An Active, Skeletally Anchored Transpalatal Appliance for Derotation, Distalization and Vertical Control of Maxillary First Molars. (September 2014)

• Record Type: Journal Article
• Authors: Hourfar, Jan; Ludwig, Björn; Kanavakis, Georgios
• Is Part Of: Journal of orthodontics. Volume 41(2014)Supplement 1
• Page Start: s24
• Page End: s32
• Publication Date: 2014-09
• Subjects: Class II correction -- molar derotation -- molar distalization -- skeletal anchorage -- vertical control; Orthodontics -- Periodicals; 617.643005
• DOI: 10.1179/1465313314Y.0000000102
• Languages: English
• ISSNs: 1465-3125

Abstract

Objective: The objective of this investigation was to evaluate treatment outcomes of the skeletally anchored 'Frog' appliance. Design: A single-centre, retrospective study was performed. Setting: Private orthodontic practice. Participants: Patients who had undergone comprehensive orthodontic treatment with the skeletally anchored 'Frog' appliance. Methods: 43 participants (20 males and 23 females) who had received treatment with the skeletally anchored 'Frog' appliance where included. In order to explore dentoalveolar and skeletal treatment outcomes, pre- (T1) and post- (T2) treatment measurements were performed on patients' plaster models and cephalometric images. Comparisons between T1 and T2 were made by means of a Student's t -test. All statistical analyses were conducted at the 0·05 level of statistical significance. Results: Study model analysis revealed a statistically significant derotation of maxillary molars (μΔT2−T1 = 9·5°, P <0·001) as well as an increase in transverse arch dimensions at the end of treatment (μΔT2–T1 = 2·2 mm, P <0·001). Cephalometric changes included bodily distalization of maxillary molars (μΔ(T2–T1) = −1·9 mm, P <0·001), as well as noticeable angular displacement (μΔT2–T1 = 4·1°, P = 0·004). No significant anchorage loss was observed, as displayed by the limited change in maxillary incisor position (μΔ(T1–T2) = 0·2 mm, P = 0·45). In addition, excellent vertical control of the maxillary molars was achieved, with no change in the mandibular plane (ML/NSL) angle (μΔT2–T1 = 0·3°, P = 0·38). Conclusions: The skeletal 'Frog' is effective in derotating and distalizing maxillary molars without anchorage loss and with excellent vertical control.