Comparative Volume Analysis of Alveolar Defects by 3D Simulation.
ABSTRACT: 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.
Project description:The aim of this article is to describe the results of the use of demineralized bone matrix putty in alveolar cleft of patients with cleft lip and palate. We performed a prospective, descriptive case series study, in which we evaluated the results of the management of alveolar clefts with demineralized bone matrix. Surgery was performed in 10 patients aged between 7 and 26 years (mean 13 years), involving a total of 13 clefts in the 10 patients. A preoperative cone beam computed tomography (CBCT) was taken to the patients in whom the width of the cleft was measured from each edge of the cleft reporting values between 5.76 and 16.93 mm (average, 11.18 mm). The densities of the clefts were measured with a CBCT, 6 months postoperative to assess bone formation. The results showed a register of gray values of 1,148 to 1,396 (mean, 1,270). The follow-up was conducted for 15 to 33 months (mean, 28.2 months). The results did not show satisfactory bone formation in the cleft of patients with the use of demineralized bone matrix.
Project description:PURPOSE:Facial asymmetry often persists even after mandibular deviation corrected by the bilateral sagittal split ramus osteotomy (BSSRO) operation, since the reference facial sagittal plane for the asymmetry analysis is usually set up before the mandibular menton (Me) point correction. Our aim is to develop a predictive and quantitative method to assess the true asymmetry of the mandible after a midline correction performed by a virtual BSSRO, and to verify its availability by evaluation of the post-surgical improvement. PATIENTS AND METHODS:A retrospective cohort study was conducted at the Hospital of Stomatology, Sun Yat-sen University (China) of patients with pure hemi-mandibular elongation (HE) from September 2010 through May 2014. Mandibular models were reconstructed from CBCT images of patients with pre-surgical orthodontic treatment. After mandibular de-rotation and midline alignment with virtual BSSRO, the elongation hemi-mandible was virtually mirrored along the facial sagittal plane. The residual asymmetry, defined as the superimposition and boolean operation of the mirrored elongation side on the normal side, was calculated, including the volumetric differences and the length of transversal and vertical asymmetry discrepancy. For more specific evaluation, both sides of the hemi-mandible were divided into the symphysis and parasymphysis (SP), mandibular body (MB), and mandibular angle (MA) regions. Other clinical variables include deviation of Me point, dental midline and molar relationship. The measurement of volumetric discrepancy between the two sides of post-surgical hemi-mandible were also calculated to verify the availability of virtual surgery. Paired t-tests were computed and the P value was set at .05. RESULTS:This study included 45 patients. The volume differences were 407.8±64.8 mm3, 2139.1±72.5 mm3, and 422.5±36.9 mm3; residual average transversal discrepancy, 1.9 mm, 1.0 mm, and 2.2 mm; average vertical discrepancy, 1.1 mm, 2.2 mm, and 2.2 mm (before virtual surgery). The post-surgical volumetric measurement showed no statistical differences between bilateral mandibular regions. CONCLUSIONS:Mandibular asymmetry persists after Me point correction. A 3D quantification of mandibular residual asymmetry after Me point correction and mandible de-rotation with virtual BSSRO sets up a true reference mirror plane for comprehensive asymmetry assessment of bilateral mandibular structure, thereby providing an accurate guidance for orthognathic surgical planning.
Project description:The symmetrically stable craniofacial bony structure supports the complex functions and delicate contour of the face. Congenital craniofacial deformities are often accompanied by bony defects and have been repetitively correlated with compromised dento-maxillary stability, but neither the extent nor the pattern of cleft-related maxillary instability has been explored in detail. Furthermore, it is largely unknown if the bony defect and related instability are correlated with secondary maxillary deformity common among patients with orofacial clefts. With the aid of finite element modeling, we studied the detailed relationship between cleft-related bony defect and maxillary stability under occlusal loading. Craniofacial models were generated based on cone-beam computed tomography data and loaded with mimicked bite forces along the axial axis of each tooth. Our data showed that all cleft models exhibited more asymmetrical deformations under mastication compared with the normal. Models with palatal cleft demonstrated greater asymmetry, greater dental arch contraction, and less maxillary protrusion compared to models with alveolar cleft only. For unilateral cleft models, alveolus on non-cleft side tended to be more protruded and lifted than the cleft side. For bilateral cleft models, the most prominent feature was the seriously contracted alveolar arch and curved and pitched premaxillae. These findings indicated cleft type-specific pattern of maxillary instability, which were largely in accordance with dentoalveolar morphological features among patients. Collectively, our study elucidated the detailed relationship between cleft bony defect and the pattern of maxillary instability, and suggested a prototype for studying the abnormal maxillary and dental arch growth among patients with craniofacial deformities.
Project description:Subtle behavioral and cognitive deficits have been documented in patient cohorts with orofacial clefts (OFCs). Recent neuroimaging studies argue that these traits are associated with structural brain abnormalities but have been limited to adolescent and adult populations where brain plasticity during infancy and childhood may be a confounding factor. Here, we employed high resolution magnetic resonance microscopy to examine primary brain morphology in a mouse model of OFCs. Transient in utero exposure to the Hedgehog (Hh) signaling pathway antagonist cyclopamine resulted in a spectrum of facial dysmorphology, including unilateral and bilateral cleft lip and palate, cleft of the secondary palate only, and a non-cleft phenotype marked by midfacial hypoplasia. Relative to controls, cyclopamine-exposed fetuses exhibited volumetric differences in several brain regions, including hypoplasia of the pituitary gland and olfactory bulbs, hyperplasia of the forebrain septal region, and expansion of the third ventricle. However, in affected fetuses the corpus callosum was intact and normal division of the forebrain was observed. This argues that temporally-specific Hh signaling perturbation can result in typical appearing OFCs in the absence of holoprosencephaly--a condition classically associated with Hh pathway inhibition and frequently co-occurring with OFCs. Supporting the premise that some forms of OFCs co-occur with subtle brain malformations, these results provide a possible ontological basis for traits identified in clinical populations. They also argue in favor of future investigations into genetic and/or environmental modulation of the Hh pathway in the etiopathogenesis of orofacial clefting.
Project description:Objectives:To evaluate sella turcica (ST) bridging, associated anomalies, and morphology, in subjects with four different types of clefts, and compare them with non-cleft (NC) subjects. Materials and Methods:A total of 123 (31 NC and 92 cleft) Saudi subjects who had their lateral cephalogram (Late. Ceph.), orthopantomogram (OPG), and clinical details for ordinary diagnosis were included in the study. Among 92 cleft subjects, 29 had bilateral cleft lip and palate (BCLP), 41 had unilateral cleft lip and palate (UCLP), nine had unilateral cleft lip and alveolus (UCLA), and 13 with unilateral cleft lip (UCL). ST bridging and seven parameters related to ST morphology and skeletal malocclusion were analyzed using Late. Ceph. Associated dental anomalies in ST bridging subjects were investigated using OPG. The images were investigated using artificial intelligence driven Webceph software. Multiple statistical tests were applied to see the differences between gender and among cleft vs NC subjects. Results:ST bridging was found to be higher in cleft subjects (22.82%). Most of the cleft subjects had severe skeletal Class III malocclusion associated with multiple types of dental anomalies (impacted canines, congenital missing, and presence of supernumerary teeth). No significant gender disparities in all seven parameters of ST morphology were found between NC and cleft groups. However, there were significant differences when compared among four different types of cleft individuals vs NC subjects. Conclusion:ST bridging is more prevalent in cleft subjects along with Class III malocclusion and associated dental anomalies. ST morphometry differs significantly between cleft vs NC subjects. BCLP exhibits smaller values of all seven parameters as compared to all other groups.
Project description:Tissue regeneration has become a promising treatment for craniomaxillofacial bone defects such as alveolar clefts. This study sought to assess the efficacy of lateral ramus cortical plate with buccal fat pad derived mesenchymal stem cells (BFSCs) in treatment of human alveolar cleft defects. Ten patients with unilateral anterior maxillary cleft met the inclusion criteria and were assigned to three treatment groups. First group was treated with anterior iliac crest (AIC) bone and a collagen membrane (AIC group), the second group was treated with lateral ramus cortical bone plate (LRCP) with BFSCs mounted on a natural bovine bone mineral (LRCP+BFSC), and the third group was treated with AIC bone, BFSCs cultured on natural bovine bone mineral, and a collagen membrane (AIC+BFSC). The amount of regenerated bone was measured using cone beam computed tomography 6 months postoperatively. AIC group showed the least amount of new bone formation (70 ± 10.40%). LRCP+BFSC group demonstrated defect closure and higher amounts of new bone formation (75 ± 3.5%) but less than AIC+BFSC (82.5 ± 6.45%), suggesting that use of BFSCs within LRCP cage and AIC may enhance bone regeneration in alveolar cleft bone defects; however, the differences were not statistically significant. This clinical trial was registered at clinicaltrial.gov with NCT02859025 identifier.
Project description:Individuals with clefts present considerably more dental anomalies than do individuals without clefts. We used dental development to subphenotype clefts with the goal of identifying cleft subgroups that could have specific genetic contributions. We examined 1000 individuals, 500 with clefts and 500 without. We used several clinical features, such as cleft completeness or incompleteness, laterality, and the presence of dental anomalies to assess each individual's cleft status. We performed chi-square and Fisher's exact tests to compare the frequencies of observed anomalies between individuals with and individuals without clefts, and among individuals with different cleft subphenotypes. Agenesis of the lateral incisor on the non-cleft side was the most remarkable observation, and may suggest that such cases could be considered incomplete forms of bilateral clefts of the lip.
Project description:To investigate the association between unilateral/bilateral maxillary canine impaction and sella-turcica bridging using CBCT imaging.This retrospective comparative study analyzed 76 CBCT images of the craniofacial complex including sella-turcica. The impacted cuspid group consisted of thirty-eight subjects (7 males, 31 females; mean age, 14.6 ± 3.2 years) diagnosed with unilateral (left n = 14, right n = 11) or bilateral (n = 13) palatal canine impaction. The control group included thirty-eight subjects matched by sex (7 males, 31 females; mean age, 19.5 ± 3.6 years) with no impaction. Multinomial logistic regression analysis was used to determine the association between unilateral/bilateral canine impaction and right and left sella-turcica bridging.The prevalence of sella-turcica bridging was 59.3% and 50% in the impacted canine and control groups, respectively. Although the odds for unilateral canine impaction were increased in the right and left sella-turcica bridging groups compared to the controls, the difference was not statistically significant. The risk of bilateral impaction was different between the two sides of sella-turcica bridging, but, again, the findings were not statistically significant.Contrary to previous 2D studies, there is no statistically significant association between unilateral/bilateral palatal canine impaction and sella-turcica bridging when using 3D CBCT.
Project description:Orofacial clefts are the most common malformations of the head and neck, with a worldwide prevalence of 1 in 700 births. They are commonly divided into CL(P) and CP based on anatomic, genetic, and embryologic findings. A Nigerian craniofacial anomalies study (NigeriaCRAN) was set up in 2006 to investigate the role of gene-environment interaction in the origin of orofacial clefts in Nigeria.DNA isolated from saliva from Nigerian probands was used for genotype association studies and direct sequencing of cleft candidate genes: MSX1 , IRF6 , FOXE1, FGFR1 , FGFR2 , BMP4 , MAFB, ABCA4 , PAX7, and VAX1 , and the chromosome 8q region.A missense mutation A34G in MSX1 was observed in nine cases and four HapMap controls. No other apparent causative variations were identified. Deviation from Hardy Weinberg equilibrium (HWE) was observed in these cases (p = .00002). A significant difference was noted between the affected side for unilateral CL (p = .03) and bilateral clefts and between clefts on either side (p = .02). A significant gender difference was also observed for CP (p = .008).Replication of a mutation previously implicated in other populations suggests a role for the MSX1 A34G variant in the development of CL(P).