Distribution of orthognathic surgery among the Swedish population: a retrospective register-based study.

OBJECTIVE: The aim of this study was to provide a nationally representative assessment of orthognathic procedures performed in hospitalised patients in Sweden and study regional differences in prevalence, demographic parameters and hospitalisation time. MATERIAL AND METHODS: From the Swedish National Board of Health and Welfare's register, all the patients undergoing orthognathic surgery between 2010 and 2014 were identified. Outcome variables were categorised into: (1) Surgical methods and regional distribution (2) Demographic variations (3) Hospitalisation time. RESULTS: The population-prevalence-rate of orthognathic procedures over the 5-year period was 6.3 (SD 0.4) per 100,000 persons, a regional difference in the prevalence was found. Most common were Le Fort I osteotomies (43.4%) and bilateral sagittal split osteotomies (41.6%), 39% of the patients had bimaxillary surgery. The majority of the surgery was performed in the age group 19-29 (68.8%). The mean hospital stay was 2.2 days (SD = 0.9, range 1.7-3.4). A significant regional difference (p ≤ 0.001) was found in hospitalisation time for single-jaw versus bimaxillary surgery. CONCLUSIONS: Regional differences in the distribution of orthognathic surgery and demographic variations were found in Sweden in 2010-2014. The underlying causes of variations are still unknown and request further investigation.

Starting a Swedish national quality registry for orthognathic surgery: a tool for auditing fundamentals of care.

BACKGROUND: National quality registries (NQRs) provide open data for user-directed acquisition. National Quality Registry (NQR) data are often used to analyze the rates of treatment success and adverse events for studies that aim to improve treatment quality and patient satisfaction. Thus, NQRs promote the goal of achieving evidence-based therapies. However, the scientific literature seldom focuses on the complex process of initiating, designing, and implementing an NQR. Starting an NQR may be particularly challenging in a setting where specialized care is decentralized, such as orthognathic surgery in Sweden. The present study describes the initiation and early phases of a new NQR for orthognathic surgery in Sweden. METHODS: The initial inventory phase included gaining knowledge on regulations, creating economic plans, and identifying pitfalls in existing NQRs. Next, a crude framework for the registry was achieved. Outcome measures were selected with a nation-wide questionnaire, followed by a Delphi-like process for selecting parameters to include in the NQR. Our inclusive process comprised a stepwise introduction, feedback-based modifications, and preparatory educational efforts. Descriptive data were collected, based on the first 2 years (2018-2019) of registry operation. RESULTS: Two years after implementation, 862 patients that underwent 1320 procedures were registered. This number corresponded to a 91% coverage rate. Bimaxillary treatments predominated, and the most common were a Le Fort I osteotomy combined with a bilateral sagittal split osteotomy (n = 275). Reoperations were conducted in 32 patients (3.6%), and the rate of patient satisfaction was 95%. CONCLUSIONS: A National Quality Registry should preferentially be started and maintained by an appointed task force of active clinicians. A collaborative, transparent, inclusive process may be an important factor for achieving credibility and high coverage, particularly in a decentralized setting.

Treatment outcomes and patient-reported quality of life after orthognathic surgery with computer-assisted 2- or 3-dimensional planning: A randomized double-blind active-controlled clinical trial.

INTRODUCTION: Thorough treatment planning is essential for a good clinical outcome in orthognathic treatment. The planning is often digital. Both 2-dimensional (2D) and 3-dimensional (3D) software options are available. The aim of this randomized 2-arm parallel double-blinded active-controlled clinical trial was to compare the outcomes of computer-based 2D and 3D planning techniques according to patient-reported health related quality of life. The hypothesis was that a 3D technique would give a better treatment outcome compared with a 2D technique. METHODS: Orthognathic treatment for 62 subjects, aged 18 to 28 years, with severe Class III malocclusion was planned with both 2D and 3D techniques. After treatment planning but before surgery, the patients were randomly allocated via blind collection of 1 enveloped card for each subject in a 1:1 ratio to the test (3D) or the control (2D) group. Thus, the intervention was according to which planning technique was used. The primary outcome was patient-reported outcome measures. The secondary outcome was relationship between patient-reported outcome measures and cephalometric accuracy. Questionnaires on the patient's health-related quality of life (HRQoL) were distributed preoperatively and 12 months after surgical treatment. The questionnaires were coded, meaning blinding throughout the analysis. Differences between groups were tested with the Fisher permutation test. The HRQoL was also compared with measurements of cephalometric accuracy for the 2 groups. RESULTS: Three subjects were lost to clinical follow-up, leaving 57 included. Of these, 55 subjects completed the questionnaires, 28 in the 2D and 27 in the 3D groups. No statistically significant difference regarding HRQoL was found between the studied planning techniques: the Oral Health Impact Profile total showed -3.69 (95% confidence interval, -19.68 to 12.30). Consistent results on HRQoL and cephalometric accuracy showed a difference between pretreatment and posttreatment that increased in both groups but to a higher level in the 3D group. A difference between pretreatment and posttreatment HRQoL was shown for both groups, indicating increased quality of life after treatment. This supports recent findings comparing 3D and 2D planning techniques. No serious harm was observed during the study. CONCLUSIONS: Improvements of HRQoL were shown after treatment independent of which planning technique, 2D or 3D, was used. No statistically significant difference was found between the planning techniques. REGISTRATION: This trial was not registered. PROTOCOL: The protocol was not published before trial commencement. FUNDING: This project was supported by personal grants to Martin Bengtsson from the Scandinavian Association of Oral and Maxillofacial Surgeons (25000 SEK), the Southern Region of the Swedish Dental Association (50000 SEK), and the Swedish Association of Oral and Maxillofacial Surgeons (25000 SEK). The sponsors had no influence on the study design, analysis of the data, or the writing of the article.

Sinus floor elevation procedures to enable implant placement and integration: techniques, biological aspects and clinical outcomes.

Implant treatment in an atrophied edentulous posterior maxilla constitutes a challenge for the therapeutic team. The authors of the present study acknowledge that modern micro-rough surface implants in lengths of about 8-10 mm or longer and of different brands are similarly successful. Consequently, the authors propose that the use of different sinus floor elevation techniques should be considered when < 8 mm of bone is available below the maxillary sinus. The type of sinus floor elevation technique selected is mainly based on residual vertical bone height, marginal bone width, local intrasinus anatomy and the number of teeth to be replaced, although other factors (such as surgical training and surgical experience) may have an impact. It is proposed that a transcrestal sinus floor elevation approach can be considered as a first-choice method for single tooth gaps in situations with sufficient width for implant placement and a residual bone height of 5-8 mm, while lateral sinus floor elevation, with or without grafting materials, is indicated when < 5 mm of bone is available and when several teeth are to be replaced. With regard to time of implant placement, a one-stage procedure is preferred provided that high primary stability can be ensured.

An open, prospective, non-randomized, controlled, multicentre study to evaluate the clinical outcome of implant treatment in women over 60 years of age with osteoporosis/osteopenia: 1-year results.

BACKGROUND: Osteoporosis has been called a potential risk factor for bone healing around implants. AIM: The aim of this multicentre study was to verify the clinical performance of fluoridated implants in the maxilla of subjects with diagnosed systemic primary osteoporosis/osteopenia. MATERIAL AND METHODS: Postmenopausal women in need of 2-8 splinted implants in maxilla underwent bone mineral density measurements in the hip and spine, using dual-energy X-ray absorptiometry scans. Based on their T-scores, they were divided into two study groups: Group O (osteoporosis/osteopenia group) subjects had a T-score ≤-2, Group C (control group) had a T-score of ≥-1, and subjects with a T-score <-1 but >-2 were excluded. Implants were placed with a two-stage procedure and loaded 4-8 weeks after abutment surgery. At 6 months and 1 year after functional loading, clinical parameters (including peri-apical radiographs) were assessed. RESULTS: One hundred and forty-eight implants were placed in 48 subjects (mean age: 67 years (range [59-83]). Sixty-three implants were placed in 20 osteoporosis subjects (Group O, mean age: 69 years; range [59-83]), and 85 were placed in control subjects (Group C, mean age: 65 years; range [60-74]). The cumulative survival rate, on an implant level, was 99.3% (Group O: 98.4%; Group C: 100.0%). The cumulative survival rate, on a subject level, was 97.9% (Group O: 94.7%; Group C: 100.0%). Marginal bone level (MBL) alterations from functional loading to the 1-year follow-up visit were measured on an implant level and a subject level. The overall MBL alteration on an implant level was -0.01 ± 0.51 mm (Group O: -0.11 ± 0.49 mm; Group C: 0.05 ± 0.52 mm). The overall MBL alteration on a subject level was -0.04 ± 0.27 mm (Group O: -0.17 ± 0.30 mm; Group C: 0.04 ± 0.23 mm). CONCLUSION: Within the limitations of this prospective, non-randomized, controlled, multicentre study, it can be concluded that oral implant therapy in patients suffering from osteoporosis/osteopenia is a reliable treatment option with comparable integration rates as in healthy patients. Long-term follow of the study groups is necessary to compare marginal bone alterations and treatment outcomes.

Quality of Life After Orthognathic Surgery in Swedish Patients: A Register-Based Cohort.

OBJECTIVE: This study aimed to evaluate the effect of orthognathic surgery on quality of life among Swedish patients. MATERIALS AND METHODS: Patients subjected to orthognathic surgery due to dentofacial deformity (DFD) and registered in the National Register of Orthognathic Surgery (NROK) in Sweden between 2017 and 2020 were eligible for inclusion in this study. The Swedish-validated Orthognathic Quality of Life Questionnaire (S-OQLQ) was used to evaluate patient quality of life before and after surgery. The S-OQLQ measured each patient's subjective experience regarding social aspects. RESULTS: Eighty-four participants were included in this cohort study, including 45 men (mean age 24.7 years), 48 women (mean age 23.4 years), and eight patients who stated no gender. Women generally graded several aspects of the S-OQLQ higher than men, including facial aesthetics p = 0.029), oral function (p < 0.001), and awareness of facial deformity (p = 0.0054). For all domains of the questionnaire (social, facial aesthetics, function, and awareness), a significant improvement was seen 6-24 months after surgery (p < 0.001). Women rated improvement of function and awareness of facial deformity higher than men (p < 0.001 and p = 0.039, respectively). CONCLUSION: Quality of life aspects of orthognathic surgery have a strong impact on the treatment outcome. Although functional impairment is often considered a major indication for surgery, the social and aesthetic influence of DFD is highly rated by patients, whereas pain is not an issue before or after treatment.

A retrospective evaluation of iatrogenic dental root damage with predrilled vs drill-free bone anchor screws for intermaxillary fixation.

AIMS: The aim of this study was to retrospectively evaluate iatrogenic dental root damage, caused by two different techniques that utilized bone anchor screws, for intermaxillary fixation (IMF) in orofacial trauma. MATERIALS AND METHODS: The techniques used included either predrilled or drill-free bone anchor screws. A total of 123 patients who required IMF were evaluated (97 men and 26 women). Sixty-four patients were treated in the predrilled group, and 59 patients were treated in the drill-free group. The data were collected over an 8-year period and were analyzed using crosstabs and Fisher's exact test. RESULTS: Injuries to dental roots were found only in the predrilled group. Twenty-nine patients (45.3%) were injured at the time of surgery. One year after surgery, 10 patients (15.6%) had permanently injured dental roots. There was a significant difference in injury rates between the predrilled and drill-free groups 1 year after surgery (P < 0.001). CONCLUSION: There is an increased potential risk of iatrogenic injury and permanent damage to the dental roots when a technique that involves predrilled holes for bone anchor screws is used.

Molecular Response to Nanopatterned Implants in the Human Jaw Bone.

Implant surface modification by nanopatterning is an interesting route for enhancing osseointegration in humans. Herein, the molecular response to an intentional, controlled nanotopography pattern superimposed on screw-shaped titanium implants is investigated in human bone. When clinical implants are installed, additional two mini-implants, one with a machined surface (M) and one with a machined surface superimposed with a hemispherical nanopattern (MN), are installed in the posterior maxilla. In the second-stage surgery, after 6-8 weeks, the mini-implants are retrieved by unscrewing, and the implant-adherent cells are subjected to gene expression analysis using quantitative polymerase chain reaction (qPCR). Compared to those adherent to the machined (M) implants, the cells adherent to the nanopatterned (MN) implants demonstrate significant upregulation (1.8- to 2-fold) of bone-related genes (RUNX2, ALP, and OC). No significant differences are observed in the expression of the analyzed inflammatory and remodeling genes. Correlation analysis reveals that older patient age is associated with increased expression of proinflammatory cytokines (TNF-α and MCP-1) on the machined implants and decreased expression of pro-osteogenic factor (BMP-2) on the nanopatterned implants. Controlled nanotopography, in the form of hemispherical 60 nm protrusions, promotes gene expressions related to early osteogenic differentiation and osteoblastic activity in implant-adherent cells in the human jaw bone.

The epidemiology and management of ameloblastomas: A European multicenter study.

The present study aimed at assessing the epidemiology including demographic variables, diagnostic features, and management of ameloblastomas at several European departments of maxillofacial and oral surgery. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, type, histopathological features, kind of treatment, length of hospital stay, complications, recurrence, management and complications of the recurrence. A total of 244 patients, 134 males and 110 females with ameloblastomas were included in the study. Mean age was 47.4 years. In all, 81% of lesions were found in the mandible, whereas 19% were found in the maxilla. Mean size of included ameloblastomas was 38.9 mm. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 94 ameloblastomas, followed by segmental resection (60 patients), simple enucleation (46 patients), and marginal resection (40 patients). A recurrence (with a mean follow up of 5 years) was observed in 47 cases out of 244 ameloblastomas (19.3%). Segmental resection was associated with a low risk of recurrence (p = 0003), whereas enucleation plus curettage/peripheral ostectomy was associated with a high risk of recurrence (p = 0002). A multilocular radiographic appearance was associated with a high risk of recurrence (p < .05), as well as the benign solid/multicystic histologic type (p < .05). Within the limitations of the study it seems that the management of ameloblastomas will probably remain controversial even in the future. Balancing low surgical morbidity with a low recurrence rate is a difficult aim to reach.

Effects of early functional loading on maintenance of free autogenous bone graft and implant osseointegration: an experimental study in dogs.

PURPOSE: The aim of the present study was to investigate the healing, integration, and maintenance of autogenous onlay bone grafts and implant osseointegration either loaded in the early or the delayed stages. MATERIALS AND METHODS: A total of 5 male dogs received bilateral blocks of onlay bone grafts harvested from the contralateral alveolar ridge of the mandible. On one side, the bone block was secured by 3 dental implants (3.5 mm x 13.0 mm, Osseospeed; AstraTech AB, Mölndal, Sweden). Two implants at the extremities of the graft were loaded 2 days after installation by abutment connection and prosthesis (simultaneous implant placement group); the implant in the middle remained unloaded and served as the control. On the other side, the block was fixed with 2 fixation screws inserted in the extremities of the graft. Four weeks later, the fixation screws were replaced with 3 dental implants. The loading procedure (delayed implant placement group) was performed 2 days later, as described for the simultaneous implant placement sites. The animals were sacrificed 12 weeks after the grafting procedure. Implant stability was measured through resonance frequency analysis. The bone volume and density were assessed on computed tomography. The bone to implant contact and bone area in a region of interest were evaluated on histologic slides. RESULTS: The implant stability quotient showed statistical significance in favor of the delayed loaded grafts (P = .001). The bone-to-implant contact (P = .008) and bone area in a region of interest (P = 0.005) were significantly greater in the delayed group. Nevertheless, no difference was found in terms of graft volume and density between the early loaded and delayed-loaded approaches. CONCLUSIONS: The protocol in which the implant and bone graft were given delayed loading allows for effective quality of implant osseointegration and stabilization, with healing and remodeling occurring in areas near the implant resulting in denser bone architecture.

Treatment outcome in orthognathic surgery - A prospective comparison of accuracy in computer assisted two and three-dimensional prediction techniques.

The main objective of the present study was to assess the accuracy of two- and three-dimensional prediction techniques in orthognathic surgery. It was also a test of the very planning sequence. The scientific question was how well does the software support the surgeon in his way to find the perfect correction of the facial appearance while normalizing the occlusion? Thirty patients with a class III occlusion were included in this prospective study. Surgical planning with both techniques were undertaken for all patients. Surgery was performed according to the two-dimensional technique. The cephalometric measurements from two-dimensional and three dimensional predictions were compared with the postoperative results at the 12 months follow-up respectively. Together with an analysis of tracing error, placements of 2020 markers, 1860 measurements and 1280 comparisons was performed. The analysis showed an equally high accuracy for the studied techniques. The highest accuracy was found in the anterior maxilla. There was a tendency for an overestimation for the three-dimensional technique and an underestimation for the two-dimensional technique. CONCLUSIONS: The present study indicates an equal high accuracy in predicting facial outcome for both studied techniques. However, in those patients with asymmetric malocclusion and/or facial appearance the three-dimensional technique has an obvious advantage.

The role of whole blood in thrombin generation in contact with various titanium surfaces.

Understanding of the thrombotic response (activation of the intrinsic coagulation system followed by platelet activation) from blood components upon contact with a titanium dental implant is important and not fully understood. The aims of this study were to evaluate: (1) the thrombogenic response of whole blood, platelet-rich plasma (PRP) and platelet-poor plasma (PPP) in contact with a highly thrombogenic surface as titanium, (2) the thrombogenic response of clinically used surfaces as hydroxyapatite (HA), machined titanium (mTi), TiO2 grit-blasted titanium (TiOB) and fluoride ion-modified grit-blasted titanium (TiOB-F). An in vitro slide chamber model, furnished with heparin, was used in which whole blood, PRP or PPP came in contact with slides of the test surfaces. After incubation (60 min rotation at 22 rpm in a 37 degrees C water bath), blood/plasma was mixed with EDTA or citrate, further centrifuged at +4 degrees C (2200 g at 10 min). Finally, plasma was collected pending analysis. Whole blood in contact with Ti alloy resulted in the binding of platelets to the material surface and in the generation of thrombin-antithrombin (TAT) complexes. With whole blood TAT levels increased 1000-fold compared with PRP and PPP, in which both almost no increase of TAT could be detected. In addition, the platelet activation showed a similar pattern with a 15-fold higher release of beta-TG in whole blood. In the in vitro chamber model with the clinically relevant materials, the fluoride-modified surface (TiOB-F) showed pronounced TAT generation compared with TiOB, mTi and HA. Similar results were achieved for platelet consumption and activation markers of the intrinsic coagulation system. Taken together these results implicate first that whole blood is necessary for sufficient thrombin generation and platelet activation during placement of implants. Second, a fluoride ion modification seems to augment the thrombogenic properties of titanium.

Treatment outcome in orthognathic surgery-A prospective randomized blinded case-controlled comparison of planning accuracy in computer-assisted two- and three-dimensional planning techniques (part II).

PURPOSE: The aim of the present study was to compare the accuracy of two-dimensional (2D) and three-dimensional (3D) prediction methods. The hypothesis was that a 3D technique would give a more accurate outcome of the postoperative result. MATERIAL AND METHODS: Patients with severe class III occlusion were included and planed with both a 2D and 3D prediction technique. They were there after randomly subdivided into a control (2D) and test (3D) group and treated according to the technique randomized for. Cephalometric measurements from 2D and 3D predictions were compared with 12-month follow-up respectively. Together with an analysis of tracing error, placements of 3580 cephalometric markers, 2460 measurements, 680 intra-individual analyses and 1200 preop/postop comparisons were performed in 57 individuals. RESULTS: Statistically significant differences for accuracy between the two groups were seen for 11/NSL-112/NSL2 and for A-A2 (p < 0.05). Both groups showed a high level of accuracy for SNA and SNB. The test group also showed a relatively high level of accuracy for 11/NSL and for the A-point. No prediction method achieves a perfect accuracy. As expected from this, measuring accuracy within each group showed statistically significant difference for all markers and cephalometric measurements (p < 0.001). Mandibular markers showed greater differences than maxillary markers. CONCLUSION: The present study indicates an equal high accuracy in predicting facial outcome for both studied techniques. However, in patients with asymmetry the three-dimensional technique has an obvious advantage.

Incidence and risk factors predisposing plate removal following orthognathic surgery.

OBJECTIVE: The aim of this study was to investigate the incidence and reasons for titanium fixation plate removal following orthognathic surgery, identify risk factors predisposing removal, and explore if discomfort was reduced postoperatively. STUDY DESIGN: Medical records of 404 consecutive cases were retrospectively reviewed. All patients received a questionnaire for follow-up, and 323 patients answered the questionnaire, thus forming the sample group. RESULTS: Of all the responding patients, 15% had plates removed, and 92% of these patients experienced relief from discomfort after removal of the plates. Infection was the most common reason for plate removal (10%). Smoking (hazard ratio 2.74) and surgery performed in the mandible (hazard ratio 2.40) increased the need for plate removal. For each plate added in the mandible, the risk for removal increased by 34%. CONCLUSIONS: Smoking, osteotomies, and additional numbers of plates in the mandible resulted in a higher incidence of plate removal. Most of the patients experienced relief from discomfort after plate removal.

The influence of controlled surface nanotopography on the early biological events of osseointegration.

The early cell and tissue interactions with nanopatterned titanium implants are insufficiently described in vivo. A limitation has been to transfer a pre-determined, well-controlled nanotopography to 3D titanium implants, without affecting other surface parameters, including surface microtopography and chemistry. This in vivo study aimed to investigate the early cellular and molecular events at the bone interface with screw-shaped titanium implants superimposed with controlled nanotopography. Polished and machined titanium implants were firstly patterned with 75-nm semispherical protrusions. Polished and machined implants without nano-patterns were designated as controls. Thereafter, all nanopatterned and control implants were sputter-coated with a 30nm titanium layer to unify the surface chemistry. The implants were inserted in rat tibiae and samples were harvested after 12h, 1d and 3d. In one group, the implants were unscrewed and the implant-adherent cells were analyzed using quantitative polymerase chain reaction. In another group, implants with surrounding bone were harvested en bloc for histology and immunohistochemistry. The results showed that nanotopography downregulated the expression of monocyte chemoattractant protein-1 (MCP-1), at 1d, and triggered the expression of osteocalcin (OC) at 3d. This was in parallel with a relatively lower number of recruited CD68-positive macrophages in the tissue surrounding the nanopatterned implants. Moreover, a higher proportion of newly formed osteoid and woven bone was found at the nanopatterned implants at 3d. It is concluded that nanotopography, per se, attenuates the inflammatory process and enhances the osteogenic response during the early phase of osseointegration. This nanotopography-induced effect appeared to be independent of the underlying microscale topography. STATEMENT OF SIGNIFICANCE: This study provides a first line of evidence that pre-determined nanopatterns on clinically relevant, screw-shaped, titanium implants can be recognized by cells in the complex in vivo environment. Until now, most of the knowledge relating to cell interactions with nanopatterned surfaces has been acquired from in vitro studies involving mostly two-dimensional nanopatterned surfaces of varying chemical composition. We have managed to superimpose pre-determined nanoscale topography on polished and micro-rough, screw-shaped, implants, without changes in the microscale topography or chemistry. This was achieved by colloidal lithography in combination with a thin titanium film coating on top of both nanopatterned and control implants. The early events of osseointegration were evaluated at the bone interface to these implants. The results revealed that nanotopography, as such, elicits downregulatory effects on the early recruitment and activity of inflammatory cells while enhancing osteogenic activity and woven bone formation.

Influence of Skeletal and Local Bone Density on Dental Implant Stability in Patients with Osteoporosis.

BACKGROUND AND PURPOSE: Osteoporosis is a major skeletal disease affecting millions of people worldwide. Recent studies claim that patients with osteoporosis do not have a higher risk of early implant failure compared to non-osteoporotic patients. The aim of this study was to assess the effect of skeletal osteoporosis and local bone density on initial dental implant stability. MATERIALS AND METHODS: Seventy-three patients were recruited and were assigned (based on a Dual-energy X-ray Absorptiometry scan) to either the osteoporosis (Opr), osteopenia (Opn), or control (C) group. Forty nine of the 73 patients received dental implants and had implant stability measured by means of resonance frequency analysis (RFA) at implant placement and at prosthetic abutment placement. On the computerized tomography scans, the cortical thickness and the bone density (Hounsfield Units) at the sites of implant placement were measured. RESULTS: At implant placement, primary stability was on average lower in group Opr (63.3 ± 10.3 ISQ) than in group Opn (65.3 ± 7.5 implant stability qutient (ISQ)), and group C (66.7 ± 8.7 ISQ). At abutment placement, a similar trend was observed: group Opr (66.4 ± 9.5 ISQ) scored lower than group Opn (70.7 ± 7.8 ISQ), while the highest average was for group C (72.2 ± 7.2 ISQ). The difference between groups Opr and C was significant. Implant length and diameter did not have a significant effect on implant stability as measured with RFA. A significant correlation was found between local bone density and implant stability for all regions of interest. CONCLUSIONS: Implant stability seems to be influenced by both local and skeletal bone densities. The lower stability scores in patient with skeletal osteoporosis reinforce the recommendations that safe protocols and longer healing times could be recommended when treating those patients with dental implants.

Immediate loading of implants in the edentulous mandible: a multicentre study.

PURPOSE: The aim of this prospective study was to investigate the two-year outcomes following immediate loading of mono-cortically engaged implants. MATERIALS AND METHODS: Thirty healthy mandible edentulous patients with an average age of 67.3 years and presenting with sufficient bony ridge at the mandible symphysis were included in the study. Four Astra Tech, Ti-Oblast® implants were installed between the mental foramina using the mono-cortical anchorage technique. The primary stability of the implants was assessed by resonance frequency analysis (RFA). After uni-abutments were placed, a temporary bridge was constructed and fixed the same day. The definitive bridges were installed 6 weeks after implant surgery. Five of 120 placed implants were lost in four patients during the first 6 weeks and these patients were excluded from the follow-up. The changes in marginal bone level (n = 20) were evaluated in Brazilian and Swedish groups at baseline, 6 weeks, 6 months, 12 months and 24 months. The RFA (n = 30) was evaluated at baseline, 6 weeks, 6 months, 12 months and 24 months postoperatively. RESULTS: Compared with baseline measurements, the postoperative values for marginal bone level (6 weeks, 6 months, 12 months and 24 months) were significantly reduced (p < 0.05), while no differences were observed in the RFA analysis (12 months and 24 months). CONCLUSIONS: The immediate loading of mono-cortically engaged implants in the edentulous mandible is safe and predictable and implant stability remains excellent after 2-year follow-up.

A 10-year follow-up study of titanium dioxide-blasted implants.

BACKGROUND: Dental implants with moderately rough surfaces are commonly used in the treatment of edentulous patients. However, long-term data on survival rates and marginal bone conditions are lacking. PURPOSE: This prospective study evaluated the cumulative survival rate of the TiOblast implant (Astra Tech AB, Mölndal, Sweden) after 10 years of prosthetic loading. MATERIALS AND METHODS: A total of 199 TiOblast implants were placed in 36 consecutive edentulous patients (23 males and 13 females). All patients were treated at one clinic and by the same team. The patients were edentulous in either the maxilla (n = 16) or the mandible (n = 20). The average age of the patients at the start of the trial was 64 years (range, 59-82 years). Of the 199 implants inserted 108 were in the mandible and 91 were in the maxilla. Clinical evaluations were undertaken after completion of the prosthetic superstructure (baseline) and after 6 months, 1 year, 3 years, 5 years, 7 years, and 10 years. Mean marginal bone level was evaluated for the first 100 placed implants for up to 7 years. RESULTS: Six implants failed during the study (3 in the mandible and 3 in the maxilla). All failures occurred within the first year, giving a cumulative survival rate of 96.9% (96.6 % in the maxilla and 97.2 % in the mandible) after 10 years of follow-up. The survival rate for the superstructures was 100%. The mean marginal bone level in the measured sample was 0.2 mm (standard deviation [SD], 0.31) below the reference point at baseline, 0.28 mm (SD, 0.20) and 1.27 mm (SD, 1.15) below the same point 7 years later (mean, 0.15 mm per year). CONCLUSION: This study showed that titanium dioxide-blasted implants offer predictable long-term results as supports for fixed prostheses in both the maxilla and mandible.

Reconstruction of the severely resorbed maxilla with autogenous bone, platelet-rich plasma, and implants: 1-year results of a controlled prospective 5-year study.

BACKGROUND: Prosthetic treatment of the edentulous maxilla may require bone augmentation to enable placement and integration of dental implants. This constitutes a complex healing situation, and resorption of the grafted bone and failure of the implants often occur. The application of autogenous platelet-rich plasma (PRP) has been suggested to improve incorporation and preservation of bone grafts. PURPOSE: The aim of this controlled clinical study was to evaluate whether PRP in conjunction with grafting of particulated autogenous bone to the maxilla could improve the integration and clinical function of dental implants. An additional aim was to compare block bone grafts without PRP with PRP-treated particulated bone. MATERIAL AND METHODS: Nineteen consecutive patients were included in the study and treated with iliac bone grafts and dental implants in the maxilla according to a split-mouth design. In the anterior maxilla, particulated bone mixed with PRP (test) was compared with onlay block grafts without additional PRP (control). In the posterior maxilla, particulated bone grafts with (test) or without (control) PRP were placed as sinus inlay grafts. After 6 months of healing, 152 implants (8 implants/patient) (TiOblast, Astra Tech AB, Mölndal, Sweden) were placed. Test (PRP; 76 implants) and non-PRP (76 implants) sides were evaluated and compared by implant survival rate, marginal bone level, and implant stability using resonance frequency analysis (RFA) during 1 year in function. RESULTS: Two control implants in control sites in two patients were lost at abutment connection. After 1 year in function, no further implants were lost, giving an overall survival rate of 98.7%. The marginal bone level measurements showed no significant differences, although there was a tendency toward less resorption on PRP sides. RFA measurements showed statistically significantly higher implant stability quotient values for PRP sites at abutment connection in the anterior but not in the posterior regions. CONCLUSIONS: The present clinical study showed that a high implant survival rate and stable marginal bone conditions can be achieved after 1 year of loading in the maxilla following autogenous bone grafting whether or not PRP is used. RFA measurements revealed differences at abutment connection, which could be explained by the type of graft rather than as an effect of PRP. Although no obvious positive effects of PRP on bone graft healing could be demonstrated, the handling of the particulated bone grafts was improved.

Simultaneous or delayed placement of surface modified and fluoridated dental implants into autogenous block bone grafts: a histologic and biomechanical study in the rabbit.

BACKGROUND: A delayed approach is recommended for reconstruction of the jaws with autogenous bone grafts and dental implants. Experimental studies have shown stronger bone tissue responses to surface modified implants than to nonmodified ones. AIM: The aim of the study was to evaluate bone integration and stability of surface modified and fluoridated implants when placed with fresh or healed autogenous bone grafts. MATERIAL AND METHODS: Six rabbits were used in this study. Each right rabbit tibia (control) received an autogenous bone graft, harvested from the calvarium. Eight weeks later, a second graft was harvested from the other side of the calvarium and placed on the left tibia (test) with an implant. Another implant was installed in the healed graft of the right tibia. TiO2-blasted and fluoridated OsseoSpeed(TM) implants (Astra Tech AB, Mölndal, Sweden), 3.5 mm in diameter and 9 mm long, were used. After additional 8 weeks, the rabbits were sacrificed and the implants were removed en bloc for light-microscopic analysis. Bone-to-implant contact (BIC) was registered as well as the amount of bone filling a rectangle indicating a region of interest (ROI). Resonance frequency analysis (RFA) was conducted both at the time of surgery and at the end of the experiment. RESULTS: There were no statistically significant differences either in BIC or ROI between the test and control sides. RFA showed higher implant stability for the control side at the time of the surgery, but the difference had leveled out at the time of the sacrifice. CONCLUSION: The present study showed similar bone tissue responses and stability for surface modified and fluoridated implants after 8 weeks of healing in fresh or healed autogenous bone grafts.