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Dental Clinics of North America Jul 2006The use of dental implants to replace missing teeth is becoming a preferred alternative for restorative dentists and their patients. There are two general surgical... (Review)
Review
The use of dental implants to replace missing teeth is becoming a preferred alternative for restorative dentists and their patients. There are two general surgical approaches for the placement and restoration of missing teeth using endosseous dental implants. One approach places the top of the implant at the alveolar crest and the mucosa is sutured over the implant. An alternative approach places the coronal aspect of the implant coronal to the alveolar crest and the mucosa is sutured around the transmucosal aspect of the implant. This article reviews one-piece and two-piece implants as well as biologic implications of submerged and non-submerged surgical techniques for placing implants.
Topics: Alveolar Process; Dental Abutments; Dental Implantation, Endosseous; Dental Implants; Dental Plaque; Dental Prosthesis Design; Gingiva; Humans; Surface Properties
PubMed: 16818019
DOI: 10.1016/j.cden.2006.03.008 -
The American Surgeon Mar 2022Refractory seizure activity represents a difficult problem for both patients and practitioners. Implantation of the vagal nerve stimulator has been posited as an...
BACKGROUND
Refractory seizure activity represents a difficult problem for both patients and practitioners. Implantation of the vagal nerve stimulator has been posited as an effective treatment for refractory seizure activity. These devices are inserted by placing leads into the carotid sheath along the vagus nerve. We evaluated a vascular surgeon's experience placing vagal nerve stimulators.
METHODS
We examined all patients treated with placement of vagal nerve stimulator by a single surgeon from October 2016 to October 2018. Data collected included demographics, medical and surgical history, intraoperative variables, and complications.
RESULTS
Thirty-four patients underwent placement of a vagal nerve stimulator. About 29.4% had a previous vagal nerve stimulator placed on the ipsilateral side. Intraoperative bradycardia was seen in 1 patient. Postoperative complications were identified in 5 patients, all of which were transient dysphagia or changes in voice quality which did not require intervention. There was no significant difference between patients with the previous operation and those without for developing postoperative complications ( = .138). Average blood loss was higher in patients who had undergone previous stimulator placement than those who had not ( = .0223), and the operative time was longer ( ≤ .0001).
DISCUSSION
Given the anatomical location of placement, vascular surgeons may be called upon to place these devices. In our single surgeon series, we found that the placement was safe, with minimal complications. Intraoperatively, this case appears to be more difficult (with higher blood loss and longer operative time) in patients who have had previous device placement, but this does not appear to lead to increased complications.
Topics: Adult; Aged; Blood Loss, Surgical; Bradycardia; Carotid Arteries; Deglutition Disorders; Drug Resistant Epilepsy; Female; Humans; Male; Middle Aged; Operative Time; Postoperative Complications; Prosthesis Implantation; Retrospective Studies; Surgeons; Vagus Nerve Stimulation
PubMed: 33026229
DOI: 10.1177/0003134820943553 -
European Journal of Sport Science Jul 2023This study investigated whether skilled batsmen in a state cricket pathway could anticipate ball types when congruency of field-placings was manipulated with a bowler's...
This study investigated whether skilled batsmen in a state cricket pathway could anticipate ball types when congruency of field-placings was manipulated with a bowler's action. Twenty-four male cricket batsmen were recruited who had played either first-class cricket ( = 6), were part of under 17 ( = 8) or under 19 ( = 10) state cricket squads. Participants completed a video-based temporal occlusion test where they were required to anticipate ball types from a swing bowler. In condition one, contextual field-placing information was presented to be congruent with the delivery type and bowler's action, whilst in condition two it was incongruent. Results did not reveal skill level differences across conditions for anticipation. In the congruent condition, all skill groups predicted above the chance level at the beginning and end of the bowler's delivery stride. In the incongruent condition, first-class players predicted above chance at the beginning of the bowler's delivery stride, and to a higher magnitude above chance compared to other skill groups at ball release. Under 17 and 19 players could not predict above chance at the start of the bowler's delivery stride with their magnitude of prediction lower than first-class players at ball release. Results indicate skilled batsmen find it challenging to integrate contextual and kinematic information to anticipate. This is likely due to greater emphasis placed upon contextual information in part supplied by data analysts. Findings have theoretical and practical implications respectively for lower body positioning for bat-ball interception and perceptual training to improve pick-up of kinematic cues.Skilled batsmen in a high-performance state cricket pathway could integrate congruent field-placings and bowler kinematics to anticipate ball types.First-class batsmen could integrate incongruent field-placing information to the start, but not the end, of the bowler's delivery action to anticipate ball types.Under 17 and 19 batsmen could not integrate incongruent field-placings to bowler kinematics to anticipate ball types.Skilled batsmen who cannot use kinematic information to anticipate ball types should be given visual-perceptual simulation training to accelerate performance.
Topics: Humans; Male; Sports; Cues; Biomechanical Phenomena; Probability
PubMed: 36481092
DOI: 10.1080/17461391.2022.2157337 -
The International Journal of... 2010Interest in insectivoran grade mammals has been reawakened by taxonomic changes that place tenrecs and golden moles in a new order and separate hedgehogs from moles,... (Review)
Review
Interest in insectivoran grade mammals has been reawakened by taxonomic changes that place tenrecs and golden moles in a new order and separate hedgehogs from moles, shrews and solenodons. This survey of their placentation shows there is great variation even within families. As an example three subfamilies of tenrec have been examined. The interhemal region is cellular hemomonochorial in Echinops and Microgale but endotheliochorial in Micropotamogale. Golden moles, which are placed in the same order, have hemodichorial placentation. Many insectivores have complex arrangements for histotrophic nutrition involving columnar trophoblast cells. These range from areolae in moles through complexly folded hemophagous regions in tenrecs to the trophoblastic annulus in shrews. Of these placental characters, few offer support to current phylogenies. However, the case for placing hedgehogs and gymnures in a separate order (Erinaceomorpha) is bolstered by the presence of interstitial implantation, amniogenesis by cavitation, a hemochorial barrier and a prominent spongy zone; these features do not occur in shrews, moles or solenodons (Soricomorpha). Three insectivoran grade mammals deserve close attention as they have been selected for genome sequencing. One of these, the European hedgehog (Erinaceus europaeus), has not been studied with current methodology and renewed investigation of this or the closely related genus Atelerix should be a priority.
Topics: Animals; Eulipotyphla; Female; Phylogeny; Placenta; Placentation; Pregnancy; Trophoblasts
PubMed: 19876821
DOI: 10.1387/ijdb.082830ac -
Ear and Hearing 2016Although it has been shown previously that changes in temporal coding produce changes in pitch in all cochlear regions, research has suggested that temporal coding might...
OBJECTIVES
Although it has been shown previously that changes in temporal coding produce changes in pitch in all cochlear regions, research has suggested that temporal coding might be best encoded in relatively apical locations. The authors hypothesized that although temporal coding may provide useable information at any cochlear location, low rates of stimulation might provide better sound quality in apical regions that are more likely to encode temporal information in the normal ear. In the present study, sound qualities of single electrode pulse trains were scaled to provide insight into the combined effects of cochlear location and stimulation rate on sound quality.
DESIGN
Ten long-term users of MED-EL cochlear implants with 31-mm electrode arrays (Standard or FLEX) were asked to scale the sound quality of single electrode pulse trains in terms of how "Clean," "Noisy," "High," and "Annoying" they sounded. Pulse trains were presented on most electrodes between 1 and 12 representing the entire range of the long electrode array at stimulation rates of 100, 150, 200, 400, or 1500 pulses per second.
RESULTS
Although high rates of stimulation are scaled as having a Clean sound quality across the entire array, only the most apical electrodes (typically 1 through 3) were considered Clean at low rates. Low rates on electrodes 6 through 12 were not rated as Clean, whereas the low-rate quality of electrodes 4 and 5 were typically in between. Scaling of Noisy responses provided an approximately inverse pattern as Clean responses. High responses show the trade-off between rate and place of stimulation on pitch. Because High responses did not correlate with Clean responses, subjects were not rating sound quality based on pitch.
CONCLUSIONS
If explicit temporal coding is to be provided in a cochlear implant, it is likely to sound better when provided apically. In addition, the finding that low rates sound clean only at apical places of stimulation is consistent with previous findings that a change in rate of stimulation corresponds to an equivalent change in perceived pitch at apical locations. Collectively, the data strongly suggest that temporal coding with a cochlear implant is optimally provided by electrodes placed well into the second cochlear turn.
Topics: Adult; Cochlear Implantation; Cochlear Implants; Deafness; Electric Stimulation; Electrodes, Implanted; Female; Humans; Male; Middle Aged; Pitch Perception
PubMed: 26583480
DOI: 10.1097/AUD.0000000000000250 -
Journal of Dental Research Mar 2015Implants placed with high insertion torque (IT) typically exhibit primary stability, which enables early loading. Whether high IT has a negative impact on peri-implant...
Implants placed with high insertion torque (IT) typically exhibit primary stability, which enables early loading. Whether high IT has a negative impact on peri-implant bone health, however, remains to be determined. The purpose of this study was to ascertain how peri-implant bone responds to strains and stresses created when implants are placed with low and high IT. Titanium micro-implants were inserted into murine femurs with low and high IT using torque values that were scaled to approximate those used to place clinically sized implants. Torque created in peri-implant tissues a distribution and magnitude of strains, which were calculated through finite element modeling. Stiffness tests quantified primary and secondary implant stability. At multiple time points, molecular, cellular, and histomorphometric analyses were performed to quantitatively determine the effect of high and low strains on apoptosis, mineralization, resorption, and collagen matrix deposition in peri-implant bone. Preparation of an osteotomy results in a narrow zone of dead and dying osteocytes in peri-implant bone that is not significantly enlarged in response to implants placed with low IT. Placing implants with high IT more than doubles this zone of dead and dying osteocytes. As a result, peri-implant bone develops micro-fractures, bone resorption is increased, and bone formation is decreased. Using high IT to place an implant creates high interfacial stress and strain that are associated with damage to peri-implant bone and therefore should be avoided to best preserve the viability of this tissue.
Topics: Animals; Apoptosis; Biomechanical Phenomena; Bone Remodeling; Bone Resorption; Calcification, Physiologic; Cell Death; Cell Survival; Collagen; Dental Implantation, Endosseous; Dental Implants; Dental Materials; Dental Prosthesis Retention; Elastic Modulus; Femur; Finite Element Analysis; Male; Mice; Osseointegration; Osteocytes; Osteogenesis; Osteotomy; Pliability; Stress, Mechanical; Surface Properties; Titanium; Torque
PubMed: 25628271
DOI: 10.1177/0022034514566029 -
Multiple central place foraging by spider monkeys: travel consequences of using many sleeping sites.Oecologia Jun 1989Central place foraging models assume that animals return to a single central place such as a nest, burrow, or sleeping site. Many animals, however choose between one of...
Central place foraging models assume that animals return to a single central place such as a nest, burrow, or sleeping site. Many animals, however choose between one of a limited number of central places. Such animals can be considered Multiple Central Place Foragers (MCPF), and such a strategy could reduce overall travel costs, if the forager selected a sleeping site close to current feeding areas. We examined the selection of sleeping sites (central places) by a community of spider monkeys (Ateles geoffroyi) in Santa Rosa National Park, Costa Rica in relation to the location of their feeding areas. Spider monkeys repeatedly used 11 sleeping trees, and they tended to choose the sleeping site closest to their current feeding area. A comparison of the observed travel distances with distances predicted for a MCPF strategy, a single central place strategy, and a strategy of randomly selecting sleeping sites demonstrated (1) that the MCPF strategy entailed the lowest travel costs, and (2) that the observed travel distance was best predicted by the MCPF strategy. Deviations between the observed distance travelled and the values predicted by the MCPF model increased after a feeding site had been used for several days. This appears to result from animals sampling their home range to locate new feeding sites.
PubMed: 28313485
DOI: 10.1007/BF00378668 -
Forensic Science International Dec 2017This paper presents a forensic methodology that determines, from among a set of recording places, the probable place where allegedly a disputed digital audio recording...
This paper presents a forensic methodology that determines, from among a set of recording places, the probable place where allegedly a disputed digital audio recording was made. The methodology considers that digital audio recordings are noisy signals that have two involved noise components. One component is the multiplicative noise, which is an internal feature on the audio recording that is related to the recording device. The other component is the additive noise, which is an external feature on the audio recording that can be related to the recording place. Therefore, the proposed methodology estimates a likelihood rate that helps to decide which recording place is more plausible to be associated with a disputed audio recording. This likelihood rate is defined as the probability of a finding, supposing that a specific proposition is true, divided by the probability of a finding if an alternative proposition is true. Such probabilities are calculated by performing a statistical comparison through the Kullback-Leibler divergence [1], between the probability distribution function of the additive noise associated to the disputed recording and the probability distribution function of the additive noises associated to a set of audio recordings made on the possible recording places. Then, in order to determine the recording place, the analyst requires a list of possible places where the recording could have been carried out; in these places some reference recordings will be made. In this work, the additive noise is estimated by the Geometric Approach to Spectral Subtraction (GA-SS) filter [2], applied to the noisy audio recording.
PubMed: 29128653
DOI: 10.1016/j.forsciint.2017.10.031 -
Journal of Clinical Periodontology Mar 1982Free gingival grafts can be utilized, alone or in combination with a coronally positioned flap, for the prevention and the treatment of gingival recession. The graft can... (Review)
Review
Free gingival grafts can be utilized, alone or in combination with a coronally positioned flap, for the prevention and the treatment of gingival recession. The graft can be placed directly on the denuded root, as first described by Sullivan & Atkins (1968). This technique will provide adequate results, especially in cases with relatively little recession. After placing a free gingival graft in such an area, one can often observe bridging and/or creeping attachment. In the case of bridging, some of the grafted tissue will remain vital over the avascular zone, i.e. the root. Creeping attachment is the result of coronal migration of the grafted gingiva and will take place during the years following surgery. Bridging and creeping are most likely to occur in cases of narrow recession where the grafts had been placed directly over the denuded zone. In a second type of surgical procedure, an enlargement of the attached gingiva is first obtained through the graft. The area of recession is later covered by a coronally positioned flop. Several cases are presented which illustrate the results obtained with this procedure. In children, when there is insufficient attached gingiva, it is often desirable to place grafts before orthodonic therapy. In the prevention or treatment of gingival recessions, four possibilities may be considered: 1) no treatment, 2) placement of a graft to prevent recession, 3) stabilizing an existing recession, 4) attempt to cover the denuded root.
Topics: Adolescent; Adult; Child; Female; Gingiva; Gingival Diseases; Humans; Methods; Orthodontics, Corrective; Surgical Flaps; Time Factors; Wound Healing
PubMed: 7042767
DOI: 10.1111/j.1600-051x.1982.tb01226.x -
Knee Surgery, Sports Traumatology,... 1998Reconstruction of a form anterior cruciate ligament (ACL) cannot be successful without a properly placed tibial tunnel. Preventable complications such as anterior knee... (Review)
Review
Reconstruction of a form anterior cruciate ligament (ACL) cannot be successful without a properly placed tibial tunnel. Preventable complications such as anterior knee pain, effusions, extension loss, and recurrent instability can occur when the tibial tunnel is improperly placed and the roof and notchplasty are insufficient. This article reviews the principles for anatomic placement of the tibial tunnel so that complications associated with impingement of the ACL graft on the intercondylar roof can be prevented. Five factors that contribute to roof impingement are discussed, including differences in the size and shape of the ACL and the graft, variability in knee extension and roof angle between patients, inability to view the contact between the intercondylar roof and the graft, accentuation of roof impingement from anterior tibial translation caused by quadriceps contraction, and the use of tibial guides that rely on soft-tissue landmarks. A surgical technique is presented which consistently places the tibial tunnel in the pathway of the normal ACL (i.e., anatomic placement) and avoids roof impingement. The indications and need for roof- and wallplasty are discussed.
Topics: Anterior Cruciate Ligament; Anterior Cruciate Ligament Injuries; Humans; Knee Joint; Postoperative Complications; Range of Motion, Articular; Plastic Surgery Procedures; Tibia
PubMed: 9608464
DOI: 10.1007/s001670050223