Analysis of bone volume using computer simulation system for secondary bone graft in alveolar cleft

Comparison of Alveolar Bone Grafting Outcomes using CBCT in Individuals with UCLP Based on the Presurgical Orthodontic Treatment Methods

OBJECTIVE

The purpose is to evaluate outcomes of alveolar bone grafting based on the pre-grafting orthodontic preparation methods.

DESIGN

Retrospective analysis of individuals with unilateral cleft lip and palate.

SUBJECTS AND SETTINGS

28 individuals with non-syndromic UCLP from two craniofacial centers, 14 individuals each from XXXX and XXXX.

INTERVENTIONS

The alignment group underwent maxillary expansion with incisors alignment while the non-alignment group underwent only maxillary expansion for presurgical orthodontic preparation.

METHODS

Initial and post-surgical CBCT scans were compared to observe changes in angulation of the incisor adjacent to the cleft site, alveolar bony root coverage, and bone graft outcomes.

RESULTS

In the alignment group, the buccolingual rotation decreased by 32.35 degrees (p = .0002), the anteroposterior inclination increased by 14.01 degrees (p = .0004), and the mesiodistal angulation decreased by 17.88 degrees (p = .0001). Alveolar bony coverage did not change after bone graft in both groups, and no difference was observed between the groups. Chelsea scale showed satisfactory bone graft outcome (category A, C) in 12 cases (85.71%) in the alignment group and 11 cases (78.51%) in the non-alignment group. The volumetric measurement showed the alignment group had better bone fill of 69.85% versus 51.45% in the non-alignment group (p = .0495).

CONCLUSIONS

Alveolar bony coverage on the tooth adjacent to cleft sites did not change with alveolar bone grafting surgery in either of the alignment and non-alignment group. Presurgical orthodontic alignment does not induce root exposure nor poorer bone grafting outcome.

AAPM Task Group Report 261: Comprehensive quality control methodology and management of dental and maxillofacial cone beam computed tomography (CBCT) systems

Cone-beam computed tomography (CBCT) systems specifically designed and manufactured for dental, maxillofacial imaging (MFI) and otolaryngology (OLR) applications have been commercially available in the United States since 2001 and have been in widespread clinical use since. Until recently, there has been a lack of professional guidance available for medical physicists about how to assess and evaluate the performance of these systems and about the establishment and management of quality control (QC) programs. The owners and users of dental CBCT systems may have only a rudimentary understanding of this technology, including how it differs from conventional multidetector CT (MDCT) in terms of acceptable radiation safety practices. Dental CBCT systems differ from MDCT in several ways and these differences are described. This report provides guidance to medical physicists and serves as a basis for stakeholders to make informed decisions regarding how to manage and develop a QC program for dental CBCT systems. It is important that a medical physicist with experience in dental CBCT serves as a resource on this technology and the associated radiation protection best practices. The medical physicist should be involved at the pre-installation stage to ensure that a CBCT room configuration allows for a safe and efficient workflow and that structural shielding, if needed, is designed into the architectural plans. Acceptance testing of new installations should include assessment of mechanical alignment of patient positioning lasers and x-ray beam collimation and benchmarking of essential image quality performance parameters such as image uniformity, noise, contrast-to-noise ratio (CNR), spatial resolution, and artifacts. Several approaches for quantifying radiation output from these systems are described, including simply measuring the incident air-kerma (Kair) at the entrance surface of the image receptor. These measurements are to be repeated at least annually as part of routine QC by the medical physicist. QC programs for dental CBCT, at least in the United States, are often driven by state regulations, accreditation program requirements, or manufacturer recommendations.

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.

Differences in Practice in Alveolar Bone Grafting Among American Cleft Palate-Craniofacial Association Members

The purpose of this study is to determine areas of agreement and disagreement among American Cleft Palate-Craniofacial Association (ACPA)members in the clinical practice of alveolar bone grafting (ABG), to guide further research to optimize ABG practices.

A cross-sectional survey was conducted.

The respondents were in an academic, combination, or private practice.

The respondents were either plastic or oral and maxillofacial surgeons (OMFS) from various countries.

A de-identified 24-question online survey was distributed to ACPA surgeon members utilizing the Research Electronic Data Capture (REDCap) tool.

Data collected included surgeon specialty, use of various alveolar bone graft surgical techniques, as well as protocols.

There was more variability than consensus between specialties with regards to the preoperative workup, timing of surgery, materials used for bone graft, surgical techniques, perioperative management, and postoperative evaluation. There was consensus on grafting during mixed dentition, not staging soft and hard tissue closure, and using iliac crest for primary and secondary grafting. Disagreements involved factors used to time the procedure and type of imaging used to assess viability. Technical differences involved incision type, part of bone grafted, use of minimally invasive technique, and material used for revisions.

Aside from areas of consensus among surgeons on ABG, several areas, including use of bone substitutes in revision grafting, incision and type of iliac crest graft used during initial grafting, and postoperative protocols, had no consensus. These areas should be targets of further research to determine if there truly is an optimal method to perform ABG.

The study was approved by the University of Illinois at Chicago Institutional Review Board. A de-identified 24-question online survey was distributed to surgeon members of the ACPA utilizing the REDCap tool on August 7, 2020. The survey questions consisted of multiple choice and multiple selection questions including an option to select "other" and specify the information in a blank space. Data collected included surgeon specialty, use of various alveolar bone graft surgical techniques, as well as pre and postoperative protocols. The full survey is included in online Supplemental material. Data analysis was performed in SPSS Statistics 27 (IBM Corp.). Descriptive statistics were performed, and chi-square was used to test for significant differences in survey responses between groups.

Interpretable artificial intelligence for classification of alveolar bone defect in patients with cleft lip and palate

Cleft lip and/or palate (CLP) is the most common congenital craniofacial anomaly and requires bone grafting of the alveolar cleft. This study aimed to develop a novel classification algorithm to assess the severity of alveolar bone defects in patients with CLP using three-dimensional (3D) surface models and to demonstrate through an interpretable artificial intelligence (AI)-based algorithm the decisions provided by the classifier. Cone-beam computed tomography scans of 194 patients with CLP were used to train and test the performance of an automatic classification of the severity of alveolar bone defect. The shape, height, and width of the alveolar bone defect were assessed in automatically segmented maxillary 3D surface models to determine the ground truth classification index of its severity. The novel classifier algorithm renders the 3D surface models from different viewpoints and captures 2D image snapshots fed into a 2D Convolutional Neural Network. An interpretable AI algorithm was developed that uses features from each view and aggregated via Attention Layers to explain the classification. The precision, recall and F-1 score were 0.823, 0.816, and 0.817, respectively, with agreement ranging from 97.4 to 100% on the severity index within 1 group difference. The new classifier and interpretable AI algorithm presented satisfactory accuracy to classify the severity of alveolar bone defect morphology using 3D surface models of patients with CLP and graphically displaying the features that were considered during the deep learning model's classification decision.

Consequence of Synthetic Bone Substitute Used for Alveolar Cleft Graft Reconstruction (Preliminary Clinical Study)

Background  The outcome of alveolar grafting with synthetic bone substitute (Osteon III) in various bone defect volumes is highlighted. Methods  A prospective study was accomplished on 55 patients (6-13 years of age) with unilateral alveolar bone cleft. Osteon III, consisting of hydroxyapatite and tricalcium phosphate, is used to reconstruct the defect. Alveolus defect diameter was calculated before surgery (V1), after 3 months (V2), and finally after 6 months (V3) postsurgery. In the t -test, a significant difference and correlation between V1, V2, and V3 are stated. A p- value of 0.01 is considered a significant difference between parameters. Results  The degree of cleft is divided into three categories: small (9 cases), medium (20 patients), and large (26 cases).The bone volume of the clefted site is divided into three steps: volume 1: (mean 18.1091 mm 3 ); step 2: after 3 months, volume 2 resembles the amount of unhealed defect (mean 0.5109 mm 3 ); and the final bone volume assessment is made after 6 months (22.5455 mm 3 ). Both show statistically significant differences in bone volume formation. Conclusion  An alloplastic bone substitute can also be used as a graft material because of its unlimited bone retrieval. Osteon III can be used to reconstruct the alveolar cleft smoothly and effectively.

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).

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.

Correlation between alveolar cleft morphology and the outcome of secondary alveolar bone grafting for unilateral cleft lip and palate

Background

Secondary alveolar bone grafting (SABG) is an integral part of the treatment for cleft lip and alveolus and cleft lip and palate. However, the outcome of SABG was not satisfactory as expected, factors that affecting the outcome were still controversial. The aims of this study were to summarize a new method for the classification of alveolar cleft morphology in patients with unilateral cleft lip and alveolus or unilateral cleft lip and palate, to evaluate the correlation between the morphology and SABG outcomes, to identify factors that might predict the outcomes.

Methods

The characteristics of the cleft morphologies of 120 patients who underwent SABG were observed using the preoperative Cone-Beam Computed Tomography (CBCT) images. 52 patients who had CBCT scans performed at least 6 months after SABG were included for the evaluation of outcomes. Both categorical and continuous evaluation methods were measured. Correlations between cleft morphology and SABG outcomes were assessed using the Pearson correlation coefficient in SPSS 27.0.0.

Results

A new method for the classification of cleft morphology was summarized:type I, prism type (labial defect size ≥ palatal defect size; nasal defect size ≥ occlusal defect size); type II, prism’ type (labial defect ≥ palatal defect; nasal defect < occlusal defect); type III, inverted prism type (palatal defect ≥ labial defect); type IV, funnel type (presented as a significantly narrow defect area in the middle towards the vertical dimension); and type V, undefinable (extremely irregular morphology can’t be defined as any of the above types). Categorical evaluation showed 8 failure, 11 poor, 12 moderate, and 21 good results, while the average bone filling rate was 59.24 ± 30.68%. There was a significant correlation between the cleft morphology and categorical/continuous evaluation outcome (p < 0.05).

Conclusion

The new method for the classification of alveolar cleft morphology summarized in this study was comprehensive and convenient for clinical application. Both categorical and continuous methods should be used for radiographic assessments in patients undergoing SABG. The chances of a successful procedure might be better when the patient has type I or IV morphology, in which the shape is like a funnel in the relatively palatal or occlusal area towards the vertical dimension. A relatively great amount of bone resorption was observed in most patients.

Trial registration Chinese clinical trial registry; registration number: ChiCTR2100054438.

Pilot study of factors contributing to canine impaction after secondary alveolar bone grafting in unilateral cleft lip and palate patients

Alveolar bone grafting (ABG) is broadly performed for cleft lip and palate patients. The rate of canine impaction post-ABG is much higher than the prevalence of canine impaction in non-cleft patients. This pilot study was designed to investigate factors involved in canine eruption failure after ABG and to predict the possibility of canine impaction in unilateral cleft lip and palate (UCLP) patients. This retrospective observational study examined 45 patients with UCLP (mean age 7.9 years) classified into an impacted group (n = 9) and a spontaneously erupted group (n = 36). From 3D images, we measured lateral incisor presence or absence, lateral incisor position on the cleft side, canine position, movement change, cleft volume, and canine and first premolar overlap-area. Multivariate logistic regression analysis using independent variables indicated significant differences in results, selecting highly relevant items. Multivariate analysis indicated a significant association between the overlap-area between the canine and the first premolar at pre-ABG (p = 0.038) and the distance between the cleft side cusp tips of canine and the lateral cleft margin of pre-ABG (p = 0.005). Results suggest that canine impaction is predictable at an early stage in pre-ABG and show the possibility of comprehensive diagnosis of canine impaction using computed tomography.

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.

Correlation between alveolar cleft volume and alveolar bone quality in patients with unilateral cleft lip and palate: A cone-beam computed tomography study

OBJECTIVES

This study aimed to determine the correlation between alveolar cleft volume and fenestration and dehiscence in the adjacent alveolar bone in patients with unilateral cleft lip and palate (UCLP) using cone-beam computed tomography (CBCT) sections.

MATERIALS AND METHODS

In this descriptive, cross-sectional study, CBCT scans of 68 non-syndromic patients with UCLP aged between 6 and14 years were selected. All patients were treated in Iran and had undergone lip and palate repair surgery within the first 3 to 18 months after birth. CBCT scans had been taken after orthodontic expansion and prior to alveolar bone grafting surgery. Cleft volume, fenestration and dehiscence were assessed using Mimics software. Data were analyzed using independent t-test, Kruskal-Wallis test, Spearman's correlation coefficient and logistic regression model.

RESULTS

The mean alveolar cleft volume was 628.66±172.84 mm³. There was a significant negative correlation between cleft volume and fenestration (P<0.001). Also, there was a significant positive correlation between cleft volume and dehiscence (P<0.001) in the adjacent bone.

CONCLUSION

The Mimics software can be successfully used to estimate the cleft volume prior to surgical procedures in UCLP patients. The results suggest that the alveolar cleft volume can be used as an aid to assess the periodontal condition of adjacent teeth. The cleft volume has a negative and positive correlation with fenestration and dehiscence respectively.

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.

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.

Alveolar Cleft Reconstruction Using Morphogenetic Protein (rhBMP-2): A Systematic Review and Meta-Analysis

OBJECTIVE

This study aimed to review the existing evidence regarding reconstruction of the alveolar cleft using recombinant human bone morphogenetic protein-2 (rhBMP-2) in terms of bone volume and bone height.

DESIGN

Systematic review and meta-analysis.

PATIENTS—PARTICIPANTS

A systematic search was done. Randomized and nonrandomized clinical trials, where rhBMP-2 was used in the reconstruction of human alveolar cleft were included.

INTERVENTIONS

Reconstruction of alveolar cleft with rhBMP-2.

MAIN OUTCOME MEASURES

Average bone volume formation and average bone height formation in the alveolar cleft. Mean difference was calculated and pooled by meta-analysis.

RESULTS

Of 709 identified articles, 5 studies met the inclusion criteria. The average bone volume formation was higher in the rhBMP-2 group than in the control group (61.11% vs 59.12%). The average bone height formation was higher in the control group compared to the rhBMP-2 group (75.4% vs 61.5%). The risk of bias in the selected articles was high. The meta-analysis showed that rhBMP-2 treatment may benefit bone formation compared to iliac crest graft (low certainty evidence; mean difference: -208.76; 95% confidence interval: -253.59 to -163.93; -I² = 0%).

CONCLUSIONS

The results obtained in primary articles are promising but have a high risk of bias and have low quality of evidence; therefore, it is necessary to conduct controlled clinical trials with a greater number of patients to recommend the use of rhBMP-2 in the treatment of the alveolar cleft. PROSPERO registration number: CRD42018077741.

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.

Quantifying Soft Tissue Changes in Cleft Lip and Palate Using Nonionizing Three-Dimensional Imaging: A Systematic Review

PURPOSE

The use of nonionizing 3-dimensional (3D) imaging in cleft lip and palate (CLP) research is well-established; however, general guidelines concerning the assessment of these images are lacking. The aim of the present study was to review the methods for quantification of soft tissue changes on 3D surface images acquired before and after an orthopedic or surgical intervention in CLP patients.

MATERIALS AND METHODS

A systematic literature search was performed using the databases MEDLINE (through PubMed), CENTRAL, Web of Science, and EMBASE. The literature search and eligibility assessment were performed by 2 independent reviewers in a nonblinded standardized manner. Only longitudinal studies reporting the assessment of pre- and postoperative 3D surface images and at least 10 CLP patients were considered eligible.

RESULTS

Fifteen unique studies (reported from 1996 to 2017) were identified after an eligibility assessment. The assessment of the 3D images was performed with landmark-dependent analyses, mostly supported by superimposition of the pre- and postoperative images. A wide spectrum of superimposition techniques has been reported. The reliability of these assessment methods was often not reported or was insufficiently reported.

CONCLUSIONS

Soft tissue changes subsequent to a surgical or an orthopedic intervention can be quantified on 3D surface images using assessment methods that are primarily based on landmark identification, whether or not followed by superimposition. Operator bias is inherently enclosed in landmark-dependent analyses. The reliability of these methods has been insufficiently reported.

Compensations in Bone Morphology and the Dentition in Patients With Untreated Unilateral Cleft Lip and Palate: A Cone-Beam Computed Tomographic Analysis

OBJECTIVE

The purpose of this study was to quantitatively assess dentoalveolar and skeletal compensations in patients with untreated unilateral cleft lip and palate (UCLP). We hypothesized that there are significant skeletal and dental adaptations in UCLP cases compared to a comparison maxillary crossbite group.

DESIGN

A convenience retrospective sample of 30 patients with UCLP and a comparison group of 30 patients with unilateral posterior crossbite without CLP. Cone-beam computed tomography scans (CBCTs) were used to evaluate dental and skeletal compensations. In addition, alveolar bone thickness was measured at 2-mm increments in mesiodistal and faciolingual cross-sectional views along the long axis of the central incisors. Alveolar bone height was measured, and the percentage of root length supported by bone was calculated.

RESULTS

Compensations for unilateral cleft lip and palate were restricted to the cleft site and adjacent structures. Dental compensations include alteration in the position of cleft-adjacent maxillary incisors and maxillary canines. No gross skeletal compensations were found. Alveolar support of cleft adjacent incisors was similar to controls except for measurements in the most coronal and apical regions. The cleft group contralateral incisors exhibited buttressing effects and had significantly higher alveolar thickness in the coronal half of the tooth. There was less (5%) alveolar coverage of the cleft-facing aspect of the central incisor root than all other incisors.

CONCLUSION

The bone adaptation to the presence of a cleft was localized in the vicinity of the cleft, and adaptations in the mandible were not apparent.

[Resorbable vs nonresorbable fixation in alveolar bone grafting in unilateral cleft lip and palate patients]

The aim of the study was to evaluate the resorbable vs nonresorbable fixation efficiency in bone grafting for unilateral cleft lip and palate (UCLP) patients. Thirty eight UCLP patients aged from 7 to 17 years (mean 11.5±3.1 years) were divided in two groups with different types of cortical graft fixation: group 1 ─ titanium screws (22 patients), group 2 ─ resorbable pins (16 patients). The Bergland and Chelsea scales were used to evaluate the outcomes 8 months after surgery. Additional authors' original scales were introduced: bone volume scale and pyriform rim restoration scale. The Bergland and Chelsea scales have shown good results in groups 1 and 2 in 91 and 81% of cases, satisfactory in 4.5 and 19% of cases, respectively. Upon the bone volume scale good results were achieved in groups 1 and 2 in 64 and in 75% of cases, satisfactory results - in 18 and 19% of cases, respectively. Upon the pyriform rim restoration scale good results achieved in 59 and 88% of cases, respectively. We also took into consideration the influence of age, diagnosis, post-op complications. No statistically significant difference between groups was found, with neither age nor diagnosis showing any influence. Only postsurgical complications and the stability of the orthodontic design seem to be important for good bone formation after alveolar bone grafting.

An Analysis of Mandibular Symphyseal Graft Sufficiency for Alveolar Cleft Bone Grafting

The purpose of this study was to evaluate the sufficiency of the mandibular symphysis as a donor site for unilateral and bilateral alveolar grafting, measuring both the alveolar cleft volume and maximum bone graft volume that can be harvested from the mandibular symphysis using 3-dimensional computed tomography (CT) and software in children and adults. Computed tomography data obtained from 20 unilateral and bilateral cleft lip palates patients in the preoperative period were used in this study. The patients were divided into 2 groups: children (female, n = 5; male, n = 5) and adults (female, n = 5; male, n = 5). The required bone graft volume for grafting and the maximum bone graft volume that can be harvested from the mandibular symphysis were measured based on cone beam CT data and software. The average required bone graft volume (cleft volume) for unilateral alveolar grafting was 963.51 ± 172.31 mm in the children and 1001.21 ± 268.16 mm in the adults. The average required bone graft volume for bilateral alveolar grafting was 1457.82 ± 148.18 mm in the children and 2189.59 ± 600.97 mm in the adults. The average the mandibular symphysis bone graft volume was 819.29 ± 330.85 mm in the children and 2164.9 ± 1095.86 mm in the adults. The results demonstrated that the mandibular symphysis region provided an adequate bone volume for alveolar grafting in adults with unilateral alveolar clefts. However, it is difficult to standardize these results, due to cleft volume and graft volume that could be harvested from the mandibular symphysis are highly variable among individuals.

Computed Tomographic Estimation of Particulate Cancellous Bone and Marrow Weight for Successful Transplant in Unilateral Cleft Lip and Palate Patients

Objective

The defect volume measured on computed tomography (CT) for secondary bone graft (SBG) is well correlated to the actual amount of particulate cancellous bone and marrow (PCBM) transplanted in unilateral cleft lip and palate (UCLP) patients. However, the validity of such measurements have not been completely verified due to lack of evaluation of treatment results. The objective of this study was to propose an estimation method by CT based on the data of successfully treated patients. For this purpose, the association was initially verified between the weight of transplanted PCBM and the defect volume measured on CT using the results of successfully treated patients.

Methods

Treatment results were evaluated 1 year after SBG by intraoral radiography in 50 UCLP patients. For the patients with good results, the correlation was investigated between the defect volume on CT and the transplanted PCBM weight, and a method was proposed based on PCBM density, calculated as PCBM weight divided by defect volume on CT.

Results

In successfully treated patients showing level 3 or 4 alveolar resorption, a strong correlation ( r = .87) was found between the volume on CT and the PCBM weight. Level 4 results were observed in 22 of 23 (95.7%) patients who had calculated PCBM densities of more than 6 g/cm3.

Conclusions

Volume estimation on preoperative CT was confirmed to have sufficient validity. The weight of PCBM transplanted should be greater than the defect volume on CT multiplied by 6.

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

OBJECTIVE

The aims of this study were to propose a new method for volumetric assessment of alveolar bone grafting and to quantitatively assess alveolar bone grafting based on this method.

STUDY DESIGN

Cone beam computed tomography images of 18 patients with unilateral cleft alveolus were selected. Volume of the alveolar cleft before grafting operation (VOLcleft), graft bone filled into cleft immediately after operation (VOLgraft), and bony bridge formed 1 year after operation (VOLbridge) were obtained. The grafting fill rate (VOLgraft/VOLcleft × 100%), bony bridge formation rate (VOLbridge/VOLcleft × 100%), and grafting resorption rate [(VOLgraft - VOLbridge)/VOLgraft × 100%] were calculated. Correlations between these parameters were investigated. Intraobserver and interobserver reliability of this method was assessed.

RESULTS

Intraobserver and interobserver reliability was good as no statistically significant difference was seen, and the Pearson correlation coefficient was significant (intraobserver R ≥ .953; interobserver, R ≥ .859). A positive linear correlation (R² = .808; P < .001) between grafting fill rate and bony bridge formation rate and a negative linear correlation (R² = .458, P = .002) between grafting fill rate and grafting resorption rate were found.

CONCLUSIONS

This method was practical and valuable for quantitative assessment of alveolar bone grafting.

Juvenile Swine Surgical Alveolar Cleft Model to Test Novel Autologous Stem Cell Therapies

Reconstruction of craniofacial congenital bone defects has historically relied on autologous bone grafts. Engineered bone using mesenchymal stem cells from the umbilical cord on electrospun nanomicrofiber scaffolds offers an alternative to current treatments. This preclinical study presents the development of a juvenile swine model with a surgically created maxillary cleft defect for future testing of tissue-engineered implants for bone generation. Five-week-old pigs (n=6) underwent surgically created maxillary (alveolar) defects to determine critical-sized defect and the quality of treatment outcomes with rib, iliac crest cancellous bone, and tissue-engineered scaffolds. Pigs were sacrificed at 1 month. Computed tomography scans were obtained at days 0 and 30, at the time of euthanasia. Histological evaluation was performed on newly formed bone within the surgical defect. A 1 cm surgically created defect healed with no treatment, the 2 cm defect did not heal. A subsequently created 1.7 cm defect, physiologically similar to a congenitally occurring alveolar cleft in humans, from the central incisor to the canine, similarly did not heal. Rib graft treatment did not incorporate into adjacent normal bone; cancellous bone and the tissue-engineered graft healed the critical-sized defect. This work establishes a juvenile swine alveolar cleft model with critical-sized defect approaching 1.7 cm. Both cancellous bone and tissue engineered graft generated bridging bone formation in the surgically created alveolar cleft defect.

CBCT in orthodontics: assessment of treatment outcomes and indications for its use

Since its introduction into dentistry in 1998, CBCT has become increasingly utilized for orthodontic diagnosis, treatment planning and research. The utilization of CBCT for these purposes has been facilitated by the relative advantages of three-dimensional (3D) over two-dimensional radiography. Despite many suggested indications of CBCT, scientific evidence that its utilization improves diagnosis and treatment plans or outcomes has only recently begun to emerge for some of these applications. This article provides a comprehensive and current review of key studies on the applications of CBCT in orthodontic therapy and for research to decipher treatment outcomes and 3D craniofacial anatomy. The current diagnostic and treatment planning indications for CBCT include impacted teeth, cleft lip and palate and skeletal discrepancies requiring surgical intervention. The use of CBCT in these and other situations such as root resorption, supernumerary teeth, temporomandibular joint (TMJ) pathology, asymmetries and alveolar boundary conditions should be justified on the basis of the merits relative to risks of imaging. CBCT has also been used to assess 3D craniofacial anatomy in health and disease and of treatment outcomes including that of root morphology and angulation; alveolar boundary conditions; maxillary transverse dimensions and maxillary expansion; airway morphology, vertical malocclusion and obstructive sleep apnoea; TMJ morphology and pathology contributing to malocclusion; and temporary anchorage devices. Finally, this article utilizes findings of these studies and current voids in knowledge to provide ideas for future research that could be beneficial for further optimizing the use of CBCT in research and the clinical practice of orthodontics.

Tomographic Assessment of Bone Formation After the Collares Technique of Gingivoperiosteoplasty in Patients With Cleft Lip and Palate

OBJECTIVES

This cross-sectional study sought to assess bone formation and spontaneous tooth eruption in a cohort of 25 consecutive patients aged 6 to 11 years who underwent primary gingivoperiosteoplasty by the Collares technique.

DESIGN

Cross-sectional study assessing bone formation in the cleft area using a within-group time series design.

SETTING

Hospital de Clínicas de Porto Alegre (HCPA), a tertiary hospital in Brazil.

PATIENTS

Twenty-five patients with nonsyndromic, complete unilateral cleft lip and palate, no comorbidities, and unerupted permanent canines.

INTERVENTION

Cheiloplasty was performed by means of the Millard II technique, with the addition of a triangle at the mucocutaneous junction, vomer flap nasal floor closure, and wide subperiosteal elevation, followed by gingivoperiosteoplasty by the Collares technique.

MAIN OUTCOME MEASURES

Cone-beam computed tomography was used to assess treatment effect. In a novel method, software was used to obtain two three-dimensional reconstructions, one each of the cleft and noncleft sides, enabling quantitative comparison of bone presence in the alveolar defect area.

RESULTS

Of the 25 patients, 24 achieved bone bridge formation. The cleft side had 75.1% (67.9%-82.3%) of the bone volume, 70.5% (53.1%-87.9%) of the height, and 63.3% (44.1%-82.5%) of the width of the noncleft side. Bone formation was 17.28% lower in patients with lateral incisor agenesis.

CONCLUSION

Collares gingivoperiosteoplasty performed well as a technique for alveolar repair in patients with cleft lip and palate, allowing spontaneous eruption of deciduous and permanent lateral incisors through the bone bridge created.

A Novel Semiautomatic Technique for Volumetric Assessment of the Alveolar Bone Defect Using Cone Beam Computed Tomography

Objective

The aims of this study were (1) to determine the three-dimensional anatomical boundaries of the alveolar bone defect in cleft lip and palate (CLP) patients, (2) to precisely translate these anatomical boundaries into reliable cephalometric landmarks and planes that can be used for cone beam computed tomography (CBCT) analysis, (3) to standardize image acquisition and reconstruction parameters, and (4) to test the reproducibility of the proposed protocol for measuring the predefined alveolar bone defect, using a third-party software.

Methods

The alveolar bone defect volume of 10 randomly selected patients with unilateral CLP (UCLP) aged 8 years and 6 months to 11 years and 2 months was evaluated on preoperative and 1-year postoperative CBCT scans using a semiautomatic, standardized protocol. The alveolar bone graft outcome was calculated as a percentage of the bone fill using the formula (VOLpre – VOLpost)/VOLpre) × 100. Intra- and interobserver reliability was assessed.

Results

Intra- and interobserver reproducibility was excellent for volumes and bone fill as no statistically significant difference ( P < .001) was seen between the different sets of measurements, and Pearson correlation coefficients were large (intraobserver: r > .9849, interobserver: r > .8784). The Bland-Altman plots indicated that the differences between the plots were not patterned.

Conclusions

Volume determination using CBCT, third-party medical image processing software, and the presently defined image acquisition and reconstruction parameters, including anatomical boundaries, is a reproducible and practical method for assessing the volumetric outcome of secondary alveolar bone grafting in patients with UCLP.

Mandibular Symphyseal Bone Graft for Reconstruction of Alveolar Cleft Defects: Volumetric Assessment With Cone Beam Computed Tomography 1-Year Postsurgery

OBJECTIVE

The aims of this retrospective study were to evaluate the volumetric outcome of mandibular symphyseal bone graft in patients with unilateral cleft lip and palate by estimating the bone fill 1-year postoperatively on cone beam computed tomography. The outcome was assessed in relation to the (1) root development stage of the cleft side canine, (2) presence/absence of a cleft side lateral incisor, and (3) volume size of the preoperative cleft defect.

METHODS

The alveolar bone defect volume of 32 consecutive unilateral cleft lip and palate patients aged 8 years 1 month to 11 years 11 months was evaluated using a recently defined and standardized protocol. The outcome was calculated as the percentage of bone fill using the formula (VOLpre - VOLpost) / VOLpre) × 100.

RESULTS

The preoperative mean alveolar cleft volume was 934 mm(3), and the average percentage bone fill was 87%. There was no significant difference between bone fill and root developmental stage of the cleft-side canine (P = .882) nor presence/absence of the cleft side lateral incisor (P = .803). The size of the cleft defect did not correlate with the bone fill (r = .03, P = .84).

CONCLUSIONS

Secondary alveolar bone grafting with mandibular symphyseal bone graft in patients with unilateral cleft lip and palate is an attractive procedure assessed from the volumetric outcome using cone beam computed tomography. The 1-year average bone fill of 87% was not significantly influenced by root development stage of the cleft-side canine, presence or the absence of a cleft side lateral incisor, or size of the alveolar defect.

Three-Dimensional Simulation of the Nasoalveolar Cleft Defect

This study describes the planning process for a three-dimensional (3D) model of a nasoalveolar bone graft in patients with unilateral cleft lip and palate. A 3D reconstruction of the alveolar cleft based on cone-beam computed tomography was performed in 10 patients. Graft models were planned using a 3D planning software (iPlan ENT 3.0, Brainlab, Feldkirchen, Germany) and printed using a 3D printer (Objet30 Pro, Objet Ltd., Rehovot, Israel). A reproducible, step-by-step planning method was established, which is manual rather than automatic. Still, the 3D visualization and a life-size graft template could be useful during secondary alveolar osteoplasty.

Three-dimensional imaging techniques: A literature review

Imaging is one of the most important tools for orthodontists to evaluate and record size and form of craniofacial structures. Orthodontists routinely use 2-dimensional (2D) static imaging techniques, but deepness of structures cannot be obtained and localized with 2D imaging. Three-dimensional (3D) imaging has been developed in the early of 1990's and has gained a precious place in dentistry, especially in orthodontics. The aims of this literature review are to summarize the current state of the 3D imaging techniques and to evaluate the applications in orthodontics.

Three-dimensional imaging methods for quantitative analysis of facial soft tissues and skeletal morphology in patients with orofacial clefts: a systematic review

Background

Current guidelines for evaluating cleft palate treatments are mostly based on two-dimensional (2D) evaluation, but three-dimensional (3D) imaging methods to assess treatment outcome are steadily rising.

Objective

To identify 3D imaging methods for quantitative assessment of soft tissue and skeletal morphology in patients with cleft lip and palate.

Data sources

Literature was searched using PubMed (1948–2012), EMBASE (1980–2012), Scopus (2004–2012), Web of Science (1945–2012), and the Cochrane Library. The last search was performed September 30, 2012. Reference lists were hand searched for potentially eligible studies. There was no language restriction.

Study selection

We included publications using 3D imaging techniques to assess facial soft tissue or skeletal morphology in patients older than 5 years with a cleft lip with/or without cleft palate. We reviewed studies involving the facial region when at least 10 subjects in the sample size had at least one cleft type. Only primary publications were included.

Data extraction

Independent extraction of data and quality assessments were performed by two observers.

Results

Five hundred full text publications were retrieved, 144 met the inclusion criteria, with 63 high quality studies. There were differences in study designs, topics studied, patient characteristics, and success measurements; therefore, only a systematic review could be conducted. Main 3D-techniques that are used in cleft lip and palate patients are CT, CBCT, MRI, stereophotogrammetry, and laser surface scanning. These techniques are mainly used for soft tissue analysis, evaluation of bone grafting, and changes in the craniofacial skeleton. Digital dental casts are used to evaluate treatment and changes over time.

Conclusion

Available evidence implies that 3D imaging methods can be used for documentation of CLP patients. No data are available yet showing that 3D methods are more informative than conventional 2D methods. Further research is warranted to elucidate it.

Systematic review registration

International Prospective Register of Systematic Reviews, PROSPERO CRD42012002041

One-year volume stability of human facial defects filled with a β-tricalcium phosphate-hydroxyl apatite mixture (Atlantik)

INTRODUCTION

We investigated the applicability and 1-year stability of a β-tricalcium phosphate-hydroxyl apatite mixture (Atlantik) for secondary reconstruction of craniofacial defects and the application of OsiriX in evaluating bone and implant volumes.

METHODS

We included 6 patients (25-59 years) with craniofacial defects. A computed tomography scan was made preoperative, directly postoperative, and at least 1 year postoperative to evaluate volume changes. OsiriX was used to quantify volumes of the implanted Atlantik. Measurements were performed by 2 independent investigators and analyzed by calculating both Pearson correlation and interclass correlation coefficient.

RESULTS

After 1 year, the mean volume reduction of the implanted Atlantik was 9.8%. The absolute volume reduction in 1 year was 0.38 cm (range, 0.10-0.69 cm(3)). Pearson correlation test was 0.996, with a significance level of P < 0.01, and the interclass correlation coefficient was 0.998.

CONCLUSIONS

Atlantik is a stable osteoconductive material for the repair of various craniofacial defects. There is a reduction of only 10% of the augmented volume in the long term. Applying OsiriX for computed tomography image volume analysis proved to be a well-reproducible technique.

Evaluation of bone volume after secondary bone grafting in unilateral alveolar cleft using computer-aided engineering

The purpose of this study was to evaluate the initial defect and the outcome of bone grafts for unilateral alveolar cleft. To determine the absorption of the bone graft in patients with unilateral cleft, computer-aided engineering (CAE) with multi-detector row computed tomography (MDCT) was used. MDCT scans of 29 patients were taken immediately preoperatively and at 1 month and 6 months postoperatively. The patients underwent bone grafting between 8 and 14 years of age using iliac crest bone grafts. Three-dimensional models were created in each period, and the defect at the alveolar cleft and volume of the bone graft were determined in each patient using CAE. Cleft volume and success of alveolar bone grafting were significantly correlated (P < .01). Alveolar clefts with cleft palate required more bone volume than those without cleft palate (P < .01), but the resorption rate did not significantly differ between alveolar clefts with and without cleft palate (0.48 ± 0.14 and 0.49 ± 0.18, respectively; P = .93). In conclusion, three-dimensional reconstruction of bone grafts using CAE based on MDCT provides a valuable objective assessment of graft volume.

Influence of the Alveolar Cleft Type on Preoperative Estimation Using 3D CT Assessment for Alveolar Cleft

BACKGROUND

The bone graft for the alveolar cleft has been accepted as one of the essential treatments for cleft lip patients. Precise preoperative measurement of the architecture and size of the bone defect in alveolar cleft has been considered helpful for increasing the success rate of bone grafting because those features may vary with the cleft type. Recently, some studies have reported on the usefulness of three-dimensional (3D) computed tomography (CT) assessment of alveolar bone defect; however, no study on the possible implication of the cleft type on the difference between the presumed and actual value has been conducted yet. We aimed to evaluate the clinical predictability of such measurement using 3D CT assessment according to the cleft type.

METHODS

The study consisted of 47 pediatric patients. The subjects were divided according to the cleft type. CT was performed before the graft operation and assessed using image analysis software. The statistical significance of the difference between the preoperative estimation and intraoperative measurement was analyzed.

RESULTS

The difference between the preoperative and intraoperative values were -0.1±0.3 cm(3) (P=0.084). There was no significant intergroup difference, but the groups with a cleft palate showed a significant difference of -0.2±0.3 cm(3) (P<0.05).

CONCLUSIONS

Assessment of the alveolar cleft volume using 3D CT scan data and image analysis software can help in selecting the optimal graft procedure and extracting the correct volume of cancellous bone for grafting. Considering the cleft type, it would be helpful to extract an additional volume of 0.2 cm(3) in the presence of a cleft palate.

Cone beam computed tomography use in orthodontics

Cone beam computed tomography (CBCT) is widely used by orthodontists to obtain three-dimensional (3-D) images of their patients. This is of value as malocclusion results from discrepancies in three planes of space. This review tracks the use of CBCT in orthodontics, from its validation as an accurate and reliable tool, to its use in diagnosing and treatment planning, and in assessing treatment outcomes in orthodontics.

Postoperative evaluation of grafted bone in alveolar cleft using three-dimensional computed tomography data

Objective : Postoperative evaluation of bone formation in the alveolar cleft by computed tomography imaging has been reported. We quantitatively evaluated bone grafts in the alveolar cleft preoperatively and postoperatively using three-dimensional data and superimposition of images. Subjects : A total of 12 patients with complete unilateral cleft lip and palate (six left-sided and six right-sided) were studied. Methods : Helical computed tomography scans were taken immediately before surgery and at 6 months after surgery and the DICOM files obtained were processed using Mimics and 3-matic software for three-dimensional data analysis. The preoperative and postoperative computed tomography data were superimposed, and the position and length of the unerupted canines and width of the alveolar cleft measured. Results : Strong and significant correlations were observed between bone formation in the alveolar cleft bone graft region and preoperative canine position (r  =  -.766, p < .01) and canine length (r  =  .681, p < .05). Stepwise multiple regression analysis demonstrated that only the preoperative canine position was independently and significantly correlated with bone formation in the alveolar cleft. Conclusion : These results indicate that the optimal timing for surgery is when the canine cusp is close to the alveolar plane.