To what extent does hyaluronic acid affect healing of xenografts? A histomorphometric study in a rabbit model

ABSTRACT Among the many graft materials that have been used for the treatment of bone defects in oral and maxillofacial regions is xenograft. To improve osteoconductive effects of xenografts, they have been combined with various biocompatible materials, such as hyaluronic acid and bone morphogenetic protein. Objective: To determine bone-healing capacity of high molecular weight hyaluronic acid (HA) combined with xenograft in rabbit calvarial bone defects. Material and methods: Ten adult male New Zealand rabbits (mean weight 3 kg) were included in the study. Three 6-mm-diameter bicortical cranial defects were created on calvarial bone of all rabbits. These defects were filled as follows: a) xenograft; b) HA+xenograft; c) autograft. One month after the first operation, rabbits were sacrificed. Specimens were evaluated histomorphometrically. Results: Considering multiple comparisons, differences regarding new bone were statistically significant between all groups (p<0.05). The volume of residual graft was significantly decreased in HA group compared to xenograft group (p=0.035). Marrow space, trabecular thickness (TbTh), trabecular width (TbWi), trabecular separation (TbSp), and number of node: number of terminus (NNd:NTm) in the autograft group were significantly better than xenograft and HA groups (p<0.05). However, regarding marrow space, TbTh, TbWi, TbSp, and NNd:NTm values, xenograft and HA groups showed similar results and the difference were not significant (p>0.05). Conclusion: These results support that high molecular weight hyaluronic acid could contribute to the healing of xenograft by improving the percentage of new bone formation and reducing the percentage of residual graft. However, HA did not significantly affect the quality of newly formed bone assessed by microarchitectural parameters.

Can Resorbable Fixation Screws Replace Titanium Fixation Screws? A Nano-Indentation Study.

PURPOSE: The aim of this study was to compare the nano-hardness and elastic modulus of titanium and resorbable screws and determine whether resorbable screws could completely replace titanium screws. MATERIALS AND METHODS: The mechanical properties (nano-hardness and decreased elastic modulus) of TriMed titanium, resorbable Inion CPS, and Synthes RapidSorb samples were measured using a nano-indentation technique. In this study, a Hysitron TriboIndenter TI 950 with a resolution less than 1 nN and a displacement resolution of 0.04 nm was used for the nano-indentation tests. The unloading segments of the nano-indentation curves were analyzed using the method of Oliver and Pharr (J Mater Res 7:1564, 1992). RESULTS: Statistical analysis showed that the values of the elastic modulus and nano-hardness of the TriMed titanium screws were significantly higher than those of the resorbable Inion CPS and Synthes RapidSorb screws (P < .05). A statistical difference was not observed between the values of the elastic modulus and the nano-hardness of the Inion CPS and Synthes RapidSorb screws (P > .05). CONCLUSIONS: In this study, the resorbable screws were found to be soft and flexible compared with the titanium screw. According to the results of this nano-indentation study, resorbable and titanium screws cannot be used interchangeably.

Angioleiomyoma of the gingiva: a report of two cases.

Leiomyoma is a type of benign smooth muscle neoplasm that is a common neoplasm of the uterus and gastrointestinal tract but rarely affects the head and neck region and is especially unlikely to affect the oral cavity. The diagnosis of leiomyoma is mainly determined by histopathological studies due to variation in its clinical appearance and symptoms. In the present paper we report two rare cases of gingival angioleiomyoma in the posterior maxilla and mandible. After total excision, hematoxylin-eosin and smooth muscle actin staining confirmed the diagnosis of angioleimyoma.

Effects of glucosamine-chondroitin combination on synovial fluid IL-1ß, IL-6, TNF-α and PGE2 levels in internal derangements of temporomandibular joint.

BACKGROUND: The aim of the present study was to evaluate the effects of glucosamine-chondroitin sulphate combination on internal derangements of temporomandibular joint in clinical and biochemical manners. MATERIAL AND METHODS: This randomized clinical study included 31 cases reporting joint tenderness, in which disc displacement was detected on MR imaging. In all patients, synovial fluid sampling was performed under local anesthesia. In the study group, the patients were prescribed a combination of 1500 mg glucosamine and 1200 mg chondroitin sulphate, while patients in the control group were only prescribed 50 mg tramadol HCl (twice daily) for pain control. After 8 weeks, synovial fluid sampling was repeated in the same manner. The levels of pain, maximum mouth opening (MMO), synovial fluid IL-1ß, IL-6, TNF-α and PGE2 measured before and after pharmacological intervention were compared. RESULTS: The reduction in pain levels was significant in both groups. There was no significant difference between two groups in terms of pain reduction. The improvement in MMO was significant in the study group but it was not in the control group. The MMO improvement was significantly higher in the study group compared to the control group. In the study group, significant decrease was observed in PGE2 level, while the decreases in IL-1ß, IL-6 and TNF-α levels were not significant. In the control group, no significant decrease was observed in any of the inflammatory cytokines after 8 weeks, moreover IL-1ß and IL-6 levels were increased. Alterations of IL-1ß and IL-6 levels were significant in study group while TNF-α and PGE2 levels were not, compared to control group. CONCLUSIONS: In conclusion, these results might suggest that glucosamine-chondroitin combination significantly increases the MMO and decreases the synovial fluid IL1ß and IL6 levels in internal derangements of TMJ compared to tramadol. The modifications of synovial fluid TNF-α and PGE2 levels do not reach statistical significance. This combination also provides efficient pain relief in similar level with tramadol, a narcotic analgesic.

Comparison of osteoconductive properties of three different ß-tricalcium phosphate graft materials: a pilot histomorphometric study in a pig model.

AIMS: The aim of this study was to compare the de novo bone formation ability and osteoconductive effects of three different ß-tricalcium phosphate (ß-TCP) graft materials. The micro-architectural parameters of the newly formed bone tissues were also compared among the different graft materials. MATERIAL AND METHODS: Eight male Swiss domestic pigs were used in the study. Five bony defects were made with a trephine bur. Three of the defects were filled with Cerasorb®, Kasios® and Poresorb®. The fourth defect was filled with an autogenous bone graft. The last defect remained empty. All subjects were sacrificed after 8 weeks. RESULTS: When compared to a negative control group, significant healing was observed in all the groups except the Cerasorb group. The osteoconductivity of the Poresorb group was better than that of the other groups (p < 0.05). The difference in the osteoconductivity of the Kasios and Cerasorb groups was statistically significant (p < 0.05). Comparison of the micro-architectural properties of newly formed bone tissues retrieved from the defects showed that those filled with Poresorb were the best. CONCLUSION: ß-TCP materials show different results in terms of the volume and characteristics of new bone formation, although they have a similar chemical structure.

Treatment of displaced mandibular condylar fracture with botulinum toxin A.

The aim of this case report is to discuss the effect on condylar reduction of botulinum toxin A treatment used in a child with displaced fracture at condylar neck of mandible. A 3-years old boy was admitted to our clinic for incomplete fracture of mandibular symphysis and displaced condylar fracture at the left side. An asymmetrical occlusal splint with intermaxillary fixation was used instead of open reduction and internal fixation because of incomplete fracture of symphysis and possible complications of condyle surgery. However, it was observed that condylar angulation persisted despite this procedure. Thus, botulinum toxin A was administered to masseter, temporalis and pterygoideus medialis muscles. At the end of first month, it was seen that mandibular condyle was almost completely recovered and that fusion was achieved. In conclusion, Botulinum A toxin injection aiming the suppression of masticatory muscle strength facilitates the reduction in the conservative management of displaced condyle in pediatric patients.

Effects of smoking on periimplant health status and IL-1ß, TNF-α, and PGE2 levels in periimplant crevicular fluid: a cross-sectional study on well-maintained implant recall patients.

PURPOSE: The aim of this cross-sectional study was to evaluate the effects of smoking on periimplant health status and inflammatory cytokines interleukin-1ß, tumor necrosis factor-α, and prostaglandin E2 levels in periimplant crevicular fluid (PICF) and to determine their correlation with clinical parameters in well-maintained implant recall patients. MATERIAL AND METHODS: A total of 60 dental implants placed in 60 patients (27 patients were smoker and 33 were nonsmoker) were included in the study. Plaque index, gingival index, probing depth, periimplant bone loss, PICF volume, and biochemical cytokine levels in PICF were determined and analyzed statistically. The correlation between PICF cytokine levels and clinical parameters were also analyzed. RESULTS: All clinical parameters with the exception of plaque scores were significantly higher in the smoker group. Significantly increased levels of cytokines were observed in the smoker group. The correlation between the cytokine levels and clinical parameters were more marked in smokers. CONCLUSIONS: Although the implants of the smoker patients seem to be clinically healthy, the results demonstrate that the implants are relatively at risk even if in a well-maintained population.

Diagnostic concordance characteristics of oral cavity lesions.

PURPOSE: The objective of this study was to evaluate the diagnostic concordance characteristics of oral cavity lesions by comparing the clinical diagnosis of the lesions with the histopathologic diagnosis. MATERIAL AND METHOD: A retrospective analysis was conducted on the patients, who were admitted with oral cavity pathology and underwent biopsy procedure between 2007 and 2011. The oral cavity lesions were classified into 6 different groups as odontogenic cysts, nonodontogenic cysts, odontogenic tumors, nonodontogenic tumors, malignant tumors, and precancerous lesions in accordance with the 2005 WHO classification. The diagnoses were also recategorized into 3 groups expressing prognostic implications as benign, precancerous, and malignant. The initial clinical diagnoses were compared with the histopathologic diagnoses. Data were analyzed statistically. RESULTS: A total of 2718 cases were included. Histopathologic diagnosis did not match the clinical diagnosis in 6.7% of the cases. Nonodontogenic tumors and malignant tumors had the highest misdiagnosis rates (11.5% and 9%, resp.), followed by odontogenic tumors (7.7%), precancerous lesions (6.9%), and odontogenic cysts (4.4%). Clinicians were excelled in diagnosis of benign and precancerous lesions in clinical setting. CONCLUSION: The detailed discordance characteristics for each specific lesion should be considered during oral pathology practice to provide early detection without delay.

Influence of two different flap designs on the sequelae of mandibular third molar surgery.

PURPOSE: The aim of this study was to compare the influence of triangular and envelope flaps on trismus, pain, and facial swelling after mandibular third molar surgery. METHODS: Twenty healthy patients with bilateral, symmetrically impacted mandibular third molars were included in this double-blinded, prospective, cross-over, randomized study. The patients were operated with envelope flap on one side and triangular flap on the other side. Trismus was determined by measuring maximum interincisal opening, and facial swelling was evaluated using a tape measuring method. Pain was determined using visual analog scale (VAS) and recording the number of pain pills taken. RESULTS: The facial swelling measurements and VAS scores were lower in the envelope flap group compared to the triangular flap group. There was no significant difference between the two flap designs in operation time, maximum interincisal opening, and the number of analgesics taken. CONCLUSION: Envelope flap yields to less facial swelling and reduced VAS scores in comparison to triangular flap. There is no clinical difference in trismus between the two flap designs. Despite the higher VAS scores with triangular flap, no additional doses of analgesics were required in triangular flap.

Effect of zoledronic acid on osseointegration of titanium implants: an experimental study in an ovariectomized rabbit model.

PURPOSE: Zoledronic acid (ZA), a new-generation intravenous bisphosphonate, exhibits the greatest affinity for bone mineral with the longest retention, thereby leading to its ability to be dosed at annual intervals in the treatment of osteoporosis. The purpose of this preliminary study was to evaluate the effects of systemic administration of a single dose of ZA on osseointegration and bone healing around titanium dental implants. MATERIALS AND METHODS: Thirty-six female New Zealand rabbits (aged 6-12 months) were used in this study. Rabbits were randomly assigned to 1 of 3 groups: sham control group (SH), ovariectomy group (OVX), and OVX and ZA group (OVX + ZA). Animals in the OVX and OVX + ZA groups were subjected to bilateral ovariectomy, whereas animals in the SH group were sham operated. Eight weeks later, 1 implant was placed in each tibia of the animals. ZA was administered in the OVX + ZA group during the implantation, whereas the OVX and SH groups received saline solution infusions. All of the subjects were sacrificed 8 weeks after the implantation, and tibial specimens were harvested. Histomorphometric bone-to-implant contact analysis, resonance frequency analysis, removal torque testing, and digital radiographic absorptiometry were administered, and the data were statistically analyzed. RESULTS: Histomorphometric, resonance frequency, and radiodensitometric analyses showed significant improvement in osseointegration of implants in the OVX + ZA group compared with the OVX group. However, the differences in removal torque results between the groups were not statistically significant. CONCLUSIONS: The results of this study suggest that systemic ZA administration may improve osseointegration of titanium implants placed in estrogen-deficient states of bone.