Integrity, Reliability and Failure of Mechanical Systems IRF’2013 1 PAPER REF: 4043 Please leave these first three lines blank for the Editors Please leave these first three lines blank for the Editors Please leave these first three lines blank for the Editors RETROSPECTIVE EVALUATION OF THERAPEUTIC OUTCOMES OF FUNCTIONAL APPLIANCES COMBINED WITH HEADGEAR Please leave this line blank Maria João Ponces 1(*) , José Pedro Tavares 2 , Eugénio Martins 3 , Paula Vaz 4 , Afonso Pinhão Ferreira 5 1, 3, 5 Department of Orthodontics, Faculty of Dental Medicine (FMDUP), University of Porto, Porto, Portugal. 2 Department of Civil Engineering, Transport Infrastructures Division, University of Porto, Portugal. 4 Department of Medical and Orofacial Genetics, Faculty of Dental Medicine, University of Porto, Porto, Portugal. (*) Email: mponces@fmd.up.pt. Please leave these two lines blank Please leave these two lines blank ABSTRACT Functional appliances were developed to correct mainly Class II malocclusions in growing children but the influence of those appliances on craniofacial growth is still controversial, even when used in combinations with headgear. The aim of this retrospective study was to investigate skeletal, dental and tegumental cephalometric modifications induced by Teuscher activator. This study was accomplished in a mixed dentition sample of Class II malocclusions subjects with mandibular retrognatism. This appliance was effective in treating growing patients with mandibular deficiency: the correction of Class II malocclusions was an arrangement of skeletal and dentoalveolar changes and leaded to the improvement of soft tissue facial profile. Keywords: activator, headgear, orthopaedics, Class II, cephalometry, treatment outcome. INTRODUCTION Teuscher activator is a variety of functional appliance combined with extraoral forces. The action of these “orthopedic” appliances is based on producing muscle stretching by holding the mandible anteriorly positioned, in order to stimulate condylar growth. The association of headgear intends to restraint sagittal and vertical maxillary growth. (Pfeiffer and Grobety, 1982) The correction of Class II division 1 malocclusion using this combined device produces a restriction of anterior maxillary growth, an inhibition of anterior and vertical displacement of maxillary teeth, condylar remodelling and a muscle pattern improvement. (Janson et al., 2004) Regarding the control of posterior vertical dimension, data reported in literature show a variability of responses. (Williams and Melsen, 1982; Dermaut et al., 1992; Basciftci et al., 2003; Marsan, 2007) The aim of this clinical trial was to investigate the outcomes of orthodontic treatment with Teuscher appliance, an activator in combination with a high-pull headgear in patients with Class II malocclusion with mandibular retrognatism. An evaluation of skeletal, dentoalveolar and soft tissue profile impact was performed. The sample was selected from a single orthodontic office and comprised 30 patients in late mixed dentition. They were divided in two groups: group 1 comprised 20 individuals, 10 females and 8 males treated with Teuscher activator and, for comparison purposes, the group 2, a control group of 12 untreated subjects. Treatment progress was documented with cephalograms taken before (T0) and after (T1) the functional treatment. In the control group radiographs were obtained at the start (T0) and after a period of observation (T1). Statistical