Efecto de la prolongación de la máscara facial en el desarrollo de los caninos maxilares impactados: un estudio retrospectivo.

Objective: The aim of the present study was to evaluate if maxillary protraction with facemask increases the risk of maxillary canine impaction. Materials and method: The records of 76 skeletal Class III subjects with a cervical vertebral maturation stage between CS1 and CS3 and a displaced maxillary canine were retrospectively collected. Intraoral photographs, orthopantomography and lateral cephalograms were collected, and patients were divided into three groups depending on the type of treatment received – a Rapid Palatal Expander (RPE), a RPE in conjunction with a facemask (RPE-FM), or a Class III functional appliance (FA). The patient’s records were used to determine if the maxillary canines were correctly erupted after that phase of treatment. A binary logistic regression was used to evaluate the effect of treatment modality and skeletal maturation stage on the chance of maxillary canine impaction. Results: No effect of the three different treatment modalities and of the skeletal maturation stage on the risk of canine impaction was observed. Conclusions: The protraction facemask can be used in growing skeletal Class III subjects without increasing the risks of maxillary canine displacement.El objetivo del presente estudio fue evaluar si la protracción maxilar con mascarilla aumenta el riesgo de impactación canina maxilar. Materiales y método: se recogieron retrospectivamente los registros de 76 sujetos esqueléticos de Clase III con una etapa de maduración vertebral cervical entre CS1 y CS3 y un canino maxilar desplazado. Se recogieron fotografías intraorales, ortopantomografía y cefalogramas laterales, y los pacientes se dividieron en tres grupos según el tipo de tratamiento recibido: un expansor palatino rápido (RPE), un RPE junto con una máscara facial (RPE-FM) o un aparato funcional (FA) clase III. Los registros del paciente se usaron para determinar si los caninos maxilares entraron en erupción correctamente después de esa fase del tratamiento. Se utilizó una regresión logística binaria para evaluar el efecto de la modalidad de tratamiento y la etapa de maduración esquelética sobre la posibilidad de impactación canina maxilar. Resultados: no se observó ningún efecto de las tres modalidades de tratamiento diferentes y de la etapa de maduración esquelética sobre el riesgo de impactación canina. Conclusiones: la mascarilla de protracción se puede usar en sujetos esqueléticos clase III en crecimiento sin aumentar los riesgos de desplazamiento canino maxilar

Long-term effect on adenoid dimensions and craniocervical angulation after maxillary expansion with fixed or functional appliances

Maxillary expansion is a common orthodontic procedure that could have a positive effect also on airway patency. The aim of the present study was to evaluate the long-term effects of rapid maxillary expansion (RME) on nasopharyngeal area and cranio-cervic

Determinants of maxillary canine impaction : retrospective clinical and radiographic study

The aim of this study is to evaluate determinants of maxillary canine impaction taking into account both canine position related variables and the pattern of facial growth. A retrospective clinical and radiographic analysis was carried out on 109 patients aged between 9 and 10 years at the time of first evaluation. At baseline, SN-GoMe angle, the interincisal angle, the canine angle ? and the canine distance d were used to characterize canine location and vertical facial growth. At the end of a two years follow up period the eruption state of each canine of each patient was recorded and accordingly classified as erupted or impacted on a clinical and radiographic basis. Univariate and multivariate statistical analyses were performed, including correlation among the studied variables and principal components analysis; several machine learning methods were also used in order to built a predictive model. At the end of the two years follow up period after the first examination, 54 (24.77%) canines were classified as impacted. Except for Angle ? values, there were no statistically significant differences between impacted and erupted canines. The studied variables were not significantly correlated, except for the SN-GoMe Angle and the distance d in the impacted canine group and the angle ? and the distance d in erupted canines group. All variables, except for SN-GoMe Angle in erupted canines, have a partial communality with the first two principal components greater than 50%. Among the learning machine methods tested to classify data, the best performance was obtained by the random forest method, with an overall accuracy in predicting canine eruption of 88.3%. The studied determinants are easy to perform measurements on 2D routinely executed radiographic images; they seems independently related to canine impaction and have reliable accuracy in predicting maxillary canine eruption

Post-orthodontic position of lower incisors and gingival recession : a retrospective study

To evaluate if changes in lower incisor position following orthodontic treatment are correlated with development of gingival recessions. Pre- and post-treatment digital models and lateral cephalograms of 22 subjects were collected retrospectively. The clinical crown length, gingival scallop, and papilla height of the central lower incisor were measured along with the cephalometric incisor?s inclination, the distance from the mandibular plane, and the distance between the Infradentale and Menton points. Statistical correlations between gingival and cephalometric variables were studied. In addition, two groups were defined based on the post-treatment incisor inclination value (?normal? or ?proclined?) and compared. The incisor inclination was correlated with the change in gingival scallop and papilla height. Moreover, there was a statistically significant difference in clinical crown height and gingival scallop between the ?normal? group and the ?proclined? group. Changes in lower incisor position, especially an excessive proclination, after orthodontic treatment may play a role in the development of gingival recession