. Surgeries were performed mainly outside a syndromic context and without a family history after orthodontic preparation. The radiographic success rate at 1 year was 80.4%. Mixed dentition stage (odds ratio [OR] = 7.3, p = 0.024), absence of syndromic context (OR = 20.7, p = 0.024) and female sex (OR = 4.88, p = 0.021) were factors predictive of surgical success. The use of BG 45S5 instead of autograft is relevant for SABG, with a 1-year success rate of over 80%. The stage of mixed dentition, the absence of syndromic context, and female sex were factors for good prognosis.

Clinical Effect of Platelet-Rich Fibrin Combined with BIO-GENE Artificial Bone Meal in Bone Defects After Jaw Cyst Surgery

Purpose

To compare the clinical repair effects of leaving the defect empty and using Platelet-Rich Fibrin (PRF) combined with BIO-GENE artificial bone powder in patients with bone defects 6 months after jaw cystectomy.

Patients and Methods

From June 2021 to June 2022, 70 patients who were admitted to the Department of Stomatology, Affiliated Hospital of Yanbian University, and were diagnosed with jaw cysts postoperatively were selected. All of the patients were divided into two groups according to random method, among which 35 patients who underwent cystectomy alone were recorded as group A, which served as blank control; 35 patients who underwent cystectomy and PRF combined with BIO-GENE artificial bone meal repaired bone defects during the same period were recorded as group B. 3D Slicer 5.0.3 software was used to reconstruct Cone Beam Computed Tomography (CBCT) after operation. In this study, the preoperative and postoperative CBCT data of the patients were analyzed using 3D Slicer 5.0.3 software in DICOM format to calculate the cleft volume before surgery and the newly formed bone volume after surgery. The osteogenesis rate was measured based on these calculations.The bone formation percentage in the bone defect area was recorded at 6 months, and the clinical curative effects of the two groups were compared.

Results

After 6 months of surgery, the patients showed varying degrees of restoration in the jaw cyst area.The osteogenesis rate at 6 months in group A was 76.06±13.38%, while group B had a rate of 92.87±5.72%.The CBCT values in group B were higher than those in group A at 6 months post-surgery (P<0.05), t=-6.84.Group A and Group B showed a statistically significant difference.

Conclusion

Compared with simple cystectomy, PRF combined with BIO-GENE artificial bone powder has a better effect on the speed of bone repair after cystectomy within 6 months and provides more favorable effects for the repair of postoperative dentition defects, and provides support to repair teeth after defects such as dental implants.

Influence of osseous structure characteristics of unilateral alveolar cleft on outcomes of alveolar bone grafting: a retrospective study

BACKGROUND

To enhance the success rate of alveolar bone grafting, it is crucial to identify the factors that may influence the postoperative bone formation. This study aimed to investigate the impact of various osseous structure characteristics of alveolar clefts on the survival ratio of autogenous cancellous bone particle grafts.

METHODS

A retrospective study was conducted on 60 patients who underwent surgery performed by the same surgeon between 2016 and 2022. Two researchers measured and recorded the bone defect volume (DV), postoperative bone formation volume at 1 year, contact area between the graft and the bone surface within the cleft (S), cleft width (CW), osseous occlusion relationships, and presence of a cleft palate and initial bone bridge within the cleft for each patient. Pearson correlation analysis, Spearman's correlation analysis, and multiple linear regression analysis were performed.

RESULTS

The analysis results revealed statistical correlations between DV, CW, ratio of S to DV, cleft palate, initial bone bridge presence, and occlusion relationships with the survival rate. Multiple linear regression analysis showed that initial bone bridge and occlusion relationships affected the graft survival rate.

CONCLUSIONS

Based on the presence of initial bone bridges and occlusions, we can make a rough estimate of the postoperative bone formation outcome in patients. However, the underlying mechanisms by which these two factors influence the bone formation require further investigation. In addition, preoperative orthodontic treatment to improve occlusal relationships may improve the postoperative bone formation outcomes in alveolar bone grafting.

Secondary alveolar cleft grafting using autogenous mineralized plasmatic matrix (MPM) versus cancellous bone particles derived from anterior iliac crest

OBJECTIVE

The essential concern of alveolar cleft grafting in patients of cleft lip and palate at the mixed dentition phase is to gain bone within the cleft area that provides closure of the oronasal communication with continuous and stable maxilla for future cleft teeth eruption or implantation. This study aimed to compare the effectiveness of mineralized plasmatic matrix (MPM) versus cancellous bone particles harvested from anterior iliac crest in secondary alveolar cleft grafting.

PATIENTS AND METHODS

This prospective randomized controlled trial was conducted on ten patients with unilateral complete alveolar cleft requiring cleft reconstruction. Patients were randomly divided into two equal groups; group (1) included 5 patients who received particulate cancellous bone derived from anterior iliac crest (control group) and group (2) included 5 patients who received MPM graft prepared from cancellous bone derived from anterior iliac crest (study group). All patients received CBCT preoperatively, immediately postoperatively and after 6 months. On the CBCT, graft's volume, labio-palatal width, and height were measured and compared.

RESULTS

The outcome of the studied patients 6 months postoperatively showed that the control group had significant decrease in the graft volume, labio-palatal width, and height compared to the study group.

CONCLUSION

MPM allowed for the integration of bone graft particles inside a fibrin network, which offers positional stability of the bone particles, thus preserving their shape with subsequent "in situ" immobilization of the graft components. This conclusion was reflected positively in terms of maintained graft volume, width, and height compared to that of the control group.

CLINICAL RELEVANCE

MPM allowed for maintenance of grafted ridge volume, width, and height.

Clinical Application of Allograft Bone of Alveolar Cleft Repair

OBJECTIVES

To investigate the osteogenic effect of allograft bone (BIO-GENE) and autologous iliac crest bone graft in the alveolar cleft repair.

MATERIALS AND METHODS

A total of 131 patients with congenital unilateral alveolar cleft who consulted in our hospital from January 2016 to May 2021 were selected and divided into 3 groups according to the different bone restoration materials used. Group A totaling 43 cases was the autologous bone group; group B totaling 41 cases was the BIO-GENE group; and group C totaling 47 cases was the BMP-2+BIO-GENE group. The preoperative and postoperative cone beam CT data of the same patient were imported into MIMICS 21.0 in DICOM format. The preoperative cleft volume and newly formed bone volume were calculated by 3-dimensional reconstruction to measure their osteogenic rate.

RESULTS

The differences in osteogenesis rates were not statistically significant in the group B compared with the group A, and in the group C compared with the group B ( P >0.05 for both). The differences in osteogenesis rates were statistically significant in the group C compared with the group A ( P =0.003).

CONCLUSIONS

Comparative studies found the allograft bone with an ideal artificial material to repair alveolar clefts has become possible. Meanwhile, the addition of BMP-2 in the allograft bone significantly increased the osteogenic rate.

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).

Machine learning in 3D auto-filling alveolar cleft of CT images to assess the influence of alveolar bone grafting on the development of maxilla

BACKGROUND

Machine learning based auto-segmentation of 3D images has been developed rapidly in recent years. However, the application of this new method in the research of patients with unilateral cleft lip and palate (UCLP) is very limited. In this study, a machine learning algorithm utilizing 3D U-net was used to automatically segment the maxilla, fill the cleft and evaluate the alveolar bone graft in UCLP patients. Cleft related factors and the surgery impact on the development of maxilla were analyzed.

METHODS

Preoperative and postoperative computed tomography images of 32 patients (64 images) were obtained. The deep-learning-based protocol was used to segment the maxilla and defect, followed by manual refinement. Paired t-tests and Mann-Whitney tests were performed to reveal the changes of the maxilla after surgery. Two-factor, two-level analysis for repeated measurement was used to examine the different trends of growth on the cleft and non-cleft sides of the maxilla. Pearson and Spearman correlations were used to explore the relationship between the defect and the changes of the maxillary cleft side.

RESULTS

One-year after the alveolar bone grafting surgery, different growth amount was found on the cleft and non-cleft sides of maxilla. The maxillary length (from 34.64 ± 2.48 to 35.67 ± 2.45 mm) and the alveolar length (from 36.58 ± 3.21 to 37.63 ± 2.94 mm) increased significantly only on the cleft side while the maxillary anterior width (from 11.61 ± 1.61 to 12.01 ± 1.41 mm) and posterior width (from 29.63 ± 2.25 to 30.74 ± 2.63 mm) increased significantly only on the non-cleft side after surgery. Morphology of the cleft was found to be related to the pre-surgical maxillary dimension on the cleft side, while its correlation with the change of the maxilla after surgery was low or not statistically significant.

CONCLUSION

The auto-segmentation of the maxilla and the cleft could be performed very efficiently and accurately with the machine learning method. Asymmetric growth was found on the cleft and non-cleft sides of the maxilla after alveolar bone graft in UCLP patients. The morphology of the cleft mainly contributed to the pre-operation variance of the maxilla but had little impact on the maxilla growth after surgery.

Comparison of Preoperative Measurement Methods of Alveolar Cleft Volume Using Cone Beam Computed Tomography between Computer Simulation and Water Displacement Methods

OBJECTIVE

To compare the use of a computer simulation by Mimics software and the water displacement method as means for measurement of alveolar cleft volume on cone beam computed tomography (CBCT) data.

DESIGN

Prospective study.

SETTLING

Institutional research.

PATIENTS

Patients with unilateral complete cleft lip and palate (UCCLP) who would undergo alveolar bone grafting.

INTERVENTIONS

CBCT images of twenty patients with UCCLP were included in the study. In the first method, the water displacement method was adopted to measure volume of plasticine filled in the alveolar cleft imprinted on 3D printed model of maxilla. In the second method a volumetric assessment function in Mimics software was adopted to measure volume of 3D virtual model of alveolar cleft constructed from CBCT images. A comparison on the alveolar cleft volumes derived from the two methods was assessed using the statistical paired t-test.

MAIN OUTCOME MEASURE

The paired-t test showed no statistically significant difference between alveolar cleft volumes measured by the two methods (P = 0.075).

RESULTS

Mean volume of the alveolar cleft measured by the water displacement method was 1.03 ± 0.31 ml whereas by the computer simulation using Mimics software the value was 1.00 ± 0.31 ml. The mean difference between the two methods was 0.03 ± 0.08 ml.

CONCLUSION

The computer simulation by Mimics software as a means for measurement of alveolar cleft volume on CBCT data is as accurate as the measurement by the water displacement method.

Cone Beam Computed Tomographic Analysis Demonstrates a 94% Radiographic Success Rate in 783 Alveolar Bone Grafts

PURPOSE

Success of alveolar bone grafting has been estimated using 2-dimensional periapical radiographs that are associated with image distortion. Cone beam computed tomography (CBCT) accurately displays 3-dimensional anatomy. This study sought to develop and apply a radiographic measure of alveolar bone grafting success using CBCT.

METHODS

This was a retrospective case series composed of patients with cleft lip/palate who had iliac crest bone grafting by 1 surgeon from 2005 to 2020. CBCT scans were obtained ≥4 months after graft. The outcome variables included vertical bone height on cleft adjacent teeth, labiopalatal thickness, and nasal floor symmetry and were scored using a 1 to 4 ordinal scale. Vertical height was determined by the distance from the cementoenamel junction to the marginal bone level of cleft adjacent teeth (1: ≥75% root length, 2: ≥50 to <75%, 3: ≥25 to <50%, 4: <25%), labiopalatal thickness was scored by comparing graft thickness with root width of cleft adjacent teeth (1: <50%, 2: ≥50, 3: ≥75%, 4: ≥100%), and piriform symmetry was established by comparing the nasal floor height between sides (1: ≥6 mm, 2: ≥3 and < 6 mm, 3: ≥1 and < 3 mm, 4: a score of ≥3 < 1 mm). To be considered a successful graft, each dimension scored ≥3. Grafts were also successful if piriform symmetry scored 2, when all other measures indicated success.

RESULTS

The sample was composed of 618 patients with 783 alveolar cleft sites. Subjects' median age was 10.0 (interquartile range 1.6 years), and 59% were male. CBCT scans were obtained a median of 9.7 months (interquartile range 68.8 months) after grafting. There was good-to-excellent intrarater and inter-rater agreement for measurements. Alveolar bone grafting was radiographically successful in 94% of patients.

CONCLUSIONS

This is a valid and reliable assessment tool, and when applied to a large cohort, it demonstrated a 94% graft success rate. Future studies will identify predictor variables associated with bone graft outcomes.

Validation of a 3D methodology for the evaluation and follow-up of secondary alveolar bone grafting in unilateral cleft lip and palate patients

OBJECTIVE

The aim of the study was to propose and validate a method for three-dimensional (3D) quantitative assessment of secondary alveolar bone grafting (SABG) and its stability in time for patients with unilateral cleft lip and palate (UCLP).

SETTINGS AND SAMPLE POPULATION

Ten non-syndromic UCLP patients (9 males and 1 female with a mean age of 9.5 ± 0.9 years) undergoing SABG with good quality preoperative, immediate postoperative (6 weeks) and 6 months postoperative Cone Beam Computed Tomography (CBCT) scans were selected.

MATERIALS AND METHODS

The preoperative and 6 months postoperative scans were registered onto the immediate postoperative scan. The bone-grafted region was defined on the immediate postoperative scan and refined on the registered preoperative scan resulting in a 3D volume. The residual bone graft was calculated by applying threshold based segmentation on the registered 6 months postoperative scan within the segmented bone graft volume of the previous step. Inter and intra observer tests using intra-class correlation coefficient (ICC) were applied comparing the volumes of the 3D models.

RESULTS

An excellent reliability was found for inter and intra observers with ICC ≥ 0.95.

CONCLUSIONS

The presented method proved to be reliable for volumetric assessment of the alveolar bone graft in UCLP patients, as well as to assess the percentage of bone resorption during follow-up.

Mind the Gap: Alveolar Bone Graft Revision in the Era of Computed Tomography

OBJECTIVE

To determine the rate of revision alveolar bone grafting (ABG) in patients with cleft lip and palate (CLP) before and after the introduction of postoperative computed tomography (CT).

DESIGN

Retrospective case-control study analyzing the incidence of revision ABG in patients with and without postoperative CT scans for graft success evaluation.

SETTING

Academic tertiary care pediatric hospital.

PATIENTS

Eighty-seven patients with CLP or cleft lip and alveolus treated with autologous iliac crest bone grafting for alveolar clefts over a 10-year period (January 2009 to March 2019) with minimum 6-month follow-up. Fifty patients had postoperative CT evaluation; 37 did not.

INTERVENTIONS

Postoperative CT to determine ABG success, versus standard clinical examination and 2-dimensional radiographs.

MAIN OUTCOME MEASURES

Requirement for revision ABG, defined as failure of the original graft by clinical or radiographic examination.

RESULTS

Fifty-eight percent of patients underwent a postoperative CT scan at median interval of 10 months after surgery. Patients with postoperative CT evaluation had a 44% rate of revision ABG (22/50) for inadequate graft take, compared to 5% (2/37) in patients without postoperative CT (P < .001; 95% CT, 31%-58% in the CT group, 1%-16% in the non-CT group).

CONCLUSIONS

Computed tomography evaluation after ABG is associated with a significantly increased revision rate for inadequate graft take. The presence of a secondary palatal fistula at the time of original ABG is not associated with revision requirement. Lack of standardized dental and orthodontic records complicates the study of ABG outcomes and presents an area for systems-based improvement.

Regeneration in Experimental Alveolar Bone Defect Using Human Umbilical Cord Mesenchymal Stem Cells

Cleft lip and palate is a congenital disorder including cleft lip, and/or cleft palate, and/or alveolar cleft, with high incidence.The alveolar cleft causes morphological and functional abnormalities. To obtain bone bridge formation and continuous structure between alveolar clefts, surgical interventions are performed from infancy to childhood. However, desirable bone bridge formation is not obtained in many cases. Regenerative medicine using mesenchymal stem cells (MSCs) is expected to be a useful strategy to obtain sufficient bone bridge formation between alveolar clefts. In this study, we examined the effect of human umbilical cord-derived MSCs by transplantation into a rat experimental alveolar cleft model. Human umbilical cords were digested enzymatically and the isolated cells were collected (UC-EZ cells). Next, CD146-positive cells were enriched from UC-EZ cells by magnetic-activated cell sorting (UC-MACS cells). UC-EZ and UC-MACS cells showed MSC gene/protein expression, in vitro. Both cells had multipotency and could differentiate to osteogenic, chondrogenic, and adipogenic lineages under the differentiation-inducing media. However, UC-EZ cells lacked Sox2 expression and showed the lower ratio of MSCs than UC-MACS cells. Thus, UC-MACS cells were transplanted with hydroxyapatite and collagen (HA + Col) into alveolar cleft model to evaluate bone formation in vivo. The results of micro computed tomography and histological staining showed that UC-MACS cells with HA + Col induced more abundant bone formation between the experimental alveolar clefts than HA + Col implantation only. Cells immunopositive for osteopontin were accumulated along the bone surface and some of them were embedded in the bone. Cells immunopositive for human-specific mitochondria were aligned along the newly formed bone surface and in the new bone, suggesting that UC-MACS cells contributed to the bone bridge formation between alveolar clefts. These findings indicate that human umbilical cords are reliable bioresource and UC-MACS cells are useful for the alveolar cleft regeneration.

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.

Construction and validity of a midsagittal plane based on the symmetry of a 3-dimensional model of the relevant cranial base

INTRODUCTION

The midsagittal plane (MSP) is the foundation for 3-dimensional (3D) cephalometric analyses. This article aimed to provide a protocol to construct a reliable and accurate MSP for 3D cephalometric craniofacial analysis.

METHODS

Cone-beam computed tomography data of 16 adult patients without obvious bilateral asymmetry were collected. The model of the anterior cranial base and sphenoid bone was constructed, and the candidate MSP was determined on the basis of the symmetry of this model. Intraclass correlation coefficients were used to assess intra- and interexaminer reliability of the candidate MSP. To investigate the accuracy of this candidate MSP, we constructed a true plane of symmetry of craniomaxillofacial structure and a control plane on the basis of 3 cranial midline points. We then compared these with the candidate MSP.

RESULTS

This candidate MSP resembled the true plane of symmetry with all the mean absolute errors <1 mm, and all the absolute errors for the candidate MSP were significantly smaller than the control plane (P ≤0.002). The relative intra- and interexaminer reliability for this candidate MSP was almost perfect (intraclass correlation coefficients >0.9).

CONCLUSIONS

The candidate MSP constructed using this method was thought to be reliable and accurate for 3D cephalometric analysis in patients without obvious cranial asymmetry.

Comparison of early and conventional autogenous secondary alveolar bone graft in children with cleft lip and palate: A systematic review

PURPOSE

The literature is scarce on studies comparing secondary alveolar bone graft (SABG) performed early at approximately 5-6 years and at the conventional time at 9-11 years. This systematic literature review(SLR) aimed to compare clinical outcomes after two different timings of SABG in children with unilateral and bilateral cleft lip and palate.

METHODS

The inclusion criteria were autogenous iliac grafts and the following study designs: case control, cohort, clinical controlled trial (CCT), randomized CCT (RCCT), and previous SLRs. Ovid MEDLINE, Ovid EMBASE, Web of Science, Scopus, Cochrane, ProQuest and Google Scholar were the primary databases. Two calibrated examiners worked independently to select the articles. The MINORS evaluation method for surgical non-RCTs was used to assess for quality.

RESULTS

1,111 articles were retrieved and 19 qualified. Different clinical and radiographic outcomes such as bone level, periodontal status, canine eruption and cleft-side tooth survival were evaluated by different assessment methods such as CBCT volume, computed tomography, periodontal evaluation, panoramic, intraoral radiographs, and Bergland scale. No RCCT or meta-analysis was found. None of the studies received the ideal score, which is 16 for non-comparison studies and 24 for comparison studies.

CONCLUSION

Methodological variation, lack of standardization for initial cleft dimension and low-quality level rendered a fair comparison unfeasible. Although further studies are necessary, it can be assumed that early SABG also can be an acceptable option, but this was based on a single study with a reasonable level of evidence.

Comparison of 2- and 3-dimensional radiologic evaluation of secondary alveolar bone grafting of clefts: a systematic review

OBJECTIVE

Secondary alveolar bone grafting (SABG) has become the principal means of treating alveolar cleft defects. We reviewed the literature on 2-dimensional (2-D) and 3-dimensional (3-D) radiographic evaluation of SABG in patients with cleft lip and alveolus (CLA) and those with cleft lip and palate (CLP), with a focus on outcomes.

STUDY DESIGN

We searched several electronic databases to the end of 2018. The inclusion criteria were nonsyndromic CLA or CLP treated with SABG at an optimal age and evaluation performed no earlier than 3 months postoperatively. Study quality was evaluated by using the Methodological Index for Non-Randomized Studies and the Cochrane Collaboration tool.

RESULTS

We identified 282 articles from 3 databases. Full texts of 102 articles were analyzed, and finally 11 articles were included for qualitative analysis. 2-D and 3-D radiographic evaluations were performed in each study. Traditional 2-D radiographic imaging tended to overestimate success; bone resorption in the labiopalatal direction was inaccurate in 2-D views. Most articles were observational in nature and of moderate methodologic quality.

CONCLUSIONS

2-D evaluation tended to overestimate SABG outcomes; 3-D evaluation was more precise and reliable than 2-D radiography. A gold standard 3-D evaluation protocol is required for quantitative comparisons in the future.

An Accurate Volumetric Analysis Method for Evaluating Outcomes of Alveolar Cleft Reconstruction

An accurate volumetric analysis method for evaluating the outcomes of different types of alveolar cleft reconstruction is essential because it can help determine which graft material is more effective, confirm favorable times for alveolar bone grafting, and improve surgical techniques. This study aimed to introduce a novel method of precisely calculating the bone formation ratio using computer-aided engineering after surgery. A patient with a unilateral alveolar cleft who was treated with anterior iliac crest bone grafting was enrolled in this study. Helical computed tomography scans were performed preoperatively and 12 months postoperatively. The Digital Imaging and Communications in Medicine (DICOM) data were reconstructed as three-dimensional images and saved in the STL format by using Mimics software. STL data were processed by Geomagic Wrap 2017, using the Boolean operation, the newly formed bone of the alveolar was segmented by identifying the differences between the preoperative and the postoperative three-dimensional images. For this patient, the mean volume of the newly formed bone was 0.387 cm, the morphology was clear, the bone formation ratio was 41.4%, the mean time required for calculating the newly formed bone volume was 23 minutes, and the bone survival ratio was 38.7%. This method is a clinically practical, accurately measurement and time-saving method to evaluate the outcome of alveolar cleft reconstruction. Both the volumetric assessment and morphological analysis of the newly formed bone could be determined in a precise manner.

Comparative Volume Analysis of Alveolar Defects by 3D Simulation

A precise volumetric assessment of maxillary alveolar defects in patients with cleft lip and palate can reduce donor site morbidity or allow accurate preparation of bone substitutes in future applications. However, there is a lack of agreement regarding the optimal volumetric technique to adopt. This study measured the alveolar bone defects by using two cone-beam computed tomography (CBCT)-based surgical simulation methods. Presurgical CBCT scans from 32 patients with unilateral or bilateral clefts undergoing alveolar bone graft surgery were analyzed. Two hands-on CBCT-based volumetric measurement methods were compared: the 3D real-scale printed model-based surgical method and the virtual surgical method. Different densities of CBCT were compared. Intra- and inter-examiner reliability was assessed. For patients with unilateral clefts, the average alveolar defect volumes were 1.09 ± 0.24 and 1.09 ± 0.25 mL (p > 0.05) for 3D printing- and virtual-based models, respectively; for patients with bilateral clefts, they were 2.05 ± 0.22 and 2.02 ± 0.27 mL (p > 0.05), respectively. Bland–Altman analysis revealed that the methods were equivalent for unilateral and bilateral alveolar cleft defect assessment. No significant differences or linear relationships were observed between adjacent different densities of CBCT for model production to obtain the measured volumes. Intra- and inter-examiner reliability was moderate to good (intraclass correlation coefficient (ICC) > 0.6) for all measurements. This study revealed that the volume of unilateral and bilateral alveolar cleft defects can be equally quantified by 3D-printed and virtual surgical simulation methods and provides alveolar defect-specific volumes which can serve as a reference for planning and execution of alveolar bone graft surgery.

Current methods for secondary alveolar bone grafting assessment in cleft lip and palate patients - A systematic review

INTRODUCTION

The development of 3D X-ray diagnostics has led to new methods for secondary alveolar bone grafting (SABG) assessment. The aim of this study was to collect and present literature from the years 2007-2018, and review on the current treatment outcome assessment methods for SABG.

MATERIALS AND METHODS

A systematic review of literature from 2007 to 2018 was carried out, following PRISMA guidelines. 426 records were identified after duplicate references had been removed. 25 articles were included in the review. The Cochrane Collaboration tool or the methodological index for non-randomized studies was used for quality evaluation.

RESULTS

Computed tomography and cone beam computed tomography were preferentially used for SABG treatment outcome verification. There were different assessment protocols. Due to the ways in which results were presented, methods were divided into five groups: linear measurements, volumetric measurements, density measurements, percentage ratios, and scales. There was only one randomized, controlled trial with high methodological quality.

CONCLUSIONS

1. Currently, 3D X-ray imaging is a standard treatment outcome verification method for SABG. 2. It is necessary to establish the required postoperative follow-up time for best SABG treatment outcome assessment. More prospective studies to assess bone graft outcomes after 6 months and 1 year are required.