Can bone marrow aspirate concentrate change the mineralization pattern of the anterior maxilla treated with xenografts? A preliminary study.

OBJECTIVE: To evaluate bony reconstruction of the atrophic anterior maxilla using particulate grafts with or without autologous bone marrow aspirate concentrate (BMAC). MATERIALS AND METHODS: Eight patients with atrophy of the anterior maxilla due to teeth loss were selected and split into groups according to the type of material used: Control Group (CG) (n = 4) - particulate xenograft only and Test Group (TG) (n = 4) - a combination of particulate xenograft and BMAC. Both groups received a collagen membrane to cover the xenograft. After 4 months, during implant placement, a sample of bone was removed from the graft area using a 2 mm diameter trephine bur. The specimens were fixed and preserved for histomorphometric evaluation, which included the following parameters: Mineralized tissue (MT) and non-MT (NMT). Cone beam computed tomography was performed at 3 time intervals to measure bone thickness: (1) Before grafting, (2) 4 months and (3) 8 months postgrafting, using localized bone gain (mm) as the outcome variable. RESULTS: Tomographic analysis revealed bone gain in CG of 3.78 ± 1.35 mm and 4.34 ± 1.58 mm at 4 and 8 months, respectively. TG showed an increase of 3.79 ± 0.52 mm and 4.09 ± 1.33 mm after 4 and 8 months, respectively. Histomorphometric analysis revealed that, for CG, MT- and NMT-related values were 52.3% ± 16.78% and 47.70% ± 5.55%, respectively, whereas for TG, they were 65.04% ± 20.98% and 34.96 ± 10.38, respectively. CONCLUSION: Although radiographic bone gain appeared similar between the groups, the use of BMAC obtained via the BMAC(®) method revealed an increased mineralization trend in the anterior maxilla. It must be highlighted, however, that this is a preliminary study with a relatively small sample population and further studies with larger sample sizes are needed to verify these results.

Comparing patients with Apert and Crouzon syndromes--clinical features and cranio-maxillofacial surgical reconstruction.

Cranio-maxillofacial malformations, as seen in Crouzon and Apert syndromes, may impose an immense distress on both function and aesthetics of the person affected. The aims of this study were to describe and compare the main facial and intraoral features of patients with Apert and Crouzon syndromes, the clinical manifestations that may be present, additionally to the main syndromic traits, as well as the cranio-maxillofacial surgical treatment protocols followed.Twenty-three patients with Apert syndrome (6 males, 17 females), and 28 patients with Crouzon syndrome (20 males, 8 females) were evaluated for general medical aspects, craniofacial characteristics, dentoalveolar traits before and after the final orthognathic surgery, and types and timing of cranio-maxillofacial operations. Mental retardation, associated additional malformations, cleft palate, and extensive lateral palatal soft tissue swellings were more common in children with Apert syndrome. In both syndromes, clinical findings included concave profile, negative overjet, posterior crossbites, anterior openbite, and dental midline deviation, which were corrected in almost all cases with the final orthognathic surgery, with the exception of the lateral crossbites, including more than one tooth pair, which were persisting in about half of the cases. Cranial vault decompression and/or reshaping, midfacial and orbital advancement procedures, often in conjunction with a mandibular setback, were the most frequent cranio-maxillofacial operations performed. In conclusion, Apert syndrome is more asymmetric in nature and a more severe clinical entity than Crouzon syndrome. The syndromic dentofacial features of both conditions could be significantly improved after a series of surgical procedures in almost all cases with the exception of the posterior crossbites, with haIf of them persisting post-surgically.

Local sinus lift for single-tooth implant. I: clinical and radiographic follow-up.

BACKGROUND: For single-tooth implant replacement in the posterior maxilla, it is often necessary to do an augmentation of the alveolar process because of post-extraction resorption and include part of the maxillary sinus. PURPOSE: The purpose of this study is to present a technique for a local sinus lift with autogenous bone in a one-stage procedure. Additionally, volume changes of the grafted area were evaluated radiographically up to 2 years. MATERIALS AND METHODS: Twenty patients, 12 female and 8 males, were included in the study. Single-tooth replacement was made in the second premolar area in 7 cases and in the molar area in 13 cases. Local sinus lift and implant installation were made simultaneously. Abutment connection was made after 6 months of healing. RESULTS: Two years of clinical and radiographic follow-ups have been made in all patients. The survival rate was 100%. The residual bone volume in the actual area was 2-5 mm preoperatively, after sinus lifting in mean 13 mm, after 1 year in mean 11.4 mm, and 2 years postoperatively in mean 10.6 mm. CONCLUSIONS: Local sinus lift with simultaneous bone augmentation and single-tooth replacement in the posterior maxilla is a predictable method although a certain bone volume reduction around the implant was evident at the 2-year follow-up.

Dental agenesis patterns in Crouzon syndrome.

Dental agenesis may be present in an isolated familiar manner, or occur as a part of a syndrome.To date, this clinical trait seems to have been overlooked in patients with Crouzon syndrome.The aim of the present study was to investigate dental agenesis and dental agenesis patterns in a population of persons with Crouzon syndrome in Sweden. Serial panoramic radiographs of 26 individuals with Crouzon syndrome (20 males, 6 females) were examined.Third molars were excluded from the assessment. The prevalence of agenesis for at least one tooth was 42.3%. Each affected patient was found to have up to 5 missing teeth. Upper and lower second premolars were the most frequently congenitally missing teeth. Eleven dental agenesis patterns of the entire dentition were identified, as described by the tooth agenesis code (TAC). All patterns were unique and asymmetric,with only one exception, a symmetric pattern of the maxillary and mandibular second premolars. In conclusion, persons with Crouzon syndrome were found to have a high prevalence of dental agenesis and a remarkable variability of dental agenesis patterns. It is important to be aware of this clinical situation, especially when orthodontic treatment planning for these patients is performed as early as in the mixed dentition.

Orthognathic surgery in patients with craniofacial syndrome. I. A 5-year overview of combined orthodontic and surgical correction.

We studied orthognathic correction of dentofacial deformities in patients with craniofacial syndromes (Crouzon, Apert, and Treacher Collins) during a 5-year period. The number of patients treated within this time period was 17 with Crouzon syndrome, 12 with Apert syndrome, and six with Treacher Collins syndrome. Individual follow-up was 2.5 years. Bimaxillary operation, sometimes with genioplasty, has been done after preoperative orthodontic treatment of 1.5-2.5 years. Clinical and radiographic cephalometric evaluations of the orthodontic results were made. The functional and aesthetic results were satisfactory in most patients, although there were large individual variations. The experience of a craniofacial centre such as the one in Gothenburg, Sweden, which has different odontological and medical specialities, is invaluable for an optimal result.

Immediate implant placement in fresh extraction sockets: a clinical report.

PURPOSE: To study the outcome of implant placement in fresh extraction sockets with simultaneous use of particulate bone graft material. MATERIALS AND METHODS: Patients referred to the maxillofacial surgery clinic for extraction and implant therapy were included in the study. A consecutive series of patients suitable for immediate placement in combination with extraction was subjected to implant surgery. Patients with ongoing inflammatory, exacerbating processes were not included. The space between implants and sockets was filled with autologous bone graft material. A two-stage surgical procedure was planned to optimize marginal bone healing. All patients were to be followed clinically and radiologically for 2 years according to a standard protocol. RESULTS: Forty implants were placed in fresh extraction sockets in 26 patients (nine women and 17 men) with an average age of 60 years (range, 19 to 76 years). The most frequent site for implant placement was the anterior maxilla. Autologous bone graft material was used in all cases to fill the space between the implant and the socket borders. All implants were osseointegrated at the time of abutment connection. No complications were observed. Radiographic examination showed only slight marginal bone reduction of 0.13 mm mesially and 0.19 mm distally. CONCLUSION: Implants can be placed successfully in fresh extraction sockets using autologous bone graft material to fill the gap between implant and labial bone through a submerged surgical technique. This technique demonstrated acceptable clinical and radiographic outcomes over a 2-year period in 26 patients with 40 implants.

Sinus lift procedure using a 2-stage surgical technique: I. Clinical and radiographic report up to 5 years.

PURPOSE: The aim of this study was to report the long-term results of a 2-stage sinus lift procedure with autologous bone graft and Astra Tech Tioblast ST implants (Astra Tech, Mölndal, Sweden). MATERIALS AND METHODS: Sinus lift procedures were carried out in 36 patients, 25 unilateral and 11 bilateral. Bone grafts were obtained from the iliac crest, mandibular angle, or chin region. Healing time for bone grafts varied between 4 and 5 months. Implants were allowed to heal for 6 months. The patients were followed in a standardized clinical and radiographic method for up to 5 years. Patients with partial dentition in the maxilla and limited bone volume below the sinus cavity (6 to 7 mm) were consecutively included in the study. Smoking was a contraindication to inclusion in the study unless patients who smoked quit smoking for at least 6 months prior to surgery. RESULTS: All patients have been successfully restored with fixed complete dentures. There was no implant loss. Radiographic examination showed minor changes in bone graft height (1 to 1.5 mm) over 5 years and moderate bone remodeling (1 to 2 mm over 5 years). Signs of sinus infection appeared in 8 patients. In 4 patients, partial loss of bone graft material occurred. CONCLUSION: Two-stage sinus lift procedure with autologous bone graft material in combination with Astra Tech Tioblast ST implants has a predictable outcome. The method is reliable and useful for patients with severe resorption of the posterior maxilla.

Clinical evaluation of the zygoma implant: 3-year follow-up at 16 clinics.

PURPOSE: The purpose of this clinical investigation was to evaluate the treatment outcome with zygoma implants with regard to implant survival, patient satisfaction, and function of prosthesis replacement after 3 years. PATIENTS AND METHODS: The treatment outcome of 76 patients treated with 145 zygoma fixtures at 16 centers was evaluated with regard to implant survival. Status of peri-implant mucosa and amount of plaque were registered annually. Patients' and dentists' evaluations of the functional and esthetic outcome of the treatment were assessed at delivery of prosthesis and thereafter at each follow-up visit. RESULTS: Sixty of 76 patients were followed for 3 years after prosthetic delivery. Five of 145 placed zygoma implants failed during the course of the study resulting in an overall implant survival rate of 96.3%. At the 3-year follow-up, 75% of the implants sites were registered with normal peri-implant mucosa and 68% with no visible plaque. The patients were fully satisfied with the esthetic and functional outcome of the treatment in 86% and 71%, respectively, at the 3-year follow-up visit. All reported data from dentists scored from acceptable to excellent. CONCLUSION: The multicenter study showed a high predictability of the zygoma implant-supported rehabilitation.

Sagittal split advancement osteotomy: comparison of the tendency to relapse after two different methods of rigid fixation.

Mandibular advancement was studied in 32 patients with mandibular retrognathia in whom the only intervention was in the mandible. Fifteen patients were treated with fixation by lag screws and 17 with monocortical miniplates. Lateral radiographs were taken preoperatively, postoperatively, 2 months postoperatively, and 1.5 years postoperatively, and mandibular movement analysed. All patients healed uneventfully. Cephalometric analysis of lateral radiographs showed no significant differences between the two groups in skeletal relapse during any of the control periods up to 18 months. Mandibular advancement for treatment of mandibular retrognathia using rigid fixation with either lag screws or miniplates was reproducable with only minor skeletal relapse.

The approach to dentofacial skeletal deformities using a multisegmentation technique.

This article describes the authors' approach to correcting dentofacial skeletal deformities requiring multisegmentation of the maxilla. Achieving optimal results requires a close collaboration within the orthodontic-surgical team. The importance of attention to detail in the course of the surgical procedure cannot be overemphasized, because complications of avascular necrosis cannot be corrected easily. The multisegmental maxilla is a valuable technique and adds to the versatility of the LeFort I in the treatment of open bite and transverse discrepancies in dentoalveolar deformities.

Transverse expansion of the maxilla using a multisegmentation technique.

In a long-term prospective study multisegmentation for transverse widening of the maxilla was followed up to calculate tendency to relapse and clinical outcome. Thirty-six patients were followed up for 30 months and 13 for 60 months postoperatively. There were no complications after the maxillary operations. Transverse widening varied from 2 mm to 1.5 cm in the posterior part of the maxilla, and was posterior to the canine teeth by a multisegmentation technique in the palatal bone. Although there was a tendency to relapse, which varied from 0.3-0.8 mm in the series, the clinical results are highly satisfactory.

A randomized double-blind comparative study of Biolight light therapy following surgical extraction of impacted lower third molars.

Monochromatic light has been used in many studies and indicated that phototherapy might be effective in the treatment of pain relief. The aim of this investigation was to evaluate the efficacy of monochromatic light phototherapy on patients who had undergone impacted third molar surgery. Sixty adult patients were included in the study. The patients were divided into 2 groups; the Biolight therapy group and the placebo therapy group. All the subjects received phototherapy 6 minutes preoperative and 10 minutes postoperative. They were examined 3 and 7 days after surgery to evaluate postoperative pain and wound healing. One patient was excluded from the study due to extraction of the third molar in maxilla. All the patients received a questionnaire to answer regarding pain and the number of pain killers consumed. The results from this study showed that Phototherapy using monochromatic light Biolight therapy had no significant differences compared to the placebo group.

Maxillary osteotomy with an interpositional bone graft and implants for reconstruction of the severely resorbed maxilla: a clinical report.

PURPOSE: The aim of this study was to report the outcome of using a maxillary osteotomy with an interpositional bone graft and implants in the treatment of extremely resorbed maxillae. MATERIALS AND METHODS: Twenty-two consecutive patients (mean age 65.7 years) were included in the study. Bone grafts from the iliac bone were used. The patients were followed in a standardized clinical and radiographic method for up to 5 years. RESULTS: A total of 176 Astra Tioblast ST implants were placed. Six implant losses occurred. All patients had fixed prostheses. Only minor bone resorption (1.0 to 1.5 mm) occurred in the bone graft, as well as a certain amount of marginal bone remodeling around the implants (1.0 to 1.9 mm) during periods up to 5 years. Remodeling and resorption in the bone graft and around the implants occurred during the first postoperative year. The results represent cumulative success and survival rates of 97%, which is comparative to implant integration in conventional maxillary bone. DISCUSSION AND CONCLUSIONS: The orthognathic surgical technique using maxillary osteotomy with interpositional bone graft and implants in a 2-stage procedure has been shown to be a predictable and reliable method for rehabilitation of patients with extreme resorption of the maxilla when conventional implant surgical methods cannot be used. Although the procedures are trying for the patients, overall satisfaction with the end result can be rewarding.

A clinical evaluation of the Zygoma fixture: one year of follow-up at 16 clinics.

PURPOSE: To evaluate treatment outcome with Zygoma fixtures (Nobel Biocare, Göteborg, Sweden) with regard to fixture survival, patient satisfaction, and function of prosthesis replacement. MATERIALS AND METHODS: The treatment outcome of 76 patients treated with 145 Zygoma fixtures at 16 centers was evaluated. Patient's and dentist's evaluations of the functional and aesthetic outcome of the treatment were assessed at delivery of prosthesis and at the 1-year follow-up visit. At the 1-year follow-up visit, the status of the peri-implant mucosa around the abutments and the amount of plaque were registered. RESULTS: Sixty-six of the 76 patients, with 124 Zygoma fixtures supporting the prosthetic restorations, were evaluated at the 1-year follow-up. The overall survival rate for the Zygoma fixtures was 97.9% after 1-year of follow-up. Eighty percent of the patients were fully satisfied with both aesthetic and functional outcome at the time of prosthetic insertion and at the 1-year follow-up. All reported data from the dentists, with the exception of one restoration with several abutment screw loosenings, scored from acceptable to excellent for the aesthetic and functional outcome of the treatment. The status of peri-implant mucosa was recorded as normal in approximately 60% of the sites. Plaque, when present, was more often detected on the palatal surfaces compared with the buccal surfaces. CONCLUSION: This 1-year follow-up of Zygoma fixtures has shown good results with an acceptable number of minor complications and a majority of satisfied patients.

Experimental autogenous tooth transplantation in the dog: a comparison between one- and two-stage surgical techniques.

Crucial if tooth transplantation is to succeed is preservation of the vitality of the cells of the periodontium and cementum of the tooth graft. Poor contact between the tissues of the recipient site and the root surface when teeth are transplanted to recipient sites prepared immediately prior to transplantation (one-stage technique) could, after transplantation, result in insufficient nutrition to the cells of the root surface and contribute to necrosis of the cells. To improve nutrition, tooth transplantation to recipient beds left to heal for 14 days was performed (two-stage technique). Clinical trials of tooth transplantation by the two-stage technique resulted in a low incidence of tooth graft loss and root resorption. The different results between these two methods, as well as difficulties in evaluating clinical trials, called for an experimental model to be established. In 5 beagle dogs, fully developed autogenous teeth were transplanted using both one-stage and two-stage surgical techniques. The control teeth were transplanted by the one-stage method to recipient beds prepared immediately before transplantation. The test teeth were transplanted using the two-stage method to recipient beds prepared and left to heal for 5 days prior to transplantation. Four pairs of teeth (1 test and 1 control) were transplanted in each dog. One pair of incisors and one pair of premolars were transplanted in the maxilla and in the mandible. Altogether 20 pairs of teeth were included in the study. One pair of teeth fractured during extraction and was therefore excluded from the study. Two pairs of teeth were lost in the first hours after transplantation. Evaluation of the remaining 17 pairs of teeth was made by routine histological examinations after a 6-month period of healing. The blinded examination failed to show a difference between the two surgical methods in terms of frequency of various types of root resorption. The differences between the results after long-term observation of human teeth transplanted by the one- and two-stage tooth transplantation techniques were not found by this experimental model.

Functional rehabilitation using orthognathic surgery, bone transplants and implants after irradiation of malignancy in early childhood.

Functional rehabilitation has been carried out in four young patients by use of orthognathic surgery, bone grafting and implants. All four patients had been successfully treated for malignant tumours in the midface during early childhood by use of full dose irradiation. Retarded growth of the maxilla together with missing root formation of permanent teeth prevented the alveolar process to develop. Bimaxillary osteotomies with inlay bone graft have been made in two cases and maxillary osteotomy le Fort I with interpositional and inlay grafting in two individuals. Implants surgery has been made in a second stage surgery. A total of eighteen implants has been inserted and during five years follow-up two implants have been lost (survival rate 90%). All patients have been successfully rehabilitated with fixed bridge prosthesis.

Effects of a mechanical barrier on the integration of cortical onlay bone grafts placed simultaneously with endosseous implant.

BACKGROUND: Previous experimental studies on onlay bone graft integration have shown either advantages or disadvantages to the use of mechanical barriers. This indicates that the role played by the biologic properties of transplanted bone and membrane in graft revascularization and bone remodeling has not yet been established. The outcomes regarding osseointegration of titanium dental implants applied in such a condition are still contradictory. PURPOSE: The rabbit's radius model that is grafted onto the mandibular lower border and covered by membrane can reproduce a challenging experimental situation to preliminarily study the factors involved in osseointegration under deprived blood vessels source. MATERIALS AND METHODS: Fourteen New Zealand White rabbits had a 2.5-cm segment of the right radius osteoectomized and fixed onto the right mandibular lower border using titanium screws. Two screw-shaped titanium implants (2.5 mm wide yen 2.5 mm long) were installed 7 mm apart in the mid length of the grafted bone. In experimental sites, the graft with the implants and graft-host bone junction were covered by expanded polytetrafluoroethylene (e-PTFE) membrane; control sites were left uncovered. Eight animals from the experimental group and six animals from the control group were sacrificed at 6 and 24 weeks after surgery. Ground sections obtained from en bloc tissues containing graft, implants, and recipient bone were subjected to histologic evaluation and histomorphometric analysis (area occupied by the graft and bone-to-implant contact). RESULTS: The graft showed significantly more resorption after 24 weeks than at 6 weeks (p < or =.05) irrespective of the treatment (with or without membrane), although the amount of new bone was greater at 24 weeks in sites where a membrane was covering the graft. Compared with 6 weeks postoperatively, the bone-to-implant contact was considerably improved at 24 weeks (p < or =.05), and the membrane seemed beneficial for implant osseointegration when compared with unprotected sites (p .05). As a result of graft resorption, the amount of soft tissue was considerably expanded in sites beneath membrane, accompanied by a sustained process of trabecular bone deposition close to the barrier. CONCLUSIONS: Cortical onlay grafts covered by membrane demonstrated delayed remodeling, probably as a consequence of a hindered process of graft revascularization. Grafts covered by membrane might rely on previous host bone resorption both to become revascularized and to remodel. The findings that the membrane-protected grafts were most resorbed at 24 weeks might be attributable to better implant osseointegration, because the fixtures were exposed to greater mechanical stimulation in these sites. key words: bone regeneration, implant osseointegration, onlay bone-graft

Augmentation of a retrognathic chin. I. Use of HTR-polymer implants in a long-term prospective clinical and radiographic study.

A total of 37 patients have had chin augmentation procedures with HTR-polymer implants. Indications were mandibular retrognathia in connection with dentofacial deformities in 13 and the remaining 24 had a normal occlusion. Three patients with micrognathia also had juvenile rheumatoid arthritis. The patients have been followed for at least one year and in 17 cases up to five years both clinically and radiographically. Cephalometric measurements of the effects and stability of augmentation showed that chin augmentation has highly predictable results, and few side-effects.

Editorial: Dedicated to the Memory of Marshall R. Urist.

BACKGROUND:  Previous experimental studies have shown a higher degree of bone-implant contact for surface-enlarged implants compared with machined implants. Yet, there is insufficient evidence that such implants show higher stability and an increased survival rate. PURPOSE:  The purpose of this investigation was to study the integration and stability of grit-blasted implants with retention elements on the implant neck, with and without marginal bone defects, compared with machined implants without retention elements. MATERIALS AND METHODS:  After tooth extraction of the mandibular premolars in six dogs, two grit-blasted, partly microthreaded Astra Tech implants and one standard Brånemark implant were bilaterally placed in each dog. On one side, 3 yen 3 mm large buccal defects were created, to expose three to four implant threads. The contralateral side served as control, and no defects were made. The animals were sacrificed after 4 months of healing. Implant stability was measured using resonance frequency analysis at implant installation and after 4 months of healing. Histologic and histomorphometric evaluation was made after 4 months of healing. RESULTS:  Resonance frequency analysis indicated that all implants in the test and control groups were osseointegrated after 4 months, with a tendency toward higher implant stability for the Astra Tech implants. There was a statistically significant higher increase in resonance frequency for the Astra test implants compared with their corresponding controls. Histology and histomorphometry showed well-integrated implants with varying degrees of bone repair at the defect sites. The greater bone-implant contact for the Astra implants was statistically significant. No significant difference between the implants in amount of bone filling the threads was recorded. CONCLUSIONS:  The Astra Tech implants tested showed a higher degree of bone-implant contact and higher level of bone regenerated at defect sites compared with the Brånemark implants. Resonance frequency analysis demonstrated a significantly higher increase in the Astra test implants compared with their control groups than did the Brånemark test implants versus their controls.