Date of Completion

7-3-2014

Embargo Period

6-25-2019

Advisors

Ravindra Nanda, David Shafer

Field of Study

Dental Science

Degree

Master of Dental Science

Open Access

Open Access

Abstract

Objective: The objective of this prospective study was to quantify the maxillary incisor and first molar changes and further, evaluate the Class II correction with tipback mechanics.

Methods: Lateral cephalograms of 16 adolescents (7 males, 9 females) taken at T1 (pre-tipback), T2 (after tipback) and T3 (after molar root uprighting) were evaluated. Average age of study subjects was 12.63 + 1.1 years. Wilcoxon signed rank test was performed to test the significance at T1, T2 and T3. P-value of

Results: The maxillary first molar distalized by 1.53mm with 6.65 degrees of distal tipping and extrusion of 0.86mm with tipback mechanics. At T3, first molar crown came forward by 0.09mm, tipped mesially by 1.84 degrees and intruded by 0.12mm. At T2, the maxillary incisors labially flared by 0.4mm, the incisor root moved palatally by 1.19mm. At T3, the maxillary incisor root moved palatally by 1.5mm and 0.12mm of incisor flaring was present. Vertically, an incisor intruded by 0.97mm at T2 and 0.56mm of intrusion was lost at T3. Tipback mechanics with class II elastics corrected the Class II malocclusion in 10 subjects. However, 5 subjects had to use fixed functional appliance and 1 patient had upper bicuspid extractions for Class correction.

Conclusions: Tipback mechanics produced significant distalization of maxillary molars and second premolar to contra-lateral second premolar anchor units successfully prevented the intrusion and flaring of maxillary incisors with tipback mechanics. Tipback mechanics followed by using Class II elastics aided in the correction of Class II malocclusion in 62% of study subjects.

Major Advisor

Flavio Uribe

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