Quick Method for Presurgical Volumetric Analysis of Alveolar Cleft Defects

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.

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.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

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

ABSTRACT

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

Evaluating the efficacy of recombinant human bone morphogenic protein-2 in the treatment of alveolar clefts with autologous bone grafting using computer-aided engineering techniques

Recent studies have indicated the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) to be a viable adjunctive to alveolar cleft reconstruction owing to its osteoinductive capacity. This study aimed to evaluate the efficacy of rhBMP-2 in the treatment of alveolar cleft with autologous bone grafts by precise volumetric analysis. Twenty-six patients (aged 8-14) with unilateral alveolar clefts were enrolled in this comparative study. Patients were divided into two groups: the iliac crest bone graft (ICBG) was placed at the side of the cleft in the control group (ICBG group), and rhBMP-2 was mixed with the ICBG in the rhBMP-2 group (BMP group). Helical computed tomographic images were obtained preoperatively and 12 months postoperatively. The datasets were reconstructed as three-dimensional (3D) images using Mimics software and processed using Geomagic Wrap. The newly formed bone of the alveolar cleft was segmented by identifying the differences between preoperative and postoperative 3D images. In the ICBG group, the volume of newly formed bone ranged from 0.25 to 0.88 cm³, and the mean (SD) bone formation percentage was 42.01% (15.57%). In the BMP group, the volume of newly formed bone ranged from 0.34 to 1.09 cm³, and the bone formation mean (SD) percentage was 55.79% (11.84%). There was a statistically significant difference between the two groups in terms of the postoperative percentage of bone formation (p = 0.022). Thus, rhBMP-2 combined with an autologous bone graft is a promising technique to improve the results of secondary alveolar bone grafting.