Retrospective investigation of the 3D effects of the Carriere Motion 3D appliance using model and cephalometric superimposition

Abstract

Objectives: Carriere Motion 3D™ appliance (CMA) represents a method for molar distalization and correction of class II malocclusion. The aim was to investigate the 3D effects of the CMA by superimposing digital models and cephalometric X-rays.

Materials and methods: We retrospectively examined 16 patients treated with CMA in combination with class II elastics. We compared digitized models and cephalometric X-rays of records taken before therapy and after the removal of CMA. The records were superimposed to assess the skeletal and dentoalveolar changes. The results of the cephalometric X-ray analysis were compared to an untreated age- and gender-matched sample.

Results: Class II occlusion was corrected after 11.85 ± 4.70 months by 3.45 ± 2.33 mm. The average distalization of the upper first molars was 0.96 ± 0.80 mm. The analysis of the cephalometric X-rays confirmed a distalization of the upper first molars with distal tipping and revealed a mesialization of the lower first molars of 1.91 ± 1.72 mm. Importantly, CMA resulted in a mild correction of the skeletal class II relationship (ANB: - 0.71 ± 0.77°; Wits: - 1.99 ± 1.74 mm) and a protrusion of the lower incisors (2.94 ± 2.52°). Compared to the untreated control group, there was significant distalization of the upper first molars and canines with mesialization and extrusion of the lower first molars.

Conclusion and clinical relevance: CMA is an efficient method for treating class II malocclusions. However, the class II correction is only partially caused by a distalization of the upper molars.

Keywords: 3D evaluation; Carriere Motion 3D appliance; Carriere distalizer; Cephalometric superimposition; Class II malocclusion; Model superimposition.

Fig. 1

Visualization of CMA on a model (a) and before insertion (b, c). Clinical use of CMA: initial situation (d, e) and situation after CMA treatment (f, g)

Fig. 2

Models digitized with orthoX scan (a before and b after CMA)

Fig. 3

Superimposition of maxillar models (initial and intermediate models) using the palatal folds

Fig. 4

a Cephalometric landmarks. b Cephalometric analysis according to Kircelli 2006. Linear measurements: (1) U6 MB cusp - PTV, (2) U6 M cont - PTV, (3) U3 cusp - PTV, (4) U3 M cont - PTV, (5) L6 MB cusp - PTV, and (6) L6 M cont - PTV. Angular measurements: (7) U6 – FH and (8) U3 – FH. Additional measurements: (9) L6 MB cusp – GoMe and (10) L3 cusp - GoMe

Fig. 5

3D effects with distances (including standard deviation) of the CMA using the model superimposition (gray small arrows: occlusal correction; blue horizontal arrows: pure distalization; blue vertical arrow: extrusion)