[Histoplasmosis of the oral cavity]. / L'histoplasmose buccale.

Histoplasmosis is an endemic mycosis. Histoplasma capsulatum, and duboisiï are the pathogenic agents in humans. The disease is reported as endemic in more than 30 countries. Three clinical forms are distinguished; acute, chronic and disseminated. Oral lesions may take on different clinical aspects which are often associated with disseminated histoplasmosis. Disseminated histoplasmosis is frequently diagnosed in immunocompromised hosts. High risk of mortality dictates rapid diagnosis and treatment.

[Mandibular ameloblastic fibro-odontoma]. / Fibro-odontome ameloblastique mandibulaire.

Ameloblastic fibro-odontoma is a rare and benign tumor. It usually affects young patients. This report describes the case of a ten year old child presenting an asymptomatic and slow-growing tumor located in the posterior region of the mandible. The course was normal and no recurrence was found after simple enucleation of the tumor.

External temperature during KTP-Nd:YAG laser irradiation in root canals: an in vitro study.

To avoid the damage of periodontal tissues during laser irradiation of the root canal, the conditions of lasering must be carefully controlled. The aim of this study was to determine the safety parameters of the irradiation conditions during the use of a KTP-Nd:YAG laser in root canals. Root canals of 60 freshly extracted teeth were prepared (step-back technique) and filled with a photosensitiser (Acid Red 52). Different irradiation conditions [output power (P), pulse width (PW), pulse repetition rate (PRR, Hz)] were used. The laser beam was delivered by means of the KTP-Nd:YAG fibre tip with a beam spot-size diameter of 200 microm. The temperature increases were measured on the external apical third of the root surface using a thermocouple. The results showed that the temperature rise was always below 7 degrees C at the following laser settings: (1) single irradiation, P < or = 4 W, PW < or = 2.55 ms and PRR < or = 20 Hz; (2) repetitive irradiation series, five pulses of 1 s each, four resting times of 1 s each, P < or = 2.25 W, PW < or = 2.55 ms and PRR < or = 20 Hz. The use of resting times was necessary so as to avoid thermal cumulative effects. In these in vitro irradiation conditions, the use of the KTP-Nd:YAG laser in endodontics may be considered harmless for periodontal tissues.

Safety parameters for pulp temperature during selective ablation of caries by KTP laser in vitro.

OBJECTIVE: To define the optimal parameters of KTP laser irradiation during a selective caries removal. MATERIALS AND METHODS: Twelve decayed human teeth, recently extracted were used. Their root canals were prepared for insertion of a thermocouple probe into the pulp chamber. The demineralized tissues were colored by Acid Red 52 before proceeding to different conditions of irradiation. RESULTS: Pulpal temperature increases (below 3 degrees C) were found under the following parameters with 15 sec of continuous lasing: 400 mWatts, 0.10-msec pulse width, PRR <50 Hz for efficient caries removal. A resting time average of 70 sec was necessary to allow pulp temperature to get back to its baseline. CONCLUSION: KTP laser can be used safely and without any pulp over-heating under certain irradiation conditions.

[Prevention of postoperative bleeding in patients taking oral anticoagulants. Effects of tranexamic acid]. / Prévention des saignements postopératoires chez des patients sous anticoagulants oraux. Effets de l'acide tranexamique.

INTRODUCTION: We present a prospective clinical study on use of tranexamic acid mouthwashes in patients taking oral anticoagulants and who have to undergo minor ambulatory oral surgery, without modifying their anticoagulant therapy. MATERIAL AND METHODS: Forty patients (18 men and 22 females) aged from 42 to 81 were studied from April 2000 to December 2002. All patients were under the same anticoagulant, vitamin K antagonist, (Sintrom) for different pathologies. The anticoagulant therapy was not modified neither before nor after surgery. More than 70 oral procedures were carried out under local anesthesia. The International Normalized Ratio of prothrombin time (INR) was<=4. Tranexamic acid 5% (Exacyl) mouthwashes were prescribed during and after surgery. RESULTS: All the patients were followed up during 2 weeks after surgery. There were no postoperative bleedings. DISCUSSION: Use of tranexamic acid mouthwashes under a specific protocol is an efficient, reliable and economic method in preventing postoperative bleeding in patients under oral anticoagulant therapy.

Adsorption of peroxidase on titanium surfaces: A pilot study.

The present study demonstrates the in vitro and in vivo adsorption of peroxidase onto titanium surfaces. Titanium foils (mean +/- SEM: 365 +/- 2 mm(2), n = 114) were incubated during 30 min with lactoperoxidase (4 mg in 5 mL 100 mM phosphate buffer pH 7). After 15 washings by H(2)O, titanium foils were incubated with o-phenylenediamine (6 mg/mL) and H(2)O(2) (7 mM) during 30 min. The reaction was then stopped by the addition of HCI 1M and the absorbance of the liquid phase was read on a spectrophotometer at 492 nm. In vitro adsorbed lactoperoxidase onto titanium surfaces was 0.70 +/- 0.05 ng/mm(2) (mean +/- SEM, n = 30). X-ray photoelectron spectroscopy confirmed the incorporation of protein nitrogen onto titanium surfaces: the nitrogen atomic percentage increased from 0.9 +/- 0.3 to 12.7 +/- 0.2% (n = 3) and from 3.7 +/- 0.1 to 14.4 +/- 0. 4% (n = 5) when titanium foils were incubated in the lactoperoxidase solution during 30 min and 24 h respectively. In vivo, oral peroxidases adsorbed on titanium healing abutments from 0.01 to 0.58 ng/mm(2) (n = 19) after 2 weeks in the oral environment.

[Expression of heat shock proteins in salivary gland tumors. Immunohistochemical study of HSP27, HSP70, HSP90, and HSP110: apropos of 50 cases]. / Expression des protéines de choc thermique dans les tumeurs des glandes salivaires.

Heat shock proteins (HSPs) are known to be increased in response to biological stress. Recently some authors described their presence in tumors. Our immunohistochemical investigations revealed the expression of HSP27, HSP70, HSP90 and HSP110 in most of benign tumors of salivary glands (33 cases). In the malignant tumors, the reaction was immunopositive for HSP70 and HSP90 in 13/17 cases; but HSP27 and HSP110 were only expressed in 5/17 cases. In conclusion HSPs were expressed less in malignant than in benign cells. These results suggest that the loss of some HSPs may be a possible sign of malignancy.

The soft tissue response to contaminated and cleaned titanium surfaces using CO2 laser, citric acid and hydrogen peroxide. An experimental study in the rat abdominal wall.

The soft tissue response to clinically retrieved and decontaminated cover screws was evaluated in a rat model. The cover screws were cleaned by using citric acid, sterile water, hydrogen peroxide and CO2 laser alone or with a combination of these. In addition, decontaminated but not cleaned and unused cover screws were used as negative and positive controls, respectively. After cleaning the cover screws were implanted in the abdominal wall of the rat for 6 weeks. The thickness of the fibrous capsule and the number of macrophages within the capsule were measured by means of light microscopical morphometry. As compared to the negative control, CO2 laser on dry surface, CO2 laser + hydrogen peroxide and the positive control had statistically significant thinner fibrous capsules. As compared to the positive, only laser alone resulted in a similar tissue response. It is concluded that CO2 laser used alone or in combination with hydrogen peroxide may be used clinically for sufficient decontamination of titanium surfaces.

Re-establishment of the atomic composition and the oxide structure of contaminated titanium surfaces by means of carbon dioxide laser and hydrogen peroxide: an in vitro study.

BACKGROUND: In clinical situations with peri-implant bone resorption, re-integration of the exposed implant surface is sometimes preferable, which requires a clean surface. Previous investigations have shown that cleaning of contaminated titanium surfaces using chemical and abrasive methods is difficult. PURPOSE: The aim of this investigation was to evaluate the efficacy of different combinations of chemical and physical methods (citric acid, hydrogen peroxide, and carbon dioxide [CO2] laser irradiation) for removal of contaminants and subsequent reconstruction of the surface oxide of intraorally contaminated titanium foils. MATERIALS AND METHODS: Commercially pure titanium foils (99.6%, 5 x 5 mm in size) were contaminated by placement on dentures in volunteering patients, simulating a peri-implantitis situation. The contaminated foils and clean control foils were treated by seven and six combinations of citric acid, hydrogen peroxide, and CO2 laser irradiation, respectively. The effect of the cleaning procedures was evaluated by x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). RESULTS: The initial elemental composition of the contaminated foils was 70% carbon (C), 20% oxygen (O), 10% nitrogen (N), and only traces of titanium (Ti) (< 1%). One treatment proved to be more effective than the others: irradiations by 5-second cycles of superpulsed CO2 laser at a power of 7 W, 10-millisecond pulse width, and with an 80-Hz frequency on a wet surface, followed by repeated application of supersaturated citric acid for 30 seconds, each time followed by rinsing with ultrapure water until all tissue remnants had been removed. Finally, hydrogen peroxide of 10-mM concentration was added to the implant surface and evaporated by CO2 laser at the same settings. This treatment protocol resulted in 10% Ti, 45% O, 41% C, and 2 to 3% N, a composition comparable to that of unused foils: 9% Ti, 40% O, 48% C, and traces of N and chlorine (CI). X-ray photoelectron spectroscopy profiles showed that the thickness of the surface oxide was restored and even augmented with this protocol for treatment of contaminated titanium. CONCLUSION: A combination of citric acid, hydrogen peroxide, and CO2 laser irradiation seems to be effective for cleaning and reestablishment of the atomic composition and oxide structure of contaminated titanium surfaces.

Temperature increases during surface decontamination of titanium implants using CO2 laser.

The purpose of the present in vitro investigation was to measure temperature changes at the implant surface when using pulsed CO2 laser in a simulated implant surface decontamination protocol. Six threaded titanium implants were placed in a fresh resected pig mandible. A 4 x 4 mm defect was created buccally to each implant in order to expose the implant head and approximately 5 threads. Temperature changes were monitored by two thermocouples placed near the dehiscence and at the apical part of the implant. Several setting combinations of the CO2 laser with regard to output power, pulse width, pulse repetition rate and irradiation time were tested on dry and wet (distilled water) surfaces. Only minor temperature increases were measured when lasing wet titanium surfaces, while the temperature at dry surfaces exceeded the proposed thresholds for bone damage at clinically relevant settings. It is concluded that the CO2 laser when used on a wet implant surface in a pulsed mode at 8 W/10 ms/20 hz during 5 s induces a temperature increase of less than 3 degrees C. This would minimize the risk of temperature induced tissue damage as a result of lasing implant surfaces.

An XPS and SEM evaluation of six chemical and physical techniques for cleaning of contaminated titanium implants.

The purpose of the present study was to analyse clinically failed and retrieved implants prior to and after cleaning by means of scanning electron microscopy (SEM) and X-ray induced photoelectron spectroscopy (XPS) as compared to unused controls. Six different chemical and physical techniques for cleaning of contaminated titanium implants were evaluated: 1) rinsing in absolute ethanol for 10 min, 2) cleaning in ultrasonic baths containing trichloroethylene (TRI) and absolute ethanol, 10 min in each solution, 3) abrasive cleaning for 30 s, 4) cleaning in supersaturated citric acid for 30 s, 5) cleaning with continuous CO2-laser in dry conditions at 5 W for 10 s, 6) cleaning with continuous CO2-laser in wet conditions (saline) at 5 W for 10 s. SEM of failed implants showed the presence of contaminants of varying sizes and XPS showed almost no titanium but high carbon signals. XPS of unused titanium implants showed lower levels of titanium as previously reported, probably due to contamination of carbon which increased with time in room air. Cleaning of used implants in citric acid followed by rinsing with deionized water for 5 min followed by cleaning in ultrasonic baths with TRI and absolute ethanol gave the best results with regard to macroscopical appearance and surface composition. However, as compared to the unused implants the results from an element composition point of view were still unsatisfactory. It is concluded that further development and testing of techniques for cleaning of organically contaminated titanium is needed.

[Temporomandibular joint prosthesis. A retrospective study from 1947]. / Les prothèses d'articulation temporo-mandibulaires. Une étude retrospective depuis 1947.

Degenerative troubles of the temporo-mandibular joint constitute a major pathology for the maxillo-facial surgeon. While articular replacements have long been developed and used by orthopedic surgeons, none of these seem to give satisfaction in the TMJ. After a short historical and physiological recall, a number of techniques are described, together with a short evaluation of their use. In all 597 cases are reported, whilst an attempt at classification is made in the different types of prostheses used, ie interpositional, endo-osseous, extra-cortical, and prostheses designed for extensive reconstruction.

[Titanium condylar abutment: the contribution of 3D computed tomography]. / Butées condyliennes en titane: apport du CT 3D.

Various techniques have been described in the treatment of recurrent TMJ dislocations amongst which, joint arresters form a prominent part. We describe a new type of bio-integrable joint stop, custom made with 3D-CT help, which alleviates the two main drawbacks of the technique: lack of retention through insufficient extension, and secondary mobilization of the stop. Two cases are reported, amounting to four stops with satisfactory two years follow-up.

[The frequency of various types of disk displacement and its relation to occlusion]. / Fréquence des différents types de déplacements discaux et rapports avec l'occlusion.

The aim of this study is to observe the frequency of the different types of disc displacements (d.d.) of the TMJ (ATM) and to evaluate if these types are related or not with malocclusions. One hundred patients and 13 asymtomatic volunteers underwent full clinic examination. sagittal MRI (mouth open and closed) and coronal MRI (mouth closed). The different types of disc displacements were noted and cumulated in frequency and in relation with several occlusal criteria. Unlike the general opinion stating that the antero-medial d.d. (d.d. a-m) are the most frequent amongst the internal derangements, the result of this study reveals that the antero-lateral d.d. (d.d. a-l) are more frequent amongst the patients (35.1%) and the asymptomatic volunteers in general and particularly in view of a malocclusion (exagerated anterior overlapping and posterior cross bite). The study gives rise to the question of the etiology of a antero-lateral d.d. and sets back the hypothesis of the lateral pterygoid muscle fundamental role in the disc displacements.

[Oromandibular dystonia and botulinum toxins]. / Dystonies oro-mandibulaires et toxines botuliques.

The authors describe the Meige's Syndrome also known as blepharospasm or mandibulo-oral dystonia. This Syndrome rather known by Neurologists and Ophthalmologists than by Stomatologists actually benefits by a specific treatment based on botulin toxins.

[Kinesitherapy in the field of maxillofacial surgery]. / La kinésithérapie dans le domaine de la chirurgie maxillo-faciale.

The aim of this article is to present the possibilities offered by physiotherapy in maxillo-facial surgery. Physiotherapy has different objectives: to restore normal function in all mandibular movements to improve tissue trophicity to oppose fibrosis pain treatment We show different reeducation techniques and their indications by the means of two clinical cases. The punctual analysis of the obtained results allows to show the repercussions of treatment modifications on the TMJ mobility recuperation.

[The use of a polyglycolic acid membrane in the reconstruction of the orbital floor and in loss of bone substance in the maxillofacial region]. / Utilisation d'une membrane d'acide polyglycolique dans les reconstructions de plancher orbitaire et dans les pertes de substances osseuses de la sphère maxillo-faciale.

The use of a new alloplastic biodegradable implant called BIOFIX made of polyglycolate is described. We used it to cover bone defects in maxillo-facial surgery, principally for orbital floor restoration and frontal sinus repair, with very good results. It is an excellent material of temporary support and guidance during the healing period and new bone formation. However, it will be necessary to wait for the results of a multicentric european study to confirm its superiority in maxillofacial surgery.