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At least 19 recordsLinked to original sources

PubMed1999

CT demonstration of accessory nasal turbinates: secondary middle turbinate and bifid inferior turbinate.

Normally, there are three pairs of nasal turbinates in the nasal cavity. Coronal computed tomographies of 253 cases of sinusitis were examined for the presence of additional turbinates and bilateral secondary middle turbinates were detected in two cases. Also, we describe another accessory turbinate, 'bifid inferior turbinate', in one of these cases. Existence of these accessory turbinates may occur during embryologic development of lateral nasal wall.

Adolescent↗

PubMed1999

Effect of steam sterilization inside the turbine chambers of dental turbines.

OBJECTIVE: It has been demonstrated that contamination of the insides of high-speed dental turbines occurs and that bacteria as well as viruses may remain infectious when expelled from such turbines during subsequent use. Consequently, it has been widely recommended that a high-speed turbine be sterilized after each patient. The purpose of this study was to evaluate the effect of steam autoclaving on a high-speed dental turbine with a contaminated turbine chamber. STUDY DESIGN: Streptococcus salivarius and endospores of Bacillus stearothermophilus were used as test organisms to determine the effectiveness of 4 different small non-vacuum autoclaves and one vacuum autoclave. RESULTS: The study demonstrated different efficiencies among the small non-vacuum autoclaves, the best showing close to a 6 log reduction of the test organisms inside the turbine chamber. When cleaning and lubrication of the high-speed dental turbine was carried out before autoclaving, this level of reduction was observed for all the examined non-vacuum autoclaves. CONCLUSIONS: It is concluded that cleaning before sterilization is essential for safe use of high-speed dental turbines and that small non-vacuum autoclaves should be carefully evaluated before being used for the reprocessing of hollow instruments such as high-speed turbines.

Dental High-Speed Equipment↗

PubMed2004

Relationship between pediatric sinusitis and middle turbinate pneumatization--ethmoidal sinus pyocele thought to be caused by middle turbinate pneumatization.

OBJECTIVE: To investigate whether the presence of pediatric middle turbinate pneumatization causes narrowing of the ostiomeatal complex (OMC) and is associated with the development of paranasal sinusitis. METHODS: CT scans of 190 nasal sides of 95 children (1-15 years old) were analyzed for the presence of middle turbinate pneumatization and mucosal thickness in the paranasal sinus. RESULTS: Middle turbinate pneumatization was detected in nine (4.6%) of the nasal cavities. Only one of these sides was in a patient younger than 10 years of age, while the other eight sides were in patients at least 13 years old. In six of those nine sides with pneumatization, paranasal sinusitis was also found. However, the images showed that in five sides the middle turbinate pneumatization itself did not obstruct the OMC. In addition, the mean +/- standard deviation (S.D.) of the total score for the paranasal sinus opacification on the side which had the middle turbinate pneumatization was 5.67 +/- 2.95. The corresponding value for the 76 sides without pneumatization was 5.29 +/- 2.53, and the difference between these mean total scores was not statistically significant. However, in one side, the OMC was obstructed or narrowed due to the middle turbinate pneumatization, and an ethmoidal sinus pyocele formed on this side. CONCLUSION: A causal relationship was not found between middle turbinate pneumatization and the mechanism of development of paranasal sinusitis in children. However, in the event that the OMU becomes obstructed at some time, frequent cycles of improvement and aggravation of pediatric paranasal sinusitis may occur and lead to the development of a serious condition.

Adolescent↗

PubMedDate not supplied

The forgotten turbinate: the role of the superior turbinate in endoscopic sinus surgery.

The fate of the middle turbinate in endoscopic sinus surgery has been a subject of debate for some time. The superior turbinate's role, however, has been largely passed over. Past anatomic descriptions and illustrations have given surgeons the incorrect impression that this structure is well superior and out of the field of dissection. Injury to the superior turbinate may account for postoperative hyposmia. The superior turbinate also serves as a constant landmark for the sphenoethmoidal recess, and a limited resection allows the surgeon to identify and include the natural ostium of the sphenoid sinus in the sphenoidotomy. The embryology and anatomy of the superior turbinate are reviewed. An approach to the natural ostium of the sphenoid sinus from the lateral side of the middle turbinate, using the superior turbinate as a guide, is described.

Dissection↗

PubMed1981

[Studies on the performance of the dental air turbine handpieces. (Part 4) Analysis of the rotational performance of air turbine handpieces (N = N0 - CvFv gamma (author's transl)].

By the introduction of the diamond instruments and carbide burs measurably improved the quality and ease of cavity preparation, the several kinds of the air turbine handpieces, that is, standard type, torque type and miniature type air handpieces have been recently developed. In this paper, the performance tests of these air turbine handpieces have been carried out, and obtained the relations are indicated speeds and the vertical and horizontal loads or torque using the test bur. These relations are indicated by the logarithmic expressions, N = N0 - CvFv gamma, where N is the rotational speed of the air turbine handpieces during rotation, N0 is the free rotational speed of the air turbine handpieces, Fv is the vertical loads on the tests burs and Cv and gamma is the experimental constants. And then, the maximum performed work or the air turbine handpieces is presented by the expression as follows. W max = pimicrod/60(1/Cv)1/ gamma gamma (N0/gamma + 1)(1 + gamma)/gamma And we proposed the formula to be calculated for the performance ability of the air turbine handpieces.

Dental High-Speed Equipment↗

PubMed1980

[Studies on the performance of the dental air turbine handpieces. (Part 2) Classification and rotational performance of the dental air turbine handpieces (author's transl)].

For the purpose of the clinical and technical uses, air turbine handpieces are widely used for the high speed cutting instruments. And then, there are the many kinds of air turbine handpieces which are classified with the standard, minutia and torque types etc. So, in this paper, we examined the rotational properties of air turbine handpieces in the consideration of these classifications. And the relations between the reduction of the rotational speed and the rotational loads on the handpieces are fundamentally investigated. As the results of these investigations, it was revealed that rotational forces of the toque type air turbine are very excellent and the rotational speed of the air bearing type air turbine is higher than that of other type handpieces. And we obtained the practical properties of the rotational ability of air hand pieces.

Air↗

PubMed1982

[Studies on the performance of the dental air turbine handpieces. (Part 6) Investigation on the power of several air turbine handpieces (N = No-CvEv gamma) (author's transl)].

We have examined the basic studies on the rotational performance of the air turbine handpieces by using the brake method. Once, we used the constant feed speed testing method in which the test bur was pressed to the brake block at a constant feed speed. In the case of this method, the load increases in inverse proportion to the rotational speed as the loading time increases. In this paper for analyzing on the problem of the brake block materials used to this testing method, we did the performance test of the usually used air turbine handpieces by using the glass and the supper alloy which were superior to the frictional resistance as the brake materials. Consequently, by the difference of these brake materials, the characteristics of handpieces are not influences. But, in the long loading times, the dynamic friction coefficient between the glass block and the test bur became the great values. Therefore, in the constant feed speed testing method, the measured values of normal loads on the test bur, are influenced with the dynamic friction coefficients in the high load levels. On the rapidly dropped phenomenon of the rotational speed of air turbine handpieces, we measured the moment values at the support of test bur. And then we discussed the relation between the rotational performance and the length of burs or points using for cutting instruments. On the basis of the theoretical and experimental investigations of air turbine's rotational performance, we measured and examined the maximum works of the various kinds of the handpieces used in clinical field. The characteristics of the four-type handpieces, such the standard, torque and miniature types and air bearing type, used in this studies, were influenced with the materials of the brake block as far as the bounds of the loads were high in the rotational performance tests.

Dental High-Speed Equipment↗

PubMed2006

A secondary middle turbinate co-existing with an accessory middle turbinate: an unusual combination of two anatomic variations.

The anatomy of the nasal cavity lateral wall is quite complex; this is where most anatomical anomalies occur. The secondary middle turbinate, a bony projection that arises from the lateral nasal wall, is a rare variation, differing from the accessory middle turbinate by its distinct developmental origin. We report on an unusual case involving a combination of these two turbinate variations. We believe that detailed knowledge of anatomical anomalies in the sinonasal tract is critical for successful clinical management and important in allowing the surgeon to perform safe functional endoscopic sinus surgery.

Humans↗

PubMed2003

Degloving of the inferior turbinates: pilot study to assess the effectiveness of a new technique in turbinate reduction.

A pilot study to assess the safety and efficacy of 'degloving' of the inferior turbinate is described. This prospective study reports on the effectiveness of the technique in 37 patients with nasal obstruction due to inferior turbinate hypertrophy. Both objective and subjective measurements of nasal patency were made pre-operatively, and repeated at six weeks, six months and two years post-operatively using nasal inspiratory peak flow rates, saccharin clearance time and an end referenced visual analogue scale to record nasal symptoms. There was a significant improvement in the peak inspiratory flow at six weeks (96.4 to 151.2 l/min) and at six months (148.4 l/min), which was sustained at two years (117.1 l/min, p<0.001). There was an overall improvement in patient satisfaction with nasal symptoms (23.4 to 76.7, 76.8 and 66.8 at six weeks, six months and two years, p<0.001) and a decrease in the sensation of nasal obstruction (71.9 to 21.5, 32.9 and 29.8, p<0.001), which was also sustained. Rhinorrhoea was reduced, and sense of smell increased across the group, but the improvements did not reach statistical significance. The results for postnasal drip and saccharin clearance did not show a significant change over the period of the study. There were no haemorrhagic complications in the group studied. This pilot study demonstrates a new surgical technique for reduction of the inferior turbinates, that yields significant improvement in nasal obstruction, an acceptably low complication rate and is well tolerated by patients. A randomized controlled trial is being planned.

Adolescent↗

PubMed1993

[Transsubmucosal maxilloethmoid sinus surgery through inferior turbinate (swinging of nasolacrimal duct and inferior turbinate)].

We recently devised a new technique for endonasal surgery, which simplifies maxillary antrotomy and ethmoidectomy, and dilates the middle nasal meatus widely enough to allow easier postoperative observation. Surgery is initiated by an incision similar to the one used for submucosal resection of the inferior turbinate. The bony inferior turbinate is resected, and the nasolacrimal duct is freed from the bone. Subsequently, the maxillary and ethmoidal sinuses are excenterated, with swinging of the membranaceous inferior turbinate and the nasolacrimal duct. Postoperative observation confirmed satisfactory results.

Adolescent↗

PubMed2001

Contribution of heat transfer to turbine blades and vanes for high temperature industrial gas turbines. Part 2: Heat transfer on serpentine flow passage.

The improvement of the heat transfer coefficient of the 1st row blades in high temperature industrial gas turbines is one of the most important issues to ensure reliable performance of these components and to attain high thermal efficiency of the facility. This paper deals with the contribution of heat transfer to increase the turbine inlet temperature of such gas turbines in order to attain efficient and environmentally benign engines. Following the experiments described in Part 1, a set of trials was conducted to clarify the influence of the blade's rotating motion on the heat transfer coefficient for internal serpentine flow passages with turbulence promoters. Test results are shown and discussed in this second part of the contribution.

Journal Article↗

PubMed1981

[Studies on the performance of the dental air turbine handpieces. (Part 5) Rotational performance of various kinds of dental air turbine handpieces (N = N0--CvFv gamma) (author's transl)].

Making research on the rotational performance of the dental air turbine handpieces widely used for dental cutting instruments, we investigated with the relation between rotational speed and load on many kinds of dental handpieces used for clinical divisions and with the applications of the theoretical equations to have be shown in the previous report. And then we have the investigation on these properties. Dental handpieces to measured with these properties were classified the four types, standard types, torque type, miniature type and air bearing type. And we applied the experimental equations to these experimental values and determined the rotational coefficients, gamma and Cv. The rotational speed N and normal force Fv, which occurred the maximum work of air turbine handpieces, were calculated with our analysis and then these values of N and Fv were compared with the experimental results. These results, that is, experimental and calculated values have a good agreement and the development of the theoretical approach is useful for the estimation of the rotational performance. And we examined the possibility of rotational performance's estimation with the process of simple experiment on these air turbine handpieces.

Dental High-Speed Equipment↗

PubMed2001

Contribution of heat transfer to turbine blades and vanes for high temperature industrial gas turbines. Part 1: Film cooling.

This paper deals with the contribution of heat transfer to increase the turbine inlet temperature of industrial gas turbines in order to attain efficient and environmentally benign engines. High efficiency film cooling, in the form of shaped film cooling and full coverage film cooling, is one of the most important cooling technologies. Corresponding heat transfer tests to optimize the film cooling effectiveness are shown and discussed in this first part of the contribution.

Journal Article↗

PubMed1980

[Studies on the performance of the dental air turbine handpieces. (Part 3) Torque measurements of the air turbine handpieces (author's transl)].

Air turbine handpieces, electro-micro motors and electric engines are widely used as the dental cutting instruments for the clinical use. So, this paper examined the measurement of rotational torque of the high speed dental instruments used for cutting works. For the measurement of torque of the dental instrument, we have measured the pushing load of the test but as used for cutting tools. But, in this paper, we attempted the new trials which are the measuring the tangential force of test bur rotated with the high speed velocity. And then, the kinetic energy values of rotational bur are obtained with using the value of the test bur's rotational torque. Besides we examined the interrelations of the rotational torque and pushing as the results, and both measurement value show the good relations for air turbine handpieces.

Air↗

PubMed1998