Accurate Evaluation of Cone-Beam Computed Tomography to Volumetrically Assess Bone Grafting in Alveolar Cleft Patients

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.

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.

Validation and comparison of volume measurements using 1 multidetector computed tomography and 5 cone-beam computed tomography protocols: An in vitro study

Purpose

The purpose of this study was to compare volume measurements obtained using 2 image software packages on Digital Imaging and Communications in Medicine (DICOM) images acquired from 1 multidetector computed tomography and 5 cone-beam computed tomography devices, using different protocols for physical volume measurements.

Materials and Methods

Four pieces of bovine leg were prepared. Marrow was removed from 3 pieces, leaving cortical bone exposed. The resulting space of 1 piece was filled with water, another was filled with propylene glycol, and the third was left unfilled. The marrow in the fourth sample was left fully intact. Volume measurements were obtained after importing DICOM images into the Dolphin Imaging 11.95 and ITK-SNAP software programs. Data were analyzed using 3-way analysis of variance with a generalized linear model to determine the effects of voxel size, software, and content on percentage mean volume differences between tomographic protocols. A significance level of 0.05 was used.

Results

The intraclass correlation coefficients for intraobserver and interobserver reliability were, respectively, 0.915 and 0.764 for the Dolphin software and 0.894 and 0.766 for the ITK-SNAP software. Three sources of statistically significant variation were identified: the interaction between software and content (P=0.001), the main effect of content (P=0.014), and the main effect of software (P=0.001). Voxel size was not associated with statistically significant differences in volume measurements.

Conclusion

Both content and software influenced the accuracy of volume measurements, especially when the content had gray values similar to those of the adjacent tissues.

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.

Secondary Alveolar Bone Grafting in Patients with Unilateral and Bilateral Complete Cleft Lip and Palate: A Single-Institution Outcomes Evaluation Using Three-Dimensional Cone Beam Computed Tomography

BACKGROUND

Secondary alveolar bone grafting of autologous bone from the iliac crest is a widely accepted modality for repair of residual alveolar cleft in patients with mixed dentition with previously repaired complete cleft lip and palate. There remains debate regarding surgical timing and preoperative, perioperative, and postoperative management of these cases.

METHODS

This retrospective study reviewed patient demographic information in addition to preoperative, perioperative, and postoperative course to evaluate how patient and practice factors impact graft outcomes as assessed by three-dimensional cone beam computed tomographic evaluation at the 6-month postoperative visit.

RESULTS

On univariate analysis, age at operation older than 9 years, history of oronasal fistula, history of cleft lip or palate revision, and history of international adoption were all found to significantly increase likelihood of graft failure (p < 0.05). On multivariate analysis, age older than 9 years was found to be the single most significant predictor of graft failure (p < 0.05). There was no significant difference in graft outcomes between patients with unilateral or bilateral cleft lip and palate, and no single variable was found to significantly correlate to increased complication rates. The graft success rate overall of the authors' practice was 86.2 percent, with a complication rate of 7.7 percent.

CONCLUSIONS

Secondary alveolar bone grafting is an integral part of the cleft lip and palate surgical treatment series; this study identified several outcome predictors for both graft failure and adverse events, the most significant of which was age at operation. Although the mixed dentition phase often extends to 12 years of age, it is recommended that bone grafting be performed before 9 years of age to optimize outcomes.

CLINICAL QUESTIONS/LEVEL OF EVIDENCE

Risk, III.

A Novel and Practical Protocol for Three-Dimensional Assessment of Alveolar Cleft Grafting Procedures

OBJECTIVE

To evaluate the reproducibility and accuracy of a new, easy-to-use volumetric assessment of the alveolar cleft.

DESIGN

Twelve cone-beam computed tomography (CBCT) datasets of patients with a unilateral cleft lip, alveolus, and palate were evaluated by two investigators. Residual alveolar cleft calcified volume one year after surgery was analyzed by using standardized landmarks to determine the borders of the cleft defect and semi-automatically segment the alveolar cleft defect.

RESULTS

The Dice-coefficient between observers for the segmented preoperative alveolar cleft defect was 0.81. Average percentage of residual alveolar cleft calcified material was 66.7% one year postoperatively.

CONCLUSIONS

This study demonstrates a reliable and practical semi-automatic three-dimensional volumetric assessment method for unilateral clefts using CBCT.

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.

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.

A Novel Classification of Relationship Between Nasal Septum and Inferior Turbinate Associated With Nasal Airway Obstruction in Patients With Unilateral Alveolar Cleft

OBJECTIVE

This study aims to investigate nasal morphologies associated with nasal airway obstruction in unilateral alveolar cleft patients.

METHODS

A total of 234 unilateral alveolar cleft cases were performed cone beam computed tomography scans. The digital imaging and communication in medicine data were imported into Simplant Pro software. The radiographic features including nasal septum deviation and inferior turbinate hypertrophy as well as nasal airway volume and sinusitis were analyzed.

RESULTS

A new radiographic classification of relationship between nasal septum and inferior turbinate (NS-IT) on the cleft side was proposed and three types of NS-IT relationship (type I, II and III) were identified in 234 cases. The statistical analysis revealed that the nasal airway volume on non-cleft side was significantly higher than that on cleft side in each of three types (P  < 0.0001), while no difference of nasal airway volume on non-cleft side was found among three types. In addition, the nasal airway volume on non-cleft side in type I and II was significantly higher than that in type III (P < 0.0001). Also, type III presented higher rate of maxillary sinusitis (P = 0.0154) and ethmoid sinusitis on cleft side (P = 0.0490) than type I and II. The other indexes including clinical variances were not significant among three types.

CONCLUSIONS

Unilateral alveolar cleft patients with type III NS-IT relationship could have nasal airway obstruction and higher rate of maxillary and ethmoid sinusitis on cleft side, which may be taken into account at primary cleft repair and alveolar bone grafting treatment.

Comparison of Anatomical Features of Alveolar Cleft in Unilateral Cleft Lip and Palate Patients of Different Ages

OBJECTIVES

This study aimed to compare the anatomical features of alveolar cleft in patients with complete unilateral cleft lip and palate (UCLP) of different ages.

METHODS

Sixty UCLP patients were divided into 3 groups as follows: group 1 (7-12 years old), group 2 (13-18 years old) and group 3 (more than 18 years old). The radiographic images were analyzed based on cone beam computed tomography (CBCT) images.

RESULTS

The mean age in 3 groups was 10.45 ± 1.15, 15.05 ± 1.90, and 22.55 ± 3.00 years (P < 0.0001). The lip-palatal width in Group 2 and 3 was 15.14 ± 3.67 mm and 15.50 ± 3.92 mm, which was significantly larger than 12.97 ± 1.82 mm in Group 1 (P = 0.037). The volume of alveolar defect was 1.09 ± 0.23 cm, 1.28 ± 0.38 cm and 1.40 ± 0.58 cm in 3 groups, and the difference between any 2 of them was significant (P = 0.0004). The prevalence of ipsilateral but contralateral maxillary sinusitis was significant among 3 groups (P = 0.0015) while the other nasal deformities including nasal septum deviation and inferior turbinate hypertrophy was not found significant.

CONCLUSIONS

Alveolar cleft volume increased with age, which is properly due to enlarged width of lip-palatal defect. The significant higher frequencies of ipsilateral maxillary sinusitis in patients under 18 could increase the risk of bone infection.

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.

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.

Alveolar Cleft Reconstruction Using Different Grafting Techniques

BACKGROUND

Cleft lip and palate CLP is a frequent congenital malformation that manifests in several varieties including unilateral or bilateral anomalies due to either genetic or acquired causes. Alveolar cleft graft ACG remains controversial as regard timing, grafting materials and surgical techniques. The primary goal of alveolar cleft grafting in ACG patients is to provide an intact bony ridge at the cleft site to allow maxillary continuity for teeth eruption, proper orthodontic treatment for dental arch alignment, oronasal fistula closure and providing alar support for nasal symmetry.

AIM

This study aims to compare different grafting techniques to treat the alveolar cleft defect.

METHODS

This study included 24 cases divided into three groups of patients: Group A was treated with autogenous iliac crest bone; Group B was treated with nano calcium hydroxyapatite with collagen membrane and Group C was treated with tissue engineering method using bone marrow stem cells extract and PRF membrane.

RESULTS

According to clinical and radiographic examination measuring bone density in the CT preoperatively compared to six months postoperatively. Group C with bone marrow stem cells extract showed superior results among all followed by group B, while group A with autogenous iliac crest showed resorption in some cases and gave the least values, in addition to its drawbacks as regard donor site affection with pain & scar formation.

CONCLUSION

Bone substitutes as Nano calcium hydroxyapatite and bone marrow stem cells extract showed to be reliable methods for bone grafting than autogenous iliac crest.

Comparative Outcomes of Block and Cancellous Iliac Bone Grafting in Older Unilateral Alveolar Cleft Patients

OBJECTIVE

To compare osseous outcomes of block and cancellous iliac bone grafting in older unilateral alveolar cleft patients.

DESIGN

Retrospective and observational follow-up study.

SETTING

Cleft Lip and Palate Centre, Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, China.

PATIENTS

Forty-five nonsyndromic patients with unilateral complete alveolar cleft were enrolled in this study (25 patients in block bone graft group and 20 patients in cancellous bone graft group).

INTERVENTIONS

In cancellous bone graft group, the alveolar cleft was filled with iliac cancellous bone particulate. In group of block bone graft, the harvested bone block was trimmed and fixed in alveolar defect.

MAIN OUTCOME MEASURES

A novel method was proposed to investigate the volume and density of residual bone graft at 1-week, 3- and 6-month, 1- and 2-year postoperatively based on cone beam computed tomography scans.

RESULTS

No difference in bone graft volume was found between 2 groups at 1-week and 3-month postoperatively; however, the residual volume of block bone graft group was significantly larger than that of cancellous bone graft group at 6-month, 1- and 2-year postoperatively. The bone density of block bone graft group was lower at 1-week and 3-month postoperatively but was comparable at 6-month, 1- and 2-year postoperatively. Our method was reliable and accurate to identify the range of residual bone graft when the boundary of grafted bone could not be identified clearly.

CONCLUSION

Block bone graft could achieve comparable bone density and retain a greater amount of residual bone comparing to cancellous bone graft.

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.

Block iliac bone grafting enhances osseous healing of alveolar reconstruction in older cleft patients: A radiological and histological evaluation

Background

Older alveolar cleft patients (&12 years old) often have wide bone defect as well as teeth loss, resulting in poor osseous healing with conventional alveolar bone grafting (ABG). In this study, we investigated a surgical technique of block iliac bone grafting for the alveolar cleft reconstruction and evaluated the clinical and radiological outcomes of these cleft patients.

Material and Methods

Fifteen patients were included in this study. All cases received preoperative cone bean computed tomography (CBCT) scans for the alveolar cleft evaluation. Osseous outcomes of block iliac bone grafting were assessed at 1 week, 3- and 6-month postoperatively. Volume changes and bone resorption rates were calculated using the measurement modules of Simplant software. Bone samples from one patient undergoing dental implantation were assessed by micro-CT and histological examination. The morbidities of donor-site were analyzed by clinical examination and questionnaire survey.

Results

The average age of the case series was 18.53±2.50 years. The intraoral incision of thirteen cases healed well. However, two cases had oronasal fistula and graft exposure at 1-week postoperatively. The results of follow-up CBCT scans showed significant resistance to radiation on both sides of the bone graft, suggesting a good osseous healing and new bone formation. The mean residual bone volume was 1.68±0.26 cm3, 1.29±0.23 cm3 and 1.15±0.23 cm3 at 1-week, 3- and 6-month postoperatively. Correspondingly, the mean bone resorption rates in 3- and 6-month postoperative were 21.78±6.88% and 30.66±8.97%, respectively. From micro-CT and HE examinations, the block bone samples exhibited a cancellous structure in which mature bone trabecula and functional blood vessels appeared. The average scores of donor-site morbidities were drastically decreased at 3- and 6-month postoperatively compared with those at 1-week postoperatively.

Conclusions

Our results demonstrated that block iliac bone grafting could achieve satisfying osseous outcomes in older alveolar cleft patients, and this technique provided favorable bony condition for further treatments, especially dental implantation.

Key words:Alveolar bone grafting, Block bone grafting, Osseous healing, CBCT.