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<p>41 VOLUME L NUMBER 1 © 2016 JCO, Inc. Dr. Locatelli Dr. Contardo Dr. Perinetti Dr. Scalia Dr. Scalia is an orthodontic postgraduate student, Dr. Perinetti is a Research Fellow, Dr. Locatelli is a Clinical Instructor, and Dr. Contardo is an Assistant Professor, Department of Medical, Surgical and Health Sciences, School of Dentistry, University of Trieste, Piazza Ospitale 1, Trieste, Friuli-Venezia Giulia 34129, Italy. Dr. Locatelli is also in the private practice of orthodontics in Portogruaro, Italy. E-mail Dr. Scalia at dott.alessandro. scalia@gmail.com. ALESSANDRO SCALIA, DDS GIUSEPPE PERINETTI, DDS, MS, PhD RANIERI LOCATELLI, MD, MS LUCA CONTARDO, DDS, MS Various extraoral and intraoral fixed appliances have been used in Class II cases to distalize the upper molars without extrac- tions.1,2 The main disadvantage of these appliances is anchorage loss, which may cause mesial tipping of the anterior teeth unless skele- tal anchorage is added.3,4 There is also some controversy regarding the effectiveness of distalizing ap- pliances once the second and third molars have erupted.5,6 This case report describes the use of heat-activated nickel titanium wires for molar distaliza- tion, referred to as the Loca-Sys- tem, to correct a Class II maloc- clusion with skeletal asymmetry.7 Diagnosis and Treatment Planning A 17-year-old female pre- sented with the chief complaints of overlapping anterior teeth and crowding. She displayed a severe mandibular skeletal asymmetry; a Class II, division 1 malocclu- sion; maxillary crowding; exces- sive overjet and overbite; and a mandibular midline shift of 2mm to the left (Fig. 1). Cephalometric analysis indicated retrognathia of the maxilla and mandible, flaring of the upper incisors, a normal inclination of the lower incisors, and a normal vertical facial pat- tern (Table 1). CASE REPORT Correction of Bilateral Class II Malocclusion Using Heat-Activated Nickel Titanium Wires ©2016 JCO, Inc. May not be distributed without permission. www.jco-online.com 42 JCO/JANUARY 2016 Correction of Bilateral Class II Malocclusion Fig. 1 17-year-old female patient with mandibular skeletal asymmetry; Class II, division 1 malocclusion; deep bite; and excessive overjet before treatment. 43 VOLUME L NUMBER 1 Scalia, Perinetti, Locatelli, and Contardo the upper third molars and distal- ization of the upper first molars with heat-activated nickel titani- um wires to achieve a dental Class I relationship, alleviate the crowding, and normalize the overjet and overbite.7 Since the patient’s com- plaints were only the crowding and overlapping of her anterior teeth, and because she did not want to have the first premolars extracted, she chose the third treatment option. Treatment Progress The biomechanics used in this treatment involve an .018" × .025" Neo-Sentalloy* superelas- tic nickel titanium archwire de- flected between the first premo- lar and first molar by the length of the molar tube, about 6mm (Fig. 2). As the wire straightens, it applies a force to both sides of the arch. If the upper second mo- Three treatment options were proposed. The first was a combined surgical-orthodontic approach involving extraction of the upper first premolars, with the aim of correcting the mandibular asymmetry, maxillomandibular retrusion, and crowding. The sec- ond option also proposed extrac- tion of the upper first premolars, followed by orthodontic correc- tion of the maxillary crowding, overjet, and overbite. The third option consisted of extraction of TABLE 1 CEPHALOMETRIC ANALYSIS Norm Pretreatment Post-Treatment SNA 82.0° 77.2° 77.4° SN-Pg 80.0° 73.6° 76.2° AN-Pg 2.0° 3.6° 1.2° Maxilla-Cranial base 8.0° 8.7° 10.5° Mandible-Cranial base 33.0° 35.4° 36.3° Maxillomandibular angle 25.0° 26.7° 25.9° U1-Maxillary plane 110.0° 116.0° 102.0° L1-Mandibular plane 94.0° 96.0° 99.0° Compensation of L1 2.0mm −0.7mm 1.2mm Overbite 3.5mm 5.6mm 3.5mm Overjet 2.0mm 7.5mm 1.1mm U1-L1 132.0° 124.4° 135.8° Fig. 2 Biomechanics: .018" × .025" superelastic nickel ti- tanium archwire deflected between first premolar and first molar by length of molar tube (about 6mm); Class II elastics worn from upper first premolar to lower first molar to prevent protrusion of maxillary anterior teeth; lip bumper used to control mesialization of lower arch. *Registered trademark of Dentsply GAC, Islandia, NY; www.dentsply.com. 44 JCO/JANUARY 2016 Correction of Bilateral Class II Malocclusion lars are fully erupted, a 200g archwire is advised; if not, a 100g archwire can be used. Class II elastics applying 180g of force are attached from upper first pre- molar to lower first molar to pre- vent protrusion of the maxillary anterior teeth; a lip bumper is used to control mesialization of the lower arch.7 Full-arch Bidimensional fixed appliances were bonded, us- ing .018" × .025" brackets for the incisors and .022" × .028" brack- ets for the canines and posterior teeth. Initial leveling and align- ment were carried out on .014" and .016" × .016" nickel titanium archwires. In the meantime, the upper third molars were extract- ed. After three months of treat- ment, a 200g, .018" × .025" Neo- Sent alloy heat-activated nickel titanium wire was inserted in the upper arch to finalize leveling, and an .018" × .022" stainless steel archwire with lacebacks was applied in the lower arch (Fig. 3). To distalize the upper mo- lars, crimpable stops were added distal to the first premolar brackets and to the upper first-molar tubes. A superelastic nickel titanium archwire was then inserted, with the stops mesial to the first-molar tubes, creating a curve and leaving the upper second premolars disen- gaged (Fig. 4). Kobaya shi liga- tures were used on the upper first premolars for attachment of 180g Fig. 3 After three months of treatment, .018" × .025" heat-activated nickel titanium Neo-Sentalloy* wire (200g) inserted in upper arch to finalize leveling; .018" × .022" stainless steel wire with lacebacks applied in lower arch. Fig. 4 After 10 months of treatment, superelastic nickel titanium arch- wire applied to distalize upper molars, Kobayashi ligatures placed on upper first premolars for attachment of Class II elastics, and lip bum- per inserted in lower first-molar tubes. *Registered trademark of Dentsply GAC, Islandia, NY; www.dentsply.com. 45 VOLUME L NUMBER 1 Scalia, Perinetti, Locatelli, and Contardo mesial to the upper first molars. An open-coil spring was initially placed between the premolars. Four weeks later, once the second premolars were distalized, the spring was moved between the first premolars and canines. Class II elastics were continued for anchorage. Realignment occurred in nine weeks. At that point, an .018" × .022" stainless steel archwire was inserted in the upper arch, and the canines and upper inci- sors were retracted with elastic chain, again using Class II elastics for anchorage. Distalization of the upper premolars, canines, and in- cisors took 10 months. After a Class I dental relationship was ob- tained, a small space was left be- tween the upper left canine and premolar to coordinate the maxil- lary and mandibular midlines. To- tal treatment time was 29 months. Treatment Results Post-t reatment records demonstrated an improvement in facial esthetics from the frontal and lateral perspectives, with a harmonious soft-tissue profile (Fig. 6A). Maxillary and mandib- ular midline coordination and overjet reduction improved the smile esthetics, although the pa- tient’s skeletal asymmetry re- mained. The maxillary and man- dibular dental arches were well aligned, Class I molar and canine relationships were achieved, and the overbite and overjet were nor- malized. Cephalometric super- impositions showed that the up- per arch was distalized, the lower arch was mesialized, and the upper-incisor inclination was normalized, while the lower- incisor inclination was slightly increased (Fig. 6B). Class II elastics, which were worn from the upper first premolars to lower first molars to prevent pro- trusion of the maxillary anterior teeth. A lip bumper was inserted in the lower first-molar tubes to prevent undesirable mesial move- ment of the lower arch. The upper molars were dis- talized for six months, until a super-Class I molar relationship was achieved (Fig. 5). The upper second premolars followed spon- taneously by means of the pull of the transseptal fibers. Some anchorage loss occurred in the maxillary anterior segment, as evidenced by bite opening. To prevent relapse of the distalization, realign the upper second premolars, and begin dis- talization of the upper premolars, another 200g, .018" × .025" heat- activated nickel titanium archwire was inserted with crimpable stops Fig. 5 After 13 (A) and 16 (B) months of treatment. A A B B 46 JCO/JANUARY 2016 Correction of Bilateral Class II Malocclusion Fig. 6 A. Patient after 29 months of treatment (continued on next page). A 47 VOLUME L NUMBER 1 Scalia, Perinetti, Locatelli, and Contardo miniscrews for indirect skeletal anchorage of the upper first pre- molars may be an effective solu- tion to these problems. ACKNOWLEDGMENT: We thank Drs. Patrizia Martin and Giulia Michelini for their help in this case. REFERENCES 1. Haydar, S. and Uner, O.: Comparison of Jones Jig molar distalization appliance with extraoral traction, Am. J. Orthod. 117:49-53, 2000. 2. Carano, A. and Testa, M.: The Distal Jet for upper molar distalization, J. Clin. Orthod. 30:374-380, 1996. 3. Fudalej, P. and Antoszewska, J.: Are orthodontic distalizers reinforced with the temporary skeletal anchorage devic- es effective? Am. J. Orthod. 139:722- 729, 2011. 4. Hilgers, J.J.: The Pendulum appliance for Class II non-compliance therapy, J. Clin. Orthod. 26:706-714, 1992. 5. Ghosh, J. and Nanda, R.S.: Evaluation of an intraoral maxillary molar distal- ization technique, Am. J. Orthod. 110:639-646, 1996. 6. Karlsson, I. and Bondemark, L.: Intra- oral maxillary molar distalization: Movement before and after eruption of second molars, Angle Orthod. 76:923- 929, 2006. 7. Locatelli, R.; Bednar, J.; Dietz, V.S.; and Gianelly, A.A.: Molar distalization with superelastic NiTi wires, J. Clin. Orthod. 26:277-279, 1992. Discussion Distalization with heat-acti- vated nickel titanium archwires proved to be a simple, effective, and noninvasive biomechanical system for achieving a Class I dental relationship in this Class II patient with skeletal asymme- try, although her cooperation was required. Temporary anchorage loss and bite opening occurred, and the prolonged use of Class II elastics caused a mesialization of the lower arch, despite the use of a lip bumper. The application of Fig. 6 (cont.) B. Superimposition of pre- and post-treatment cephalometric tracings. B </p>
