Gómez OJF, Ballesteros LM, Flores LA

Language: Spanish
References: 13
Page: 15-20
PDF size: 262.11 Kb.

ABSTRACT

Tipping, mesiodistal root inclination, torque and in-out movements; they are information prescribed in the bracket. They locate the tooth in the three planes of space; it is thought that by filling the slot, expression of the prescription is obtained. Prescription provides specific measurements of tipping to distribute forces adequately on the long axis of the tooth thus resulting in treatment stability and health of the stomatognathic system. When these conditions are not obtained, trauma might develop (widening of the periodontal space, root resorption, bone defects). Objective: To compare tipping expression before and during treatment as well as the trans-treatment tipping against the one established by MBT and Roth prescriptions. Methods: Pre and trans-treatment tipping was evaluated in panoramic radiographs (n = 60) from the angle formed by a baseline (infraorbital axis) and the long axis of the tooth in the upper arch, premolar to premolar. The comparison of the pre and trans-treatment tipping was performed per tooth and per group (central, lateral, canines, premolars). Student’s T test and a one-sample T test were used to compare the values obtained by group against the values of each prescription. Results: Trans-treatment tipping was affected in a negative way in most of the teeth; except in the canines, which are affected in a positive way (p ‹ 0.05, in OD 15, 23, 24 and 25). The posterior left segment was the most affected in a negative way, with differences between 4-6^o. The incisors maintained their pre-treatment tipping. With regard to the comparison of trans-treatment tipping for each prescription, it was observed that in no case the set value was obtained, with differences of 4-6^o for central incisors and premolars and 8-11^o for canines and lateral incisors (p ‹ 0.05 in all groups with both techniques). Conclusions: Trans-treatment tipping is affected in a negative way in the posterior segment. The anterior sector is more stable, while the canines are favored with regard to the increase of distal tipping. In spite of the premise that pre-adjusted appliances optimize orthodontic treatment, human error or the clinician’s ability remains a relevant factor for success.

REFERENCES

1. McLaughlin RP, Bennett JC. Bracket placement with preadjusted appliance. J Clin Orthod. 1995; 29: 302-311.

2. Angle EH. The latest and best in orthodontic mechanism. Dental Cosmos. 1928; 70: 1143-1158.

3. Andrews LF. The straight-wire appliance. British Journal of Orthodontics. 1979; 6: 125-143.

4. Eliades T, Gioka C, Papaconstantinou S, Bradley G. Premolar bracket position revised: proximal and occlusal contacts assessment. World J Orthod. 2005; 6: 149-155.

5. Fukuyo K, Nishi Y, Nojima K, Yamaguchi H. A comparative study of three methods of bracket placement. Orthodontic Waves. 2004; 63: 63-70.

6. Moesi B, Dyler F, Benson P. Roth versus MBT: does bracket prescription have an effect on the subjective outcome of pre-adjusted edgewise treatment? Eur J Orthod. 2013; 35: 236-243.

7. Milne J, Andreasen GF, Jakobsen JR. Bond strength comparison. A simplified indirect thecnique versus direct placement of brackets. Am J Orthod Dentofac Orthop. 1989; 96: 8-15.

8. Armstrong D, Shen G, Petocz P, Darendelinder A. A comparison of accuracy in bracket positioning between two techniques-localizing the centre of the clinical crown and measuring the distance from the incisal edge. Eur J Orthod. 2007; 29: 430-436.

9. Joiner M. In-house precision bracket placement with the indirect bonding technique. Am J Orthod Dentofacial Orthop. 2010; 137: 850-854.

10. Park DE, Kim HK, Lim YS, Nakatsuka M, Kwon HB, Han SH et al. Different mandibular first molar shapes according to groove and cusp configuration in relation to suggested bracket position. Eur J Orthod. 2013; 35 (6): 730-736.

11. Israel M, Kusnoto B, Evans CA, Begole E. A comparison of traditional and computer- aided bracket placement methods. Angle Orthod. 2011; 81: 828-835.

12. Carlson SK, Johnson E. Bracket positioning and resets: Five steps to align crowns and root consistently. Am J Orthod Dentofacial Orthop. 2001; 119: 76-80.

13. Suárez C, Vilar T. The effect of constant height bracket placement on marginal ridge levelling using digitized models. Eur J Orthod. 2010; 32: 100-105.