RESUMEN
The purpose of this study was to evaluate the bone thickness of the nasomaxillary and zygomaticomaxillary buttresses to identify the most favourable region for the installation of miniplates. Bilateral tomographic images of 103 individuals were evaluated, for a total of 206 nasomaxillary and zygomaticomaxillary buttresses. Measurements of bone thickness were performed in the parasagittal reconstructions along three vertical lines on the nasomaxillary buttress (21 measurement points) and four vertical lines on the zygomaticomaxillary buttress (28 measurement points). The vertical line measurements for each buttress were compared using the Kruskal-Wallis test. Spearman's correlation coefficient was used to determine the correlation between the thicknesses obtained and patient sex and side (right/left). The level of significance adopted was 5%. The nasomaxillary and zygomaticomaxillary buttresses presented statistical differences in thickness at their respective points (P=0.001). The analysis of the nasomaxillary buttress showed that the thicker bone for the installation of miniplates follows the long axis of the upper canine at a distance of 3mm from the root apex. For the zygomaticomaxillary buttress, thicker bone to install miniplates was found distal to the distobuccal root of the first molar, at a distance of 3.5mm from the limit of the infraorbital foramen.
Asunto(s)
Maxilar , Procedimientos de Cirugía Plástica , Tomografía Computarizada de Haz Cónico , Humanos , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Diente Molar , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: Enamel etching for brackets is usually done with phosphoric acid. Er:YAG lasers have been recently used for this purpose with conflicting results. The effects of lasers on tooth demineralization and the effects of different combinations of laser treatments and bonding agents were evaluated in this study. METHODS: The enamel contents of fluorine, calcium oxide and phosphorus pentoxide (P(2) O(5)) were analysed using acid etching, laser treatment or both. The tensile bond strength of metallic and ceramic brackets using Transbond XT and Fuji Ortho LC were also tested, using acid etching, laser treatment or a combination of both. RESULTS: All treatments reduced the contents of fluorine, P(2)O(5) and calcium oxide, and acid reduced P(2) O(5) levels more than laser. The bond strength with laser was weaker than with acid, and stronger when combining both. When using laser, the best adhesive was the Fuji Ortho LC. The combination of laser and acid produced the best results when using Transbond XT. CONCLUSIONS: The demineralization promoted by laser was lower than the one produced with acid. Laser treatment produced lower tensile stress strength than acid, but still enough to produce clinically efficient retention. The combination of laser and acid produced the best retention results.
Asunto(s)
Recubrimiento Dental Adhesivo , Grabado Dental/métodos , Soportes Ortodóncicos , Resinas Acrílicas , Silicatos de Aluminio , Análisis de Varianza , Compuestos de Calcio/análisis , Esmalte Dental/química , Esmalte Dental/efectos de los fármacos , Esmalte Dental/efectos de la radiación , Análisis del Estrés Dental , Flúor/análisis , Humanos , Láseres de Estado Sólido , Microscopía Electrónica de Rastreo , Óxidos/análisis , Ácidos Fosfóricos , Compuestos de Fósforo/análisis , Cementos de Resina , Espectrometría por Rayos X , Estadísticas no Paramétricas , Resistencia a la TracciónRESUMEN
The present paper introduces a new concept in the physiopathology and treatment of the called 'temporomandibular dysfunction'. This paper was divided into two parts, this first explaining its definition, aetiology and hypothesis of the idiopathic facial pain. The second part, will mention its treatment, prognosis and recommendations. Under this new view, this 'dysfunction' is part of the called Idiopathic Facial Pain. The idiopathic facial pain is didactically subdivided in (1) facial artromialgia, (2) atypical facial pain, (3) atypical odontalgia and (4) oral dysestesia. Occlusal factors are less important in its aetiology, and psychological and biochemical factors are more recognised. Correct diagnosis is essential, and a full history, including psychological and social aspects is very important. The present management is based on a working model developed in this department and in other world centres, and is revolutionising the clinical management of the patients with idiopathic facial pain.
Asunto(s)
Dolor Facial , Dolor Facial/clasificación , Dolor Facial/etiología , Humanos , Estrés Fisiológico/complicaciones , Estrés Psicológico/complicacionesRESUMEN
The present paper introduces a new concept in the physiopathology and treatment of the called "temporomandibular disfunction". This paper was divided into two parts, the first explained the definition, etiology and hypothesis of the idiopathic facial pain. In this second part, its treatment, prognosis and recommendations are explained. The treatment consists basically in counselling, and, in a second stage, the use of tricylic antidepressants or similar drugs is used. Occlusal devices are some times used, but have been of less value. Arthroscopy can be used in resistant patients, and surgery is usually not indicated. The present management is based on a working model developed in this department and in other world centres, and is revolutionising the clinical management of the patients with idiopathic facial pain.
Asunto(s)
Dolor Facial/terapia , Síndrome de la Disfunción de Articulación Temporomandibular/terapia , Dolor Facial/diagnóstico , Dolor Facial/etiología , Humanos , Pronóstico , Síndrome de la Disfunción de Articulación Temporomandibular/diagnóstico , Síndrome de la Disfunción de Articulación Temporomandibular/etiologíaRESUMEN
A controlled study was performed to evaluate the effects of different ultrasound (US) intensities on 5-day-old mouse calvaria bone in tissue culture. A special technique to apply the US was developed, and the following parameters were measured: collagen and noncollagenous protein (NCP) synthesis (bone formation), and temperature change. It was found that ultrasound at 0.1 W/cm2 (SATA), pulsed 1:4, 3 MHz, 5 min, significantly stimulates bone formation (i.e., the synthesis of collagen and NCP) (p < 0.001 and p < 0.01). However, pulsed ultrasound at higher doses (1.0-2.0 W/cm2 (SATA), pulsed 1:4, 3 MHz, 5 min) significantly inhibited the synthesis of both collagen and NCP (p < 0.05). The temperature measurements showed a maximum rise of 1.8 degrees C [at 2.0 W/cm2 (SATA)] and no detected rise at 0.1 W/cm2 (SATA), suggesting that the effects in this study were primarily nonthermal. These results may reflect the healing effect of US on fractures and osteoradionecrosis and reinforces the use of low intensity US regimens [0.1 W/cm2 (SATA)] in clinical practice.
Asunto(s)
Desarrollo Óseo , Terapia por Ultrasonido , Animales , Matriz Ósea/metabolismo , Proteínas Morfogenéticas Óseas/biosíntesis , Colágeno/biosíntesis , Técnicas de Cultivo , Ratones , TemperaturaRESUMEN
A study of the frontozygomatic region (FZ) to determine an anatomic basis for the use of miniplates in this area was done. Plaster models were obtained from 35 adult skulls and were sectioned at six defined points. Osseous thickness measurements were made perpendicularly to the bone surface. Measurements to determine the risk of penetrating the cranial cavity were also done. The results show that above the FZ suture 5-mm screws should be used. At the two points below the suture, 7-mm screws can be used. The risk of penetrating to the cranial cavity occurs 10 mm above the suture. The diploe thickness at the level of the anterior cranial fossa floor indicates the use of a 7-mm screw at a distance 13.5-18.5 mm from the suture and 5-mm screws above 18.5 mm.