Twenty-year clinical experience with fixed functional appliances

ABSTRACT Introduction: Considering the large number of fixed functional appliances, choosing the best device for your patient is not an easy task. Objective: To describe the development of fixed functional appliances as well as our 20-year experience working with them. Methods: Fixed functional appliances are grouped into flexible, rigid and hybrid. They are different appliances, whose action is described here. Four clinical cases will be reported with a view to illustrating the different appliances. Conclusions: Rigid fixed functional appliances provide better skeletal results than flexible and hybrid ones. Flexible and hybrid appliances have similar effects to those produced by Class II elastics. They ultimately correct Class II with dentoalveolar changes. From a biomechanical standpoint, fixed functional appliances are more recommended to treat Class II in dolichofacial patients, in comparison to Class II elastics.

RESUMO Introdução: considerando-se o grande número de aparelhos propulsores mandibulares, não é uma tarefa fácil escolher o melhor deles para o seu paciente. Objetivo: descrever o desenvolvimento desses aparelhos e a experiência clínica de vinte anos dos autores na sua utilização. Métodos: os aparelhos funcionais fixos aqui apresentados foram classificados em flexíveis, rígidos e híbridos, e o modo de ação de cada um deles foi descrito e ilustrado por meio de quatro casos clínicos. Conclusões: os aparelhos propulsores rígidos fornecem mais resultados esqueléticos do que os flexíveis e os híbridos. Esses últimos têm efeito semelhante ao uso de elásticos com direção de Classe II e, basicamente, corrigem a má oclusão de Classe II com alterações dentoalveolares. Do ponto de vista biomecânico, os propulsores fixos estão mais indicados para tratar a Classe II em pacientes dolicofaciais do que os elásticos de Classe II.

Evaluation of the upper airway in obstructive sleep apnoea.

The evaluation of the upper airway (UA) includes the physical examination of pharyngeal structures and a number of imaging techniques that vary from the mostly used lateral cephalometry and computed tomography to more sophisticated methods such as tri-dimensional magnetic resonance image (MRI). Other complex techniques addressing UA collapsibility assessed by measurement of pharyngeal critical pressure and negative expiratory pressure however are not routinely performed. These methods provide information about anatomic abnormalities and the level of pharyngeal narrowing or collapse while the patient is awake or asleep. Data suggest that individual patients have different patterns of UA narrowing. So, the best method for evaluating obstruction during obstructive events remains controversial. In general, in clinical practice physical examination including a systematic evaluation of facial morphology, mouth, nasal cavity and the pharynx as well as simple imaging techniques such as nasopharyngoscopy and cephalometry have been more routinely utilized. Findings associated with obstructive sleep apnoea (OSA) are UA narrowing by the lateral pharyngeal walls and enlargements of tonsils, uvula and tongue. Additionally cephalometry identifies the most significant craniofacial characteristics associated with this disease. MRI studies demonstrated that lateral narrowing of UA in OSA is due to parapharyngeal muscle hypertrophy and/or enlargement of non adipose soft tissues. The upper airway evaluation has indubitably contributed to understand the pathophysiology and the diagnosis of OSA and snoring. Additionally, it also helps to identify the subjects with increased OSA risk as well as to select the more appropriate modality of treatment, especially for surgical procedures.