Kaplan-Meier Algorithm Research Articles

PMS2 mutation spectra in Norway and risk of cancer for carriers of pathogenic variants

BackgroundIn Norway, we have offered testing of PMS2 since 2006, and have a large national cohort of carriers. The aim of this study was to describe all PMS2 variants identified, and to describe frequency, spectrum and penetrance of cancers in carriers of class 4/5 variants.MethodsAll detected PMS2 variants were collected from the diagnostic laboratories and reclassified according to ACMG criteria and gene specific guidelines. Data on variant, gender, cancer diagnosis, age at diagnosis, and age at last known follow-up was collected on all carriers of class 4/5 variants from electronic patient records. The Kaplan-Meier algorithm was used to calculate cumulative risk of any cancer, colorectal cancer and endometrial cancer.ResultsIn total, 220 different PMS2 variants were detected. Twenty nine class 4/5 variants were identified in 482 carriers. The most common pathogenic variant was the founder mutation c.989-1G > T, detected in 204 patients from 58 families. Eighty seven out of 482 (18.0%) had been diagnosed with colorectal cancer, 10 of these (11.8%) before 40 years. Cumulative risk at 70 years in our cohort was 34.7% for colorectal cancer and 26.1% for endometrial cancer.ConclusionsAfter 15 years of genetic testing, 29 different class 4/5 variants have been detected in Norway. Almost half of Norwegian PMS2 carriers have the founder variant 989-1G > T. Penetrance of colorectal cancer in our cohort was moderate but variable, as 11.5% of those diagnosed were younger than 40 years.

Performance of Bonded Lithium Disilicate Partial-coverage Crowns in the Restoration of Endodontically Treated Posterior Teeth: An Up to Seven-Year Retrospective Study.

To evaluate the clinical performance of adhesively bonded lithium disilicate glass-ceramic (LDG) partial-coverage crowns in restoring posterior endodontically treated teeth (ETT). A total of 121 morphologically compromised posterior ETT were restored with LDG partial-coverage crowns between October 2015 and January 2018. The restorations were fabricated in the laboratory or at the chairside. Two adhesive systems and resin cements were used to cement the restorations. Tooth and restoration survival rates were calculated. The restorations were evaluated clinically using the modified United States Public Health Service (USPHS) criteria for an observation period of 5-7 years. The Cox proportional hazards model was used to estimate relative failure risks such as tooth type, resin cements, gender, and sleep bruxism. The standard chi-squared test was used to compare the survival of different tooth types for significant differences (α=0.05). In addition, survival probability was calculated using the Kaplan-Meier algorithm. Among seven failed cases, one was a tooth fracture, and six were restoration fractures. According to the Kaplan-Meier analysis, the estimated survival rate of the teeth was 99% for seven years, while the estimated survival rate of the restorations was 94.8% for 5 years and 92.8% for 7 years. Tooth type and resin cements did not influence restoration survival rates (p>0.05), while sleep bruxism and male patients might increase the risk of failure (p<0.05). The indirect adhesively bonded LDG partial-coverage crowns of posterior ETT exhibited favorable clinical outcomes. Ceramic fracture was the most common failure pattern.

Retrospective Clinical Evaluation of RMGIC/GIC Class V Restorations.

The aim of this retrospective study was to evaluate the clinical performance of glass-ionomer cement (GIC) and resin-modified glass-ionomer cement (RMGIC) materials in Class V carious cervical lesions restored by dental students. Ninety-six (96) restorations performed with either GIC (Fuji IX) (n = 39) or RMGIC (Fuji II LC) (n = 57) were evaluated using the modified USPHS criteria by two independent investigators at two follow-up evaluations (two years apart). The Fisher statistical test was used to compare USPHS criteria and examine significant differences, with a significance level set at p < 0.05. The Kaplan-Meier algorithm was used to calculate the survival probability. The overall success rate of Class V restorations was 72.9% at the second follow-up evaluation, with restorations ranging in age from 2.5 to 3.5 years. The RMGIC (Fuji II LC) restorations exhibited a significantly higher overall success rate compared to the GIC (Fuji IX) restorations (p = 0.0104). Significant differences were observed in retention (p = 0.0034) and color match (p = 0.0023).

Racial disparities in conditional survival of patients with bladder cancer: a population-based study

BackgroundTraditional estimates can only provide static predictions of cancer outcomes and cannot assess the evolving effect of race on patient survival. This study aims to reveal the dynamic survival of patients with bladder cancer and to explore the evolving effect of race on patient prognosis.MethodsUsing data from the Surveillance, Epidemiology, and End Results (SEER) registry, 99,590 white, 6,036 African American, and 4,685 Asian/Pacific Islander (API) patients with bladder cancer were identified. Conditional cancer-specific survival (CSS) rates, which could reflect the dynamic survival prediction of cancer patients, represented the primary outcomes, and were estimated by the Kaplan-Meier algorithm. The evolving effect of race on patient survival was evaluated by multivariable Cox regression in combination with conditional survival (CS) estimates.ResultsThe 5-year CSS for African American patients who had survived 1, 2, 3, 4, or 5 years after definitive therapy improved from the baseline calculation by + 5.8 (84.4%), + 9.5 (87.4%), + 12.8 (90.0%), + 14.4 (91.3%), and + 14.7% (91.5%), respectively. The increasing trend also held for overall white and API patients, and for all patient subsets when CS was calculated according to different levels of sex, age, and disease stage. African Americans, despite having the worst survival at baseline, could have CSS comparable to their white and API counterparts after 4 years of survivorship. In addition, the risk of death for African Americans tended to decrease with increasing survival, and the risk was no longer significantly different from that of whites after 4 years of survival.ConclusionsWhile having the worst initial predicted outcomes, African Americans may eventually achieve comparable survival to white and API patients given several years of survivorship. As patient survival increases, African American race may lose its role as an indicator of poorer prognosis.

Prognostic implications of visceral obesity on gastric adenocarcinoma: does it really matter?

PurposeTo evaluate the association of visceral adiposity measured on computed tomography (CT) in preoperative period with lymph node (LN) metastasis and overall survival in gastric adenocarcinoma patients. MethodsPreoperative CT scans of 246 gastric adenocarcinoma patients who did not receive neoadjuvant chemoradiotherapy were evaluated. Visceral fat area (VFA), subcutaneous fat area (SFA) and Total fat area (TFA), VFA/TFA ratio were quantified by CT. VFA/TFA > 29% was defined as visceral obesity. The differentiation, t-stage, n-stage and the number of harvested-metastatic LNs were noted. The maximum thickness of tumor and localization were recorded from CT. Chi-square, Student's t-test, multiple Cox regression, Spearman's correlation coefficient, and Kaplan-Meier algorithm were performed. ResultsThe overall survival (OS) rates and N-stage were not different significantly between viscerally obese and non-obese group (p = 0.994, p = 0.325). The number of metastatic LNs were weakly inversely correlated with VFA (r = −0.144, p = 0.024). Univariate analysis revealed no significant association between visceral obesity and OS or LN metastasis (p = 0.377, p = 0.736). In multivariate analyses, OS was significantly associated with poorly differentiation (HR = 1.72, 95% CI =1.04–2.84, p = 0.035), higher pathologic T and N stage (T4 vs T1 + T2 HR = 2.67, 95% CI =1.18–6.04, p = 0.019; T3 vs T1 + T2 HR = 1.98, 95% CI = 0.90–4.33, p = 0.089; N3b vs N0 HR = 2.97, 95% CI1.45–6.0, p = 0.003; N3 (3a+ 3b) vs N0 HR = 2.24 95% CI =1.15–4.36, p = 0.018). ConclusionVisceral obesity may not be a prognostic factor in resectable gastric adenocarcinoma patients.

Effect of machine learning methods on predicting NSCLC overall survival time based on Radiomics analysis

BackgroundTo investigate the effect of machine learning methods on predicting the Overall Survival (OS) for non-small cell lung cancer based on radiomics features analysis.MethodsA total of 339 radiomic features were extracted from the segmented tumor volumes of pretreatment computed tomography (CT) images. These radiomic features quantify the tumor phenotypic characteristics on the medical images using tumor shape and size, the intensity statistics and the textures. The performance of 5 feature selection methods and 8 machine learning methods were investigated for OS prediction. The predicted performance was evaluated with concordance index between predicted and true OS for the non-small cell lung cancer patients. The survival curves were evaluated by the Kaplan-Meier algorithm and compared by the log-rank tests.ResultsThe gradient boosting linear models based on Cox’s partial likelihood method using the concordance index feature selection method obtained the best performance (Concordance Index: 0.68, 95% Confidence Interval: 0.62~ 0.74).ConclusionsThe preliminary results demonstrated that certain machine learning and radiomics analysis method could predict OS of non-small cell lung cancer accuracy.

Retrospective clinical evaluation of ceramic onlays placed by dental students

Statement of problemIndirect restorations with partial or complete occlusal surface coverage have been recommended to restore teeth with weakened walls in order to prevent cusp fracture. The success of these restorations when performed by dental students is unknown. PurposeThe purpose of this retrospective study was to evaluate the clinical performance of adhesively bonded ceramic onlay restorations placed by third- and fourth-year dental students. Material and methodsSixty-five ceramic onlays were placed in patients between 2009 and 2015. The onlays were laboratory or chairside fabricated with a computer-aided design and computer-aided manufacturing (CAD-CAM) system, using either IPS e.max Press or IPS e.max CAD. An adhesive technique and luting composite resin agent were used to cement the restorations. Thirty-seven onlays were evaluated clinically using the modified United States Public Health Service (USPHS) criteria. Data were statistically analyzed using the Cox proportional hazards model to compare tooth type and failures and the Fisher exact and McNemar tests to compare the USPHS criteria for significant differences (α=.05). Survival probability was calculated using the Kaplan-Meier algorithm. ResultsFive onlays were considered to be failures and needed replacement. According to the Kaplan-Meier analysis, the estimated survival rate was 96.3% after 2 years and 91.5% at 4 years. All 5 of the failures occurred on molars (13.5%) and none on premolars (P=.025). A statistically significant difference was found for marginal discoloration between onlays placed within 0 to 3 years and 3 to 6 years (P<.05) but no differences between any other criteria. ConclusionsCeramic onlays placed by dental students demonstrated acceptable long-term clinical performance.

Parameters and outcomes in 525 patients operated on for oral squamous cell carcinoma.

This report analyzed the outcomes of patients undergoing surgery for oral squamous cell carcinoma (OSCC) to identify the value of prognostic factors. A total of 525 patients were studied who had undergone surgery for oral squamous cell carcinoma (OSCC) between 2000 and 2011, of whom 222 had received postoperative radiation-therapy (PORT) and or chemoradiation-therapy (PORTC). For each patient, personal data, histological findings, treatment and outcome were recorded and analyzed statistically. Survival curves were calculated using the Kaplan-Meier algorithm, and the difference in survival among subgroups was examined. The overall survival (OS) and disease-specific survival (DSS) 5-year survival rate in the 525 patients were respectively 71.38% and 73.18%. The differences in the overall survival and disease-specific 5-year survival were significant (p<0.05) for age<40 years, site of origin, N status, staging, grading, osseous medullar infiltration, and perineural invasion. In patients undergoing radiation therapy, only perineural invasion negatively influenced the survival prognosis. In 150 pT1 cases of tongue and floor-of-mouth cancer, an infiltration depth (ID)>4mm was statistically correlated with poorer prognosis. The results demonstrate an improvement in the 5-year OS and DSS rates during the past decade compared with the previous decade. Univariate analysis revealed that age, tumor staging, and lymph node involvement, extracapsular spread, grading, perineurial invasion, infiltration depth, and osseus medullary invasion were associated significantly with overall survival and disease-specific survival.

To evaluate disparity between clinical and pathological tumor-node-metastasis staging in oral cavity squamous cell carcinoma patients and its impact on overall survival: An institutional study.

Background:Accurate clinical staging is important for patient counseling, treatment planning, prognostication, and rational design of clinical trials. In head and neck squamous cell carcinoma, discrepancy between clinical and pathological staging has been reported.Objective:To evaluate any disparity between clinical and pathological tumor-node-metastasis (TNM) staging in oral cavity squamous cell carcinoma (OCSCC) patients and any impact of the same on survival.Materials and Methods:Retrospective chart review from year 2007 to 2013, at a tertiary care center.Statistical Analysis:All survival analyses were performed using SPSS for Windows version 15 (Chicago, IL, USA). Disease-free survival curves were generated using Kaplan–Meier algorithm.Results:One hundred and twenty-seven patients with OCSCC were analyzed. Seventy-nine (62.2%) were males and 48 (37.8%) females with a mean age at presentation 43.6 years (29–79 years). The highest congruence between clinical and pathological T-staging seen for clinical stage T1 and T4 at 76.9% and 73.4% with pathological T-stage. Similarly, the highest congruence between clinical and pathological N-stage seen for clinical N0 and N3 at 86.4% and 91.7% with pathological N-stage. Of clinically early stage patients, 67.5% remained early stage, and 32.5% were upstaged to advanced stage following pathological analysis. Of the clinically advanced stage patients, 75% remained advanced, and 25% were pathologically downstaged. This staging discrepancy did not significantly alter the survival.Conclusion:Some disparity exists in clinical and pathological TNM staging of OCSCC, which could affect treatment planning and survival of patients. Hence, more unified and even system of staging for the disease is required for proper decision-making.

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Introduction: In the United States at least 150,000 patients die and 1.5 million develop a medical complication within 30 days after surgery. We explored postoperative complications (PC) and mortality and cause of death after general surgical procedures. We hypothesize that there is an association between the number of PC and long-term mortality. Methods: This is a retrospective cohort study of 50,314 adult surgical patients admitted between 2000 and 2010 in an academic tertiary medical center. We considered seven major PC including acute kidney injury (AKI), mechanical ventilation more than 48 hours, severe sepsis, ICU admission more than 48 hours, cardiovascular complications and/or need for pressors, delirium/neurologic complications, and procedural/wound complications and grouped the number of PC as 0, 1, 2, and 3 or more. AKI was defined by the consensus RIFLE criteria. Patient survival was determined through the National Social Security Death Index and cause of death was obtained from the Bureau of Vital Statistics at the Florida Department of Health. Three categories of cause of death were examined: cancer, cardiovascular/cerebrovascular, and infectious. Survival times were initiated at the time of hospitalizations and followed until death or last follow up time. Survival probabilities were estimated with the Kaplan–Meier algorithm. Survival differences between groups were analyzed using the log-rank tests. Bonferroni adjustments were made for multiple comparisons. Results: In our cohort 41.2% of patients had no PC, 26.2% had 1, 12.1% had 2, and 20.5% had 3 or more PC. Cumulative survival probabilities were 94%, 90%, 86%, and 71% at one year and 77%, 63%, 59%, and 44% at ten years for patients with 0, 1, 2, and 3 or more PC, respectively (p<0.0001). Log-rank test showed significant differences in long-term survival probabilities among the four groups (p<0.0001) with smaller survival probabilities for groups with higher numbers of PC. Higher numbers of complications were associated with worse long term mortality for patients who died of infectious or cardiovascular/cerebrovascula causes but not for patients who died of cancer. 89% of patients who died in-hospital had 3 or more PC and 40% of these deaths were cardiovascular/cerebrovascular. Conclusions: There is a significant association between number of PC and long-term mortality in general surgical patients.

OP064: Reirradiation of head and neck cancers with IMRT: Updated outcomes and analysis

Purpose Head and neck (H&N) cancers arising in previously irradiated volumes were rarely treated with radiotherapy due to concerns of toxicity. With improved precision in planning and delivery, reirradiation has been increasingly used. We reviewed our institutional experience using IMRT in the management of previously irradiated H&N carcinoma. Materials and methods The records of 136 patients treated with IMRT reirradiation at U.T. M.D. Anderson Cancer Center for H&N cancer between 1999 and 2012 were retrospectively reviewed. Reirradiation was defined as any overlap between the two radiation treatment volumes. Severe toxicity related to reirradiation included events requiring hospitalization, urgent intervention, or death. Survival estimates were calculated using the Kaplan–Meier algorithm, excluding those patients treated with palliative intent. Results Thirty-three (24%) patients underwent surgical resection and 70 (51%) patients received chemotherapy. Twenty of these patients received radiation with palliative intent. Median time interval between initial radiation and reirradiation was 23 months. Median follow-up after reirradiation was 33 months. Median reirradiation dose was 60 Gy (range 15–70 Gy), while the median cumulative radiation dose was 120 Gy. The 2- and 5-year overall survival and locoregional control rates were 58% and 63%, and 39% and 51%, respectively. Re-treatment doses ⩾66 Gy trended towards improved LRC ( p = 0.14). Severe reirradiation related toxicity occurred in 35 patients (26%), including three treatment-related deaths. Severe toxicity did not correlate with total or re-treatment dose but was associated with retreatment volumes >150 cc. Conclusions IMRT yields promising local control and survival outcomes in select patients receiving reirradiation for H&N cancer. However, treatment related toxicity continues to be significant despite the increased conformality of IMRT over 3D conformal radiation. Alternative treatment strategies, including the possible use of stereotactic radiotherapy, to further improve conformality and thereby increase the therapeutic ratio, may be explored in the future.

Effects of epidural analgesia on labor length, instrumental delivery, and neonatal short-term outcome

We aimed to clarify whether the short-term adverse neonatal outcomes associated with epidural analgesia are due to the epidural analgesia itself or to the instrumental delivery. A retrospective case-control study was conducted to evaluate the relationship between epidural analgesia, labor length, and perinatal outcomes. A total of 350 pregnant women at term who delivered under epidural analgesia (cases) were compared with 1400 patients without epidural analgesia (controls). Vacuum extraction (6.5 vs. 2.9 %) and cesarean section (19.9 vs. 11.1 %) were more frequently performed in the cases than controls (p < 0.001). Using a Kaplan-Meier algorithm, it was determined that the mean lengths of the 1st and 2nd stages of labor and the overall durations of labor and delivery were significantly longer in cases compared with controls. A Cox regression analysis showed that the longer labor remained even after adjustment for parity. The neonatal variables stratified by mode of delivery were not different in cases and controls, except for a slightly lower umbilical arterial pH in spontaneous delivery for the cases group. However, the Apgar scores and umbilical arterial pH were significantly lower in the neonates delivered by vacuum extraction compared with those in the neonates delivered by spontaneous delivery or cesarean section, regardless of whether epidural analgesia was performed. A multivariable analysis showed that vacuum extraction much more consistently affected the arterial pH than the analgesia itself (the β coefficients were -0.036 for epidural analgesia vs. -0.050 for vacuum extraction). Epidural analgesia was associated with slowly progressing labor, thus resulting in an increased rate of instrumental delivery. This instrumental delivery appears to adversely affect the neonatal outcomes more strongly than the analgesia itself.

The pregnancy outcome in women with incidental diagnosis of septate uterus at first trimester scan

Septate uterus seems to be strongly associated with an adverse pregnancy outcome. However, the possible relationship between septate uterus and miscarriage has only been retrospectively ascertained. The aim of our study was to describe the reproductive outcome in women with incidental diagnosis of malformed uterus at first trimester scan. Women at their first pregnancy attending our centre for a routine viability scan with an incidental suspicion of uterine anomaly at standard sonography were submitted to transvaginal volume ultrasound. All the cases with a 3D diagnosis of septate uterus were prospectively recruited and followed up. Overall 24 patients with a single intrauterine pregnancy were included at a median gestational age of 8.2 weeks. The cumulative pregnancy progression rate, as quoted by Kaplan-Meier algorithm, was 33.3% due to the occurrence of early (≤ 13 weeks) or late miscarriages (14-22 weeks) in 13 and 3 cases, respectively. The pregnancy outcome is poor if a septate uterus is incidentally diagnosed in the early stage of a viable intrauterine pregnancy.

Exam‐indicated cerclage in patients with fetal membranes at or beyond external os: A retrospective evaluation

To evaluate pregnancy outcome in women with fetal membranes at or beyond external os who underwent exam-indicated cerclage or conservative management. Retrospective cohort study including 52 patients with fetal membranes at or beyond external os between 17 and 27 weeks of gestation, treated in two third-level hospitals, between January 2001 and April 2009. The outcomes of interest of the study, prolongation of pregnancy and neonatal survival rate, were stratified according to type of management, parity, clinical conditions and blood tests at admission and calculated using the Kaplan-Meier algorithm. Of 52 women, 37 received exam-indicated cerclage and 15 were managed conservatively. The rate of patients still pregnant beyond 180 days within the cerclage group differed significantly from those of the conservative management group (80% vs 0%, respectively) (P-value<0.001). No difference has been found according to neonatal survival (82% versus 53%, respectively). Exam-indicated cerclage appears to prolong gestation compared to expectant management.

Implants in grafted and native bone in patients with ectodermal dysplasia

Ectodermal dysplasia (ED) is a congenital syndrome characterized by abnormalities of tissues of ectodermal origin, namely skin, nails, hair, and teeth. Dental treatment of patients with ED is necessary because it provides the opportunity to develop normal speech, chewing, swallowing, and facial support. Because there are few reports on implants inserted in grafted bone in patients with ED, we performed a retrospective study on 44 implants in 4 patients to determine variables that affect survival and crestal bone remodeling around the implant neck in such subjects. Forty-four fixtures were analyzed. Several patient-related (age and sex), anatomic (maxilla, mandible, tooth site), implant (type, length, diameter), surgical (sites and types of grafts), and prosthetic variables (type of loading) were investigated. Implant failure and peri-implant bone resorption were considered as predictors of clinical outcome. Kaplan-Meier algorithm and Cox regression analysis were then performed to detect those variables that are associated with clinical outcome. Implant length and diameter ranged from 11.5 to 15 mm and from 3.5 to 4.0 mm, respectively. Implants were inserted to replace 12 incisors, 12 cuspids, 11 premolars, and 9 molars. No implant was lost. Particular importance of implant length, graft sites, and type of loading was shown by univariate analysis, but these data were not confirmed by multivariate algorithm. In ED patients, dental implants and bone grafts proved to be valuable treatment options which are as effective as in patients not affected by ED, at least in adults. We also analysed the choice to conserve all teeth present in the frontal region. Orthognatic rehabilitation prior to any intervention has been the paramount criterion. In molar regions with tooth agenesis, placement of implants required bypassing of the Nervus mandibularis. In the interforaminal sector, bone reconstruction was achieved by bone grafting surgery.

Implant Treatment in Grafted and Native Bone in Patients Affected by Ectodermal Dysplasia

Ectodermal dysplasia (ED) is a congenital syndrome characterized chiefly by abnormalities of tissues of ectodermal origin, namely skin, nails, hair, and teeth. Dental treatment of patients with ED is necessary because it affords the opportunity to develop normal forms of speech, chewing, swallowing, and normal facial support. Because there are few reports focusing on implants inserted in bone grafted in patients with ED, we therefore performed a retrospective study on 44 implants inserted in 4 patients to detect those variables acting on survival and crestal bone remodeling around implant neck in such subjects. Forty-four fixtures were analyzed. Several patient-related (age and sex), anatomic (maxilla and mandible and tooth site), implant (type, length, and diameter), surgical (sites and types of grafts), and prosthetic (type of loading) variables were investigated. Implant failure and peri-implant bone resorption were considered as predictors of clinical outcome. Kaplan-Meier algorithm and Cox regression were then performed to detect those variables statistically associated with the clinical outcome. Implant length and diameter ranged from 11.5 to 15 mm and from 3.5 to 4.0 mm, respectively. Implants were inserted to replace 12 incisors, 12 cuspids, 11 premolars, and 9 molars. No implant was lost. On the contrary, implant's length, grafted sites, and type of loading affected univariate analysis, but these data were not confirmed by multivariate algorithm. Dental implants and bone grafts to orally rehabilitate patients with ED are valuable devices with no difference if compared with unaffected patients, at least in adults.

Implant Rehabilitation in Grafted and Native Bone in Patients Affected by Ectodermal Dysplasia: Evaluation of 78 Implants Inserted in 8 Patients

Ectodermal dysplasia (ED) is a congenital syndrome characterized chiefly by abnormalities of tissues of ectodermal origin, namely skin, nails, hair, and teeth. Dental treatment of patients with ED is necessary, because it affords the opportunity to develop normal forms of speech, chewing, swallowing, and normal facial support. Because there are few reports focusing on implants inserted in bone grafted in patients affected by ED. This is a retrospective study of 78 implants inserted in 8 patients to detect those variables acting on survival and crestal bone remodeling around the implant neck in such subjects. Seventy-eight fixtures were analyzed. Several patient-related (age and gender), anatomical (maxilla and mandible, tooth site), implant (type, length, and diameter), surgical (sites and types of grafts), and prosthetic (type of loading and implant/crow ratio) variables were investigated. Implant failure and peri-implant bone resorption were considered as predictors of clinical outcome. Kaplan-Meier algorithm and Cox regression were then performed to detect those variables statistically associated with the clinical outcome. Implant length and diameter ranged from 11.5 to 18 mm and from 3.5 to 6.0 mm, respectively. Implants were inserted to replace 19 incisors, 19 cuspids, 21 premolars, and 19 molars. One implant was lost. On the contrary, implant' length, grafted sites, and type of loading have an impact on univariate analysis, but this datum was not confirmed by multivariate algorithm. The use of dental implants and bone grafts to orally rehabilitate patients affected by ED is a valuable service with no difference in the results compared with unaffected patients, at least in adults.

Alveolar ridge augmentation with calvaria, iliac crest and mandibular autologous bone grafts: a retrospective study on 261 implants

PURPOSE: In the last decade, several investigators have reported that autografts can be used to restore alveolar volume prior to implant insertion successfully. However, no report is available comparing implant inserted into calvarial, mandibular and iliac crest bone autografts. MATERIALS AND METHODS: A retrospective study on 261 implants inserted in 42 patients was performed. Several variables related to patients, anatomic sites, implants and grafts were investigated. Implant's failure and peri-implant bone resorption were considered as predictor of clinical outcome. The Kaplan–Meier algorithm and Cox regression were then performed to detect those variables statistically associated with the clinical outcome. RESULTS: A total of 261 implants were inserted: 89 (34.1%) into the mandible and 172 (65.9%) into the maxilla. Nine different implant types were used. Implant length and diameter ranged from 8 to 15 mm and from 3.5 to 6.0 mm, respectively. Implants were inserted to replace 42 incisors, 32 cuspids, 77 premolars and 110 molars. The mean post-loading follow-up was 32 months. No implant was lost (i.e. survival rate SVR = 100%) and no differences were detected amongst the studied variables. On the contrary, crestal bone resorption correlates with jaws site and implant type. CONCLUSION: Implants can be inserted in autografted jaws successfully although a higher resorption could be expected in the molar region. In addition the type of implant can have an impact on clinical outcome.

A Retrospective Study on 287 Implants Installed in Resorbed Maxillae Grafted with Fresh Frozen Allogenous Bone

Several studies have been performed to evaluate the clinical outcome of implants inserted into maxillae grafted with autogenous bone but few reports have focused on maxillae grafted with fresh-frozen allogenous bone (FFAB). The purpose of this study is to retrospectively evaluate the clinical outcome of implants installed in resorbed maxillae augmented with FFAB. A total of 69 patients whom had been treated with FFAB grafts to their maxillae and implant placement 4 to 6 months later were retrospectively evaluated. Edentulism was total and partial in 22 and 47 cases, respectively. A total of 287 implants of various systems had been used. A life table analysis was performed. Marginal bone loss was calculated in radiographs. Five of the 287 implants were lost, giving a survival rate (SVR) of 98.3% over a mean follow-up time of 26 months. The marginal bone resorption at the implants was 1.68 mm (SD = 0.44) after 1 year and 1.85 mm (SD = 0.98) after 4 years. The cumulative success rate based on defined criteria was 96% in the first year but decreased to 40% at 4 years because of marginal bone loss. The Kaplan-Meier algorithm demonstrated a better outcome for female patients, removable dentures, and total edentulism. No differences were detected among diameters, lengths, and implant site. Implants placed in FFAB showed a high SVR similar to that reported in previous studies on maxillae grafted with autogenous iliac crest bone. Although our data point to more marginal bone loss in partially edentulous patients and for fixed prosthetic restorations, the use of FFAB for reconstruction of the atrophic jaw prior to implant placement can be considered as a reliable alternative to autogenous bone.

One-Step Oral Rehabilitation by Means of Implants' Insertion, Le Fort I, Grafts, and Immediate Loading

In the last decade, several investigators have reported that autologous and homologous fresh frozen bones are effective materials to restore alveolar ridges before insertion of dental implants. Recently, we have used femur homograft derived from living donors. Here, we reported a 1-step oral rehabilitation of the severely resorbed maxilla by means of implants' insertion, Le Fort I osteotomy for maxillary advancement, grafts, and immediate loading. Patients were treated with 1-step oral rehabilitation. Age, sex, implant length and diameter, tooth site, loading, and grafts were the investigated variables. Implant failure and peri-implant bone resorption were considered as predictors of clinical outcome. Kaplan-Meier algorithm and Cox regression were then performed to detect those variables statistically associated with the clinical outcome. Eighty-four implants were inserted in 11 patients. Implants were inserted to replace 22 incisors, 21 cuspids, 20 premolars, and 21 molars. The mean follow-up was 17 months. Two of 84 implants were lost (ie, survival rate = 97.6%), and no differences were detected among the studied variables. By using the 82 fixtures processed with Kaplan-Meier and Cox regression, only implant site has an impact on clinical outcome, and molars have a worse outcome than incisors. One-step oral rehabilitation can be used in selected patients. It significantly shortened the time of rehabilitation without adverse effects. Femur homograft derived from living donors is a valuable material for grafting jaw: it is safer, cheap, and available in programmed amounts and avoids a second operation field.