Comparison of the regenerative effect of adipose-derived stem cells, fibrin glue scaffold, and autologous bone graft in experimental mandibular defect in rabbit.

BACKGROUND/AIMS: One of the main concerns for maxillofacial and orthopedic surgeons is finding a method to improve regeneration of large craniofacial bone defects. The aim of this study was to investigate the healing and regenerative effects of fibrin glue associated with adipose-derived stem cells (ADSCs) and fibrin glue scaffold alone with autologous bone grafts in experimental mandibular defects of the rabbit. METHODS: Bilateral uni-cortical osteotomies were performed in the mandible of 20 male Dutch rabbits. The animals were randomly divided into 2 equal groups. In one group, the defect on the right side was treated by fibrin glue associated with ADSCs and the defect on the other side remained as the control. In another group, the defect on the right side was treated with fibrin glue and on the left side with autologous bone graft. After 28 and 56 days, five rabbits from each group were evaluated by computed tomography (CT) and histopathological examinations. RESULTS: Coronal CT showed a remarkable reconstruction of cortical bone in the fibrin glue associated with ADSCs group at 28 and 56 days post-surgery. Histopathologically, new cortical bony bridge formation was seen increasingly in the fibrin glue, fibrin glue associated with ADSCs, and autologous bone graft groups after 28 days. Statistical analysis of the thickness of new cortical bone in the treatment versus control groups showed a significant difference between fibrin glue alone and fibrin glue associated with ADSCs groups (P = 0.02). No significant difference was found between the fibrin glue associated with ADSCs and the autologous bone graft groups (P > 0.05). CONCLUSIONS: The healing process had a significant increase in the thickness of new cortical bone when fibrin glue scaffold associated with ADSCs was used.

Correlation of clinical predictions and surgical results in maxillary superior repositioning.

This is a prospective study to evaluate the accuracy of clinical predictions related to surgical results in subjects who underwent maxillary superior repositioning without anterior-posterior movement. Surgeons' predictions according to clinical (tooth show at rest and at the maximum smile) and cephalometric evaluation were documented for the amount of maxillary superior repositioning. Overcorrection or undercorrection was documented for every subject 1 year after the operations. Receiver operating characteristic curve test was used to find a cutoff point in prediction errors and to determine positive predictive value (PPV) and negative predictive value. Forty subjects (14 males and 26 females) were studied. Results showed a significant difference between changes in the tooth show at rest and at the maximum smile line before and after surgery. Analysis of the data demonstrated no correlation between the predictive data and the surgical results. The incidence of undercorrection (25%) was more common than overcorrection (7.5%). The cutoff point for errors in predictions was 5 mm for tooth show at rest and 15 mm at the maximum smile. When the amount of the presurgical tooth show at rest was more than 5 mm, 50.5% of clinical predictions did not match the clinical results (PPV), and 75% of clinical predictions showed the same results when the tooth show was less than 5 mm (negative predictive value). When the amount of presurgical tooth shown in the maximum smile line was more than 15 mm, 75% of clinical predictions did not match with clinical results (PPV), and 25% of the predictions had the same results because the tooth show at the maximum smile was lower than 15 mm. Clinical predictions according to the tooth show at rest and at the maximum smile have a poor correlation with clinical results in maxillary superior repositioning for vertical maxillary excess. The risk of errors in predictions increased when the amount of superior repositioning of the maxilla increased. Generally, surgeons have a tendency to undercorrect rather than overcorrect, although clinical prediction is an original guideline for surgeons, and it may be associated with variable clinical results.

The impact of acemannan, an extracted product from Aloe vera, on proliferation of dental pulp stem cells and healing of mandibular defects in rabbits.

OBJECTIVES: Dental pulp stem cells (DPSCs) were shown to play an important role in regenerative medicine including reconstruction of various bone lesions. This study determined the impact of acemannan, an extracted product from Aloe vera, on in vitro proliferation of DPSCs and in vivo healing of mandibular defects in rabbits. METHODS: DPSCs were isolated and characterized. The growth kinetics of cells exposed to acemannan (8 mg/mL) and Hank's balanced salt solution (HBSS) were compared in vitro. Fifteen male rabbits were divided into 3 groups. Five animals were left as control group without any therapeutic intervention. Five rabbits were considered as experimental group 1 and received 20 µL of a cell suspension containing 106 DPSCs in the bone defect. Another 5 rabbits were regarded as experimental group 2 and were injected in the bone defect with 20 µL of a cell suspension containing 106 DPSCs treated with acemannan for 24 h. After 60 days, the animals were assessed by radiography and histologically. RESULTS: The mesenchymal properties of DPSCs were confirmed. Population doubling time (PDT) of DPSCs treated with acemannan (29.8 h) was significantly shorter than cells were just exposed to HBSS (45.9 h). DPSCs together with acemannan could significantly accelerate the healing process and osteogenesis in mandibular defects. CONCLUSIONS: As DPSCS showed an increased proliferation when treated with acemannan and accelerated the healing process in mandibular defects, these findings can open a new avenue in dentistry regenerative medicine when remedies of bone defects are targeted.

Outcome of bone availability after secondary alveolar bone graft in two age groups.

The aim of this study is to evaluate outcome of bone availability after the secondary alveolar bone graft in 2 age groups: group 1 patients were between 9 and 13 years old and group 2 patients were above 14 years old. Acceptance success criteria (ASC) consisted of sufficient bone height (more than 10 mm), bone width (more than 4 mm), and adequate continuity between maxillary segments. The height and width of alveolar grafted bone were measured by using the cone-beam CT scans. We studied 45 patients who underwent a bone graft in their alveolar cleft in 2 groups (25 patients in group 1 and 20 in group 2). The results showed that as the patients' ages increased, the incidence of ASC significantly decreased. In group 1, 23 patients had ACS (92%), and in group 2, only 4 patients (20%) had ASC. Cleft type did not affect the ASC. The critical age for decreasing ASC was 14.5 years. Our study showed successful outcomes of grafted bone were good when done in the mixed dentition period. Additionally, bone availability was more predictable at the mixed dentition stage.

Comparison of nonsurgical treatment options in pediatric condylar fractures: rigid intermaxillary fixation versus using guiding elastic therapy.

A prospective study was done to compare rigid intermaxillary fixation and guiding elastic for treatment of condylar fractures in pediatric patients. Sixty-one children younger than 12 years with condylar fractures were studied in 2 groups. Group 1 consisted of 31 patients who were treated with arch bar and intermaxillary fixation for 7 to 12 days, and group 2 consisted of 30 patients who were treated with arch bar and elastics without rigid intermaxillary fixation. Patients had minimal function during treatment time, which lasted 7 to 12 days. Evaluation of deviation on opening between both groups (groups 1 and 2) with a χ test did not show any relationship between them. Incidence of temporomandibular dysfunction signs was 25.8% in group 1 patients and 23.3% in group 2 patients. Comparison of temporomandibular dysfunction signs in both treatment groups did not show a statistically significant relationship. Our study showed the same results using guiding elastics as using rigid intermaxillary fixation in pediatric condylar fractures. Guiding elastic is more tolerable, and children have function during treatment.

Reconstruction of human mandibular continuity defects with allogenic scaffold and autologous marrow mesenchymal stem cells.

Mandibular continuity defects occur after tumor resection, maxillofacial injury, or osteomyelitis. In this clinical pilot study, we report a novel method for reconstruction of mandibular continuity defect by in vivo tissue engineering. In 3 patients with critical-size mandibular bone defects, the allogenic mandibular bone scaffold was customized, loaded by ex vivo expanded mesenchymal stem cells, and transplanted into the surgical defect site. According to the bone scintigraphy, vascularized bone was identified in 2 cases. In spiral computed tomography, normal bone healing without significant bone resorption was seen at the 2 viable grafts, but at the failed construction, there was a lack of osteointegration to the adjacent host bone and a higher density in the medullary bone. According to the serial panoramic imaging, the patients with viable bone grafts had normal bone healing, whereas the other patient had progressive overall bone resorption. Our results demonstrate the feasibility of allogenic bone scaffold loaded by mesenchymal stem cells in the reconstruction of mandibular continuity defects. Although long-term results are not yet available, it may be a novel method of reconstruction and a basis for further studies.

Tissue Engineering in Maxillary Bone Defects.

BACKGROUND: Restoration of craniofacial bone defects has been a concern for oral and maxillofacial surgeons. In this study, the healing effect of fibrin glue scaffold was compared with autologous bone graft in mandibular defects of rabbit. METHODS: Bilateral unicortical osteotomy was performed in the diastema region of 10 male Dutch rabbits. The subjects were randomly divided into 2 equal groups. The mandibular defect on the right side was treated with fibrin glue scaffold and the defect on the left side with autologous bone graft provided from iliac crest. After 4 and 8 weeks, five rabbits from each group were sacrificed and the defects were evaluated morphologically, by coronal computed tomography scanning (CT-scan) and by histological examinations. RESULTS: The healing effect of fibrin glue scaffold and autologous bone graft was similar with appropriate osteogenesis in comparison to the control group. CONCLUSION: Using fibrin glue can be a non-invasive treatment of choice in mandibular defects and maxillofacial surgeries when compared with autologous bone graft.

Comparison of Dental Panoramic Radiography and CBCT for Measuring Vertical Bone Height in Different Horizontal Locations of Posterior Mandibular Alveolar Process.

STATEMENT OF THE PROBLEM: Accurate measurement of the available bone height is an essential step in the pre-surgical phase of dental implantation. Panoramic radiography is a unique technique in the pre-surgical phase of dental implantations because of its low cost, relatively low-dose, and availability. PURPOSE: This article aimed to assess the reliability of dental panoramic radiographs in the accurate measurement of the vertical bone height with respect to the horizontal location of the alveolar crest. MATERIALS AND METHOD: 132 cone-beam computed tomography (CBCT) of the edentulous mandibular molar area and dental panoramic radiograph of 508 patients were selected. Exclusion criteria were bone abnormalities and detectable ideal information on each modality. The alveolar ridge morphology was categorized into 7 types according to the relative horizontal location of the alveolar crest to the mandibular canal based on CBCT findings. The available bone height (ABH) was defined as the distance between the upper border of the mandibular canal and alveolar crest. One oral radiologist and one oral surgeon measured the available bone height twice on each modality with a 7-dayinterval. RESULTS: We found a significant correlation between dental panoramic radiographs and cone-beam computed tomography values (ICC=0.992, p< 0.001). A positive correlation between the horizontal distance of the alveolar crest to the mandibular canal and measured differences between two radiographic modalities had been found (r=0.755, p< 0.001). For each single unit of increase in the horizontal distance of the alveolar crest to the mandibular canal, dental panoramic radiographs showed 0.87 unit of overestimation (p< 0.001). CONCLUSION: Dental panoramic radiographs can be employed safely in the pre-surgical phase of dental implantation in posterior alveolus of mandible, especially in routine and simple cases.

Evaluation of Anatomic Variations in Maxillary Sinus with the Aid of Cone Beam Computed Tomography (CBCT) in a Population in South of Iran.

STATEMENT OF THE PROBLEM: Anatomic variations of the maxillary sinus can be detected in cone-beam computed tomography (CBCT) and may assist to locate the posterior superior alveolar artery (PSAA) and define the maxillary sinus morphology more accurately for a more strict surgical treatment plan. PURPOSE: The study aimed to determine normal variations of the maxillary sinus with the aid of CBCT in a sample population in south of Iran. MATERIALS AND METHOD: This cross-sectional prevalence study was based on evaluation of 198 projection data of CBCT scans of some Iranian patients aged 18-45 who referred to a private oral and maxillofacial radiology center in Shiraz from 2011 to 2013. CBCT scans were taken and analyzed with NewTom VGi device and software. The anatomic variations which were evaluated in the axial images included the presence of alveolar pneumatization, anterior pneumatization, exostosis, and hypoplasia. Moreover the location and height of sinus septa, and the location of PSAA were assessed. SPSS software (version 17.0) was used to analyze the data. RESULTS: In a total of 396 examined sinuses, maxillary sinus alveolar pneumatization was the most common anatomic variation detected. Anterior pneumatization was detected in 96 sinuses (24.2%). Antral septa were found in 180 sinuses (45.4%) and were mostly located in the anterior region. Meanwhile, PSAA was mostly detected intra-osseous in 242 sinuses (65.7%). CONCLUSION: Anatomic variations of the maxillary sinus were common findings in CBCT of the maxilla. Preoperative imaging with CBCT seems to be very helpful for assessing the location of PSAA and the maxillary sinus morphology, which may be used to adjust the surgical treatment plan to yield more successful treatments.

Orthognathic Surgery Patients (Maxillary Impaction and Setback plus Mandibular Advancement plus Genioplasty) Need More Intensive Care Unit (ICU) Admission after Surgery.

STATEMENT OF THE PROBLEM: Due to shortage of ICU beds in hospitals, knowing what kind of orthognathic surgery patients more need ICU care after surgery would be important for surgeons and hospitals to prevent unnecessary ICU bed reservation. PURPOSE: The aim of the present study was to determine what kinds of orthognathic surgery patients would benefit more from ICU care after surgery. MATERIALS AND METHOD: 210 patients who were admitted to Chamran Hospital, Shiraz, for bimaxillary orthognathic surgery (2008-2013) were reviewed based on whether they had been admitted to ICU or maxillofacial surgery ward. Operation time, sex, intraoperative Estimated Blood Loss (EBL), postoperative complications, ICU admission, and unwanted complications resulting from staying in ICU were assessed. RESULTS: Of 210 patients undergoing bimaxillary orthognathic surgery, 59 patients (28.1%) were postoperatively admitted to the ICU and 151 in the maxillofacial ward (71.9%). There was not statistically significant difference in age and sex between the two groups (p> 0.05). The groups were significantly different in terms of operation time (p< 0.001). Blood loss For ICU admitted patients was 600.00±293.621mL and for those who were hospitalized in the ward was 350.00±298.397 mL. Statistically significant differences were found between the two groups (p< 0.001). Moreover, there was a direct linear correlation between operation time and intraoperative estimated blood loss and this relationship was statistically significant (r=0.42, p< 0.001). Patients with maxillary impaction and setback plus mandibular advancement plus genioplasty were among the most ICU admitted patients (44%), while these patients were only 20% of all patients who were admitted to the ward. As a final point, the result illustrated that patients who were admitted to the ICU experienced more complication such as bleeding, postoperative nausea, and pain (p< 0.001). CONCLUSION: Orthognathic surgery patients (maxillary impaction and setback plus mandibular advancement plus genioplasty) due to more intraoperative bleeding and postoperative nausea and pain would benefit from ICU admission after surgery.