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The International Journal of Periodontics & Restorative Dentistry

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Malpositioned teeth are responsiblefor esthetic and occlusal aberrations inmany adults. Malocclusions may becaused by several factors, including thespread of advanced periodontal dis-ease, dental migration toward areas oftooth loss, and tooth movement pro-duced by traumatic occlusal problems.However, patients often forgo ortho-dontic treatment because of its longduration. Traditional orthodontic move-ment is the result of periodontal liga-ment compression, which produces his-tologic and biomolecular modificationsof the periodontal tissues that activatedynamics of crestal bone resorptionand apposition. Thus, orthodonticmovement is considered a “periodon-tal phenomenon” because all the peri-odontal tissues are involved. For thisreason, preservation of the integrity ofthe periodontium is generally difficult toachieve and is associated with a longduration of treatment. Although tradi-tional orthodontic therapy is the goldstandard for treating many adult den-tal malpositions, it can be problematicwhen applied to patients with a thinperiodontal biotype, who may experi-ence root dehiscence and/or recession.Also, orthodontic tooth movement

Orthodontic Microsurgery: A New Surgically Guided Technique for Dental Movement

Tomaso Vercellotti, MD, DDS*Andrea Podesta, MD, DDS**

Eight patients with malocclusions were treated with a new orthodontic-surgicaltechnique that reduces the duration of treatment compared to conventional tech-niques. The monocortical tooth dislocation and ligament distraction (MTDLD)technique combines two different dental movements that work separately butsimultaneously on opposite root surfaces. On the root surface corresponding tothe direction of movement, vertical and horizontal microsurgical corticotomies areperformed around each tooth root with a piezosurgical microsaw to eliminate cor-tical bone resistance. The immediate application of strong biomechanical forcesproduces rapid dislocation of the root and the cortical bone together. On the rootsurface opposite the direction of movement, the force of dislocation producesrapid distraction of ligament fibers. During the osteogenic process that follows,application of normal orthodontic biomechanics achieves the final tooth move-ment. All eight patients underwent periodontal and radiologic examinations formore than 1 year after treatment. No periodontal defects were observed in any ofthe patients, including one with a severe malocclusion and a thin periodontal tis-sue biotype. Compared to traditional orthodontic therapy, the average treatmenttime with the MTDLD technique in the mandible and maxilla was reduced by 60%and 70%, respectively. (Int J Periodontics Restorative Dent 2007;27:325–331.)

*Private Practice, Genova, Italy.**Private Practice in Orthodontics, Genova, Italy.

Correspondence to: Dr Tomaso Vercellotti, Via XII Ottobre 2/111, 16126 Genova, Italy;fax: +39-010-5452640; e-mail: [email protected].

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Volume 27, Number 4, 2007


may be anatomically limited in cases ofsevere jaw discrepancy. The treatmentof dental-skeletal discrepancies gen-erally requires a combination of ortho-dontic and orthognathic techniquesthat must be performed under generalanesthesia. Unfortunately, patientsoften agree to undergo maxillofacialsurgery only to correct the most severeskeletal discrepancies and avoidsurgery to correct borderline dental-skeletal malocclusions.

Traditional orthodontic therapy inadult patients often results in pro-tracted treatment time to allay peri-odontal tissue concerns. Increases inorthodontic forces do not accelerateroot movement, because the peri-odontal tissues cannot overcome theresistance of the alveolar bone withoutdamage to the periodontal ligamentand/or root resorption.

To overcome these limitations, sim-plification of the traditional orthodonticmovement with bone surgery has beenproposed by several authors to sim-plify tooth movement and possiblyreduce the risk of periodontal damage.Several reports1–4 have suggested theuse of labial/lingual vertical corticotomywith subapical horizontal osteotomy tocorrect tooth positions via bony blockmovement. Liou and Huang5 describedan ostectomy technique into the alve-olar extraction socket that would accel-erate canine distalization into the firstpremolar extraction alveolus space intoa time frame of several weeks.

For treatment of Angle Class Icrowding, Wilcko et al6–9 described a“periodontally accelerated osteogenicorthodontics” procedure. This tech-nique includes buccal and lingualflaps, bone bur decortication, bone

grafting, and fixed orthodontic treat-ment. This technique reduces treatmenttime versus conventional techniquesby 30% to 50%.

Orthodontic-surgical techniquessupport the use of osteotomy to aiddental movement and rapid distractionof the periodontal ligament.5 Surgicalalteration of the alveolar bone is per-formed to reduce mineralization of thecrestal bone. However, the decorti-cated bone may also be a recipient sitefor bone graft materials, which canincrease crestal thickness.

The authors of this article havedeveloped a new surgical-orthodontictechnique to maximize the rapidity ofmovement and prevent damage tothe periodontal tissues. These goalsmay be achieved with a piezosurgicaltechnique invented and developed byone of the authors (TV)10–26 that per-mits microsurgical corticotomy aroundeach root (Fig 1) and the immediateapplication of biomechanical force.This technique avoids involvement ofthe periodontal tissue fibers, which isnecessary in traditional orthodonticmovement, thereby preventing peri-odontal and bone resorption. Themonocortical tooth dislocation tech-nique (MDT) must be considered anew tooth movement because itoccurs without periodontal tissueresorption and apposition. Periodontalligament compression is limited to thefirst phase of treatment, which involvesrapid dislocation of the root and thecortical bone unit. Conversely, the lig-ament distraction technique (LD)should be considered a “luxationmaneuver,” which produces a rapiddistraction of ligament fibers followedby an osteogenic healing process.

The greatest amount of dentalmovement occurs in approximatelythe first 30% of total treatment timewith the MTDLD technique. The ther-apy concludes with the application ofconventional orthodontic movement.The present study discusses the surgi-cal techniques for buccal, palatal, andvertical movements.

Method and materials

Pretreatment study

Eight patients (six women, two men)were treated using the MTDLD tech-nique for the following types of mal-occlusion: deep bite, open bite, andcrossbite (Angle Classes I, II, and III). Allpatients underwent a pretreatmentscreening, which included medical his-tory, analyses of study casts, cephalo-metric study, dental radiography, peri-odontal examination, and oral hygieneinstruction. The analyses of study castsallowed evaluation of the necessarydimensions of dental movement, aswell as preparation of the necessaryfixed and removable bite appliances toeliminate occlusal interference. Thecephalometric study was performedto evaluate discrepancies in the max-illary and mandibular positions.Periapical radiographs were used todetermine the correct design of thecorticotomy. All patients providedinformed consent to undergo treat-ment with the MTDLD technique. Figs2 and 3 present aspects of the treat-ment of two patients.

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Surgical technique

All surgery was provided under localanesthesia (Septanest 1:200,000,Septodont). Six patients received anintravenous sedative (a benzo-diazepine).

The osteotomies were performedusing the 0T7 and OT8 ultrasonic micro-saws (Piezosurgery, Mectron MedicalTechnology). Only one full-thickness flapon the side corresponding to the direc-tion of movement (buccal or palatal)was elevated. The OT7 microsaw was used to perform the vertical andhorizontal corticotomies on the buccalside, whereas the OT8 microsaw wasused for the horizontal corticotomieson the palatal side. The following set-tings were used: cutting power, bone 1;irrigation solution pump level, 4.

mm apical to the root apex (see Fig1b). To encourage intrusive move-ment, a quantity of cortical bone cor-responding to the amount of desiredintrusion was removed (see Fig 3a).

In seven of the patients, the corti-cotomies were filled with autogenousbone that had been harvested fromthe apical area of the crestal boneusing the Piezosurgery bone chip har-vesting technique (OP3 Piezosurgeryinsert). In two patients, a bone graftsubstitute (Bio-Oss granules, 0.25 to 1mm, Geistlich Biomaterials) was usedto increase the cortical buccal bonethickness. The grafting material wasprotected by a resorbable collagenmembrane (Bio-Gide, GeistlichBiomaterials).

The corticotomies were per-formed on the cortical bone in thedirection of the dental movement. Toexpand the maxillary arch, buccal cor-ticotomies were performed; to retractthe anterior teeth, palatal corticot-omies were performed.

Vertical corticotomies were per-formed by cutting into the interproxi-mal bone with an internal inclination tothe root direction. To preserve thebony crest, the vertical corticotomy fin-ished with two releasing osteotomiesnext to the adjacent teeth (see Fig 2c).

The number of corticotomies andtheir design for each patient variedaccording to root and bone anatomy.The position of the horizontal corticot-omy was dependent on the type ofmovement planned. For arch expan-sion, the corticotomy was made 1 or 2

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Fig 1a (left) A microcorticotomy is per-formed around each tooth root.

Fig 1b (right) A periapical horizontal corti-cotomy (arrow) is performed with thePiezosurgery OT7 insert.

Fig 1c (left) Buccal monocortical toothdislocation and palatal ligament distractionmovement (MTDLD technique).

Fig 1d (right) After healing, there is nomodification in crestal bone thickness onthe buccal side, and the palatal side hasbeen augmented.


Orthodontic biomechanics

A buccal straight-wire technique wascombined, when possible, with anadditional palatal force, which was indi-vidualized for each patient.

The cortical bone dislocation andligament distraction were performed

with palatal appliances constructed withtitanium-molybdenum alloy archwires(SDS Ormco) (0.32-inch, 0.17- � 0.25-inch, 0.32- � 0.32-inch) and multibrack-et appliances constructed with self-ligating brackets with 0.22-inch slots(SDS Ormco, Ultradent Products; 3MUnitek) and rectangular nickel-titanium

(NiTi) or copper-NiTi archwire. An indi-rect bonding system that incorporatedthe Ray Set machine (Biaggini MedicalDevices) helped reduce the length ofthe second phase of treatment. In casesin which alignment and refinement ofthe occlusion were necessary, biome-chanics were performed convention-

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Fig 2a (above left) Class I relationship with anterior pathologic diastema in the right maxilla.

Fig 2b (above right) Class I molar and Class II canine relationship with absence of lateralincisors and a diastema in the left maxilla.

Fig 2c (far right) A vertical “Y” corticotomy is performed to preserve interproximal bone.

Fig 2e The Piezosurgery OT4 insert isused for the implant site preparation tech-nique with Piezosurgery.

Fig 2g The postoperative period wascharacterized by low morbility; soft tissuequality was good at the time of sutureremoval.

Fig 2i Day 63: Completion of therapy. Aprovisional crown has been placed on themaxillary left canine implant.

Fig 2h Day 0: after indirect bonding.

Fig 2f A 4-mm-diameter implant is placedin the expanded ridge.

Fig 2d Edentulous ridge with insufficientwidth for implant positioning. A horizontalosteotomy for the ridge expansion tech-nique is performed.

Fig 2 Patient 6.


ally with individualized NiTi or archforms.

Six patients were treated in themaxillary arch (one on the palatalside), and two received mandibulartreatment.

and interviewed to identify potentialpostoperative problems. The biome-chanical force was applied 1 to 7 daysafter surgery. For the first month, thepatients were evaluated once a weekby a periodontist and an orthodontist;during the following month, examswere performed every 2 weeks.

Postoperative management

Antibiotic therapy consisted of 1 gamoxicillin (Zimox, Pfizer) twice daily for5 days in one patient after bone graft-ing. Seven patients were given a singledose of nimesulide (100 g). All patientswere evaluated 3 days after surgeryand 7 to 8 days after suture removal

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Fig 2j (left) Initial overjet.

Fig 2k (right) Final overjet.

Fig 2l (left) Malocclusion prior to treatment.

Fig 2m (right) The final result 63 days later.

Fig 2n Radiograph prior to orthodontic-microsurgical treatment. Fig 2o Radiograph at 3 months after MTDLD treatment.


Results

The desired dental movement wasachieved in 43 to 149 days. Averagetherapy times were approximately 2months for maxillary expansion andabout 3.5 months for mandibular intru-sion (Table 1).

Radiographs showed favorableresults at 3 months after orthodontic-microsurgical therapy (see Figs 2n and2o). Postoperatively, slight oral swellingof the soft tissues of the face was visi-ble on day 3 after surgery, especially inthe corticotomized area of the maxilla,but no inflammation of the oral tissueswas present (see Fig 2g).

Discussion

In conventional orthodontic therapy,movement occurs via crestal boneresorption. Although this biomechani-cal movement is effective, its applica-tion is limited in adult patients.Prolonged and/or strong compressionof the periodontal ligament may pro-duce histologic modification of thefibers, as well as ligament ankylosis androot resorption. Orthodontists treatingadult patients generally prefer to applylight biomechanical forces to avoid therisk of periodontal damage. However,this method requires a lengthy thera-peutic period. The MTDLD technique

simplifies orthodontic treatment inadult patients and makes it possible toaccomplish complex movements in arelatively short period. The precision of the Piezosurgerymicrosaw permits a safe corticotomyaround the root. The microinvasiveosteotomy is characterized by preci-sion, maximum surgical control, andselective cutting action and facilitatesthe preservation of the root integrity.Because of the instrument’s precision,bone regeneration is more likely.Healing following the use of thePiezosurgery microsaw is rapid, withminimal morbidity.

To date, experience with micro-surgically guided orthodontic therapyin adult patients has been limited; how-ever, after 2 years, outcomes with theMTDLD technique in adult patientswith malocclusions have been favor-able. Radiographic and periodontalexaminations have confirmed that theMTDLD technique does not damagetissue. Orthodontic-microsurgical treat-ment has been shown to be a reliable,quick, and painless technique. Forthese reasons, it may have widespreadapplication in the orthodontic treat-ment of adult patients.

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Fig 3a An apical corticotomy is per-formed at the first premolar to improveintrusive movement while preserving thesinus membrane.

Fig 3b Pretreatment condition. The firstpremolar is extruded, and severe recessionis apparent at the first molar.

Fig 3c Final result. The first premolar hasbeen intruded and the root recession at thefirst molar has been reduced.

Table 1 Treatment time with the MTDLD technique

Patient/sex Treatment Treatment time (d)

1/F Maxillary expansion 882/F Maxillary expansion 433/M Maxillary expansion 464/F Maxillary expansion 675/F Maxillary expansion 1056/M Maxillary expansion 637/F Mandibular intrusion 608/F Mandibular intrusion 149

Fig 3 Patient 5.


Conclusion

The present study introduced a neworthodontic-microsurgical techniquethat permits new orthodontic move-ment while lowering the risks of boneresorption and ligament ankylosis. Thistechnique involves the application of astrong biomechanical force on corti-cotomized teeth via a Piezosurgerymicrosaw. Dental movement occursvia dislocation of the root and the cor-tical bone together, without compres-sion of the periodontal ligament andbone resorption. No serious peri-odontal problems were observed inthe eight patients treated with theMTDLD technique and followed for 1year. Compared to conventional ortho-dontic approaches, the average dura-tion of treatment in maxillae andmandibles was reduced by 70% and60%, respectively. Orthodontic micro-surgery is associated with minimal mor-bidity and offers a promising means ofimproving and simplifying orthodontictherapy in adult patients.

References

1. Kole H. Surgical operations on the alveo-lar ridge to correct occlusal abnormalities.Oral Surg Oral Med Oral Pathol 1959;12:515–529.

2. Anholm JM, Crites DA, Hoff R, RathbunWE. Corticotomy-facilitated orthodontics.Calif Dent Assoc J 1986;14(12):7–11.

3. Gantes B, Rathbun E, Anholm M. Effectson the periodontium following corticoto-my-facilitated orthodontics. Case reports.J Periodontol 1990;61:234–238.

4. Suya H. Corticotomy in orthodontics. In:Hösl E, Baldauf A (eds). Mechanical andBiological Basics in Orthodontic Therapy.Heidelberg: Hütlig Buch, 1991:207–226.

17. Lambrecht JT. Intraorale piezo-chirurgie.Schweiz Monatsschr Zahnmed 2004;114:29–36.

18. Eggers G, Klein J, Blank J, Hassfeld S.Piezosurgery: An ultrasound device for cut-ting bone and its use and limitations inmaxillofacial surgery. Br J Oral MaxillofacSurg 2004;42:451–453.

19. Vercellotti T, Nevins ML, Kim DM, et al.Osseous response following resective ther-apy with piezosurgery. Int J PeriodonticsRestorative Dent 2005;25:543–549.

20. Chiriac G, Herten M, Schwarz F, RothamelD, Becker J. Autogenous bone chips:Influence of a new piezoelectric device(Piezosurgery) on chip morphology, cellviability and differentiation. J ClinPeriodontol 2005;32:994–999.

21. Gruber RM, Kramer FJ, Merten HA,Schliephake H. Ultrasonic surgery—Analternative way in orthognathic surgery ofthe mandible. Int J Oral Maxillofac Surg2005;34:590–593.

22. Schaller BJ, Gruber R, Merten HA, et al.Piezoelectric bone surgery: A revolutionarytechnique for minimally invasive surgery incranial base and spinal surgery? Technicalnote. Neurosurgery 2005;57(4 suppl):E410.

23. Boioli LT, Etrillard P, Vercellotti T, TecucianuJF. Piézochirurgie et aménagement osseuxpréimplantaire. Greffes par apposition deblocs d’os autogène avec prélèvementramique. Implant 2005;11:261–274.

24. Preti G, Martinasso G, Navone R, Russo C,Canuto RA, Schierano G. Cytokines andgrowth factors involved in the osseointe-gration of oral titanium implants posi-tioned using piezoelectric bone surgeryversus a drill technique: A pilot study inminipigs. J Periodontol 2007;78:716–722.

25. Beziat JL, Vercellotti T, Gleizal A. What isPiezosurgery? Two-years experience incraniomaxillofacial surgery [in French]. RevStomatol Chir Maxillofac 2007;108:101–107.

26. Beziat JL, Béra JC, Lavandier B, Gleizal A.The ultrasonic osteotomy as a new tech-nique in craniomaxillofacial surgery. Int JOral Maxillofac Surg 2007;36:493–500.

5. Liou EJ, Huang CS. Rapid canine retractionthrough distraction of the periodontal lig-ament. Am J Orthod Dentofacial Orthop1998;114:372–382.

6. Wilcko WM, Wilcko MT, Ferguson DJ,Bouquot JE. Accelerated orthodonticswith alveolar reshaping: Two case reports.J Ortho Pract 2000;11:63–70.

7. Wilcko WM, Wilcko MT, Bouquot JE,Ferguson DJ. Rapid orthodontics withalveolar reshaping: two case reports ofdecrowding. Int J Periodontics RestorativeDent 2001;21:9–19.

8. Ferguson DJ, Wilcko WM, Wilcko MT.Accelerating orthodontics by altering alve-olar bone density. Good Pract 2001;2:2–4.

9. Wilcko WM, Ferguson DJ Bouquot, JE,Wilcko MT. Rapid orthodontic decrowdingwith alveolar augmentation: Case report.World J Orthod 2003;4:197–205.

10. Vercellotti T. Piezoelectric surgery inimplantology: A case report—A newpiezoelectric ridge expansion technique.Int J Periodontics Restorative Dent2000;4:359–365.

11. Vercellotti T, Crovace A, Palermo A,Molfetta A. The piezoelectric osteotomy inorthopedics: Clinical and histological eval-uations (pilot study in animals).Mediterranean J Surg Med 2001;9:89–95.

12. Vercellotti T, De Paoli S, Nevins M. Thepiezoelectric bony window osteotomy andsinus membrane elevation: Introductionof a new technique for simplification ofthe sinus augmentation procedure. Int JPeriodontics Restorative Dent 2001;21:561–567.

13. Vercellotti T. La chirurgia ossea piezoelet-trica. Il Dentista Moderno 2003;5:21–55.

14. Vercellotti T. Technological characteristicsand clinical indications of piezoelectricbone surgery. Minerva Stomatol 2004;53:207–214.

15. Robiony M, Polini F, Costa F, Vercellotti T,Politi M. Piezoelectric bone cutting in mul-tipiece maxillary osteotomies. Technicalnote. J Oral Maxillofac Surg 2004;62:759–761.

16. Boioli LT, Vercellotti T, Tecucianu JF. Lachirurgie piézoélectrique: Une alternativeaux techniques classiques de chirurgieosseuse. Inf Dent 2004;86:2887–2893.

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