Part 1 in this series of articles (JCO, February

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1 2015 JCO, Inc. May not be distributed without permission. Creative djuncts for Clear ligners Part 2 Intrusion, Rotation, and Extrusion S. JY OWMN, DMD, MSD FRNK CELENZ, DDS JOHN SPRG, DMD MOSCHOS. PPDOPOULOS, DDS, DMD KENJI OJIM, DDS JMES CHENG-YI LIN, DDS Part 1 in this series of articles (JCO, February 2015) described a number of adjuncts for improving the reliability of Class II treatment with clear aligners. This month, we will demonstrate how to perform certain difficult tooth movements with aligners. Part 3 will conclude the series with a discussion of extraction and interdisciplinary treatment. One of the most frustrating aspects of clearaligner treatment has been the unpredictability of tooth movements such as dental extrusion, resolution of rotations, and correction of deep overbites. For example, Chisari and colleagues reported that only 57% of the programmed movement of a single incisor was actually achieved over an eightweek experimental period. 31 Kravitz and colleagues found only a mean 41% accuracy. 32 s treatment progresses, this lag in tooth movement can be compounded, resulting in a tracking error that is usually first noticed as an air gap between the incisal edges of the incisors and the aligner trays. This situation may spread to other teeth, until the trays no longer fit snugly or the intended tooth movement is adversely affected. Newer plastic materials, more accurate digital scans, new attachment designs, and better programming strategies for treatment planning (including the necessity of overcorrection) have improved the predictability of outcomes. s we discussed in Part 1, however, the application of adjuncts is still indicated in some cases. Intrusion Intrusion of selected teeth 33 or dental segments, 34 as needed in patients with deep overbites, has been regarded as challenging to perform with clear aligners. In fixed-appliance treatment, miniscrews have been used to assist not only in intrusion of single posterior teeth for subsequent prosthetic restorations, 35 but in mass intrusion to help close anterior open bites and correct deep overbites. 22,36,37 It seems logical to extend the application of skeletal anchorage into the realm of clear aligners. Overeruption of teeth with no opponents is commonly seen in mutilated dentitions. Intrusion of a hypererupted tooth is one way to provide sufficient clearance for prosthetic replacement. Miniscrews are ideally suited to such a task, since a variety of forces (elastic chain, coil springs, or elastics) can be applied to predictably guide the programmed intrusion without affecting adjacent teeth, even when using clear aligners (Fig. 8). 37,38 Intrusion of multiple teeth to correct deep overbites has been acknowledged as a more challenging and less predictable aspect of clear-aligner treatment. 34 The importance of resolving deep JCO, Inc. JCO/MRCH 2015

2 Dr. owman is a Contributing Editor of the Journal of Clinical Orthodontics; an djunct ssociate Professor, St. Louis University, St. Louis; a straight-wire instructor, University of Michigan, nn rbor, MI; an ssistant Clinical Pro fessor, Case Western Reserve Uni versity, Cleveland; a Visiting Clinical Lecturer, Seton Hill University, Greens burg, P; and in the private practice of orthodontics at 1314 W. Milham ve., Portage, MI 49024; Drs. Celenza, Sparaga, and Ojima are in the private practice of orthodontics in New York City; nchorage, K; and Tokyo, re spectively. Dr. Papadopoulos is Professor and Program Director, De partment of Orthodontics, School of Dentistry, ristotle University of Thes saloniki, Thessaloniki, Greece. Dr. Lin is Clinical ssistant Professor, De partment of Orthodontics and Pediatric Dentistry, School of Dentistry, National Defense Medical University, Taipei, Taiwan, and in the private practice of orthodontics and implantology in Taipei. Dr. owman is inventor of the Clear Collection pliers and ligner Chewies. him at drjwyred@aol.com. Dr. owman overbites has become more apparent in recent years with the increasing percentage of adult orthodontic patients especially those with restricted anterior function, resulting in severe enamel attrition of both the incisal edges and the labial and lingual tooth surfaces. Recent improvements in aligner programming have been designed to assist in leveling the curve of Spee with incisor intrusion and premolar or molar extrusion. 39 These include biteplanes molded into the aligner trays behind the upper anterior teeth and bonded attachments used to deliver extrusive forces to the premolars. Since miniscrew anchorage has been highly dependable in correcting deep bites and gummy smiles, it has inevitably been applied to similar treatments with clear aligners (Fig. 9) Rotation and Extrusion Dental rotations and extrusion of anterior teeth seem to be the least predictable aligner movements. Kravitz and colleagues found that extrusion was the least accurate tooth movement in aligner treatment, at 29.6% effectiveness. 32 Reasons for these difficulties, along with strategies to improve rotation control, have been proposed by Nicozisis 40 and Humber. 41 We have incorporated several of their common themes in the following suggestions: C Fig. 8 Molar intrusion supported by miniscrew anchorage and elastics.. dult patient with missing lower right first molar and overerupted upper second premolar, initially treated with chain elastic from miniscrew to bonded button on premolar.. During later Invisalign phase, intramaxillary triangle elastics worn from miniscrew to bonded buttons on aligners, ensuring proper tray seating and consistent leveling of occlusal plane. C. Resulting slight overcorrection provided sufficient clearance for implant in 14 weeks of treatment. VOLUME XLIX NUMER 3 163

3 Creative djuncts for Clear ligners Fig. 9 Deep-bite treatment with anterior intrusion.. dult male patient with mutilated dentition and deep overbite associated with significant anterior wear before treatment.. Miniscrews inserted between roots of upper lateral incisors and canines for anchorage of intrusion elastics (continued on next page). 164 JCO/MRCH 2015

4 owman, Celenza, Sparaga, Papadopoulos, Ojima, and Lin C D Fig. 9 (cont.) C. Elastic hook formed by placing circular extrusion in facial aligner surface with Hilliard Thermoplier Hook-Forming Pliers, then notching half of plastic extrusion with cutting tool. D. Improvement in overbite after 22 months of treatment and 35 pairs of aligners. Registered trademark of Dentsply Raintree Essix Glenroe, Sarasota, FL; VOLUME XLIX NUMER 3 165

5 Creative djuncts for Clear ligners 1. To open sufficient space adjacent to the affected tooth, program a visible opening of.25-.5mm into the aligner treatment and/or use interproximal reduction. 2. Design appropriate bonded attachments to elicit rotational and/or extrusive forces. 9,42,43 3. Program overcorrection into the aligners to account for the flexibility of the plastic. 4. Use detailing pliers such as Clear Collection s The Vertical*** and The Horizontal*** to accentuate rotational or extrusive couples. 5. Supplement treatment with bonded buttons and elastics or even fixed appliances before or after aligner therapy. 6. Due to the inherent risk of rotational or vertical relapse, discuss the need for supracrestal fiberotomy (Edwards procedure 44 ) and long-term fixed retention as part of informed consent. The failure of upper lateral incisors to track properly, commonly seen with Class II, division 2 malocclusions, is especially disconcerting. In some instances, the central incisors would benefit from intrusion while the lateral incisors require extrusion and rotation. Combining selective intrusion, extrusion, root torque, and rotation of anterior teeth requires more than just casual approval of a technician s programmed treatment plan. Failure to address the arch-length discrepancy before initiating any movement of the lateral incisors is likely to result in disappointment. If extrusion is attempted with insufficient adjacent space, iatrogenic intrusion may occur as the tooth is inadvertently squeezed apically. Space opening also increases the tooth-surface area for the plastic to contact an important consideration with a small, blade-shaped lateral incisor. The addition of bonded attachments on the lingual or facial surfaces or both should be considered to increase the contact surface area and produce extrusive and/or rotational forces. If tracking is still lagging behind, other adjuncts can be considered. ligner Chewies are one of the earliest methods developed to overcome poor tracking or aligner lag (Fig. 10). 45 Like sequential aligners themselves, these simple devices were based on the concept of the tooth positioner. 46 With the trays Fig. 10 Chewies tray seater positioned at air gap between incisal edge and aligner. in place, the patient bites down repeatedly on the soft Chewies, each the size of a cotton roll, for several minutes a day to help seat the aligners, especially as each new pair is started. Chewies are also prescribed when an air gap develops at the incisal edges. In that case, the Chewie should be positioned directly over the affected region to focus the chewing forces, with the patient holding the device solidly between the teeth for seconds, releasing, and repeating for about five minutes twice a day. ***Clear Collection, Hu-Friedy Manufacturing Co., Chicago, IL; Trademark of Dentsply Raintree Essix Glenroe, Sarasota, FL; JCO/MRCH 2015

6 owman, Celenza, Sparaga, Papadopoulos, Ojima, and Lin Fig. 11 ootstrap elastics used to extrude lagging teeth for proper tray seating.. Elastics stretched from buttons bonded near gingival margin on lingual surfaces of affected teeth to hooks created in facial aligner surface by notching with Tear Drop*** plier.. Elastics in place in patient with lagging upper lateral incisors (colored elastics worn in occlusal view for demonstration purposes). Even with the best planning for clear-aligner biomechanics, aligner lag or tracking error of specific teeth can still occur, often as a result of lessthan-ideal patient compliance with aligner wear. The application of adjunct elastics may assist with the extrusion of selected teeth into the aligner trays. ootstrap elastics are attached to bonded buttons on the facial, lingual, or both surfaces of the lagging tooth at the gingival margin. 47 n orthodontic elastic is stretched across the incisal surface of the seated aligner to the button, thus extruding or pulling the tooth into the tray. The gingival margin of the aligner plastic must be cut to avoid the buttons, so that the tray can seat completely. lternatively, to avoid the need for a button on the facial side of the tooth, elastic hooks can be cut into the aligner tray (Fig. 11). ootstrap elastics may prevent or at least delay the need to interrupt a series of aligners for the fabrication of refinement trays (Fig. 12). Open-ite Treatment Passive posterior intrusion is a common issue in clear-aligner treatment. Posterior plastic can be removed to permit spontaneous settling or eruption of the posterior teeth into occlusion, and forced eruption can also be applied with intermaxillary elastics (Fig. 13). Clever methods for using clear aligners to improve the closure of anterior open bites by intrusion of posterior teeth have been proposed by oyd 39 and Dayan. 48 The underlying concept is to harness the aligners propensity to produce an iatrogenic posterior open bite simply as a result of holding plastic between the teeth for extended periods of time. 1,2,49,50 One such strategy involves sequential intrusion of specific posterior teeth while maintaining or extruding the anterior teeth, thus creating a deeper curve of Spee. 48 Using Chewies to exert intrusive forces on targeted pos- VOLUME XLIX NUMER 3 167

7 Creative djuncts for Clear ligners C Fig. 12 Maxillary retraction and anterior torque control supported by elastics.. 12-year-old female patient before treatment with Invisalign TEEN* and Class II elastics.. fter 20 months, due to progressively worsening upper left lateral incisor tracking, bonded button and bootstrap elastic added to extrude lateral incisor into aligner tray. C. Patient after completion of treatment, six months later, showing improved smile line. 168 JCO/MRCH 2015

8 owman, Celenza, Sparaga, Papadopoulos, Ojima, and Lin C D Fig. 13 Forced posterior eruption supported by elastics.. Young adult patient with anterior open bite and reverse smile line before treatment with clear aligners.. Development of posterior open bite during aligner treatment. C. uttons added for attachment of posterior rectangular intermaxillary elastics to assist refinement aligners in seating occlusion. D. Patient after 24 months of treatment; addressing curve of Wilson could have improved these results. C Fig. 14 Extrusion supported by elastics.. dult patient with poor tracking of aligner trays in anterior region.. uttons bonded to lingual surface of upper left lateral incisor and facial surface of lower left canine for attachment of intermaxillary elastics during refinement stage. C. Patient after 10 months of treatment. *Registered trademark of lign Technology, Inc., Santa Clara, C; VOLUME XLIX NUMER 3 169

9 Creative djuncts for Clear ligners Fig. 15 Posterior intrusion supported by miniscrew anchorage and elastics.. dult female patient with frank anterior open bite treated using Dayan open-bite protocol 48 combined with six miniscrew implants (two each on buccal and palatal sides of posterior maxillary alveolus, two in buccal alveolus of posterior mandible). Sling elastics worn from palatal to buccal maxillary miniscrews, across occlusal surfaces of aligners, to support intrusion. In lower arch, teardrop notches placed at lingual gingival margin of aligners mesial and distal to first molars; elastics worn from lingual notches to buccal miniscrews, across occlusal surfaces of aligners, to support mandibular vertical control.. Maxillary left palatal miniscrew relocated mesially; metal and esthetic attachments bonded in upper and lower arches for intermaxillary elastics (continued on next page). 170 JCO/MRCH 2015

10 owman, Celenza, Sparaga, Papadopoulos, Ojima, and Lin terior teeth can improve the predictability of this method. The addition of miniscrew anchorage to support biomechanics involving elastic forces for the extrusion of anterior or posterior teeth is another logical extension of their application to clear-aligner treatment (Fig. 14). n alternative type of bootstrap mechanism employs miniscrews to improve the reliability of posterior intrusion and potentially produce spontaneous mandibular autorotation (Fig. 15). 47 lthough there is seldom a need to extrude anterior teeth during the correction of anterior open bites, 51 the combination of clear aligners with miniscrew anchorage for such treatment has been described by Lin and colleagues. 36,52 (TO E CONTINUED) C D Fig. 15 (cont.) C. Rectangular intermaxillary elastics worn after sequential posterior intrusion to assist in seating occlusion. D. fter 26 months of treatment, patient in refinement stage. VOLUME XLIX NUMER 3 171

11 Creative djuncts for Clear ligners REFERENCES 1. oyd, R.L.; Miller, R.J.; and Vlaskalic, V.: The Invisalign system in adult orthodontics: Mild crowding and space closure cases, J. Clin. Orthod. 34: , Vlaskalic, V. and oyd, R.: Orthodontic treatment of a mildly crowded malocclusion using Invisalign system, ustral. Orthod. J. 17:41-46, oyd, R.L.: Complex orthodontic treatment using a new protocol for the Invisalign appliance, J. Clin Orthod. 42: , owman, S.J.: Thinking outside the box with miniscrews, in Microimplants as Temporary nchorage in Orthodontics, ed. J.. McNamara Jr. and K.. Ribbens, Craniofacial Growth Series, University of Michigan, nn rbor, 45: , Chisari, J.R.; McGorray, S.P.; Nair, M.; and Wheeler, T.T.: Variables affecting orthodontic tooth movement with clear aligners, m. J. Orthod. 145(4 suppl):s82-91, Kravitz, N.D.; Kusnoto,.; egole, E.; Obrez,.; and gran,.: How well does Invisalign work? prospective clinical study evaluating the efficacy of tooth movement with Invisalign, m. J. Orthod. 135:27-35, Turatti, G.; Womack, R.; and racco, P.: Incisor intrusion with Invisalign treatment of an adult periodontal patient, J. Clin. Orthod. 40: , Krieger, E.; Seiferth, J.; Marinello, I.; Jung,..; Wriedt, S.; Jacobs, C.; and Wehrbein, H.: Invisalign treatment in the anterior region: Were the predicted tooth movements achieved? J. Orofac. Orthop. 73: , Lin, J.C.Y.; Liou, E.J.W.; and Yeh, C.L.: Intrusion of overerupted maxillary molars with miniscrew anchorage, J. Clin. Orthod. 40: , Lin, J.C.Y.; Yeh, C.L.; Liou, E.J.W.; and owman, S.J.: Treatment of skeletal-origin gummy smiles with miniscrew anchorage, J. Clin. Orthod. 42: , Lin, J.C.Y.; Liou, E.J.W.; and owman, S.J.: Simultaneous reduction in vertical dimension and gummy smile using miniscrew anchorage, J. Clin. Orthod. 44: , Giancotti,.; Germano, F.; Muzzi, F.; and Greco, M.: miniscrew-supported intrusion auxiliary for open-bite treatment with Invisalign, J. Clin. Orthod. 48: , oyd, R.: How successful is Invisalign for treatment of anterior open bite and deep overbite? lecture, O annual session, Philadelphia, May 5, Nicozisis, J.L.: Tripping the plastic fantastic, Orthod. Prod., Nov. 2013, pp Humber, P.: Rotating canines using the Invisalign system, esth. Dent. Today 7:30-34, Kuo, E. and Duong, T.: Invisalign attachments: Materials, in The Invisalign System, ed. O.C. Tuncay, Quintessence, London, 2007, pp oyd, R.L. and Vlaskalic, V.: Three-dimensional diagnosis and orthodontic treatment of complex malocclusion with the Invisalign appliance, Semin. Orthod. 7: , Edwards, J.G.: surgical procedure to eliminate rotational relapse, m. J. Orthod. 57:35-46, Tuncay, O.: The iatrogenic crowding caused by aligner length/ arch length discrepancy, Clinical Reports & Techniques (lign Technology), Fall 2005, pp Kesling, H.D.: The philosophy of tooth positioning appliance, m. J. Orthod. 31: , Giancotti,. and Ronchin, M.: Pre-restorative treatment with the Invisalign system, J. Clin. Orthod. 40: , Dayan, W.: Techniques for posterior intrusion in the correction of anterior open bite with Invisalign, lign Technology white paper, Womack, W.R.; hn, J.H.; mmari, Z.; and Castillo,.: new approach to correction of crowding, m. J. Orthod. 122: , Schupp, W.; Haubrich, J.; and Neumann, I.: Treatment of anterior open bite with the Invisalign system, J. Clin. Orthod. 44: , Guarneri, M.P.; Oliverio, T.; Silvestre, I.; Lombardo, L.; and Siciliani, G.: Open bite treatment using clear aligners, ngle Orthod. 83: , Lin, J.C.Y.; Tsai, S.J.; Liou, E.J.W.; and owman, S.J.: Treatment of challenging malocclusions with Invisalign and miniscrew anchorage, J. Clin. Orthod. 48:23-36, JCO/MRCH 2015