Eduardo Espinar-Escalona

Obstructive sleep apnea syndrome (OSAS). Review of the literature.

Obstructive sleep apnea and hypopnea syndrome is characterized by repeated airway collapse during sleep. The li-terature describes multiple causes of the disease. The main cause is a reduction of the expansion forces of the pharyngeal dilator muscles, as in situations of genioglossal muscle dysfunction, and discoordination between the inspiratory activity of the muscle and respiratory effort, which play an important role in progression of the disease. Other described causes are soft tissue disorders, such as macroglossia or tonsillar hypertrophy, and skeletal structural alterations such as micrognathia and retrognathia. The syndrome is also more frequent in obese people, where the accumulation of fat in the neck region produces narrowing of the pharyngeal airway, thereby diminishing the passage of air. This review focuses on the pathogenesis, epidemiology, main features and diagnosis of the disease, and on its main forms of treatment. Key words:Sleep apnea, obstructive sleep apnea, sleep apnea syndrome, obstructive sleep apnea syndrome.

External apical root resorption in maxillary root-filled incisors after orthodontic treatment: A split-mouth design study

Introduction: The purpose of this study was to compare, in a split mouth design, the external apical root resorption (EARR) associated with orthodontic treatment in root-filled maxillary incisors and their contralateral teeth with vital pulps. Methodology: The study sample consisted of 38 patients (14 males and 24 females), who had one root-filled incisor before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the root resortion and the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the endodontically treated incisor and that in its contralateral incisor with a vital pulp. The student’s t-test, chi-square test and logistic regression analysis were used to determine statistical significance. Results: There was no statistically significant difference (p > 0.05) between EARR in vital teeth (1.1 ± 1.0 mm) and endodontically treated incisors (1.1 ± 0.8 mm). Twenty-six patients (68.4%) showed greater resorption of the endodontically treated incisor than its homolog vital tooth (p > 0.05). The mean and standard deviation of PPR were 1.0 ± 0.2. Multivariate logistic regression suggested that PRR does not correlate with any of the variables analyzed. Conclusions: There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root-filled incisors and their contralateral teeth with vital pulps. Key words:Endodontics, orthodontics, root canal treatment, root resorption.

Lower incisor position in different malocclusions and facial patterns

Introduction: The position of lower incisor has been of considerable concern when planning an orthodontic treatment, having been recognized as one of diagnostic keys, Very important in the development of malocclusion and facial pattern. Objectives: In this study we claim to determine the importance of the position and inclination of lower incisor in the different malocclusions and facial patterns, and to base which of the cephalometric measurement parameters are the mostreliable. Material and Methods: Ninety lateral radiographies were taken, and they were classified by skeletal malocclusion and facial pattern.These teleradiographies have been performed cephalometric analysis, which includelower incisor position belong the following analysis: Ricketts, Riolo, Tweed, McHorris, Jarabak-MSE and Holdaway. Study Design: Cross-sectional study where we perform statistical analysis Anova test, Pearson correlations and Bonferroni analysis. Results: The analyzed measurements present a statistically significant differentiation in lower incisor inclination respect to the anterior cranial base, McHorris angle, angulation of lower incisor respect to occlusal plane and mandibular plane. Conclusions: There are statistically significant differentiation in lower incisor position and inclination respect the malocclusion and individual facial pattern. Key words:Lower incisor, cephalometric analysis, facial patterns, facial biotype, skeletal malocclusions.

Effect of temperature on the orthodontic clinical applications of NiTi closed-coil springs.

NiTi spring coils were used to obtain large deformation under a constant force. The device consists on a NiTi coil spring, superelastic at body temperature, in order to have a stress plateau during the austenitic retransformation during the unloading. The temperature variations induced changes in the spring force. Objectives: The aim of this study is to investigate the effect of the temperature variations in the spring forces and corrosion behaviour simulating the ingestion hot/cold drinks and food. Study Design: The springs were subjected to a tensile force using universal testing machine MTS-Adamel (100 N load cell). All tests were performed in artificial saliva maintained at different temperatures. The corrosion tests were performed according to the ISO-standard 10993-15:2000. Results: The increase in temperature of 18oC induced an increase in the spring force of 30%. However, when the temperature returns to 37oC the distraction force recovers near the initial level. After cooling down the spring to 15oC, the force decreased by 46%. This investigation show as the temperature increase, the corrosion potential shifts towards negative values and the corrosion density is rising. Conclusions: The changes of the temperatures do not modify the superelastic behaviour of the NiTi closed-coil springs. The corrosion potential of NiTi in artificial saliva is decreasing by the rise of the temperatures. Key words:Superelasticity, NiTi, springs, orthodontic, coils, recovery, temperature.

True vertical validation in facial orthognathic surgery planning

Objectives: To validate the effectiveness of the original standards of True Vertical (TV) Subnasal Line in orthognatic surgery planning. The present study evaluates the changes occurring in patients with skeletal Class II alterations programmed for orthognathic surgery with a view to improving their facial profile. Study design: We showed a series of black profiles (composed by a first control group of subjects with normal occlusion, and another two additional groups comprised patients before –Group 2- and after orthognatic surgical correction of Class II malocclusion -Group 3-) for three groups of observers (orthodontists, surgeons and laypeople). The facial images became black silhouettes in order to determine a series of parameters (including aesthetic assessment) by means of the observers. Their observation were assessed using a 5-point Likert scale. Results: The sample was composed of 52 profile’s subjects who were tested for a total of 72 observers. Aesthetic assessment yielded mean scores of 2.57, 1.67 and 2.46 for groups 1, 2 and 3, respectively. There was a statistically significant difference (p<0.001) between group 1 versus group 2. There were no significant differences in terms of observer assessment of aesthetics, with the exception of a wider perception range among the orthodontists. Regarding the studied profile measures, significant differences were recorded for point B’ and Pg’ (p<0.02) between groups 2 and 3 (i.e., pre- versus post-surgery). Conclusions: The results of our study suggest the subnasale vertical and sagittal measures of the lower third of the face are decisive in facial aesthetics, and therefore also for the planning of orthognathic surgery. Consequently, these aesthetic parameters can be used as an objective tool for the planning of orthodontic treatment. Key words:Facial profile, Class II, orthognathic surgery, cephalometric analysis, facial soft tissue, subnasale vertical.

The segmented arch approach: A method for orthodontic treatment of a severe Class III open-bite malocclusion

An open bite is a common malocclusion, and it is generally associated with several linked etiologic factors. When establishing the treatment plan, it is essential to consider every aspect of the various etiologic causes and their evolution; this will help to correct it. This article reports the case of a girl aged 10.7 years with a skeletal Class III malocclusion and an open bite. The treatment mechanics were based on compensatory dental changes performed to close the bite and correct the skeletal Class III malocclusion. The patient had a deep maxillary deficiency, and the lower facial third was severely enlarged. In this article, we aimed to describe a simple mechanical approach that will close the bite through changes in the occlusal plane (segmentation of arches). It is an extremely simple method that is easily tolerated by the patient. It not only closes the bite effectively but also helps to correct the unilateral or bilateral lack of occlusal interdigitation between the dental arches. A Class III patient with an anterior open bite is shown in this article to illustrate the effectiveness of these treatment mechanics.

Arcos segmentados. Mecánica de cierre en las mordidas abiertas. Aportaciones clínicas

Resumen La mordida abierta es una entidad muy frecuente asociada a una etiologia multifactorial. De ahi que en el tratamiento haya que considerar todo el recorrido en su aparicion, intentando llegar hasta los procesos etiologicos que permitan la correccion de la misma. En este trabajo, presentamos una mecanica sencilla que nos permite, mediante modificaciones en el plano oclusal (segmentacion de los arcos), conseguir el cierre de la misma; este metodo resulta de extrema sencillez y facilmente tolerable por el paciente. No solo aporta un sistema eficaz en el cierre, sino una ayuda en la mecanica habitual para corregir situaciones de falta de oclusion parcial, uni o bilateral de las arcadas dentarias.