Posterior Ridge Research Articles

Effect of different implant positions for two implant-retained mandibular overdenture: a retrospective 5-years radiographic evaluation of the circumferential peri-implant bone loss and posterior ridge resorptive changes

BackgroundStudies did not recommend which position for implant overdenture poses the lowest biomechanical risk and the least chance of peri-implant bone loss and ridge resorption for those who might need a mandibular two-implant overdenture. The study objectives were to investigate the impact of implant position, in lateral incisors or canine positions, on peri-implant bone loss and posterior ridge resorption.MethodsFifty patients with mandibular two-implants were recalled and divided according to the implant position into two groups (group L: implants in lateral incisor positions and group C: implants in canine positions). The circumferential peri-implant bone level and posterior ridge resorption were assessed at implant insertion (T0), one year later (T1), and five years later (T5) using the follow-up CBCT. Data were analyzed using the Statistical Package of Social Science (SPSS) program. A Mann-Whitney test was used to compare two different groups. Paired groups were compared using the Wilcoxon signed-rank test. The threshold of significance is fixed at a 5% level (p-value).ResultsSignificant differences in the vertical bone loss between groups appeared at (T5 - T1) (Mann Whitney test, (P = 0.01)) and at (T5 - T0) (Mann Whitney test, (P = 0.005)), and a significant difference in horizontal bone loss between groups was found at (T1 - T0) (Mann Whitney test, (P = 0.041)) and (T5 - T1) (Mann Whitney test, (P = 0.041)). Also, there were significant differences over the evaluation period between groups at certain points along the ridge at M1 (Mann Whitney test, (P = 0.021)), M3 (Mann Whitney test, (P = 0.008)), and M4 (Mann Whitney test, (P = 0.015)).ConclusionsAccording to the findings of this clinical study, the placement of implants in the lateral incisor position for two implant-retained overdentures is a viable choice. In comparison to the canine position, the lateral incisor position demonstrated superior peri-implant responses, which could potentially enhance the longevity of the implants. Furthermore, the placement of implants in the lateral incisor position can promote a more even distribution of stress and help mitigate posterior ridge resorption. Conversely, implants in the canine position may cause a seesaw effect and result in greater posterior ridge resorption.Clinical Trial Registry Number(NCT06055842) (13/03/2024).

A Simplified GBR Treatment and Evaluation of Posterior Seibert Class I Ridge Defects via Bio-collagen and Platelet-Rich Fibrin: A Retrospective Study.

Classical guided bone regeneration (GBR) treatments can achieve favorable clinical results for ridge defects. However, extensive bone augmentation in the non-esthetic area in the posterior region for minor ridge defects is unnecessary. Therefore, this study used a collagen and Platelet-rich fibrin (PRF) mixture for bone augmentation on minor posterior ridge defects and evaluated the effects. 22 Seibert Class I ridge defects were treated with BC and covered with a PRF membrane (simplified guided bone regeneration, simplified GBR) and other 22 were treated with Bio-Oss and covered with Bio-Gide (classical GBR). Cone-beam computed tomography imaging was conducted 6months post-surgery to compare the ridge's horizontal width (HW) and buccal ridge's horizontal width to assess the osteogenic effect. In addition, the buccal ridge contour morphology was studied and classified. The buccal ridge contour of simplified GBR was Type A in 14 cases, Type B in 7 cases, and Type C in 1 case and it of classical GBR was Type A in 11 cases, Type B in 8 cases, and Type C in 3 cases. The mean HW significantly increased by 1.50mm of simplified GBR treatment, while it increased by 1.83mm in classical GBR treatment. The combined use of BC and PRF had a significant effect on bone augmentation and this treatment exhibited promising clinical results for correcting posterior Seibert Class I ridge defects. The morphological classification of the reconstructive effect in this study can be utilized in future clinical work.

Mapping Origins of Tendons on the Medial Epicondyle to Improve Treatment of Medial Epicondylitis: Anatomical Study

Medial epicondylitis is a tendinosis found commonly in throwing and golfing athletes. Although there are choices for nonsurgical treatments, when these fail, surgical intervention can be considered. When surgical treatment is performed, the objective is to debride the diseased tissue from the epicondyle. The purpose of this study was to clarify the locations and size of the common flexor tendons and medial collateral ligament (MCL) relative to each other and to the posterior ridge of the medial epicondyle. The common flexor tendons and MCL were dissected and reflected their origin on the medial epicondyle in six cadaver elbows. Measurements were taken from the posterior and distal ridges of the medial epicondyle with respect to the humerus. Each origin was also measured for its height and width. The flexor carpi ulnaris origin starts at a mean of 4.2 mm from the posterior ridge of the medial epicondyle and extends anteriorly an average of 4.8 mm. The flexor carpi radialis starts at a mean of 4.2 mm from the posterior ridge and extends anteriorly an average of 7.4 mm. The pronator teres begins at a mean of 4.6 mm from the posterior ridge and extends an average of 5.7 mm anteriorly. The MCL starts at an average of 10.4 mm from the posterior ridge and extends 5.2 mm anteriorly. The measurements found have allowed the creation of a map of the specific common flexor tendon origins and their sizes on the medial epicondyle, as well as their position relative to the MCL. A surgeon may debride 1 cm anteriorly from the posterior ridge of the medial epicondyle to safely address the affected tissues and ensure the safety and integrity of the MCL.

3-Year Bone Remodeling in Mandibular Overdenture Wearers: Results from an RCT Comparing Immediate vs Conventional Loading Using Cone Beam Computed Tomography.

To evaluate the circumferential bone level and the morphological changes in posterior mandibular ridge of mandibular overdenture wearers submitted to conventional and immediate loading through cone beam computed tomography (CBCT) at 1 and 3 years. Twenty participants who received 2 NDI (Facility - 2.9x10 mm) were randomly allocated to the conventional loading (CL: n=10) or immediate loading (IL: n=10) groups. CBCT scans were performed in each group to analyze the vertical (VBL) and horizontal (HBL) bone level around the implants, analyzed together with the posterior bone remodeling of the mandible measured at distances of 5, 10, 15, and 20 mm from the mental foramen (L1-L4). Differences between groups were verified using the student t test at a significance level of 5%. The IL group showed a significantly higher HBL in the first year (P=.028) and a significantly higher VBL in the third year (P=.032), with HBL of -0.22 mm and VBL of -0.59 mm, respectively. After the third year, measurements of the percentage of cortical and medullar height indicated that the IL group presented a significantly higher percentage of cortical bone height (40.1 ± 9.3) compared to the CL group (31.8 ± 5.8) at position L1 (P=.05). No difference was found for posterior ridge remodeling (P>.05). IL group showed slightly higher values of HBL and VBL, and locally displayed more replacement of medullary by cortical bone. However, circumferential bone level values in the IL group are still clinically acceptable and the posterior resorption rate remained stable after 3 years of function, irrespective of the loading type.

Effect of Ridge Splitting of Mandibular Knife Edge Ridges with Two-implant Retained Overdenture with Locator Attachments on Peri-implant Bone Level and Posterior Ridge Resorption: A One-year Preliminary Study.

This study was conducted to evaluate peri-implant bone height changes and posterior ridge resorption by using two-implant retained polyetheretherketone (PEEK) overdentures with locator attachments following expansion of mandibular knife edge ridges by ridge splitting. Eighteen patients were selected for ridge splitting followed by expansion, implant placement, and bone graft application. Six months later, the fabrication of PEEK overdentures retained by locator attachments was accomplished. Friedman test, Wilcoxon signed-rank test, and Spearman correlation were used to evaluate the changes over time. Peri-implant bone height loss increased significantly with the advance of time between 6 and 12 months following denture insertion. Posterior area index changes were significant over time when measured at the time of denture insertion and twelve months following denture insertion. The effect of using PEEK as overdenture base material retained with two locator attachments allowed sharing the load between the peri-implant bone anteriorly and residual ridge posteriorly in cases with ridge splitting technique. Using PEEK as an overdenture base material is a successful means of bone preservation. How to cite this article: Helmy MA, El-Shaheed NH, El Waseef FA, et al. Effect of Ridge Splitting of Mandibular Knife Edge Ridges with Two-implant Retained Overdenture with Locator Attachments on Peri-implant Bone Level and Posterior Ridge Resorption: A One-year Preliminary Study. J Contemp Dent Pract 2023;24(11):834-839.

Effects of a modified surgical protocol on the positional accuracy of dental implants placed using fully guided implant surgery in the partially edentulous posterior ridge with distal extension: a dentiform model study.

The present experiment aimed to evaluate the placement accuracy of fully guided implant surgery using a mucosa-supported surgical guide when the protocol of osteotomy and installation was modified (MP) compared to when the protocol was sequentially and conventionally carried out (CP). For 24 mandibular dentiform models, 12 dentists (6 experts and 6 beginners) performed fully guided implant placements two times at the right first and second molar sites using a mucosa-supported surgical guide, once by the CP (CP group) and at the other time by the MP (MP group). The presurgical and postsurgical stereolithographic images were superimposed, and the deviations between the virtually planned and actually placed implant positions and the procedure time were compared statistically (P < .05). The accuracies were similar in the CP and MP groups. In the CP group, the mean platform and apex deviations at the second molar site for the beginners were +0.75 mm and +1.14 mm, respectively, which were significantly larger than those for the experts (P < .05). In the MP group, only the mean vertical deviation at the second molar site for the beginners (+0.53 mm) was significantly larger than that for the experts (P < .05). The procedure time was significantly longer for the MP group (+94.0 sec) than for the CP group (P < .05). In fully guided implant surgery using a mucosa-supported guide, the MP may improve the placement accuracy when compared to the CP, especially at sites farther from the most-posterior natural tooth.

Three-dimensional morphological study of type B lateral malleolar fractures with special reference to the end-tip location of proximal apexes.

Objective: We aimed to describe the morphological characteristics of Danis-Weber type B lateral malleolar fractures, with special attention given to the end-tip locations of fracture apexes, and to construct a 3D (three-dimensional) fracture line map. Methods: A total of 114 surgically treated cases of type B lateral malleolar fractures were retrospectively reviewed. The baseline data were collected, and computed tomography data were reconstructed in a 3D model. We measured the morphological characteristics and the end-tip location of the fracture apex on the 3D model. All the fracture lines were superimposed on a template fibula to generate a 3D fracture line map. Results: Among these 114 cases, 21 were isolated lateral malleolar fractures, 29 were bimalleolar fractures, and 64 were trimalleolar fractures. All the type B lateral malleolar fractures demonstrated a spiral or oblique fracture line. As measured from the distal tibial articular line, the fracture started at -6.22 ± 4.62mm anteriorly and terminated at 27.23 ± 12.32mm posteriorly, and the average fracture height was 33.45 ± 11.89mm. The fracture line inclination angle was 56.85° ± 9.58°, and the total fracture spiral angle was 269.81° ± 37.09°, with fracture spikes of 156.20° ± 24.04°. The proximal end-tip location of the fracture apex was classified into four zones in the circumferential cortex: zone I (lateral ridge) in seven cases (6.1%), zone II (posterolateral surface) in 65 cases (57%), zone III (posterior ridge) in 39 cases (34.2%), and zone IV (medial surface) in three cases (2.6%). Altogether, 43% (49 cases) of fracture apexes were not distributed on the posterolateral surface of the fibula, as 34.2% (39 cases) were located on the posterior ridge (zone III). The aforementioned morphological parameters in fractures with zone III, sharp spikes, and further broken spikes were greater than those in zone II, blunt spikes, and fractures without further broken spikes. The 3D fracture map suggested that the fracture lines with the zone-III apex were steeper and longer than those with the zone-II apex. Conclusion: Nearly half of type B lateral malleolar fractures had their proximal end-tip of apexes not on the posterolateral surface, which may impair the mechanical application of antiglide plates. A steeper fracture line and longer fracture spike indicate a more posteromedial distribution of the fracture end-tip apex.

Efficacy of platelet-rich fibrin in maxillary sinus augmentation and simultaneous implant placement in deficient maxillary ridges: A pilot comparative study

BackgroundRehabilitation with dental implants has become the most widely accepted treatment protocol for rehabilitation of lost natural teeth. Direct sinus lift is one of the most predictable procedures for augmenting the deficient posterior maxillary ridges. MethodsThe study was designed in patients with insufficient bone for implants in the maxillary posterior ridges. The test group received platelet-rich fibrin alone as filler, and the control group received a bone allograft. The residual bone height (RBH), implant mobility, and soft tissue characteristics between and within the groups were compared and analyzed. ResultsBoth the groups had considerable gain in RBH, and the intragroup analysis revealed clinical gain in bone height in both the groups, with the test group exhibiting statistically significant gain which kept on improving from 6 months with z= -3.477 and a p value of 0.001 to 9 months with z=-3.531 and a p value of 0.027. ConclusionThe results suggest that the use of platelet-rich fibrin alone improves the bone regeneration, thereby achieving predictable and stable augmentation of the sinus floor required for the success of implant therapy.

AZYGIID PARASITES OF NORTH AMERICAN ENDEMIC PLEUROCERIDS AND CENTRARCHIDS: REVISION OF LEUCERUTHRUS MARSHALL AND GILBERT, 1905 (DIGENEA: AZYGIIDAE), DESCRIPTION OF TWO NEW SPECIES, AND PHYLOGENETIC ANALYSIS.

We revise monotypic LeuceruthrusMarshall and Gilbert, 1905 (Azygiidae Lühe, 1909) by emending its generic diagnosis, redescribing its type species (Leuceruthrus micropteriMarshall and Gilbert, 1905), reassigning 2 species (Leuceruthrus stephanocauda [Faust, 1921] n. comb., Leuceruthrus ocalana [Smith, 1935] n. comb.), describing 2 new congeners (Leuceruthrus ksepkai n. sp. and Leuceruthrus blaisei n. sp.), and providing a phylogenetic analysis based on the internal transcribed spacer 2 (ITS2). Leuceruthrus is unique by having oblique preovarian testes, a vitellarium that does not extend anteriad into the forebody, and a uterus that is intercecal and between the ovary and ventral sucker. We describe the cercaria of Leuceruthrus cf. stephanocauda from cercariae shed from Elimia cf. carinifera and Elimia cf. modesta from Big Canoe Creek, Alabama. Leuceruthrus ksepkai n. sp. is described from cercariae shed from rasp elimia, Elimia floridensis (Reeve, 1860) from Holmes Creek, Florida, and Elimia sp. 1 from the Chocktawhatchee River, Florida. It differs from its congeners by the combination of having broadly rounded furcae with slight marginal pigmentation in live cercariae, no spines on the tail stem, distinct anterior and posterior ridges that flank the tail stem portion accommodating the withdrawn distome, minute protuberances occupying the lateral margin of the tail stem for its entire length, and protuberances that encircle the anterior third of the posterior tail stem (immediately posterior to the tail stem portion containing the withdrawn distome). Leuceruthrus blaisei n. sp. infects Elimia sp. and is the only known congener having proportionally small furcae (>tail stem maximum width) with a nipple-like distal projection and numerous minute projections on the tail stem surface. Our phylogenetic analysis included all of our new sequences plus all publicly available ITS2 sequences for Leuceruthrus spp. and Proteromera spp., and supported the monophyly of Leuceruthrus. It recovered L. ksepkai and L. cf. ksepkai in a polytomy, and Leuceruthrus blaisei as monophyletic (identical sequences), with L. micropteri and L. cf. stephanocauda recovered as sister taxa. The present study comprises the first systematic treatment of Leuceruthrus in over a century, the first description of a new species of Leuceruthrus in 117 yr, and the first taxonomic characterization of a species of Leuceruthrus from the Mobile River Basin. It also increases the number of accepted congeners from 1 to 5 and provides new host records (E. cf. carinifera and E. floridensis) for Leuceruthrus spp.

Major clinical findings of short implants and virtual surgery: a systematic review

Introduction: After the confirmation and publication of the phenomenon known as osseointegration by Brånemark, dental implants have been used to repair total and partial edentulous jaws. However, the implants were long and had to be longer than 11 mm to be considered functional. Short implants compared to long ones require less remaining bone, reducing the patient's exposure to surgeries for bone grafting, the elevation of the maxillary sinus mucosa, and repositioning of the inferior alveolar nerve. Added to this, several dental treatments have benefited from this digital advance. Objective: To review the literature on short implants installed in both dental arches, evaluating their advantages, disadvantages, indications, and contraindications in the context of virtual surgery. Methods: The present study followed a systematic review model (PRISMA). The search strategy was performed in the PubMed, Scielo, Cochrane Library, Web of Science and Scopus, and Google Scholar databases. Results: A total of 110 articles were found, 64 articles were evaluated and 35 were rejected for not meeting the GRADE classification, and only 29 articles were used in this study to compose the textual part. Based on these findings, it was found that in remote years, authors reported that regions with reduced bone height are favored with the use of short implants not only because of their dimensions but also because of their surface treatment, which suggests that it is an important factor for achieving 100% success rates. The advantages of short implants are related to the simplicity of the technique, installation of implants in remaining bone, avoidance of bone grafts that present questionable results in the increases in height of the posterior alveolar ridge of the mandible, reduction of treatment time, and reduction of costs for the patient. A systematic review and meta-analysis studies analyzed the accuracy of implant placement using computer-guided surgery. A randomized study compared the precision of guided planning of new computer-assisted implant placement techniques, based on models that use CAD/CAM. Conclusion: It was concluded that short implants are a reliable, safe, and practical alternative to be used in any necessary location or situation. They do not show bone loss or resorption over the years, nor are they at risk of fracture or any damage to patients. They are safe to use, as long as they have an adequate design, therefore, fundamental tools in the dental clinic.

Complete denture treatment with closed mouth impression method for medically compromised elderly patients with flat ridge

Geriatric patient with medically compromised condition needs proper and adequate nutrition. However, patient with edentulous ridge is unable to receive the optimum intake because the masticatory and chewing ability decrease. Therefore, a proper complete denture treatment is necessary to enhance the masticatory system. Female, 86 years old, came with medical records of chronic gastritis, diabetes mellitus, and atrial fibrillation wanted to improve her masticatory ability by making a complete denture. The treatment choice in this case is a complete denture with close mouth impression method since the patient has a posterior flat ridge. This treatment resulted in a retentive, stable, comfortable denture, and patient satisfaction.

Comparison of Gonial Angle and Alveolar Bone Height Changes in Panoramic and Lateral Cephalometry Radiography in Growing Patients

Background: This study aimed to compare the gonial angle and alveolar bone height changes between panoramic and lateral cephalometry radiographic images in class II malocclusion patients before and after orthodontic treatment. Methods: The obtained radiographic images were selected from among 120 class 2 malocclusion cases. The gonial angle and alveolar bone height were measured in the midline and molar regions of panoramic and lateral cephalometric radiographs using the software tools before and after the treatment of patients. Study data were analyzed by SPSS statistical software (version 21.0), and a significance level was set to 0.05 for all statistical tests. Results: Based on the results, no significant difference was found regarding the gonial angle before and after treatment on the right and left sides in panoramic radiography and the gonial angle changes before and after treatment in cephalometric radiography (P&gt;0.05). However, the obtained results for posterior and anterior alveolar ridge height were significant in panoramic and cephalometric radiographs (P&lt;0.05). Moreover, the comparison of the measured gonial angle values before treatment in panoramic and cephalometric radiography represented a significant level (P&lt;0.05). Eventually, the statistical results suggested that the alveolar bone height differences between panoramic and cephalometry radiography were significantly different in both anterior and posterior regions after treatment (P&lt;0.05). Conclusions: The findings indicated that only measurements obtained from the panoramic radiography were valid for the gonial angle. However, panoramic and cephalometry radiography procedures cannot be replaced for assessing the anterior and posterior alveolar bone height.

Immediate Effects of Electrical Stimulation on Oropharyngeal Structure and Laryngeal Vestibular Closure: A Pilot Study in Healthy Subjects.

ABSTRACTObjectives:This study examined the immediate effects of neuromuscular electrical stimulation (NMES) on the dynamics of oropharyngeal structure and laryngeal vestibular closure (LVC) in healthy subjects.Methods:Ten healthy male volunteers participated in this controlled, before-and-after, videofluoroscopic swallowing pilot study. The study was conducted in four phases (each performed twice): (1) saliva swallow (SS) before evaluation (BEFORE), (2) NMES while at rest with no SS (NMES AT REST), (3) SS during NMES (DURING NMES), and (4) SS to examine the aftereffects of NMES (AFTER). We measured distances that oropharyngeal structures moved in the NMES AT REST phase, and we analyzed the kinematics of saliva swallowing primarily in the BEFORE and AFTER phases.Results:Four changes in the morphology of the oropharyngeal structure caused by NMES AT REST were statistically significant: anterior–upward displacement of the hyoid bone and larynx, stretch of the laryngeal vestibule, and posterior ridge of the tongue root. Regarding the kinematics measured during SS, although there was no significant change in LVC reaction times, LVC duration in the AFTER phase was significantly longer than BEFORE. Regarding maximal displacement of the hyoid bone, there was significantly greater movement AFTER than BEFORE. As additional exploratory outcomes, the velocity of hyoid bone movement was significantly slower, and the hyoid-to-larynx approximation was significantly smaller, DURING NMES than AFTER.Conclusions:Longer duration of LVC might be caused by adaptive learning with NMES-induced structural changes in the oropharynx. Further clinical studies are warranted to determine whether this approach improves dysphagia, which impairs LVC.

Circumferential bone level and bone remodeling in the posterior mandible of edentulous mandibular overdenture wearers: influence of mandibular bone atrophy in a 3-year cohort study.

Evaluate circumferential bone level and morphological alterations in the posterior mandibular ridge of atrophic (AP) and non-atrophic (NAP) patients using implant-retained mandibular overdentures (MO) over 3years. Twenty-six edentulous patients categorized according to mandibular atrophy (AP = 13/NAP = 13) received two narrow diameter implants (Facility, 2.9 × 10mm) in the anterior region of mandible. The vertical and horizontal bone level was measured along with bone remodeling at 4 distances from the mental foramen in the posterior region of the mandible (L1-L4) via CBCT. NAP showed significantly higher total height and medullary height in all posterior regions at 1 and 3years (p ≤ 0.01). Cortical height and width were significantly higher (p ≤ 0.05) in this group at distances L1 and L4, respectively, in year 1. NAP shows a significantly higher % of medullary height at distances L1 (p ≤ 0.05), L2 (p ≤ 0.01), and L3 (p ≤ 0.05) after 1year, and at all distances (p ≤ 0.05) after 3years. Bone remodeling in the groups differed significantly (p ≤ 0.05) in terms of cortical width and % medullary width at L3. AP and NAP showed similar vertical and horizontal bone level. Bone resorption in the posterior ridge was stabilized by MO over 3years; however, AP are more susceptible to the long-term substitution of medullary bone by cortical bone. This study is the first to longitudinally evaluate bone dimensions in atrophic and non-atrophic two-implant MO users by CBCT and revealed that MO is a predictable treatment based on the stabilization of the posterior bone resorption.

Bayesian credible intervals for population attributable risk from case–control, cohort and cross‐sectional studies

SummaryPopulation attributable risk (PAR) and population attributable fraction (PAF) are used in epidemiology to predict the impact of removing a risk factor from the population. Until recently, no standard approach for calculating confidence intervals or the variance for PAR in particular was available in the literature. Previously we outlined a fully Bayesian approach to provide credible intervals for the PAR and PAF from a cross‐sectional study, where the data was presented in the form of a 2×2 table. However, extensions to cater for other frequently used study designs were not provided. In this paper we provide methodology to calculate credible intervals for the PAR and PAF for case–control and cohort studies. Additionally, we extend the cross‐sectional example to allow for the incorporation of uncertainty that arises when an imperfect diagnostic test is used. In all these situations the model becomes over‐parameterised, or non‐identifiable, which can result in standard ‘off‐the‐shelf’ Markov Chain Monte Carlo (MCMC) updaters taking a long time to converge or even failing altogether. We adapt an importance sampling methodology to overcome this problem, and propose some novel MCMC samplers that take into consideration the shape of the posterior ridge to aid in the convergence of the Markov chain.

Comparison of clockwise and counterclockwise right atrial flutter using high-resolution mapping

Abstract Background To the best of our knowledge, few studies have been performed that explore the electrophysiological differences between clockwise (CW) and counterclockwise (CCW) right atrial (RA) cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) using the high-resolution Rhythmia mapping system. Objectives. Accordingly, our prospective cohort study, sought to compare CW and CCW CTI-dependent AFL in preselected pure right AFL patients (pts) using the ultra-high-definition (ultra-HD) Rhythmia mapping system. The study also aimed to mathematically develop a cartography model based on automatic velocity RA measurements to identify electrophysiological AFL specificities. Methods and results Between October 2019 and July 2020, 33 patients were recruited. The mean age was 71±13 years old. No difference was found concerning clinical variables between CCW AFL and CW AFL or regarding left ventricular ejection fraction (LVEF) (55.5±10 vs. 56.6±12; p=0.76). The AFL cycle length was very similar (248±20 vs. 252±28 ms; p=0.6). The sinus venosus (SV) block line was present in 32/33 of cases (97%) and no significant difference was found between CCW and CW CTI AFL (100% vs. 91%; p=0.7). No line was localized in the region of the crista terminalis (CT). A superior gap was present in the posterior line in 14/31 (45.2%) but this was similarly present in CCW AFL, when compared to CW AFL (10/22 [45.5%] vs. (4/10 [40%]); p=0.9). When present, the extension of the posterior line of block was observed in 18/31 pts (58%) without significant differences between CCW and CW CI AFL (12/22 [54.5%] vs. (6/10 [60%]) (p=.9) The Eustachian ridge line of block was similarly present in both groups (82% [18/22] vs. 45.5% [5/11]; p=0.2). The absence of the Eustachian ridge line of block led to significantly slowed velocity in this area (28±10cm/s; n=8),and the velocities were similarly altered between both groups (26±10 [4/22] vs. 29.8±11cm/s [4/11]; p=0.6). We created mathematical, three-dimensional RA reconstruction-velocity model measurements. In each block localization, when the block line was absent, velocity was significantly slowed (≤20cm/s). A systematic slowdown in conduction velocity was observed at the entrance and exit of the CTI in 100% of cases. This alteration to the conduction entrance was localized at the lateral side of the CTI for the CCW AFL and at the septal side of the CTI for CW AFL. The exit-conduction alteration was localized at the CTI septal side for the CCW AFL and at the CTI lateral side for the CW AFL. The only differences between CW and CCW AFL concerned activation patterns. Conclusions The ultra-HD Rhythmia mapping system confirmed the absence of significant electrophysiological differences between CCW and CW AFL. The mechanistic posterior SV and Eustachian ridge block lines were confirmed in each arrhythmia. A systematic slowing down at the entrance and exit of the CTI was demonstrated in both CCW and CW AFL, but in reverse positions. Funding Acknowledgement Type of funding sources: None.

Immediate loading of fixed partial prostheses reconstructed using either tapered or straight implants in the posterior area: A randomized clinical trial.

In immediately loaded implants within 72 h after the implant placement in the unilaterally and partially edentulous ridge, primary stability is considered critical, which can be influenced by the design of the implant fixture. To determine the outcomes at 1year after the immediate loading of multiunit fixed partial prostheses over either tapered implants (TIs) or straight implants (SIs) in the posterior region. Forty-eight patients (24 patients, 52 implants in TI group; 24 patients, 50 implants in SI group) were included for the study. Except for the one SI group patient whose two implants showed the insertion torque less than 30 Ncm, provisional prostheses designed and fabricated from intraoral scan data obtained immediately after implant surgery were delivered to rest of the 47 subjects at 3-7 days. After a year, the survival rate was estimated by intention-to-treat (ITT) and per-protocol (PP) analyses, and marginal bone loss (MBL) and implant stability were also analyzed statistically (p < 0.05). Survival rate at implant level in TI group was 96.2%, and that of SI group in the ITT analysis was 86.0%. Intergroup difference, however, was not statistically significant (p > 0.05). Insertion torque was significantly higher in TI group than SI group (47.12 ± 6.37 Ncm vs. 41.60 ± 9.77 Ncm; p < 0.05). MBLs of both groups were less than 0.1 mm at 1-year follow-up and was similar between two groups (p > 0.05). Immediate loading of fixed partial prostheses after TI and SI placement showed reliable outcomes in the partially edentulous posterior ridge. In terms of the initial mechanical stability, the performance was superior for TIs than for SIs.

Comparison of posterior residual ridge resorption in patients wearing conventional denture, two implant-retained mandibular overdenture and four implant-supported overdenture: a 5-year retrospective study.

Purpose: The aim of the following study was to assess and compare the effect of treatment with conventional complete dentures, two implant retained mandibular overdenture and four implant supported mandibular overdenture on mandibular posterior residual ridge resorption over a 5-year period. Material and methods 24 patients were selected from previous studies, where (group I) included 8 patients previously treated with conventional complete dentures. The second group (group II) 8 patients received mandibular overdenture using two osseointegrated implants, (group III)8 patients received implant supported mandibular overdenture using two implants in canine region and two implants in the first molar region connected with rigid bar. Posterior residual ridge resorption was evaluated for all groups using proportional area measurements. Results: After 5years of prosthetic treatment, regarding posterior residual ridge resorption, statistically significant bone resorption had occurred for all the three groups, also statistically significant difference was reported when comparing the two-implant overdenture group to the four-implant supported overdenture group. Conclusion Four implant supported overdenture with the posterior implants in the first molar region showed the least amount of posterior ridge resorption after 5 years of treatment in comparison to conventional complete dentures or two implant retained overdenture.

Role of Speech Aid Prosthesis as Diagnostic and Therapeutic Aid for Velopharyngeal Insufficiency Defect: A Case Report

Soft palate tumors pose the challenge during reconstructive and rehabilitating procedures. Surgical resection of these tumors leads to velopharyngeal insufficiency (VPI). The primary effects of VPI are hypernasality and air-flow escape, while the secondary effects are abnormalities in speech articulation. Surgical revision along with speech therapy is a common approach to the treatment of VPI. Prosthetic management by means of speech aid prosthesis helps to reduce resonance, nasal emission and consonants errors. This clinical report describes the different stages of rehabilitation of velopharyngeal insufficiency defect following resection of malignant melanoma of left posterior alveolar ridge and soft palate. The speech aid prosthesis helped to rehabilitate the velopharyngeal insufficiency defect and aided in the diagnosis of extent of speech function improvement by perceptual and objective methods.

A Modified Transalveolar Sinus Floor Elevation Approach With a Bilaterally Enlarged Osteotomy.

Sinus floor elevation is the most commonly used method for vertical bone augmentation in the maxillary posterior area. This clinical report describes a modified transalveolar approach to elevate the Schneiderian membrane when placing implants on a severely resorbed maxillary posterior ridge with a buccal-palatal width of more than 8.0 mm. In this approach, the osteotomy prepared on the crestal is bilaterally enlarged to 8.0-10.0 mm. The enlarged osteotomies provide better access, allowing instruments to be in direct contact with the bone of the sinus floor and thus elevate the Schneiderian membrane with a reduced risk of perforation.