Ang, H.Dreyer, C.2010-10-012010-10-012010Australian Orthodontic Journal, 2010; 26(1):66-720587-3908http://hdl.handle.net/2440/60992<h4>Background</h4>Mandibular advancement splints (MAS) are a recognised and popular treatment option for obstructive sleep apnoea (OSA) due to their simplicity, tolerance and non-invasiveness.<h4>Objectives</h4>To investigate and compare the dental changes associated with the use of monoblock and duoblock appliances.<h4>Methods</h4>Fifty-two pretreatment and follow-up study models of patients from a public hospital and private dental clinic were assessed. Seventeen subjects used a soft elastomeric monoblock appliance (MB), 29 subjects used a hard acrylic duoblock (DB) and six subjects wore a monoblock followed by a duoblock appliance (MB-DB). Measurements of dental and arch changes were obtained and analysed on study models and standardised bitewing radiographs.<h4>Results</h4>A statistically significant reduction was observed in the maxillary intercanine distance in all splint categories, with DB users showing the greatest decrease (p < 0.05). The change in the mandibular intercanine distances differed according to splint categories (p < 0.05). MB and MB-DB patients demonstrated a decrease in this measurement variable, whereas an increase was seen in DB users. A statistically significant increase in the mandibular intermolar distance was also observed in all splint categories (p < 0.05), with DB users showing the greatest increase.<h4>Conclusions</h4>Both MB and DB appliance systems produced similar, but mild dental effects. No particular appliance can be recommended and the choice of appliance should be considered on a case-by-case basis.enCopyright status unknownDental ArchMandibleMaxillaToothCuspidHumansOpen BiteSleep Apnea, ObstructiveElastomersAcrylic ResinsDental MaterialsRadiography, BitewingMandibular AdvancementFollow-Up StudiesProspective StudiesCross-Sectional StudiesOrthodontic Appliance DesignOcclusal SplintsAdultAgedMiddle AgedFemaleMaleModels, DentalJournal article00201002570002787557000122-s2.0-7795591310733690Dreyer, C. [0000-0003-2053-5486]