Peri-implant health after microvascular head and neck reconstruction-A retrospective analysis.

INTRODUCTION: Prosthodontic rehabilitation after reconstruction with microvascular revascularized free flaps following ablative tumor surgery is challenging due to the altered anatomical and functional conditions. The aim of this retrospective study was to determine whether the type of graft and the type of peri-implant tissue have an effect on peri-implant inflammatory parameters and implant survival. MATERIALS AND METHODS: Patients who received a free flap reconstruction with subsequent implant-prosthetic rehabilitation between 2010 and 2022 were retrospectively included. The primary outcome variable was the probing depth (PPD) at a minimum of 1 year after completion of prosthetic restoration. Predictive variables were type of free flap, emergence profile, and history of radiation. RESULTS: Seventy-one patients after free flap reconstruction were included in the analysis. At a minimum of 24 months after implant insertion the primary outcome, PPD showed no clinically relevant differences between the types of free flaps used. The emergence profile through a skin island resulted in an increase in BOP compared to native mucosa in the descriptive analysis (p-value > .05). The analysis showed a 5-year implant survival of 96.2% (95% CI: 0.929-0.996) in cases without irradiation and 87.6% (95% CI: 0.810-0.948) with irradiation of the region evaluated (p-value .034). CONCLUSION: Flap and associated soft tissue type had no significant effect on 5-year implant survival or peri-implant inflammatory parameters. However, the large heterogeneity of the patient population indicates that further prolonged studies are required for a more differentiated assessment of the long-term success.

Full block or split block?-Comparison of two different autogenous block grafting techniques for alveolar ridge reconstruction.

OBJECTIVE: To evaluate radiographic bone gain after alveolar ridge augmentation with two different designs of autogenous block graft harvested from the mandible. MATERIALS AND METHODS: Alveolar ridge defects were evaluated by preoperative cone beam computed tomography (CBCT) and grafted in a staged approach using intraoral block grafts. The ridge augmentation was either performed using the full-block technique (group 1) or the split-block technique (cortical plate with autogenous bone chips) (group 2). After 4 months of bone healing, a further CBCT scan was performed before implant placement. Horizontal and vertical bone gain were measured. RESULTS: In this retrospective study, 91 patients were grafted with block grafts (36 patients with full-block grafts; 55 patients with split-block grafts) resulting in 171 block grafts in total. The mean horizontal bone gain was 3.37 ± 0.71 mm in group 1 and 5.79 ± 2.20 mm in group 2. A linear mixed-effect model also showed a statistically significant group difference (p < 0.001, estimate: 3.455, 95% CI: [2.082-4.829]). The mean vertical bone gain was 2.85 ± 0.73 mm in group 1 and 7.60 ± 1.87 mm in group 2. A linear mixed-effect model also showed a statistically significant group difference (p: 0.029, estimate: 3.126, 95% CI: [0.718-5.557]). Mean marginal bone level was 0.33 ± 0.37 mm (group 1) and 0.17 ± 0.29 mm (group 2). CONCLUSION: The split-block technique resulted in a greater bone gain than the full-block technique. This effect was observed in both the vertical and the horizontal dimensions.

Colitis ameliorates cholestatic liver disease via suppression of bile acid synthesis.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by chronic inflammation and progressive fibrosis of the biliary tree. The majority of PSC patients suffer from concomitant inflammatory bowel disease (IBD), which has been suggested to promote disease development and progression. However, the molecular mechanisms by which intestinal inflammation may aggravate cholestatic liver disease remain incompletely understood. Here, we employ an IBD-PSC mouse model to investigate the impact of colitis on bile acid metabolism and cholestatic liver injury. Unexpectedly, intestinal inflammation and barrier impairment improve acute cholestatic liver injury and result in reduced liver fibrosis in a chronic colitis model. This phenotype is independent of colitis-induced alterations of microbial bile acid metabolism but mediated via hepatocellular NF-κB activation by lipopolysaccharide (LPS), which suppresses bile acid metabolism in-vitro and in-vivo. This study identifies a colitis-triggered protective circuit suppressing cholestatic liver disease and encourages multi-organ treatment strategies for PSC.

Comparison of Different Antibiotic Regimes for Preventive Tooth Extractions in Patients with Antiresorptive Intake-A Retrospective Cohort Study.

In the present study, the impacts on success rates between three different antibiotic regimes in patients receiving preventive tooth extraction during/after antiresorptive treatment were compared. For the retrospective analysis, we enrolled patients who had undergone tooth extraction from 2009 to 2019 according to the specified preventive conditions under antiresorptive therapy. Three antibiotic regimens were distinguished: (Group 1) intravenous for 7 days, (Group 2) oral for 14 days, and (Group 3) oral for 7 days of application. The primary endpoint was the occurrence of medication-related osteonecrosis of the jaw at 12 weeks after surgery. A total of 760 patients and 1143 extraction regions were evaluated (Group 1 n = 719; Group 2 n = 126; Group 3 n = 298). The primary endpoint showed no significant difference in the development of medication-related osteonecrosis of the jaw between the groups studied (Group 1 n = 50/669 (7%); Group 2 n = 9/117 (7%); Group 3 n = 17/281 (6%); p = 0.746). Overall, the success rate was 93% after intervention when preventive measures were followed. With the same success rate, a reduced, oral administration of antibiotics seems to be sufficient regarding the possible spectrum of side effects, the development of resistance and the health economic point of view.

Quantification of Remimazolam Besylate (CNS7056B) and Its Metabolite (CNS7054X) by LC-MS/MS in Human Plasma Using Midazolam-d4 Maleate as Internal Standard.

A new assay was developed to measure the concentration of remimazolam besylate (CNS7056B) and its major carboxylic acid metabolite (CNS7054X) in human plasma. For this new assay method, midazolam-d4 maleate was used as an internal standard. After setting up a previously described assay method, using CNS7056-d4 and CNS7054-d4 as internal standards, analytical results of both methods were compared. For the new analytical method, ultra-high-performance liquid chromatography (UHPLC) with tandem mass spectrometry was applied. A purification method, using solid phase extraction, was developed and validated. The chromatographic separation of the analytes was achieved with a mobile phase gradient using a Water Acquity™ UHPLC-System. The Kinetex™ biphenyl 50 × 2.1 mm UHPLC column was used with a particle diameter of 1.7 µm (Phenomenex, Germany). A measuring range of 0.6-2,000 ng/mL for CNS7056B and of 6-20,000 ng/mL for CNS7054X could be achieved with this new assay. The lower limit of quantification was 0.6 ng/mL for CNS7056B and 6 ng/mL for CNS7054X. The assay was validated according to US Food and Drug Administration guidelines. The new method showed an accuracy of 96.9-110.4% and a precision of 2.1-6.7% for both analytes.

Volcanically hosted venting with indications of ultramafic influence at Aurora hydrothermal field on Gakkel Ridge.

The Aurora hydrothermal system, Arctic Ocean, hosts active submarine venting within an extensive field of relict mineral deposits. Here we show the site is associated with a neovolcanic mound located within the Gakkel Ridge rift-valley floor, but deep-tow camera and sidescan surveys reveal the site to be ≥100 m across-unusually large for a volcanically hosted vent on a slow-spreading ridge and more comparable to tectonically hosted systems that require large time-integrated heat-fluxes to form. The hydrothermal plume emanating from Aurora exhibits much higher dissolved CH4/Mn values than typical basalt-hosted hydrothermal systems and, instead, closely resembles those of high-temperature ultramafic-influenced vents at slow-spreading ridges. We hypothesize that deep-penetrating fluid circulation may have sustained the prolonged venting evident at the Aurora hydrothermal field with a hydrothermal convection cell that can access ultramafic lithologies underlying anomalously thin ocean crust at this ultraslow spreading ridge setting. Our findings have implications for ultra-slow ridge cooling, global marine mineral distributions, and the diversity of geologic settings that can host abiotic organic synthesis - pertinent to the search for life beyond Earth.

The effect of different soft-tissue management techniques for alveolar ridge preservation: a randomized controlled clinical trial.

PURPOSE: For alveolar ridge preservation, various treatment protocols have been described. While most studies focus on the effect of the bone graft material, the aim of this study was to analyze the influence of different soft-tissue management techniques on the soft and hard tissue. METHODS: A total of 20 maxillary extraction sockets were grafted with an anorganic xenogenic bone graft and then randomly treated with either a combined epithelialized-subepithelial connective tissue graft (CECG) or a porcine collagen matrix (CM) placed in labial and palatal tunnels. Measurements of soft-tissue thickness were performed at tooth extraction (T0), implant insertion (T1) and second stage surgery (T2). RESULTS: In the CECG group, gingival thickness was 1.18 ± 0.56 mm (T0), 1.29 ± 0.26 mm (T1) and 1.2 ± 0.32 mm (T3). In the CM group, the measurements were 1.24 ± 0.50 mm (T0), 1.6 ± 0.6 mm (T1) and 1.7 ± 1.06 mm. Thus, there was an overall increase in gingival thickness from T0 to T2 of 0.02 ± 0.66 mm (CECG) compared to 0.46 ± 0.89 mm (CM). The thickness of keratinized soft-tissue was 3.91 ± 1.11 mm (CECG) and 4.76 ± 1.48 mm (CM) before extraction and 3.93 ± 1.17 mm (CECG) and 4.22 mm ± 1.26 mm (CM) at implant follow-up. Mean peri-implant probing depths were 3.15 ± 1.39 mm (CECG) and 3.41 ± 0.99 mm (CM). CONCLUSIONS: After ridge preservation, comparable soft-tissue parameters were observed in both groups, whether treated with a collagen matrix or a combined autologous connective tissue graft.

Mandibular Brown Tumor as a Result of Secondary Hyperparathyroidism: A Case Report with 5 Years Follow-Up and Review of the Literature.

BACKGROUND: Brown tumor is a rare skeletal manifestation of secondary hyperparathyroidism. Although diagnosis of the disease is increasingly seen in early stages due to improved screening techniques, some patients still present in a progressed disease stage. The treatment depends on tumor mass and varies from a conservative approach with supportive parathyroidectomy to extensive surgical resection with subsequent reconstruction. CASE PRESENTATION: We report a case of extensive mandibular brown tumor in a patient with a history of systemic lupus erythematosus, chronic kidney disease, and secondary hyperparathyroidism. Following radical resection of the affected bone, reconstruction could be successfully performed using a free flap. CONCLUSIONS: There were no signs of recurrence during five years of close follow-up. Increased awareness and multidisciplinary follow-ups could allow early diagnosis and prevent the need for radical therapeutical approaches.

The Influence of Different Graft Designs of Intraoral Bone Blocks on Volume Gain in Bone Augmentation Procedures: An In Vitro Study.

PURPOSE: Intraoral bone blocks from the external oblique are the gold standard for alveolar ridge bone grafting, but the limited amount of available bone limits their use for larger defects. The objective of this study was to compare whether different graft designs of intraoral bone blocks could affect the amount of bone gain. MATERIALS AND METHODS: In this in vitro study, 20 pig jaws were used to harvest bone blocks and subsequently augment single-wall bone defects. Each bone graft was first used as a full block, and then the same block was divided lengthwise into two blocks, with one block fixed at a distance as a cortical shell and the second block particulated to fill the gap between graft and bone. Three stereolithographic (STL) files (pre-OP, full block, split block) were generated using an intraoral scanner. All STL files were evaluated for volume gain and horizontal bone dimensions. RESULTS: A mean volume gain of 0.36 cm2 (SD: 0.09) was achieved for the full block and 0.78 cm2 (SD: 0.14) for the split block using the same block. The difference was statistically significant (P < .0001). A mean horizontal bone gain of 4.37 mm (SD: 0.93) was achieved with a full block and 5.77 mm (SD: 0.85) with the shell technique (P < .0001). CONCLUSION: With the same amount of bone removed, first as a full block and then as a split block, the split-block technique achieved a significantly higher bone gain compared with the full-block design.

Estimates of wind power and radiative near-inertial internal wave flux: The hybrid slab model and its application to the North Atlantic.

Energy transfer mechanisms between the atmosphere and the deep ocean have been studied for many years. Their importance to the ocean's energy balance and possible implications on mixing are widely accepted. The slab model by Pollard (Deep-Sea Res Oceanogr Abstr 17(4):795-812, 1970) is a well-established simulation of near-inertial motion and energy inferred through wind-ocean interaction. Such a model is set up with hourly wind forcing from the NCEP-CFSR reanalysis that allows computations up to high latitudes without loss of resonance. Augmenting the one-dimensional model with the horizontal divergence of the near-inertial current field leads to direct estimates of energy transfer spectra of internal wave radiation from the mixed layer base into the ocean interior. Calculations using this hybrid model are carried out for the North Atlantic during the years 1989 and 1996, which are associated with positive and negative North Atlantic Oscillation index, respectively. Results indicate a range of meridional regimes with distinct energy transfer ratios. These are interpreted in terms of the mixed layer depth, the buoyancy frequency at the mixed layer base, and the wind field structure. The average ratio of radiated energy fluxes from the mixed layer to near-inertial wind power for both years is approximately 12%. The dependence on the wind structure is supported by simulations of idealized wind stress fronts with variable width and translation speeds.

Do Functional Scores of Flap Donor Sites Recover After Reconstruction of Segmental Jaw Defects?

PURPOSE: The potential for donor-site morbidity in major maxillofacial reconstruction remains a concern. The purpose of this study was to compare the outcome of donor-site morbidity of deep circumflex iliac artery (DCIA) and scapula free flaps after radical treatment of the jaw and flap reconstruction. PATIENTS AND METHODS: We implemented a prospective cohort study design. Patients requiring segmental resection for benign pathology underwent reconstruction with either DCIA or scapula free flaps. The primary predictor variable was the use of DCIA versus scapula free flaps. The primary outcome variables were changes in orthopedic functional scores for both donor sites. The secondary outcome variable was neurosensory recovery at the recipient site. RESULTS: We included 8 patients in this study, comprising 3 women (38%) and 5 men (62%). Orthopedic scores were assigned preoperatively (T0) and at follow-up appointments at 1 to 3 months postoperatively (T1) and 6 to 12 months postoperatively (T2). In patients with DCIA flaps, a significant reduction (P = .0096) in the Larson I score between examination time points T0 and T1 was found. The score then improved on the operated side between T1 and T2 by an average of 29 points and showed no significant difference compared with the T0 level (P = .68). Patients with a scapular graft showed a significant reduction (P = .004) in the Constant-Murley score on the operated side between T0 and T1. The Constant-Murley score again improved significantly (P = .0136) between T1 and T2. Most of the patients (n = 7, 88%) had a neurologically unremarkable local situation of the recipient site at T0. At T1, 1 patient had level A (mild) neurosensory disorder and 1 had level B (moderate). At T2, all patients' initial neurologic scores were restored. CONCLUSIONS: The donor-site morbidity associated with DCIA and scapula flap reconstruction is a short-term condition and returns to baseline by 3 to 6 months postoperatively.

The influence of wound closure on graft stability: An in vitro comparison of different bone grafting techniques for the treatment of one-wall horizontal bone defects.

OBJECTIVES: The aim of this preclinical study was to analyze and compare different grafting techniques with respect to volume stability after wound closure. MATERIALS AND METHODS: Four different grafting techniques were evaluated in vitro for volume stability in a one-wall horizontal defect configuration. Group 1: guided bone regeneration (GBR) with collagen membrane, particulated xenograft; group 2: GBR with collagen membrane, particulated xenograft, pins; group 3: GBR with titanium-reinforced membrane, particulated xenograft, pins; group 4: autogenous block graft, particulated xenograft, collagen membrane. Cone beam computed tomography scans were performed before and after wound closure, and the horizontal bone dimensions were analyzed for stability at 0-5 mm apical to the implant shoulder (H0-H5). RESULTS: At H0-H2, wound closure induced a statistically significant change in bone dimensions in groups 1 and 2. In group 3, only the change in H0 was significant, and for group 4, only H2 was significant. CONCLUSION: Wound closure has a significant impact on graft stability in a one-wall horizontal defect configuration. GBR with additional membrane fixation showed better results than without. Titanium-reinforced membranes and autogenous blocks showed significantly greater volume stability than GBR with collagen membrane, especially in the coronal portion.

Oral health-related quality of life and standard of treatment in aggressive periodontitis patients more than 5 years after therapy.

OBJECTIVES: To assess OHRQoL in patients with aggressive periodontitis (AgP) after periodontal treatment using the Oral Health Impact Profile-49 (OHIP-49) and compare to patients' dental status. MATERIAL AND METHODS: More than 5 years after therapy, 71 patients were examined and answered the OHIP-questionnaire. The dental and periodontal status were assessed according to the SSO (Swiss Dental Society) criteria. Descriptive statistics were performed with SPSS, correlation analysis and tests for differences using R 3.2.2. RESULTS: More than 90% of all patients showed no probing depths (PD) >5 mm, a bleeding on probing (BOP) index below 35%, and a sufficient function. Four patients showed no visible plaque, PDs ≤ 3 mm, a BOP below 10%, and an optimum function. Non-smoking and compliant patients exhibited a more favourable status. The OHIP-49 added up to 24.9 points, representing a comparatively high satisfaction of AgP-patients with their oral status. The subscale which most patients reported impairment in was "functional limitation." A correlation between quality standard and the OHIP-49G could only be shown in the psychological disability subscale. CONCLUSION: After treatment, a moderate to high quality level can be retained over more than 5 years. Most patients are satisfied with their oral health. Correlations between the objective and subjective view could not be found, apart from the subscale "psychological disability."

Subjective and objective appearance of head and neck cancer patients following microsurgical reconstruction and associated quality of life─A cross-sectional study.

PURPOSE: Depending on the site and size of head and neck cancer, the disease affects patients' appearance and subsequently their quality of life. The aim of this study was to correlate subjective and objective evaluation of facial appearance and associated quality of life following ablative tumor surgery and microsurgical reconstruction. MATERIAL AND METHODS: A total of 99 patients with combined ablative and reconstructive microsurgical procedure for head and neck malignancy and seven patients with non-malignant disease were examined by three-dimensional (3D) (photogrammetry at least 6 months post-surgery and were evaluated by two-dimensional (2D) and 3D means for symmetry and facial proportions. Measurements were correlated with subjective reporting from the University of Washington Quality of Life Questionnaire and observer ratings. RESULTS: Of the 106 patients, three patients scored themselves as significantly disfigured (2.8%), 19 were bothered by their appearance (17.9%), 27 (25.5%) reported no change, and 57 (53.8%) reported minor changes in their appearance. On 2D evaluation, 10 patients (9.4%) showed severely abnormal facial proportions. On 3D analysis, 17 patients showed major asymmetry. There was a high correlation (0.67) between patient and observer subjective rating (p < 0.05). While 2D evaluation alone showed no significant correlation with subjective rating, 3D evaluation showed a moderate correlation (0.37; p < 0.05). The best results were achieved by combining 2D and 3D measurements (0.5; p < 0.05). Young female patients were most critical about their appearance. CONCLUSION: Following combined ablative and microsurgical reconstructive procedures, patients have a realistic perception of their appearance compared with observer ratings and a combination of 2D and 3D objective evaluation.

The value of three-dimensional photogrammetry in isolated sagittal synostosis: Impact of age and surgical technique on intracranial volume and cephalic index─a retrospective cohort study.

PURPOSE: The aim of this study was to compare the outcome of intracranial volume (ICV) and cephalic index (CI) between two different techniques for surgical therapy of sagittal synostosis. MATERIAL AND METHODS: Between 2011 and 2015, all patients scheduled for surgical therapy of sagittal synostosis were consecutively enrolled. All patients younger than 6 months underwent early extended strip craniectomy (ESC group), and patients older than 6 months underwent late modified pi-procedure (MPP group). To measure ICV and CI, data acquisition was performed via three-dimensional photogrammetry, 1 day before (T0) and between 10 and 12 weeks after surgery (T1). Results were compared with an age-matched reference group of healthy children. Perioperative parameters, as duration of surgery and the amount of blood loss of both surgical procedures were analyzed. RESULTS: A total of 85 patients were enrolled. Of the patients, 48 underwent an extended strip craniotomy with parietal osteotomies and biparietal widening and 37 patients underwent a late modified pi-procedure. There was no significant difference between the ESC group and the MPP group regarding the efficacy of improving CI (p > 0.05). Both techniques were able to normalize CI and to improve head shape. ICV was normal compared to age-matched norm-groups with both techniques, pre- and postoperatively. However, duration of the surgical procedure and calculated blood loss were significantly lower in the ESC group (p < 0.05). CONCLUSION: ESC and MPP were effective techniques to normalize cephalic index (CI) and improve head shape at their recommended time of surgery. Measurement of ICV and CI with 3D photogrammetry is a valid method to objectively evaluate patients before and after surgery without exposing pediatric patients to ionizing radiation.

Effect of occlusal plane correction on lip cant in two-jaw orthognathic surgery - A three-dimensional analysis.

INTRODUCTION: The aim of the present study was to evaluate the impact of canting correction in occlusal plane (OP) on the change of lip cant (LC) using three-dimensional (3D) photogrammetry in combination with cone-beam computed tomographic (CBCT) scans in class III asymmetric patients. MATERIALS AND METHODS: Fourteen asymmetric patients with exclusively skeletal class III malocclusion undergoing two-jaw surgery were included. All patients received 3D-photogrammetry and CBCT scans before (T1) and after orthognathic surgery (T2). After image fusion of the CBCT scans, angular correction of the occlusal plane (COP) between T1 and T2 was measured. Accordingly, angular correction of the lip cant (CLC) was analyzed after matching the preoperative 3D-photogrammetric scan to the postoperative. RESULTS: At the T1 stage, the canting of the OP was higher compared to the LC (4.95° vs. 3.77°). During T1 to T2, a significant angular cant correction was observed: COP (2.64°, p = 0.004) and CLC (1.76°, p = 0.01). In addition, a linear relationship between COP and CLC was revealed with a correlation coefficient for angular change of 0.47. For the linear regression COP turned out to be a predictor for CLC (B = 0.372, t (13) = 1.848, p = 0.089). Hence a correction of the OP of 1° resulted in a correction of the LC of only 0.372°. DISCUSSION: The use of CBCT scans in combination with 3D-photogrammetry are valuable tools to accurate analyze canting corrections of the OP and the LC during orthognathic surgery.

Donor site morbidity and quality of life after microvascular head and neck reconstruction with free fibula and deep-circumflex iliac artery flaps.

PURPOSE: Bone defects after resective tumor surgeries often require the use of microvascular reanastomized bone grafts for reconstruction. The decision as to which specific flap is most suitable for the particular patient is dependent on various factors. The aspects donor site morbidity and quality of life are rarely taken into account in this connection. The aim of this study was to analyze whether these factors, in the future, should influence the choice of donor site. MATERIAL AND METHODS: In this study, the donor sites of 46 patients with respect to deep-circumflex iliac artery (DCIA) and fibula flaps were analyzed using subjective and objective parameters. The primary outcome was postoperative pain measured by VAS. Postoperative complication evaluations as well as 2 orthopedic scores were implemented (American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score and Harris Hip Score) and the patients' quality of life was assessed using the 36-Item Short Form (SF-36) questionnaire to quantify donor site impairment. RESULTS: Postoperative pain was rated with a mean value of 42.4 mm (SD 34.8) for the DCIA group and 36.9 mm (SD 37.1) for the fibula group (p = 0.617). After a mean period of 13.72 months, pain was rated with a mean value of 15.3 mm (SD 21.7) for DCIA and 13.3 mm (SD 22.6 mm) for the fibula (p = 0.763). Persistent pain, however, was recorded only in 11.11% of DCIA patients and 5.26% of fibula patients. Furthermore pain intensity was higher in the DCIA group. A changed gait pattern was observed in 59.26% of DCIA patients and 21.05% of fibula patients. DCIA patients required walking aids for walking and stair climbing more often. Looking at the results of the 2 orthopedic scores, fibula patients showed slightly better results. Concerning quality of life, patients after reconstructive surgery with DCIA flaps showed slight better results than patients in the fibula group. CONCLUSIONS: Taking the results of this study into account, the outcome in terms of pain, morbidity and quality of life did not show a significant superiority of any donor site.

Reconstruction of the severely atrophic edentulous maxillae with calvarial bone grafts.

OBJECTIVES: Treatment of the severely atrophic maxilla with dental implants is challenging due to the insufficient horizontal and vertical bone volume and centripetal resorption pattern of the maxilla. Bone-augmentation procedures are often necessary prior to implant placement. The objective of this study was to assess the suitability of using calvarial bone grafts to enable implant placement in severely atrophic maxillae. MATERIAL AND METHODS: Seventeen patients with severe atrophic edentulous maxillae were reconstructed with autogenous calvarial bone grafts. After a 4-month healing period, the patients received a total of 134 dental implants, which were left to heal in submerged positions for 3 months before prosthetic rehabilitation was performed. Patients were followed clinically and radiographically for an average observation period of 53.94 months. RESULTS: At the intraoral recipient sites, two infections developed, causing partial loss of the respective bone grafts. Implant placement, however, was possible at all sites. No donor-site complications occurred. Two of 134 implants were lost in two patients prior to prosthetic loading. The implant survival rate was 98.51%. The implant success rate was 87.6%, and a mean marginal bone loss of 0.62 mm (SD 0.77 mm) was documented. CONCLUSIONS: Patients with severe bone atrophy of the edentulous maxilla can be successfully reconstructed with calvarial bone grafts and dental implants and show a stable clinical and radiographic situation after a mean observation period of 53 months.

Reconstruction of the maxilla following hemimaxillectomy defects with scapular tip grafts and dental implants.

BACKGROUND: Treatment of post-resective defects of the maxilla can be challenging and usually requires dental obturation or microvascular reconstruction. As compared to soft-tissue microvascular grafts, bone reconstruction can additionally allow for facial support and retention of dental implants. The aim of this study was to evaluate scapular tip grafts with respect to their applicability for maxillary reconstruction and their potential to retain dental implants for later dental rehabilitation. MATERIALS AND METHODS: In this retrospective study, 14 patients with hemimaxillectomy defects were reconstructed with free scapular tip grafts, oriented horizontally, to rebuild the palate and alveolar ridge. After bone healing, three-dimensional virtual implant planning was performed, and a radiographic guide was fabricated to enable implant placement in the optimal anatomic and prosthetic position. All patients' mastication and speech were evaluated, along with the extent of defect closure, suitability of the graft sites for implant placement, and soft-tissue stability. Pre- and postsurgical radiographs were also evaluated. RESULTS: A good postoperative outcome was achieved in all patients, with complete closure of maxillary defects that were class II, according to the system of Brown and Shaw. Additional bone augmentation was necessary in two patients in order to increase vertical bone height. Patients were subsequently treated with 50 dental implants to retain dental prostheses. In all cases, additional soft-tissue surgery was necessary to achieve a long-term stable periimplant situation. No implants were lost during the mean observation period of 34 months. CONCLUSIONS: Due to its specific form, the scapular tip graft is well suited to reconstruct the palate and maxillary alveolar ridge and to enable subsequent implant-retained rehabilitation. Due to the limited bone volume, an accurate three-dimensional graft orientation is essential. Furthermore, most cases require additional soft-tissue surgery to achieve a long-term stable periimplant situation.

Implant-prosthetic rehabilitation of hemimaxillectomy defects with CAD/CAM suprastructures.

BACKGROUND: Patients with hemimaxillectomy defects after tumor surgery can alternatively be rehabilitated with dental obturators or microvascular flaps. When general medical or oncologic conditions do not permit microvascular surgery, dental obturators are the only solution, yet retention for edentulous patients is often poor. The aim of this study was to evaluate whether CAD/CAM suprastructures supported by implants placed in both residual alveolar ridges and contralateral zygomatic bone could enhance obturator stability and improve functional outcomes. MATERIALS AND METHODS: Five edentulous patients with class IId hemimaxillectomy defects were included in the study. Implant-retained reconstructions were planned to support cross-arch CAD/CAM milled suprastructures. Patients had to rate their restorations on a 100-mm visual analogue scale before and after treatment. Additional evaluation was performed using the Oral Health Impact Profile (OHIP-EDENT) questionnaire. RESULTS: In the 5 patients, 7 conventional implants were placed in the remaining zygomatic bone and 16 in the remaining contralateral alveolar ridge. After 4 months of submerged healing, CAD/CAM suprastructures were fabricated that connected all respective implants with each other. All of the prosthetic restorations were removable and bar-retained. They all achieved good defect closure and showed significant improvements concerning general satisfaction (p = 0.0343), stability (p < 0.0001), ability to chew (p = 0.0077), esthetics (p = 0.0173) and foreign body sensation (p = 0.0207). According to the OHIP-EDENT questionnaire (p = 0.0036) the improvements were significant. During the observation period of 29.4 months, no mechanical or biological complications occurred. CONCLUSION: The CAD/CAM suprastructures improved retention in all treated patients without any complications.