The Hedgehog signalling pathway plays a fundamental role in orchestrating normal craniofacial development in vertebrates. In particular, Sonic hedgehog (Shh) is produced in three key domains during the early formation of the head; neuroectoderm of the ventral forebrain, facial ectoderm and the pharyngeal endoderm; with signal transduction evident in both ectodermal and mesenchymal tissue compartments. Shh signalling from the prechordal plate and ventral midline of the diencephalon is required for appropriate division of the eyefield and forebrain, with mutation in a number of pathway components associated with Holoprosencephaly, a clinically heterogeneous developmental defect characterized by a failure of the early forebrain vesicle to divide into distinct halves. In addition, signalling from the pharyngeal endoderm and facial ectoderm plays an essential role during development of the face, influencing cranial neural crest cells that migrate into the early facial processes. In recent years, the complexity of Shh signalling has been highlighted by the identification of multiple novel proteins that are involved in regulating both the release and reception of this protein. Here, we review the contributions of Shh signalling during early craniofacial development, focusing on Hedgehog receptor function and describing the consequences of disruption for inherited anomalies of this region in both mouse models and human populations.
Monoblock was the better MAD to improve OSA severity. No difference could be found in changes of subjective OSA indicators. Significant but similar cephalometric changes were observed, indicating both MADs alter the position of the surrounding musculature and improve upper airway patency. Therefore, the different design features of the MADs suggest an impact on some OSA indicators.
Objectives: To determine patient and parent/guardian motivation, expectation and understanding of orthodontic treatment. Design: A self-completion questionnaire survey of new patients referred for orthodontic assessment. Setting: Specialist practices in Surrey and Berkshire (United Kingdom). Participants: A total of 500 questionnaires were issued (250 were issued to patients and 250 to parents). Methods: The survey was based on a self-completed questionnaire which was issued at the assessment appointment. Both questionnaires were adapted and extended from originally validated questionnaires previously used in a hospital setting. Patients and parents were asked to complete separate anonymous questionnaires. The patient questionnaire consisted of 24 closed-ended questions divided into three domains: motivation; understanding; and expectation of orthodontic treatment. The parent questionnaire consisted of 13 questions covering the same three domains Results: The response rate for the patient and parent questionnaires was 95% and 91%, respectively. Forty-seven percent of the patients were aged 11-13 years. In 77% of cases, the referral was initiated by their dentist. Only 3% of patients thought there was nothing wrong with their teeth. There was a poor understanding of what a retainer is and for how long patients are expected to use it. Conclusions: Referral for orthodontic treatment was initiated by the patients' general dental practitioner in the majority of the cases. The anticipation of improved dental appearance was a prime motivating factor. Participants had realistic expectations and there was a good acceptance of appliances and dental extractions for orthodontic treatment. Nevertheless, both patients and parents/guardians were less well informed on the nature and duration of orthodontic retention. Keywords motivation, expectations, orthodontic treatment, patients, parents, quality of life and orthodontics, health services and quality of life aspects, psychological aspects of orthodontics Date
At first glance the humble mouse might seem an odd choice as a model for studying complex human craniofacial disorders. However, similarities in embryonic development and genome organisation, and our ability to manipulate its genes have made this species the model of choice for investigating human development. Here we describe some examples from our own laboratory of mouse models that are providing insight into the mechanisms underlying two human craniofacial syndromes.
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