Soft tissue, skeletal and dentoalveolar changes following conventional anchorage molar distalization therapy in class II Non-growing subjects: a multicentric retrospective study

Abstract

ObjectivesThe purpose of this retrospective prolective study is to evaluate soft tissue, dentoalveolar and skeletal vertical changes following conventional anchorage molar distalization therapy in adult patients. Materials and methodsForty-six patients (34 females, mean age 25 years 6 months; and 12 males, mean age 28 years 4 months) were recruited from 4 specialists Board Certified. All subjects underwent molar distalization therapy according different distalization mechanics. Cephalometric headfilms were available for all subjects before (T0) and at the end of comprehensive treatment (T1). The initial and final measurements and treatment changes were compared by means of a paired t-test or a paired Wilcoxon test. ResultsMean total treatment time was 3 years 3 months ± 8 months. Maxillary first and second molars distalized 2.16±0.84mm and 2.01±0.69mm respectively, but also maintained a slight distal tipping of 1.45° (min 2.22°, max -6.45°) and 3.35° (min 0.47°, max -15.48°) at the end of treatment. Distal movement of maxillary first molar contributed 57.6% to molar correction, and 42.4% was due to a mesial movement of mandibular first molar (1.59±0.46mm). Dentoalveolar changes contributed to overjet correction; maxillary incisors retroclined 5.78°±3.17°, lower incisors proclined 7.49°±4.52° and occlusal plane rotated down and backward 2.32°±2.10°. A significant clockwise rotation of the mandible (1.97°±1.32°) and a significant increase in lower facial height (3.35±1.48) mm were observed. Upper lip slightly retruded (-1.76±1.70mm) and lower lip protruded (0.96±0.99mm) but these changes had a negligible impact on clinical appearance. ConclusionsAlthough maxillary molar distalization therapy can be performed in adult patients, significant proclination of the lower incisors, clockwise rotation of the occlusal plane and increase in vertical facial dimension should be expected. Nevertheless, in absence of maxillary third molars and in presence of mandibular third molars this procedure could be recommended.