Effect on the contour of bone and soft tissue one year after harvesting chin bone for alveolar cleft repair

Spontaneous regeneration of bone following mandibular ramus bone harvesting: a CBCT analysis

The aim of this study was to evaluate healing at the donor site following autogenous block graft harvesting from the mandibular ramus. In this retrospective study, cone beam computed tomography images taken at different time-points were examined, and the volumes of preoperative and postoperative regions of interest were calculated in the software. Images were classified into four groups: 0-3 months, 4-6 months, 7-12 months, and >12 months post-surgery. To characterize the healing process over time, statistical analyses were conducted for both the 70% and 80% healing thresholds. Nearly half (n = 15, 47%) of the 32 patients included in this study achieved 70% bone healing within 4-12 months post-surgery. At the end of the 28-month period covered by this study, 21 patients (66%) had achieved 70% bone healing. The median time to achieve 70% healing was 9 months, while the median time to achieve 80% healing was 28 months. The findings of this study validate the feasibility of reutilizing the mandibular ramus area for additional bone augmentation when other intraoral sites are unavailable.

Effectiveness of Autogenous Chin Bone Graft in Reconstructive Surgery of Cleft Patients: A Systematic Review With Meta-Analysis and Algorithm of Treatment

PURPOSE

Bone grafting is fundamental in the treatment of cleft patients, and several grafting materials have been used for this purpose. The objective of this study is to evaluate the effectiveness of autogenous bone graft from the chin in the reconstruction of cleft alveolus.

METHODS

Searches were performed in six databases (PubMed, Scopus, Cochrane, LILACS, Embase, and Google Scholar) by two researchers individually until July 2022. This study was registered in the International Prospective Register of Systematic Reviews (CRD42021267954) and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The predictor variable is reconstruction technique, grouped into three levels: autogenous genial grafts, other endochondral autogenous grafts, and bio- or tissue-engineered materials. The outcome variables were alveolar cleft healing rate and bone height. The secondary variables were complications that included infections, necrosis, paresthesia, and dehiscence. Data analysis included the risk of bias and assessment of the certainty of evidence by the risk of bias in nonrandomized studies of interventions and grading of recommendations, assessment, development, and evaluation tools, respectively. The meta-analysis was performed with heterogeneity based on random effects of I² and 95% confidence.

RESULTS

In the initial search, 4,833 articles were found, and 10 of them were included in this systematic review. The included studies were from six countries on three different continents, with a sample of 692 patients. It was observed that the chin bone graft (214 patients) when compared to the endochondral bone graft (386 patients) reduced by 0.42 [confidence interval 95% = 0.18, 0.95] times the prevalence of bone resorption (P = .040 and I² = 70%) analyzed in radiographic images. Two studies evaluated the bone filling through computed tomography, and there was no statistically significant difference between the groups (P = .340, I² = 0%). Only two studies had a low risk of bias.

CONCLUSION

Based on a low certainty of evidence, the chin autogenous bone graft proved to be similar to the endochondral graft in the reconstruction of the cleft alveolar; however, the limited number of studies with high heterogeneity and an uncertain risk of bias decreased the strength of the results found in this systematic review. New controlled primary studies should be carried out with the purpose of safely determining the effectiveness of chin bone grafts for the reconstruction of cleft alveolar.

Cleft Alveolar Bone Graft Materials: Literature Review

INTRODUCTION

Since the early stages of alveolar bone grafting development, multiple types of materials have been used. Iliac cancellous bone graft (ICBG) remains the gold standard.

DESIGN/METHODS

A review of literature is conducted in order to describe the different bone filling possibilities, autologous or not, and to assess their effectiveness compared to ICBG. This review focused on studies reporting volumetric assessment of the alveolar cleft graft result (by computed tomography scan or cone beam computed tomography).

RESULTS

Grafting materials fall into 3 types: autologous bone grafts, ICBG supplementary material, and bone substitutes. Among autologous materials, no study showed the superiority of any other bone origin over iliac cancellous bone. Yet ICBG gives inconsistent results and presents donor site morbidity. Concerning supplementary material, only 3 studies could show a benefit of adding platelet-rich fibrin (1 study) or platelet-rich plasma (2 studies) to ICBG, which remains controversial in most studies. There is a lack of 3-dimensional (3D) assessment in most articles concerning the use of scaffolds. Only one study showed graft improvement when adding acellular dermal matrix to ICBG. Looking at bone substitutes highlights failures among bioceramics alone, side-effects with bone morphogenetic protein-2 composite materials, and difficulties in cell therapy setup. Studies assessing cell therapy-based substitutes show comparable efficacy with ICBG but remain too few.

CONCLUSION

This review highlights the lack of 3D assessments in the alveolar bone graft materials field. Nothing dethroned ICBG from its position as the gold standard treatment at this time.

A Prospective Study of Chin Bone Graft Harvesting for Unilateral Maxillary Alveolar Cleft During Mixed Dentition

PURPOSE

The chin is a common donor site for alveolar cleft bone grafting. The amount of bone available at this site can be limited, because conservative harvesting with mixed dentition must consider the incisive nerve, the unerupted mandibular canine, and the integrity of the inferior mandibular border.

MATERIALS AND METHODS

Patients with nonsyndromic unilateral alveolar cleft in the mixed dentition stage were selected for this study. The volume of bone obtained from the mandibular symphysis (symphysis menti), degree of alteration in lower lip sensation, anterior tooth vitality, remaining bone in the alveolar cleft, and bone defects at the donor site 1 year after surgery were evaluated.

RESULTS

Eighteen patients were enrolled in this study. The mean volume of bone harvested from the symphysis was 2.1 mL (range, 1.6 to 2.3 mL). For all cases, the bone volume harvested from the symphysis was insufficient to fill the alveolar cleft defect, and allograft had to be added to completely fill the cleft. Allograft was admixed in the range of 0.5 to 1 mL with autogenous bone harvested from the mandible. Lower lip sensation and vitality of the anterior teeth of the mandible were within the normal range 1 year after surgery in all cases. Fourteen of 18 patients (77.8%) had normal bone height or bone height at least three fourths of the expected height in the grafted alveolar cleft after 1 year; only 10% of the defect remained in the mandible.

CONCLUSION

The amount of bone yielded by conservative monocortical bone harvest from the mandibular symphysis during the mixed dentition stage for unilateral alveolar cleft bone grafting is not sufficient in volume and should be mixed with allograft. However, donor site morbidity is low with this approach.

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.

Complications in the use of the mandibular body, ramus and symphysis as donor sites in bone graft surgery. A systematic review

Background

To develop a systematic review by assessing and comparing the different complications that occurs in bone graft surgery using the mandibular body, ramus and symphysis as donor sites.

Material and Methods

In order to respond to the following question, a systematic review was developed: does the use of intraoral mandibular body and ramus as donor sites in bone graft surgery, produce fewer and less severe complications in comparison to the use of the mandibular symphysis in patients that present bone resorption that needs augmentation using autologous grafts? The review was carried out between January 1990 and 2015, during which only clinical essays with a minimum follow-up period of six months were included.

Results

The initial search yielded a total of 2912 articles, of which 6 were finally selected. In total, 259 graft surgeries were performed; 118 using the mandibular body and ramus as donor sites, and 141, the symphysis. The most frequent complications that arose when using the mandibular symphysis were temporary sensory alterations in the anterior teeth (33.87%), followed by sensory alterations of the skin and mucosa (18.57%). As for the mandibular body and ramus donor sites, the most frequent complications relate to temporary sensory alterations of the mucosa (8.19%) and to minor postoperative bleeding (6.55%).

Conclusions

The analyzed results show a higher prevalence and severity of complications when using mandibular symphysis bone grafts, producing more discomfort for the patient. Therefore, it would be advisable to perform further clinical essays due to the lack of studies found.

Key words:Alveolar ridge augmentation, autogenous bone, mandibular bone grafts, chin, mandibular symphysis, mandibular ramus.

Generation of a bioengineered autologous bone substitute for palate repair: an in vivo study in laboratory animals

We carried out an in vivo study to evaluate the potential usefulness of a novel bioengineered bone substitute for the repair of palate defects in laboratory rabbits, using tissue-engineering methods. Our results showed that the use of a bioengineered bone substitute was associated with more symmetrical palate growth as compared to the controls, and the length and height of the palate were very similar on both sides of the palate, with differences from negative controls 4 months after artificial bone grafting for bone length. The histological analysis revealed that the regenerated bone was well organized and expressed osteocalcin. In contrast, bone corresponding to control animals without tissue grafting was immature, with areas of osteoid tissue and remodelling, as determined by MMP-14 expression. These results suggest that bone substitutes may be a useful strategy to induce the formation of a well-structured palate bone, which could prevent the growth alterations found in cleft palate patients. This opens a door to a future clinical application of these bone substitutes. Copyright © 2015 John Wiley & Sons, Ltd.

Chin bone graft for maxillary alveolar cleft: indications and limitations

BACKGROUND

Alveolar bone grafting (ABG) is an important step in the management of patients with cleft lip and palate. Choice of autogenous bone grafting is critical to achieve the goals of alveolar cleft bone grafting. This study was designed to determine which situations are suitable for obtaining bone from the chin in ABG.

MATERIALS AND METHODS

In a retrospective study, the alveolar clefts that had been bone-grafted from the chin bone were selected from the archived files of the Oral and Maxillofacial Department, Mashhad University of Medical Sciences in 2004 to 2012. The patients were recalled and postoperative panoramic and lateral cephalometry views were obtained.

RESULTS

Seventeen patients were included in this study, with 53% females and 70.5% unilateral maxillary alveolar clefts. The follow-up was from 2 to 6 years. The mean age of the patients at the time of surgery was 17 ± 3.8 years.

CONCLUSION

Harvesting bone from the chin is easy and safe, with low morbidity. Considering the fact that the volume of the harvested bone is low, especially in the presence of unerupted mandibular canine, autogenous chin bone is recommended for late ABG, especially in unilateral cases when the plan is to close the gap in the arch orthodontically while there is no need for lateral piriform augmentation.

Evaluation of the anterior mandibular donor site one year after secondary reconstruction of an alveolar cleft: 3-dimensional analysis using cone-beam computed tomography

The aim of this study was to analyse changes in the volume of the chin after harvest of a bone graft for secondary reconstruction of an alveolar cleft. Cone-beam computed tomographic (CT) scans of 27 patients taken preoperatively, and immediately and one year postoperatively, were analysed, and 3-dimensional hard-tissue reconstructions made. The hard-tissue segmentation of the scan taken one year postoperatively was subtracted from the segmentation of the preoperative scan to calculate the alteration in the volume of bone at the donor site (chin). A centrally-orientated persistent concavity at the buccal side of the chin was found (mean (range) 160 (0-500) mm(3)). At the lingual side of the chin, a central concavity remained (mean (range) volume 20 (0-80) mm(3)). Remarkably, at the periphery of this concavity there was overgrowth of new bone (mean (range) volume 350 (0-1600) mm(3)). Re-attachment of the muscles of the tongue resulted in a significantly larger central lingual defect one year postoperatively (p=0.01). We also measured minor alterations in volume of the chin at one year. Whether these alterations influence facial appearance and long term bony quality is to be the subject of further research.

Prospective clinical assessment of pulp sensitivity after chin bone harvesting

PROPOSAL

Evaluate pulp vitality of mandibular teeth after chin bone harvesting.

MATERIALS AND METHODS

Thirty patients underwent chin bone harvesting and accompanied for 12 months, being submitted to testing for pulp vitality with Endo Ice refrigerant spray to produce a local temperature of -50 °C. The statistical analysis was executed with McNemar test with P value < 0.05.

RESULTS

Results show that canine teeth are most susceptible to alterations; 68.82% (181) of the teeth tested showed no loss of pulp sensitivity to cold 30 days after surgery (P < 0.05), and at the end of the study, that figure had risen to 100% (263) of all teeth included in the sample.

CONCLUSIONS

Pulp vitality testing showed that 31.18% (82) of teeth experienced some loss of sensitivity, but by 12 months after surgery, all teeth had recuperated their pulp sensitivity to cold unaided.

The application of digital surgical diagnosis and treatment technology: a promising strategy for surgical reconstruction of craniomaxillofacial defect and deformity

The craniomaxillofacial defect and deformity always leads to serious dysfunction in mastication and facial contour damage, significantly reducing patients' quality of life. However, surgical reconstruction of a craniomaxillofacial hard tissue defect or deformity is extremely complex and often does not result in desired facial morphology. Improving the result for patients with craniomaxillofacial defect and deformity remains a challenge for surgeons. Using digital technology for surgical diagnosis and treatment may help solve this problem. Computer-assisted surgical technology and surgical navigation technology are included in the accurate digital diagnosis and treatment system we propose. These technologies will increase the accuracy of the design of the operation plan. In addition, the intraoperative real-time navigating location system controlling the robotic arm or advanced intelligent robot will provide accurate, individualized surgical treatment for patients. Here we propose the hypothesis that a digital surgical diagnosis and treatment technology may provide a new approach for precise surgical reconstruction of complicated craniomaxillofacial defect and deformity. Our hypothesis involves modern digital surgery, a three-dimensional navigation surgery system and modern digital imaging technology, and our key aim is to establish a technological platform for customized digital surgical design and surgical navigation for craniomaxillofacial defect and deformity. If the hypothesis is proven practical, this novel therapeutic approach could improve the result of surgical reconstruction for craniomaxillofacial defect and deformity for many patients.