A novel accurate volumetric analysis protocol for evaluating secondary alveolar cleft reconstruction

Influence of Preoperative Inflammatory Status on Outcomes of Alveolar Bone Grafting in Patients With Cleft Lip

After secondary alveolar bone grafting, the outcome of bone formation is always a problem that leads to repeat surgery. Bone formation is closely related to the inflammatory and immune status of patients. To achieve better bone formation results, this study aimed to investigate the influence of preoperative inflammatory indicators on the bone survival ratio (BSR) of secondary alveolar bone grafting. A retrospective study was conducted on 62 patients who underwent surgery by the same surgeon between January 2016 to December 2022. Demographic and laboratory data were included as independent variables. The BSR calculated from computed tomography data was included as the dependent variable. Pearson correlation analysis, Spearman correlation analysis, and multiple linear regression analysis were performed. The analysis results revealed significant correlations between BSR and preoperative inflammatory markers, including neutrophil percentage, neutrophil-to-lymphocyte ratio, lymphocyte percentage (L%), lymphocyte count, and monocyte-to-lymphocyte ratio. Multiple linear regression identified L% as an independent factor of BSR, with lower L% associated with higher BSR. Preoperative inflammatory markers may influence BSR after alveolar bone grating. A lower value of L% indicates a better postoperative bone formation outcome. Understanding these associations can aid clinicians in treatment planning and patient stratification.

Three-dimensional anatomical analysis of the optic nerve canal with virtual model based on CBCT

The optic nerve canal (ONC) is a fine skeletal structure that contains the optic nerve. However, it has not been thoroughly examined. This necessitates establishing a baseline knowledge of the geometrical and volumetric parameters of the ONC. The data of twenty patients who received a cone beam computed tomography examination were prepared using a voxel-based segmentation. The measurement was performed separately by two examiners on virtual skull models in stereolithography format in Geomagic Wrap®. The results showed that the volume of the ONC varied between 92.48 mm3 and 162.7 mm3 (M = 123.46 mm3, SD = 26.61 mm3). Sex-specific statistically significant differences in volume were detected only for the right side. The angle of the ONC to the skull base was independent of the diameter of the canal. Both the intrarater and interrater comparisons of the measurements showed high values of reproducibility of the results. This study showed that a virtual anatomical model provides a feasible and reliable method to investigate the ONC. The examination technique could have a wider range of application in anthropology and application in clinical medicine. Advances in the automation of radiological diagnostics and the digital analysis of X-ray images could help to reduce examination times.

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.

An easy-to-use semi-automatic volumetric evaluation for secondary bone grafting in patients with unilateral alveolar cleft

Surgical intervention for alveolar bone formation is important in patients with alveolar cleft; however, the treatment methods and materials are still controversial. A precise evaluation method for postoperative bone formation is important for comparing outcomes and establishing the best treatment protocol. The purpose of this study is to establish a new method of evaluating surgical outcomes for patients with alveolar cleft. Computed tomography datasets from 20 patients who underwent secondary alveolar bone grafting were obtained before and 1 year after surgery. Six anatomical landmarks were used to superimpose the preoperative and mirrored preoperative volume and postoperative volume data. The cleft region was segmented by subtracting the preoperative from mirrored preoperative volume data, and the failed osteogenesis region was segmented by subtracting the postoperative volume data from the cleft region; subsequently, the bone formation ratio was calculated. Two observers performed this method using a free software 3D slicer and the average evaluation times were 12.7 and 13.2 min for observers 1 and 2, respectively. Method reliability was determined by evaluating intraclass correlation coefficients. The intra-observer intraclass correlation coefficients were 0.97 and 0.96 for observers 1 and 2, respectively. The inter-observer intraclass correlation coefficient was 0.97. Our method is practical for assessing bone formation after treatment, which does not require specific knowledge or software and can be used by ordinary physicians.

Three-dimensional Assessment of Autologous Calvarial Bone Grafting for Alveolar Clefts Reconstruction in Pediatric Population: A Retrospective Study

Reconstruction of alveolar clefts using cancellous bone graft is associated with a high rate of resorption. The aim of this study was to evaluate the osseointegration capacity of cortical calvarial bone grafting using 3-dimensional imaging assessment for alveolar cleft reconstruction in pediatric population.All alveolar bone grafting procedures performed between January 2015 and October 2017 in the maxillofacial surgery department of Lille University Hospital were included. All patients were evaluated clinically and by 3-dimensional imaging before bone grafting and at 3 months after surgery. Cleft and bone graft volumes were assessed using Horos software, v. 3.3.5, through a segmentation process. The bone filled ratio at 3 months after surgery was calculated. A total of 48 alveolar bone grafting procedures were performed in 37 patients: 3 unilateral cleft lip and alveolar, 20 unilateral cleft lip and palate, and 25 bilateral full cleft lip and palate (3 patients had only unilateral surgery). The mean bone filled ratio was 72.27%±23.65%, 81% for unilateral cleft lip and alveolus, 75.4%±20.6 for unilateral cleft lip and palate, and 65.5%±30 for bilateral complete cleft lip and palate ( P =0.1981). Calvarial bone grafting seems to be a relevant alternative to other donor sites for alveolar cleft reconstruction.

Validation of a Novel Patient Specific CT-Morphometric Technique for Quantifying Bone Graft Resorption Following the Latarjet Procedure

Bone graft resorption following the Latarjet procedure has received considerable concern. Current methods quantifying bone graft resorption rely on two-dimensional (2D) CT-scans or three-dimensional (3D) techniques, which do not represent the whole graft volume/resorption (i.e., 2D assessment) or expose patients to additional radiation (i.e., 3D assessment) as this technique relies on early postoperative CT-scans. The aim of the present study was to develop and validate a patient-specific, CT-morphometric technique combining image registration with 3D CT-reconstruction to quantify bone graft resorption following the Latarjet procedure for recurrent anterior shoulder instability. Pre-operative and final follow-up CT-scans were segmented to digitally reconstruct 3D scapula geometries. A virtual Latarjet procedure was then conducted to model the timepoint-0 graft volume, which was compared with the final follow-up graft volume. Graft resorption at final follow-up was highly correlated to the 2D gold standard-technique by Zhu (Kendall tau coefficient = 0.73; p < 0.001). The new technique was also found to have excellent inter- and intra-rater reliability (ICC values, 0.931 and 0.991; both p < 0.001). The main finding of this study is that the technique presented is a valid and reliable method that provides the advantage of 3D-assessment of graft resorption at long-term follow-up without the need of an early postoperative CT-scan.

Increased rate of pseudarthrosis in the anterior intersegmental gap after mandibular reconstruction with fibula free flaps: a volumetric analysis

OBJECTIVES

Pseudarthrosis after mandibular reconstruction leads to chronic overload of the osteosynthesis and impedes dental rehabilitation. This study evaluates the impact of gap site on osseous union in mandible reconstruction using a new volumetric analysis method with repeated cone-beam computed tomography (CBCT).

METHODS

The degree of bone regeneration was evaluated in 16 patients after mandible reconstruction with a fibula free flap and patient-specific reconstruction plates. Percentual bone volume and width changes in intersegmental gaps were retrospectively analyzed using a baseline CBCT in comparison to a follow-up CBCT. Patients' characteristics, plate-related complications, and gap sites (anterior/posterior) were analyzed. Detailed assessments of both gap sites (buccal/lingual/superior/inferior) were additionally performed.

RESULTS

Intersegmental gap width (p = 0.002) and site (p < 0.001) significantly influence bone volume change over two consecutive CBCTs. An initial larger gap width resulted in a lower bone volume change. In addition, anterior gaps showed significantly less bone volume changes. Initial gap width was larger at posterior segmental gaps (2.97 vs 1.65 mm, p = 0.017).

CONCLUSIONS

A methodology framework has been developed that allows to quantify pseuarthrosis in reconstructed mandibles using CBCT imaging. The study identifies the anterior segmental gap as a further risk factor for pseudarthrosis in reconstructions with CAD/CAM reconstruction plates. Future research should evaluate whether this outcome is related to the biomechanics induced at this site.

Clinical, volumetric and densitometric evaluation of tissue engineered constructs for secondary alveolar cleft reconstruction: A randomized clinical trial

The objective of this study was to assess the efficacy of tissue engineered (TE) constructs compared to the standard autogenous anterior iliac crest (AIC) bone graft in secondary maxillary alveolar cleft reconstruction. This clinical trial was registered on (clinical trials.gov); the trial registry number is: NCT03563495. Patients with unilateral alveolar clefts were allocated on the basis of simple randomization. Selected patients were randomly divided into two equal groups: the AIC group (control) received autogenous particulate bone graft from anterior iliac crest, whereas the TE group received tissue engineered construct. Assessment included the newly formed bone volume and density at the grafted cleft sites, which were measured immediately, 6 and 12 months postoperatively on axial computed tomograms. The study population included 10 patients; each group comprised 5 patients. There was no statistically significant difference between the 2 groups regarding the mean volume of the newly formed bone (p = 0.91 at 6 months, p = 0.994 at 1 year) and the mean density of the newly formed bone (p = 0.364 at 6 months, p = 0.073 at 1 year). However, there was a significant increase of TE graft density from 6 months to 1 year (p = 0.048). Within the limitations of the study it seems that the tissue engineered construct (collagen/osteogenically differentiated bone marrow-derived mesenchymal stem cells) might be an alternative to autogenous bone for unilateral secondary alveolar cleftgrafting.

Alveolar Volume Following Different Timings of Secondary Bone Grafting in Patients with Unilateral Cleft Lip and Palate. A Pilot Study

This study was intended to evaluate the relationship between secondary alveolar bone grafting (SABG) timing and the alveolar volume in patients with unilateral cleft lip and palate (UCLP). The material consisted of CTs of 35 patients (17 males, 18 females) with UCLP who underwent a one-stage primary cleft repair at a mean age of 8.4 months and SABG at different timings ranges of 1.8–18.8 years. The mean age at CT was 17.2 years. The relative coefficient (Ꞷ) which was independent from factors such as individual maxillary size, gender or age at the CT was introduced in order to compare volumes of the cleft-side in relation to the non-cleft-side alveolus. Pearson correlation coefficient r between Ꞷ coefficient and SABG timing was weak negative (r = −0.34, p = 0.045). The multiple regression analysis implied that the dependent variable-Ꞷ coefficient was associated with independent variables (cleft repair and SABG timings and age at CT) with r² = 0.228. Only patient’s age at SABG explained the dependent variable (p = 0.003). The study cautiously indicates a tendency to larger alveolar volume following earlier timing of SABG. Nevertheless, the further research on a larger group of patients should be performed before formulating any clinical indications.

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.

Maxillofacial morphology in post-pubertal patients with unilateral cleft lip and palate following early vs. late secondary alveolar bone grafting

The study aimed at comparing maxillofacial morphology and burden of surgical treatment in post-pubertal patients with unilateral cleft lip and palate (UCLP) following early vs. late secondary alveolar bone grafting (SABG). In this retrospective study maxillofacial morphology was assessed on lateral cephalograms of skeletally matured patients with UCLP operated on consecutively in one center by the same method of one-stage primary cleft repair followed by SABG. Cephalometric analysis comprised 8 angular and 7 linear measurements. Maxillary growth restriction was evaluated by measuring SNA angle and Co-A and PNS-A distances. Five linear regression models with SNA, SNB, ANB, Co-A, and MP/SN as dependent variables and age at primary cleft repair, age at SABG, age at taking cephalogram, surgeon, and total number of surgical interventions as independent variables were also created. 135 patients were included in the study - 70 patients (47 males and 23 females) had early SABG (E-SABG group) and 65 patients (40 males and 25 females) had late SABG (L-SABG group). Mean age at bone grafting procedure was 2.7 years (range 1.5-5.9, SD 1.1) and 10.3 years (range 6.1-18.8, SD 3.2) in E-SABG and LSABG group respectively. The variables describing the degree of maxillary growth restriction - SNA, Co-A, and PNS-A - were comparable in both groups (p = 0.707, 0.116, and 0.932, respectively). Regression models demonstrated that independent variables were not associated with the values of SNA angle, SNB angle, ANB angle, MP/SN angle, and Co-A distance (p = 0.761, 0.088, 0.249, 0.380, and 0.363, respectively). The percentages of oronasal fistula repair, VPI repair, repeated SABG, upper lip correction, rhinoplasty, orthognathic surgery were 22.9, 7.1, 15.7, 24.3, 42.9, 2.9 in E-SABG group and 27.7, 7.7, 9.2, 36.9, 47.7, 3.1 in L-SABG group respectively. Mean number of all surgical interventions was 3.2 in E-SABG and 3.4 in L-SABG group, respectively (p = 0.271). Considering the comparable maxillofacial morphology and burden of surgical care in matured patients after early and late SABG, the choice of timing of bone grafting surgery could be left to the discretion of the surgeon.