Osseous regeneration in the jaws using demineralized allogenic bone implants

Successful management of spontaneous bone regeneration after jaws cystectomy using PRGF approach; case series

In the jaws, the healing process of bone defects occurs differently compared with other anatomical sites where healing is done by the formation of scar tissue. This is due to physiological bone remodeling and continuous bone resorption and apposition. In the case of large cysts, there is an increased risk of postoperative infection due to the retraction of the blood clot on the bony walls. The use of plasma rich in growth factors (PRGF), with or without autologous bone addition, for filling the cystic cavities is beneficial not only for its antimicrobial effect, but also due to simultaneously release of growth factors from platelet alpha granules and adhesive proteins. The aim of our work was to emphasize the spontaneous bone healing of the maxilla and mandible after the enucleation of large and medium-sized cysts in asymptomatic patients of different age. The outcome of three patients who underwent surgery for removal of radicular cysts is presented. Imagistic [cone-beam computed tomography (CBCT)] and histological examination was performed aiming to evaluate the quality of new bone at the site of the bone defect, after different time intervals. By using PRGF approach, the healing of mandibular bone occurred 18 months after cystectomy in a smoker patient, 54-year-old, while the healing of maxillary bone using autologous bone mixed with PRGF occurred after six months in a 63-year-old patient. In a young patient (14 years old), the regeneration period was six months, using PRGF and a fibrin cloth for filling the defect.

Clinical and Microcomputed Topography Evaluation of the Concentrated Growth Factors as a Sole Material in a Cystic Bony Defect in Alveolar Bone Followed by Dental Implantation: A Case Report

Concentrated growth factors (CGFs) can be used to enhance wound healing. This case report describes a short-term effect of CGF grafting followed by implant placement in a cystic bony defect within the mandible. Healing conditions were monitored by 2 implant-related surgeries, radiographs, and a microcomputed topography examination. Continuous increase of radiopacity in radiographs was noticed till 6 months after grafting. Bone core specimen was taken at 3.5 months after grafting, and percent bone volume reached 32.7% analyzed by microcomputed topography. In conclusion, the present case showed bone regeneration in the cystic bony defect grafted by CGFs alone.

Regeneration of Cystic Bone Cavities and Bone Defects With Bioactive Glass S53P4 in the Upper and Lower Jaws

Cysts and tumors are common lesions in the jaws. To be able to retain a good volume of the alveolar ridge during healing as well as strengthening the angle and body of the mandible and provide an instant improved support for adjacent teeth, reliable long-term bone regeneration is needed. The purpose of this prospective study was to promote bone regeneration by filling bony defects in the upper or lower jaw with granules of the bioactive glass S53P4 (BAG), which have osteostimulative and antimicrobial properties.The authors treated 20 patients (21 defects) surgically; benign tumors, cysts, or infection related to impacted teeth in the maxilla or mandible. The tumor or cyst was removed or enucleated and thorough cleaning of the infected area was performed. The bone cavity was filled with granules of the BAG S53P4 despite signs of chronic infection in the area at the time of surgery. The patients were followed up for an average of 34 months clinically and with cone beam computerized tomography for 28 months. In 20 defects the final outcome was successful. Despite infection at the time of surgery in 65% of the patients, no material associated infection was seen during the follow-up. The BAG S53P4 granules were radiologically remodeled into bone after 2 years follow-up. The use of granules of the BAG S53P4 in the treatment of large bone defects provides infection-free reliable bone regeneration despite chronic infection at the time of surgery, which improves the prognosis of adjacent teeth.

Can Low Level Laser Therapy Benefit Bone Regeneration in Localized Maxillary Cystic Defects? - A Prospective Randomized Control Trial

AIM:

The aim of the study was to evaluate the effect of Low-Level Laser Therapy (LLLT) on bone formation in cystic defects following cyst enucleation.

PATIENTS AND METHODS:

The sample was composed of sixteen patients with enucleated maxillary bony cystic lesions. With an age range from 20 - 44 grouped as eight Laser and eight Control patients. Laser group was subjected to low intensity diode laser immediately after surgery and then for three times per week for two weeks using a therapeutic laser irradiation. Group B (control group): patients were not subjected laser therapy.

RESULTS:

The predictor variable was exposure of bone defect to LLLT or none. The outcome variable was bone density changes measured by digital radiographs at day 1 and days 90 postoperatively. Descriptive and bivariate statistics were computed. There were no statistically significant differences between the 2 groups for the bone density at day 1. There was a statistically significant difference in bone density changes in each group at day 90: Significant at P ≤ 0.05. After adjusting for differences in day 1 for bone density, the estimated mean change in bone density changes at day 90 was significantly larger for Laser compared with control.

CONCLUSION:

The results of this study suggested that LLLT can enhance bone healing in maxillary cystic defects. This can serve as an adjunct method in preventing possible delayed healing and pathological fractures This also will be helpful for more researchers in early loading in case of dental implants to accelerate osseointegration.

The effect of alloplastic bone graft and absorbable gelatin sponge in prevention of periodontal defects on the distal aspect of mandibular second molars, after surgical removal of impacted mandibular third molar: a comparative prospective study

AIM

Recent studies claim that haemostatic agents can be used as bone graft substitutes. The aim of this study was to compare the efficacy of alloplastic bone graft with absorbable gelatin sponge in prevention of periodontal defects distal to mandibular second molar after the surgical removal of impacted mandibular third molars.

MATERIALS AND METHODS

A prospective, randomized, single-blind split-mouth study was designed. The study consisted of 25 patients requiring surgical removal of bilateral impacted mandibular 3rd molars. The surgical sites were randomly divided into 2 groups: group I: G-graft (hydroxyapatite + collagen, study group) and group II: Abgel (absorbable gelatin sponge, control group). Patients were recalled on lst and 7th postoperative days and 3rd and 6th postoperative months. Probing depth, alveolar bone levels and soft tissue wound healing were evaluated. Paired t test was used to compare pre and post-operative alveolar bone levels and probing depth (PD). Wilcoxon signed ranks test was used to compare the wound healing.

RESULTS

The soft tissue wound healing, PD and the distance between the cemento-enamel junction on the distal aspect of mandibular second molar (point A) and the alveolar crest on the distal aspect of the same tooth (point B) were significantly higher in group I as compared to group II.

CONCLUSION

This study reveals an increase in the alveolar bone level, improvement of PD and better wound healing in group I. Group II subjects required longer healing time than the normal. The authors disagree the claim that the haemostatic agents can be used as bone graft substitutes. However, long-term, multicenter, randomized controlled clinical trials are required.

An unusually large destructive nasopalatine duct cyst: a case report

A case of an unusually large expansile nasopalatine duct cyst (NPDC) causing extensive destruction of the hard palate with involvement of the nasal cavity, perforation of the alveolar process and mucosa of the maxilla by pressure of the maxillary anterior teeth is being presented.

Secondary healing after removal of large keratocystic odontogenic tumor in the mandible: enucleation followed by open packing of iodoform gauze

PURPOSE

The aim of this retrospective study was to present the findings of an open packing method after enucleation of large keratocystic odontogenic tumors (KCOTs) in the mandible.

PATIENTS AND METHODS

We performed a retrospective case series study of 27 patients with KCOTs larger than 5 cm treated at our institution between September 2003 and September 2008. A conservative surgical treatment was applied, which involved enucleation of the primary lesion and open packing of the residual osseous defect with iodoform gauze for secondary healing. Bone regeneration, tumor recurrence, and surgical complications were observed and analyzed. We used the χ(2) test and Pearson correlation coefficient for statistical analysis.

RESULTS

The postoperative follow-up time was 52.3 months on average (range, 24 to 84 months). The packing gauze was changed every 2 weeks after enucleation, and the total duration for packing was 10.2 months on average (range, 7-15 months). Bone regeneration and satisfactory secondary healing were observed clinically and radiographically after treatment. Only 1 case had a recurrence 6 months after initial treatment, which was attributed to insufficient bony unroofing during enucleation. The recurrent lesion was re-treated by the same method, and no recurrence occurred in the following 6 years. No serious complications from this method of treatment were observed. No significant variables were found to be related to the recurrence.

CONCLUSIONS

Enucleation with subsequent open packing was shown to be a conservative and comfortable treatment for patients and appears to be an effective choice for the management of large KCOTs in the mandible.

Cystic lesions of the jaws - a clinicopathological study of 322 cases and review of the literature

Three hundred and twenty-two patients (192 male and 130 female) with cystic lesions of the jaw were successfully diagnosed and treated. One hundred and fifty-five (48%) were radicular cysts, 80 (25%) were dentigerous cysts, 23 (7%) were odontogenic keratocyst (=keratocystic odontogenic tumor), 19 (6%) were eruption cysts, 16 (5%) were traumatic bone cysts, and 29 (9%) were non-odontogenic cysts. There were 95 in the pediatric age group (1 month to 16 years) and 227 in the adult age group (17 years and older). Male to female ratio was 1 in the pediatric age group and 1.7 in the adult age group. The treatment modalities were: marsupialization, enucleation, enucleation with bone grafting, or resection. The distribution and characteristics of jaw cysts in children are different from those in adults. In children there is a relatively high rate of developmental cysts, whereas in adults the inflammatory cysts are more common. Following enucleation of a cystic jaw lesion, the entire surgical specimen and not only a biopsy specimen, should be examined histopathologically to prevent any possibility of an intramural squamous cell carcinoma that may be overlooked. The differences in prevalence of each type of jaw cyst during a lifetime may point toward a multifactorial polygenic pattern rather than a monogenic pattern.

Jaw cysts - filling or no filling after enucleation? A review

INTRODUCTION

Jaw cysts are common lesions in the oral and maxillofacial region. Enucleation of the lesions and primary closure of the defects, the so-called "cystectomy", has evolved as the treatment of choice. In order to reduce infections and to accelerate bone regeneration, different types of bone grafts are increasingly investigated for defect filling.

MATERIAL AND METHODS

The present review reflects the most recent studies using autogenous, allogenic, xenogenic and alloplastic bone grafts and compares the results to current investigations about conservative cyst enucleation without using any filling materials. Relevant studies with significant patient sample sizes were electronically searched in PubMed and Medline.

RESULTS

Simple cyst enucleation and blood clot healing show low complication rates and sufficient bone regeneration even in large defects. Prospective randomized trials comparing the additional use of filling materials to the "cystectomy" are rare. Currently available data do not indicate the superiority of additional bone grafts.

CONCLUSION

Enucleation of jaw cysts and primary closure without bone substitutes remains "state of the art" in most cases.

Healing of bone defects by an osteopromotion technique using solvent-dehydrated cortical bone plate: a clinical and radiological study

Osseous defects of the jaws following trauma, cysts, infection or congenital deformity may show poor osteogenesis and the affected area may never be completely filled with bone. It is widely accepted in guided tissue regeneration that physically halting soft connective tissue proliferation into bone allows bone regeneration. This concept is called the "osteopromotion principle." The purpose of the present study was to evaluate the effect of solvent-dehydrated cortical bone plates as a barrier to allow bone regeneration by assessing the osteopromotion principle. 30 patients (18 male, 12 female) with cystic lesions of the jaws were assigned to two different groups. The patients in Group A were treated by enucleation. In Group B, were treated by removal of the lesion and placing a solvent-dehydrated cortical bone plate on top of the cyst cavity to avoid ingrowth of connective tissue. Both groups were evaluated radiographically using spiral-computed tomography (CT) before surgery and 12 months postoperatively. In group B, all cystic cavities showed complete bone healing in 12 months. At the same period, invasion of the soft connective tissue were observed in the patients treated only by enuclation. This study demonstrates that solvent-dehydrated cortical bone plates can be used as a barrier in treatment of cyst cavities and they hinder ingrowth of connective tissues and promote successful bone healing.

Histomorphometric and Densitometric Evaluation of the Effects of Platelet-Rich Plasma on the Remodeling of β-Tricalcium Phosphate in Beagle Dogs

Countless possibilities are available in maxillofacial surgery for the filling of bone defects. The best bone substitute known at present is osteogenic autogenous bone, but its use is accompanied by numerous disadvantages. The question has arisen of whether results attained with osteoconductive bone substitutes approach those achieved by the transplantation of autogenous bone. The aims of the investigation were to measure the effects in animal experiments of the growth factors to be found in the platelets on the rate of remodeling of beta-tricalcium phosphate, and on the quality of the new bone formed. Defects formed in the mandibles of 10 Beagle dogs were filled with beta-tricalcium phosphate or with a mixture of beta-tricalcium phosphate and platelet-rich plasma obtained from autogenous blood. The quality of the hard tissue formed and the effect of the platelet-rich plasma were examined by statistical analysis of the densitometric results obtained after 6 weeks and the histological and histomorphometric results obtained after 12 weeks. The densitometric study revealed that the bone formation was significantly more effective when platelet-rich plasma was used; at this stage, histomorphometric evaluation did not indicate a significant difference. After 12 weeks, however, the histomorphometric study demonstrated a significant difference in favor of the bone substitute used together with platelet-rich plasma. The results strongly suggest that use of the platelet-rich plasma suspension accelerates the remodeling of beta-tricalcium phosphate and leads to the formation of hard tissue with a quality similar to that of the autogenous bone.

Attachment, growth, and activity of rat osteoblasts on polylactide membranes treated with various low-temperature radiofrequency plasmas

Nonporous and porous membranes from poly(L/DL-lactide) 80/20% were treated with low-temperature oxygen, ammonia, or sulphur dioxide-hydrogen plasmas and the late effects of plasma treatment on physicochemical characteristics of the membranes' surface were analyzed. The plasma treatment resulted in the permanent attachment of sulphur and nitrogen functionalities to the membrane's surface, and increased the surface concentration of oxygen, thereby increasing the surface wettability. To assess whether the plasma treatment affects the cellular response, primary rat osteoblasts were cultured on nontreated and plasma-treated nonporous and microporous membranes, and attachment, growth, and activity of cells were investigated. It was found that attachment and growth of osteoblasts on all the plasma-treated membranes were greater compared with nontreated controls. The treatment with ammonia plasma was most efficacious. The beneficial effects of plasma treatment on cells were most pronounced for microporous polylactide membranes irrespective of the plasma used. The results of the study suggest that the treatment of porous polylactide structures with plasma can be an effective means of enhancing their suitability for tissue engineering. Plasma exposure may also have an advantageous effect on bone healing when polylactide membranes are used to treat bone defects.

Bone defects of the facial skeleton - replacement with biomaterials

The authors report on their experience with bone defect treatment following surgery of jaw-bone cysts. This is based on the use of cadaveric ground spongiosis saturated with tetracycline and metronidazol solution. The study shows the above mentioned material is very suitable for bone defect therapy, and cost effective. The results were verified by clinical and X-ray examination.

Comparative Clinical Study of Connective Tissue Graft and Two Types of Bioabsorbable Barriers in the Treatment of Localized Gingival Recessions

BACKGROUND

Localized buccal recessions occur in more than 60% of individuals; therefore, there is a need for predictable root coverage techniques. The objective of the present study was to evaluate the clinical effectiveness of the guided tissue regeneration (GTR) procedure versus connective tissue graft (CTG) in the treatment of localized gingival recessions over a 12-month postoperative period.

METHODS

Thirty bilateral matched pairs of localized buccal recessions in 22 patients were treated with CTG and GTR in this study. For the GTR procedure, two types of bioabsorbable barriers, polylactide/polyglycolide acid (PLGA) and solvent dehydrated duramater allograft (SDDA) membranes, were used and CTG was obtained from the palatal mucosa. The selected pairs of teeth were randomly assigned to one of three groups (10 pairs per group): group 1, PLGA (10 recessions) or CTG (10 recessions); group 2, SDDA (10 recessions) or CTG (10 recessions); or group 3, PLGA (10 recessions) or SDDA (10 recessions). Statistical analysis evaluated both intra- and intergroup measurements. The height of gingival recession (GR), width of keratinized tissue (KT), clinical attachment level (CAL), and probing depth (PD) were assessed at baseline and at 6, 9, and 12 months following surgery.

RESULTS

The amount of root coverage was 74.3%, 69.6%, and 86.3% with PLGA, SDDA, and CTG, respectively. The gain in KT was significant in the CTG group (P<0.05). No significant differences were observed among the three groups with respect to PD and CAL.

CONCLUSIONS

Results of this study indicate that all techniques led to an improvement of all clinical parameters except PD from baseline. However, CTG increased KT considerably compared to GTR. The final esthetic results were similar for the two membranes and connective tissue graft.

Long-term results of the application of solvent-dehydrated bone xenograft and duramater xenograft for the healing of oroantral osseous defects: a pilot experimental study

The aim of this study was to investigate the long-term effects of the use of human cadaveric solvent-dehydrated bone graft and duramater as a barrier membrane for the treatment of oroantral communication. Standard oroantral osseous defects were created in five minipigs. Subjects received cancellous bone graft in the form of block or microchips, duramater or a combination of bone and membrane. Uneventful healing was achieved in all of the subjects, clinically including the control site which did not receive any material. The operated bone segments were evaluated both by radiological and histological examinations after 6 months. Radiological evaluation was carried out using bone density analysis software and histological evaluation made by light microscopy. Radiological and histological results revealed that bone grafting of oroantral osseous defects improved the bone quality. However, application of duramater did not change this activity, both alone or combined with bone grafts. Within the limits of this experimental study, although solvent-dehydrated bone grafts were found superior and could be applied for the healing of osseous oroantral defects, resorbable membranes did not contribute to this process.

Cystic lesions of the jaws in children

Sixty nine pediatric patients with cystic lesions of the jaws were successfully diagnosed and treated. Thirty one (45%) were dentigerous cysts (D.C.), 15 (22%) were eruption cysts (E.C.), 12 (17.3%) were traumatic bone cysts (T.B.C.), nine (13.3%) were radicular cysts (R.C.), one (1.5%) was primordial cyst (P.C.) and one (1.5%) globulomaxillary cyst (G.M.C.). The mean age for E.C., R.C., D.C., T.B.C. was 4.7, 9.2, 11.5, and 13.3 years, respectively. The mean age of E.C. is significantly (P<0.05) younger than D.C. and T.B.C. but not from R.C. No significant age differences were found between R.C., D.C. and T.B.C. The differences in mean cyst diameter were not significant. Male to female ratio was 1. The treatment modalities were: marsupialization, enucleation or enucleation with bone grafting. The findings demonstrate that the distribution and characteristics of jaw cysts in children is unique and is different from the distribution in adults. The relatively high rate of developmental cyst and the fact that they occur in an area with rapid developmental changes, suggest the need for more conservative surgical management in this selected patient population.

Implants in regenerated bone in a primate model

BACKGROUND

Earlier publications from our laboratory described the use of guided bone regeneration to fill large bone voids in the mandible created through en bloc resection in primates. The present report describes placement of implants into the regenerated bone with subsequent prostheses construction and loading.

METHODS

Lesions were created in the mandibles of 9 monkeys in a standardized mandibular defect of 8 x 19 mm. Reinforced expanded polytetrafluoroethylene membranes were placed in the animals and held in place with mini screws and sutures for anywhere from 1 to 12 months. No material was added to the defect. In each animal a root-form implant was placed 12 mm distal to the abutment teeth into the regenerated bone and was loaded with a prosthesis for 12 months. These implants were compared to original implants placed in the same monkeys years earlier in the same location in non-regenerated bone. Digital radiology and histomorphometry are described.

RESULTS

The results show that root-form implants placed in regenerated bone show the same radiological and histomorphometric characteristics as in normal bone when loaded. In addition, the percentage of bone contact with implants seen in regenerated bone versus non-regenerated bone is the same when both are loaded (65 +/- 13% SD in regenerated bone versus 59 +/- 15% SD in non-regenerated bone).

CONCLUSIONS

In a primate model root-form implants placed in regenerated bone and prosthetically loaded show no difference when compared to root-form implants placed in non-regenerated bone and prosthetically loaded.

Spontaneous bone regeneration after enucleation of large mandibular cysts: a radiographic computed analysis of 27 consecutive cases

PURPOSE

This study evaluated the spontaneous bone healing after enucleation of large mandibular cysts subjectively and with a computed analysis of postoperative panoramic radiographs.

PATIENTS AND METHODS

Twenty-nine patients had large mandibular cysts treated by surgical enucleation. Postoperative clinical and radiographic examinations were performed at 6, 12, and 24 months in 27 patients. Bone regeneration and reduction of the residual cavities and bone density were evaluated with a computed analysis of preoperative and postoperative panoramic radiographs. A subjective and clinical radiographic evaluation of the healing process also was performed.

RESULTS

Uneventful healing and spontaneous filling of the residual cavities was obtained in all cases. The computed analysis of the postoperative radiographs showed mean values of reduction in size of the residual cavity of 12.34% after 6 months, 43.46% after 12 months, and 81.30% after 24 months. The increase in bone density was 37% after 6 months, 48.27% after 12 months, and 91.01% after 24 months.

CONCLUSION

Spontaneous bone regeneration can occur in large mandibular cysts without the aid of any filling materials. This simplifies the surgical procedure, decreases the economic and biologic costs, and reduces the risk of postoperative complications.

Guided bone regeneration of large mandibular defects in a primate model

BACKGROUND

An earlier publication from our laboratory described the use of guided bone regeneration to fill large bone voids in the mandible created through en bloc resection in primates. The present report is an embellishment of this paper and describes bone regeneration experiments in 18 adult male Macaca mulatta monkeys to determine how long membranes must be in position to promote guided bone regeneration.

METHODS

Thirty-six lesions were created in the mandibles of 18 monkeys in a standardized mandibular defect of 8 x 19 mm. Reinforced ePTFE membranes were placed in the animals and held in place with mini screws and sutures for anywhere from 1 to 12 months. No material was added to the defect. In addition to clinical studies, digital subtraction radiology and fluorescent labeling with tetracycline and histomorphometry are described.

RESULTS

The results indicate that no bone gain was observed in membranes exposed for 1 month or less, but bone gain (approximately well over 90% of defects) was observed at 12 months when membranes were left in situ for 2 to 12 months (P <0.0001). No significant difference in the amount of bone gained at 12 months was observed for membranes left in place for intervals ranging from 2 to 12 months. A significant correlation between the amount of bone gain observed at 3 and 12 months was observed (P <0.0001).

CONCLUSIONS

Data therefore suggest that membranes left in situ for 1 month or less result in minimal bone gain compared with membranes left in place from 2 to 12 months. In addition, labeling and stained sections clearly showed that the bone produced after 2 months of membrane placement is mature.