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Objectives: To determine the correlation between the primary implant stability quotient and the implant percussion sound frequency., Materials and Methods: A total of 14 pigs' ribs were scanned using a dental cone beam computed tomography (CBCT) scanner to classify the bone specimens into three distinct bone density Hounsfield units (HU) value categories: D1 bone: >1250 HU; D2: 850-1250 HU; D3: <850 HU. Then, 96 implants were inserted: 32 implants in D1 bone, 32 implants in D2 bone, and 32 implants in D3 bone. The primary implant stability quotient (ISQ) was analyzed, and percussion sound was recorded using a wireless microphone connected and analyzed with frequency analysis software., Results: Statistically significant positive correlations were found between the primary ISQ and the bone density HU value (r = 0.719; p < 0.001), and statistically significant positive correlations between the primary ISQ and the percussion sound frequency (r = 0.606; p < 0.001). Furthermore, significant differences in primary ISQ values and percussion sound frequency were found between D1 and D2 bone, as well as between D1 and D3 bone. However, no significant differences were found in primary ISQ values and percussion sound frequency between D2 and D3 bone., Conclusion: The primary ISQ value and the percussion sound frequency are positively correlated., (© 2024 The Author(s). Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.)

Percussion instruments, creativity and the helping relationship are at the heart of the evolution of a rhythmic expression workshop towards a structure designed for the practice of active music therapy. Thanks to instruments within everyone's reach, the therapy based on sound production, improvisation and creativity enables patients to express themselves, communicate and create links, while constructing an identity., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Pneumonia causes the deaths of over a million people worldwide each year, with most occurring in countries with limited access to expensive but effective diagnostic methods, e.g., chest X-rays. Physical examination, the other major established method of diagnosis, suffers from several drawbacks, most notably low accuracy and high interobserver error. We sought to address this diagnostic gap by developing a proof-of-concept non-invasive device to identify the accumulation of fluid in the lungs (consolidation) characteristic of pneumonia. This device, named Tabla after the percussive instrument of the same name, utilizes the technique of auscultatory percussion; a percussive input sound is sent through the chest and recorded with a digital stethoscope for analysis. Tabla analyzes differences in sound transmission through the chest at audible frequencies as a marker for lung consolidation. This paper presents preliminary data from five pneumonia patients and eight healthy subjects. We demonstrate 92.3% accuracy in distinguishing between healthy subjects and patients with pneumonia after data analysis with a K-nearest neighbors algorithm. This prototype device is low cost and simple to implement and may offer a rapid and inexpensive method for pneumonia diagnosis appropriate for general use and in areas with limited medical infrastructure.

Fluid percussion (FP) injury model is a popular animal model of traumatic brain injury (TBI), but still there are some issues need to be addressed. To increase the validity and reliability of this technique, we adapted the FP device using electromagnetic protractor, stainless-steel cylinder, changing pressure transducer position, and foam pads to adjust the parameters of FP pulse. Besides, the adjusted FP device is more automatic. The FP pulse is promptly measured and displayed in a graphic user interface software. The modified device resulted in reliable FP pulse. The accuracy of the pendulum leveling was improved with using the electromagnetic protractor with slots. We then collected behavioral, cognition, electrophysiological, and immunohistochemical data to verify the percussion effects in TBI mice. Lateral fluid percussion injury (FPI) or sham treatment was administered at the right frontal motorsensory region of male C57BL/6J mice. TBI mice showed evident motor, cognitive, and functional impairments, characterized by evaluation of neurological, righting, geotaxis and cliff aversion reflexes, limb asymmetrical use, rotarod running, and Morris water maze testing. The neurobehavioral damages were scaled with histopathological findings. Further, the overall firing rates and theta powers in hippocampal CA1 were significantly reduced in TBI mice compared to sham mice at Days 2 and 3 after electrode implanting. The adapted device induced effects on behavior and biology in mice that agree with existing models. These findings confirmed the validity of adjustments, and the modified device may boost the interest in TBI studies., (© 2018 Wiley Periodicals, Inc.)

OBJECTIVE Experimental traumatic brain injury (TBI) models hold significant validity to the human condition, with each model replicating a subset of clinical features and symptoms. TBI is the leading cause of mortality and morbidity in children and teenagers; thus, it is critical to develop preclinical models of these ages to test emerging treatments. Midline fluid percussion injury (FPI) might best represent mild and diffuse clinical brain injury because of the acute behavioral deficits, the late onset of behavioral morbidities, and the absence of gross histopathology. In this study, the authors sought to adapt a midline FPI to postnatal day (PND) 17 and 35 rats. The authors hypothesized that scaling the craniectomy size based on skull dimensions would result in a reproducible injury comparable to the standard midline FPI in adult rats. METHODS PND17 and PND35 rat skulls were measured, and trephines were scaled based on skull size. Custom trephines were made. Rats arrived on PND10 and were randomly assigned to one of 3 cohorts: PND17, PND35, and 2 months old. Rats were subjected to midline FPI, and the acute injury was characterized. The right reflex was recorded, injury-induced apnea was measured, injury-induced seizure was noted, and the brains were immediately examined for hematoma. RESULTS The authors' hypothesis was supported; scaling the trephines based on skull size led to a reproducible injury in the PND17 and PND35 rats that was comparable to the injury in a standard 2-month-old adult rat. The midline FPI suppressed the righting reflex in both the PND17 and PND35 rats. The injury induced apnea in PND17 rats that lasted significantly longer than that in PND35 and 2-month-old rats. The injury also induced seizures in 73% of PND17 rats compared with 9% of PND35 rats and 0% of 2-month-old rats. There was also a significant relationship between the righting reflex time and presence of seizure. Both PND17 and PND35 rats had visible hematomas with an intact dura, indicative of diffuse injury comparable to the injury observed in 2-month-old rats. CONCLUSIONS With these procedures, it becomes possible to generate brain-injured juvenile rats (pediatric [PND17] and adolescent [PND35]) for studies of injury-induced pathophysiology and behavioral deficits, for which rational therapeutic interventions can be implemented.

Extracorporeal membrane oxygenation (ECMO) has been used to provide "lung rest" through the use of low tidal volume (6 ml/kg) and ultralow tidal volume (<6 ml/kg) ventilation in acute respiratory distress syndrome (ARDS). Low and ultralow tidal volume ventilation can result in low dynamic respiratory compliance and potentially increased retention of airway secretions. We present our experience using automated rotational percussion beds (ARPBs) and bronchoscopy in four ARDS patients to manage increased pulmonary secretions. These beds performed automated side-to-side tilt maneuver and intermittent chest wall percussion. Their use resulted in substantial reduction in peak and plateau pressures in two patients on volume control ventilation, while the driving pressures (inspiratory pressure) to attain the desired tidal volumes in patients on pressure control ventilation also decreased. In addition, mean partial pressure of oxygen in arterial blood (PaO2)/fraction of inspired oxygen (FiO2) ratio (109 pre-ARPB vs. 157 post-ARPB), positive end-expiratory pressure (10 cm H2O vs. 8 cm H2O), and FiO2 (0.88 vs. 0.52) improved after initiation of ARPB. The improvements in the respiratory mechanics and oxygenation helped us to initiate early ECMO weaning. Based on our experience, the use of chest physiotherapy, frequent body repositioning, and bronchoscopy may be helpful in the management of pulmonary secretions in patients supported with ECMO.

Background: A comparative ex vivo study was performed to determine electronic percussive test values (PTVs) measured by cabled and wireless electronic percussive testing (EPT) devices and to evaluate the intra- and interobserver reliability of the wireless EPT device., Methods: Forty implants were inserted into the vertebrae and forty into the pelvis of a steer, a safe distance apart. The implants were all 4.3 mm wide and 13 mm long, from the same manufacturer. PTV of each implant was measured by four different examiners, using both EPT devices, and compared. Additionally, the intra- and interobserver reliability of the wireless EPT device was evaluated., Results: Statistically significant differences (P <0.05) were observed between PTVs made by the two EPT devices. PTVs measured by the wireless EPT device were significantly higher than the cabled EPT device (P <0.05), indicating lower implant stability. The intraobserver reliability of the wireless EPT device was evaluated as excellent for the measurements in type II bone and good-to-excellent in type IV bone; interobserver reliability was evaluated as fair-to-good in both bone types., Conclusion: The wireless EPT device gives PTVs higher than the cabled EPT device, indicating lower implant stability, and its inter- and intraobserver reliability is good and acceptable.

Statement of Problem: The detection of cracks and fractures in natural teeth is a diagnostic challenge. Cracks are often not visible clinically nor detectable in radiographs., Purpose: The purpose of this study was to evaluate the diagnostic parity of quantitative percussion diagnostics, transillumination, clinical microscopy, and dye penetration., Material and Methods: Three independent examiners provided blind testing for the study. Examiner 1 transilluminated 30 extracted teeth and 23 three-dimensional copy replica control teeth and documented any visible cracks. Each tooth was then mounted in acrylic resin with a periodontal ligament substitute. Examiner 2 examined each specimen aided by the clinical microscope and transillumination and documented visible tooth cracks and fractures. Examiners 1 and 3 then independently tested all specimens with a device developed for quantitative percussion diagnostics. All visible cracks/fractures were removed with a water-cooled fine diamond rotary instrument. Crack visibility was enhanced by the use of a clinical microscope, dye penetrant, and accessory transillumination. This disassembly process was video documented/photographed for each specimen. One more quantitative percussion diagnostics testing was administered when the disassembly was complete., Results: Quantitative percussion diagnostics crack detection agreed with the gold standard microscope and transillumination method in 52 of 53 comparisons (98% agreement). Moreover, the method achieved 96% specificity and 100% sensitivity for detecting cracks and fractures in natural teeth. When all tooth cracks were removed, quantitative percussion diagnostics indicated no further structural instability., Conclusions: Quantitative percussion diagnostics can nondestructively detect cracks and fractures in natural teeth with accuracy similar to that of the clinical microscope, transillumination, and dye penetrant. In addition, the method was able to reveal the presence of many cracks that were not detected by conventional transillumination., (Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Traumatic brain injury is a leading cause of acquired epilepsy. Initially described in 1989, lateral fluid percussion injury (LFPI) has since become the most extensively used and well-characterized rodent traumatic brain injury and post-traumatic epilepsy model. Universal findings, particularly seizures that reliably develop after an initial latent period, are evident across studies from multiple laboratories. However, the LFPI procedure is a two-stage process, requiring initial surgical attachment of a skull fluid cannula and then reanesthesia for delivery of the epidural fluid pressure wave. We now describe a modification of the original technique, termed 'rapid lateral fluid percussion injury' (rLFPI), which allows for a one-stage procedure and thus shorter operating time and reduced anesthesia exposure. Anesthetized male Long-Evans rats were subjected to rLFPI through a length of plastic tubing fitted with a pipette tip cannula with a 4-mm aperture. The cannula opening was positioned over a craniectomy of slightly smaller diameter and exposed dura such that the edges of the cannula fit tightly when pressed to the skull with a micromanipulator. Fluid percussion was then delivered immediately thereafter, in the same surgery session. rLFPI resulted in nonlethal focal cortical injury in all animals. We previously demonstrated that the rLFPI procedure resulted in post-traumatic seizures and regional gliosis, but had not examined other histopathologic elements. Now, we show apoptotic cell death confined to the perilesional cortex and chronic pathologic changes such as ipsilesional ventriculomegaly that are seen in the classic model. We conclude that the rLFPI method is a viable alternative to classic LFPI, and--being a one-stage procedure--has the advantage of shorter experiment turnaround and reduced exposure to anesthetics.

Purpose: There is no quantitative gold standard instrumentation to assess the quality of implant osseointegration. The purpose of this exploratory study was to evaluate the response of two devices (one based on resonance frequency analysis, the Osstell device, and another that analyzes the percussion energy response, the Periometer) to assess the primary stability of implants embedded in artificial bone models., Materials and Methods: Standard implants were placed into polyurethane blocks of varying densities, and the two mechanical devices were challenged to test the specimen block series. Both analysis of variance and regression analysis were used to examine the output from each device over each series of specimen blocks as well as to directly compare outputs between the two devices., Results: The stability of the implants increased with the foam density for solid block specimens. Linear regression analysis showed significant correlation between the two instruments for testing with monolithic blocks ( r2 = 0.984). Both devices also indicated that a hybrid block with the greatest density at the top provided the best implant stability versus a hybrid block with relatively low density at the top of the block. However, resonance frequency analysis readings seemed to be more dependent on the density of the top layer of the hybrid blocks., Conclusion: Osstell and Periometer readings were in good agreement for monolithic blocks, and they were reasonably consistent when blocks of hybrid density were tested.

The periodontal condition was investigated by means of tooth natural frequency assessment. The correlation between tooth natural frequency and mobility was found out. The comparative estimation of percussion and spectral methods for natural frequency assessment revealed the percussion method to be more complicates because the initial acoustic signal is disturbed by external noises and hammer sound. The spectral method allows receiving reliable and reproducible results when using modified two-parametrical periodontometer.

Traumatic brain injury (TBI) research has attained renewed momentum due to the increasing awareness of head injuries, which result in morbidity and mortality. Based on the nature of primary injury following TBI, complex and heterogeneous secondary consequences result, which are followed by regenerative processes (1,2). Primary injury can be induced by a direct contusion to the brain from skull fracture or from shearing and stretching of tissue causing displacement of brain due to movement (3,4). The resulting hematomas and lacerations cause a vascular response (3,5), and the morphological and functional damage of the white matter leads to diffuse axonal injury (6-8). Additional secondary changes commonly seen in the brain are edema and increased intracranial pressure (9). Following TBI there are microscopic alterations in biochemical and physiological pathways involving the release of excitotoxic neurotransmitters, immune mediators and oxygen radicals (10-12), which ultimately result in long-term neurological disabilities (13,14). Thus choosing appropriate animal models of TBI that present similar cellular and molecular events in human and rodent TBI is critical for studying the mechanisms underlying injury and repair. Various experimental models of TBI have been developed to reproduce aspects of TBI observed in humans, among them three specific models are widely adapted for rodents: fluid percussion, cortical impact and weight drop/impact acceleration (1). The fluid percussion device produces an injury through a craniectomy by applying a brief fluid pressure pulse on to the intact dura. The pulse is created by a pendulum striking the piston of a reservoir of fluid. The percussion produces brief displacement and deformation of neural tissue (1,15). Conversely, cortical impact injury delivers mechanical energy to the intact dura via a rigid impactor under pneumatic pressure (16,17). The weight drop/impact model is characterized by the fall of a rod with a specific mass on the closed skull (18). Among the TBI models, LFP is the most established and commonly used model to evaluate mixed focal and diffuse brain injury (19). It is reproducible and is standardized to allow for the manipulation of injury parameters. LFP recapitulates injuries observed in humans, thus rendering it clinically relevant, and allows for exploration of novel therapeutics for clinical translation (20). We describe the detailed protocol to perform LFP procedure in mice. The injury inflicted is mild to moderate, with brain regions such as cortex, hippocampus and corpus callosum being most vulnerable. Hippocampal and motor learning tasks are explored following LFP.

Lateral fluid percussion injury (LFPI) is the most commonly used experimental model of human traumatic brain injury (TBI). To date, investigators using this model have produced injury using a pendulum-and-piston-based device (PPBD) to drive fluid against an intact dural surface. Two disadvantages of this method, however, are (1) the necessary reliance on operator skill to position and release the pendulum, and (2) reductions in reproducibility due to variable friction between the piston's o-rings and the cylinder. To counteract these disadvantages, we designed a low-priced, novel, fluid percussion apparatus that delivers a pressure pulse of air to a standing column of fluid, forcing it against the intact dural surface. The pressure waveforms generated by this apparatus are similar to those reported in the LFPI/PPBD literature and had little variation in appearance between trials. In addition, our apparatus produced an acute and chronic TBI syndrome similar to that in the LFPI/PPBD literature, as quantified by histological changes, MRI structural changes and chronic behavioral sequelae.

Mobility of splinted teeth was determined with the help of the device Periotest, its meterage depended upon abutment fixation nature and their number. Critical for the device sensitivity was the weight of splinting construction equal to 12.71+/-0.81 g.

Objectives: The aims of this in vitro study were to evaluate reliability of the Osstell and Periotest devices in the assessment of implant stability and to perform a method comparison., Material and Methods: Commercial dental implants were inserted into bovine rib segments of different anatomical origins and densities. Repeated measurements were performed, varying (a) the torque-in force of the devices' attachment screw (the Osstell transducer and the ball attachment, insert for the Periotest device), (b) the insertion site bone quality, and (c) the thread exposure in simulated peri-implant bone defects., Results: Both methods were comparably reliable and showed a strong association to each other in the classification of implant stability. As opposed to torque-forced screw attachment, the variations in bone composition, differences in inter-implant stability of adjacent implants, and peri-implant bone reduction were statistically significant for both methods., Conclusions: Both non-invasive diagnostic devices seem to be useful in the long-term follow-up of implant integration.

The objectives of this investigation were to: (i) assess the reliability of expert raters to detect ankylosis from recordings of percussion sounds, (ii) measure differences in Periotest values (PTV) between ankylosed and non-ankylosed incisors and (iii) identify characteristic differences in recorded percussion sounds from ankylosed and non-ankylosed incisors using digital sound wave analysis. A convenience sample of healthy children (age range 7-18 years) was invited to participate. Ankylosis group children had one or more documented ankylosed maxillary incisors. Control group children had intact, non-ankylosed incisors. Digital recordings of percussion sounds and PTV were acquired for each incisor of interest. Four experienced pediatric dentists rated the randomized percussion sound pairs for the presence of ankylosis. Percussion sounds were also subjected to digital sound wave analysis. Overall agreement for the expert raters was substantial (kappa = 0.7). Intra-rater agreement was substantial to almost perfect (kappa = 0.6-0.9). Diagnosis of ankylosis demonstrated sensitivity of 76-92% and specificity of 74-100%. PTV from ankylosed incisors were statistically lower than PTV from non-ankylosed incisors. Ankylosed incisor digital sound wave signals exhibited significantly more energy in high-frequency bands than non-ankylosed incisors. This investigation demonstrated that: (i) experienced pediatric dentists reliably detected ankylosis by percussion sound alone; (ii) PTV for ankylosed incisors were statistically lower than PTV from non-ankylosed incisors; and (iii) ankylosed incisors exhibited a higher proportion of their signal energy in high-frequency bands.

Peripheral-inserted central catheters (PICCs) offer a successful alternative to peripheral venipuncture for long term medication therapy. When catheters become occluded, the nurse must intervene to avoid delayed or missed treatments. Pharmacological interventions are costly and not without risks. The purpose of this exploratory study was to test a mechanical percussive POP technique to restore patency. Thirty PICC catheters were clotted with human blood and incubated for 8 hours in a 35 degrees saline bath. Using the percussive POP technique, a 10-mL syringe with 1 mL of saline restored patency in 86% of the occluded catheters. The safety and effectiveness of the POP technique in vitro was established.

Traumatic brain injury is a leading cause of death and disability, particularly among young adults. During closed head trauma, the injury process is initiated by the impact of the brain against the inner table of the calvarium. Subsequently, there is prompt initiation of a complex biochemical, cellular, and physiological injury cascade that may take days to complete. From a functional standpoint, this culminates in neurologic dysfunction and, if severe, death. This unit describes an impact-induced brain trauma model in rats which replicates nonpenetrating head injury. It does not model either penetrating or ischemic brain injuries.

Purpose: We compare the effectiveness of mechanical percussion and inversion with observation for eliminating lower caliceal fragments 3 months after shock wave lithotripsy., Materials and Methods: At 3 months after shock wave lithotripsy 69 patients with residual lower caliceal fragments 4 mm. or less were randomized to receive either mechanical percussion and inversion or observation for 1 month. The observation group then received crossover mechanical percussion and inversion if fragments persisted. All patients were followed with plain film of the kidneys, ureters and bladder to assess the stone area and stone-free status, and renal tomography or noncontrast spiral computerized tomography to confirm stone-free status. A blinded radiologist reviewed all films. Patients were treated with a mechanical chest percussor applied to the flank while inverted to greater than 60 degrees after receiving 20 mg. furosemide., Results: A total of 35 patients were randomized to receive immediate mechanical percussion and inversion therapy and 34 observation. Of the patients in the observation group 28 subsequently received mechanical percussion and inversion after completing the observation period. The groups were not different in gender, body mass index, side affected, stone location or renal anatomical features. The mechanical percussion and inversion group had a substantially higher stone-free rate than the observation group (40% versus 3%, respectively, p <0.001). The mechanical percussion and inversion group also had a greater improvement in total stone area than controls (-63.3% versus +2.7%, respectively, p <0.001). No significant adverse effects were noted in the mechanical percussion and inversion group., Conclusions: Mechanical percussion and inversion is a safe and effective treatment option for residual lower caliceal fragments 3 months after shock wave lithotripsy. Nearly 50% of patients become stone-free, and stone burden is decreased by 50% in the remainder.

While the Periotest continues to be used in assessing the integrity of implants, there are numerous reports of its inconsistencies. To understand more precisely what the Periotest is actually measuring, a mathematical model was developed that illustrates the effect that various geometric and clinical parameters have on the Periotest value (PTV). In addition, the model was validated with an in vitro experiment. Results of the mathematical model are shown to correlate with those obtained from the experimental test The PTV is very sensitive to the position at which the Periotest impacts the abutment and to angulation of the handpiece. It was shown that a change in position of 1 mm in striking height can produce a difference in PTV of between 1 and 2. Since the angulation of the handpiece can produce a difference in striking position of 2 mm, it must be controlled as well. The model also showed that the Periotest can detect changes in bone height of 0.5 mm.

Maintenance of the integrity of the abutment/implant interface is essential and is dependent on the abutment screw retaining a preload. Evaluation of this joint is usually done by manual assessment. The purpose of the current study was to determine whether the Periotest instrument could be used to evaluate abutment screw loosening. A custom-designed apparatus was constructed to measure abutment screw loosening. Abutment screws were torqued to 10, 20, 32, and 45 Ncm and then loosened. Objective assessment of screw loosening was carried out with the Periotest device. Subjective evaluation was done by 3 experienced clinicians. The Periotest was found to be more sensitive than manual detection of abutment screw loosening. With a change of 2 in the Periotest value, it was found that the tensile preload in the joint was lost. While the Periotest was more sensitive than manual evaluation, the instrument was not sensitive enough to indicate deterioration of abutment screw loosening prior to loss of tensile preload.

The paper describes a modern diagnostic method: Periotest for assessing the stability of intraosseous implants. The mobility of implants after remote and immediate implantation is assessed in 65 patients with dentition defects. The study yielded complete information on the status of tissue complex, detected the early signs of impaired bone integration after implantation, and helped more reliably predict the results.

Accurate master casts are essential for the construction of implant-supported prostheses with a precision of fit. The stability of the abutment replicas in the master cast is critical in the accurate reproduction of the patient's oral presentation. The Periotest method is an objective method of quantifying mobility in a tooth and implant. Eighteen gypsum implant master casts containing two brass abutment replicas per cast were evaluated. The abutment replicas were measured three times each for a total of 108 measurements. The mean periotest values and standard deviations were calculated for the master casts and the abutment replicas. The abutment replicas displayed mean periotest values that ranged from +1.3 to -8.0. The study shows that there are significant differences between stable and unstable implant master casts (P = 0.0001, ANOVA-Fisher's protected least significant difference) and abutment replicas (P = 0.0001, Contrast test). The Periotest method will quantify differences in gypsum stone implant master casts as well as the prosthesis supporting brass abutment replicas that are an integral part of the master cast.

The Periotest percussion force acting on a dental implant was estimated by assuming a mass-spring-dashpot model of the implant-bone system constructed on the basis of a clinical experiment. A theoretical value of about 10 N, comparable to hitherto reported experimental values, was obtained for an osseointegrated implant of about 1 g. The percussion force would probably be smaller for a heavier implant.

Clinicians elicit a Tinel's sign by tapping over a nerve site with their fingertips. No standard force has been established, and overzealous tapping can produce a false-positive "Tinel's sign" that is actually a positive percussion test. The purpose of our study was to determine a threshold force that produces a positive percussion test in each of seven nerve locations in the upper extremities of subjects with no known nerve injuries and in subjects with nerve injuries. These data suggest limits for the amount of force necessary to elicit a Tinel's sign. If these limits are adhered to, the incidence of false-positive responses may be kept low.

Osseointegration is a histometric process that occurs gradually over a period of time. The load that an implant is able to bear depends upon, among other parameters, the quality of the bone-implant contact. For 8 years the damping capacity of 1,182 Brånemark implants inserted consecutively in 315 patients was measured using the Periotest method. The following clinical observations were made: (1) a relationship was found between implants with a specific Periotest value range that, at the moment of the transepithelial connection, were considered to be clinically stable, asymptomatic, and whose radiograph image was not radiolucent; (2) a relationship was found between clinically nonintegrated implants with a different Periotest value range; (3) variations in the Periotest value were related to the type of bone in which the implant was placed; (4) a small percentage of borderline implants with a Periotest value between the osseointegrated and the nonosseointegrated Periotest values was detected; (5) the percentage of secondary failures was related to an initial Periotest value corresponding to a borderline implant; (6) the healing time of each implant was individualized in accordance with the successively obtained Periotest value; (7) the load and the design of the prosthesis were individualized; (8) early detection of failing implants before fabrication of prostheses is possible; (9) communication was improved between the surgeon and the prosthodontist; and (10) variations in Periotest value were related to bone remodeling. The sensitivity of the principal clinical test in evaluating osseointegration is discussed regarding the moment of its application. The use of Periotest values as an initial success criteria of an implant is proposed.

The reaction of the periodontium to a defined percussive force applied in an orofacial direction can be evaluated by a mobility meter. The elastic and viscous characteristics of the periodontium are evaluated by the device from the contact time between tapping head and the tooth, and reported as a numeric value called the PTV. In this study, the relation between PTVs and bone loss (BL), clinical attachment level (CAL), probing depth, bleeding on probing, and plaque and gingival indices were evaluated in 35 patients with moderate to advanced periodontal disease. The effects of gender, smoking, and initial periodontal therapy on PTVs were also evaluated. Repeated measures analysis of variance was used to determine whether the relationship between PTVs with CAL and BL was dependent on tooth type. Stepwise multiple linear regression was used to test which of the clinical parameters and bone loss would produce the highest predictive value with PTVs. The effects of gender and smoking on PTVs were examined by analysis of covariance. The changes in clinical parameters and PTVs before and after treatment were evaluated by repeated analysis of variance. PTVs were found to give the highest predictive value with bone loss. However, the correlation was observed to be dependent on the location of the tooth in the jaw and the tooth type. Interproximal and midpoint clinical attachment level measurements showed that PTVs correlated more strongly with the overall support, rather than the support on the direction of the percussive movement. No pronounced differences of PTVs were noted between gender. PTVs of smokers were observed to be higher than non-smokers. There was no significant change of PTVs after the initial phase of periodontal therapy. This cross-sectional study shows that the mobility meter evaluation was primarily related to the amount of bone loss while being significantly affected by the location of the tooth in the jaw. Factors such as severity of gingival and sulcular inflammation, oral hygiene, and gender do not seem to have an effect on PTVs.

The direct method of chest percussion, first described by Auenbrugger but disseminated by Corvisart, has rapidly been replaced by the indirect or digitodigital method. Chest percussion has not been evaluated by modern acoustic means, so that our present knowledge of the method does not consistently differ from the 19th century approach. Auscultatory percussion is not superior to conventional percussion.

The Periotest device was used to evaluate the damping characteristics of different bone-to-implant interfaces of Brånemark implants. Implant and abutment lengths were found to have a significant influence on Periotest value (PTV). There was no statistical difference between PTVs of implants located in the anterior and posterior areas of the same jaw at abutment connection. No differences were found between PTVs of standard and self-tapping implants. PTVs at abutment connection were highly influenced by the bone quality. The contact with two corticals, one at each extremity of the implant, was of a greater influence in the maxillary than in the mandibular jaw, indicating a firmer anchorage between the bi-cortical implants and the surrounding bone. A progressive decrease of PTVs over time was observed, significant up to 5 years of loading.

This report examines a modified fluid percussion device with specific improvements made to address deficiencies found in previously reported devices. These improvements include the use of a cylindrical saline reservoir made of stainless steel, placement of the reservoir in a 15-degree head-up position for the easy release of air bubbles, placement of the fluid flushing outlet and the pressure transducer close to the piston on the same plane, with both perpendicular to the direction of the piston, and adjustable reservoir volume to vary the waveform of the pressure pulse, and a metallic central injury screw secured to the animal's skull over the exposed dura. Using this device, midline fluid percussion (MFP) and lateral fluid percussion (LFP) injuries were performed in 70 rats. Histopathologic findings included diffuse axonal injury in the MFP model and cortical contusion in the LFP model. Survival rate was 41.4% in MFP animals and 100% in LFM animals when the device settings were 178 mm3 of the cylindrical reservoir and 50 degrees-60 degrees in height of the pendulum. Our results suggest that this modified fluid percussion device may offer significant improvements over previously reported fluid percussion models for use in experimental head injury.

Many of the presently used methods of evaluating osseointegration at implant uncovering are highly subjective. The Periotest is claimed to offer a more objective means to assess osseointegration by means of microcomputer-controlled percussion. Investigators involved in a long-term clinical study of dental implants being conducted by the Dental Implant Clinical Research Group used the Periotest to evaluate the mobility associated with all study implants at second-stage surgery and correlate the Periotest values with various bone densities. The Periotest values for 1,838 root form implants ranged from -8 to +25. Implants that appeared to be osseointegrated at uncovering recorded a mean Periotest value of -3.37 +/- 3.25, while nonosseointegrated implants had a mean Periotest value of +13.87 +/- 14.27. Mean Periotest values were -3.82 +/- 3.04 for quality 1 bone, -3.70 +/- 3.06 for quality 2 bone, -3.31 +/- 3.18 for quality 3 bone, and -1.29 +/- 3.57 for quality 4 bone. The Periotest has the potential of being a valuable instrument for assessing the status of osseointegration at second-stage surgery.

Many of the presently used methods of evaluating osseointegration at second-stage surgery are highly subjective. The Periotest is claimed to offer a more objective means to assess osseointegration by means of microcomputer-controlled percussion. In 1991 the Dental Implant Clinical Research Group initiated a long-term clinical study in cooperation with the Department of Veterans Affairs to investigate the influence of implant design, application, and site of placement on clinical performance and crestal bone height. As part of this investigation, the Periotest values for 1,565 root form implants were determined at second-stage surgery and correlated with type, material, coating, diameter, and length. Hydroxyapatite-coated implants and increased implant diameter and length produced Periotest values that indicated a greater extent of stability as compared with noncoated implants with shorter diameters and lengths. Hydroxyapatite-coated cylinder-type implants yielded the most favorable Periotest readings. Not only does the Periotest have the potential of being a valuable instrument for assessing implant mobility at second-stage surgery, but it also appears to have the capability of determining slight differences in the implant-bone complex.

In patients with lung disorders there is often a build up of mucus inside the lungs which in healthy people is normally removed by the action of cilia on the lung tissue surfaces. In the diseased lung, however, this clearance mechanism may be ineffective and so patients are offered physiotherapy in order to assist the mucus removal process. The consequences of not properly removing the mucus are impaired lung function and a much higher risk of contracting lung infections and suffering consequent permanent scarring of the lung tissues. If unchecked the latter leads ultimately to failure of the lungs and to the patient's death. The most common forms of chest physiotherapy used are percussion coupled with postural drainage and an active cycle of breathing. This requires the patient to lie head downwards on an inclined surface, so that gravity might assist the mucus removal process, whilst the physiotherapist strikes the patient's chest with the hands. The procedure is interspaced by periods of 'huffing and coughing' by the patient to remove the loosened sputum from the body. An alternative to the manual percussion described above is to use machinery to provide the stimulus to the chest. If such a procedure were found to be satisfactory then it would enable more patients to manage their own physiotherapy, may make the required duration of the physiotherapy sessions shorter, and would free much of the professional physiotherapists' time to enable them to assume more of a physiotherapy management role.(ABSTRACT TRUNCATED AT 250 WORDS)

The physical basis of the Periotest percussion diagnosis is theoretically studied by modelling the dental implant-bone system as a simple lumped parameter system. An expression of the effective stiffness k(eff) is derived as a function of the contact time tau. The validity of k(eff) obtained is verified by a comparison with experimental values estimated from other methods. Relationships between k(eff) and the pure stiffness for the Kelvin-Voigt and Maxwell models are also derived. It is suggested that an increase of viscosity as well as stiffness will decrease tau.

Periodontal disease may be diagnosed with the Periotest technique, which involves electronically controlled and reproducible percussion of tooth. The movement on percussion was investigated with high-speed film and then compared with the return of teeth after static deflection for several seconds as has been reported previously by Lukas and Scholz. The elastic and viscous properties of the periodontium and the surrounding bony tooth socket are to a large extent non-linear. The 10-20 microns deflection of the healthy tooth represents only a fraction of static tooth mobility published by Parfitt or Schulte et al. The visco-elastic properties of a healthy tooth enabling the percussion of the Periotest tapping head to be decelerated in less than 1 ms are largely lost in periodontitis. It is this essential difference which the Periotest method utilizes.

Following the simultaneous description of muscle stretch reflexes by Heinrich Erb and Carl Westphal in 1875, neurologists used direct finger taps or chest percussion hammers to elicit these phenomena. Because of inadequacies of chest percussion hammers for eliciting muscle stretch reflexes, a variety of hammers were developed specifically for this purpose. In 1888, J. Madison Taylor, working for S. Weir Mitchell at the Philadelphia Orthopedic Hospital, designed the first such "reflex hammer." Taylor's hammer had a triangular rubber head and a short, flattened metal handle. Krauss (1894), Berliner (1910), Troemner (1910), Babinski (1912), and Wintle (1925) also designed popular reflex hammers. Many of these hammers and several others are still in use.

High-frequency chest percussion (HFP) with constant fresh gas flow (VBF) at the tracheal carina is a variant of high-frequency ventilation (HFV) previously shown to be effective with extremely low tracheal oscillatory volumes (approximately 0.1 ml/kg). We studied the effects of VBF on gas exchange during HFP. In eight anesthetized and paralyzed dogs we measured arterial and alveolar partial pressures of CO2 (PaCO2) and O2 (PaO2) during total body vibration at a frequency of 30 Hz, amplitude of 0.17 +/- 0.019 cm, and tidal volume of 1.56 +/- 0.58 ml. VBF was incrementally varied from 0.1 to 1.2 l.kg-1.min-1. At low flows (0.1-0.4 l.kg-1.min-1), gas exchange was strongly dependent on flow rate but became essentially flow independent with higher VBF (i.e., hyperbolic pattern). At VBF greater than 0.4 l.kg-1.min-1, hyperventilatory blood gas levels were consistently sustained (i.e., PaCO2 less than 20 Torr, PaO2 greater than 90 Torr). The resistance to CO2 transport of the airways was 1.785 +/- 0.657 l-1.kg.min and was independent of VBF. The alveolar-arterial difference of O2 was also independent of the flow. In four of five additional dogs studied as a control group, where constant flow of O2 was used without oscillations, the pattern of PaCO2 vs. VBF was also hyperbolic but at substantially higher levels of PaCO2. It is concluded that, in the range of VBF used, intraairway gas exchange was limited by the 30-Hz vibration. The fresh gas flow was important only to maintain near atmospheric conditions at the tracheal carina.

The force of impact and frequency of percussion by physiotherapists and parents of children with cystic fibrosis were analysed on a special test rig and incorporated in a prototype percussor. In adult volunteers and cadavers a maximum intrathoracic pressure could be achieved by a critical frequency of mechanical percussion which was higher than that reached by physiotherapists and parents. Consequently the percussor was redesigned to operate at this optimum frequency. It was then discovered that if the percussor was pressed firmly enough against the chest, this maximum intrathoracic pressure could be indicated by quivering of the voice. In a continuing study of intrathoracic pressures obtained mechanically and manually the Salford percussor's produced higher pressures than the physiotherapists' and maintained them constantly, while the physiotherapists' efforts and results varied from one to another. Hospital and domiciliary use of the percussor have shown it to help in the first stage of the physiotherapy routine for patients with cystic fibrosis. The percussor should enable adolescents and adults to treat themselves and encourage twice-daily and more effective chest treatments. It is easy to apply and its speed and efficiency should enable parents to improve the quality of their chest therapy for younger children at home. Its long-term benefits are difficult to assess because of the nature of the disease.

Piorry was born in Poitiers on 31 December 1794. As a medical student he served in the Napoleonic war in Spain. His teachers in medicine included Corvisart, Bayle, Broussais, and Magendie; he qualified in 1816 with an MD thesis: "On the danger of reading medical text books by the laity"! Laënnec's invention of the stethoscope (1816) and De l' Auscultation Médiate (1819) inspired Piorry to make an analogous contribution to the technique of percussion (which had been originally described by Auenbrugger in his Inventum Novum in 1761 and translated from the Latin into French by Corvisart in 1808). This led to Piorry's invention in 1826 of the pleximeter (le plessimétre) to help outline the internal organs (l'organographisme), which he described inDe la Percussion Médiate (1828). Piorry became renowned as a professor of medicine in many of the great Parisian hospitals (Charité, Pitié, and Hôtel Dieux). In 1832 he was appointed to L'Hospice de la Salpétrière, where he held a famous course of clinical lectures. He wrote prolificly on many aspects of medicine and published more than twenty books. He was, in addition, a poet of some distinction, and wrote a remarkable long poem Dieu, L'Ame et la Nature (1853). Piorry held his neologisms-for example, toxin, toxaemia, septicaemia, etc.-are still in use. This, together with the mixed reception that his advocacy of pleximetry received from his medical contemporaries, made him a controversial figure. He died on 29 May 1879.

A standardized reproducible system for evoking jaw reflexes following chin tap is described. It represents an improvement over non-standardized and other standardized forms of instrumentation in that characteristics of the associated jaw displacement and parameters of the evoked jaw jerk reflexes recorded using this system have been shown to be reproducible. The need for standardized instrumentation to evoke jaw reflexes of any kind is emphasized by the influence of graded variations in tap force on the parameters of the evoked jaw jerk reflex response. Thus, higher levels of tap force correlate with an increased jaw jerk duration and amplitude and a decreased latency.

The use of percussion as a means of evaluating symptoms related to pulpal and periapical conditions is well documented. The literature reports no method of means for recording any relative measure of this response. A percussion instrument was developed to record the various degrees of tenderness to percussion on a calibrated basis.