Piezosurgery®-assisted periodontally accelerated osteogenic orthodontics.

Periodontally accelerated osteogenic orthodontic procedure has become useful adjunct to reduce orthodontic treatment time as compared with conventional orthodontics. This case demonstrates the use of Piezosurgery® to facilitate rapid tooth movement with relatively shorter treatment time. A 23-year-old male with Angles Class I malocclusion having spaced anterior teeth and protrusion requested orthodontic treatment with reduced time period. Before surgery, presurgical orthodontic treatment was done to do initial alignment of the teeth. This was followed by piezosurgical corticotomy and final space closure was achieved by active orthodontic tooth movement. The total treatment time required to complete the orthodontic treatment was 5 months. 1-year follow-up revealed no evidence of any adverse periodontal effects or relapse. Thus, Piezosurgery®-assisted corticotomy may prove to be a noble and effective treatment approach to decrease the orthodontic treatment time.

INTRODUCTION

Periodontally accelerated osteogenic orthodontics (PAOO), also known as Wilckodontics, has become a very useful modality in the field of surgical orthodontics to provide faster tooth movement. Regulation of the remodeling process of the periodontium to bring about rapid tooth movement gives an edge over existing traditional concepts of orthodontic treatment. Ever since its conception and patent by Wilcko and Wilcko,[1] the term Wilckodontics has become more popular. This technique involves decortication of the alveolar bone which is done to serve two purposes; first, it reduces the resistance offered by the thick alveolar housing to tooth movement and second, it initiates the regional acceleratory phenomenon (RAP) due to which there is temporary burst of hard and soft tissue remodeling which helps to regenerate the bone to its normal state.[2]

Manual instruments such as chisel and mallet or motor-driven instruments such as surgical burs, microsaws with external irrigants, or trephine burs have been used traditionally in performing corticotomy procedures. Conventional tools require greater exposure of the surgical site and are difficult to control in areas which require precise cut and are densely mineralized. In addition, the frictional heat generated by motor-driven instruments may also hinder the healing process.

To overcome these disadvantages the piezoelectric device (Piezosurgery®) has been introduced. Piezosurgery® can be used in periodontology and implantology to supplement the existing oral surgical procedures and in some cases as a replacement. The mild vibratory movements of the Piezosurgery® knife enables it to be used with greater precision of the cut and causing less discomfort to the patient when compared to traditional surgical instruments. The Piezosurgery® device is also very gentle on the hard tissues since it does not require the use of manual force, thus improving the handling with greater intraoperative control, particularly in anatomically difficult areas.[3]

There is sufficient literature suggesting the effectiveness of PAOO over conventional orthodontic treatment but very limited is available where PAOO has been done using a piezosurgical device. Therefore, we describe a case of orthodontic correction in a spaced dentition treated using the PAOO principle where the corticotomy was done using Piezosurgery® and followed up over a period of 1 year.

CASE REPORT

A 23-year-old male patient reported with a chief complaint of unesthetic appearance due to spaced dentition and proclined upper front teeth [Figure 1] and wanted faster results. Careful orthodontic examination revealed that patient had Angles Class I malocclusion. Medical history was not contributory and the patient did not report of any deleterious habits.

Figure 1

Preoperative clinical view

It was decided that after presurgical orthodontic alignment, piezosurgical corticotomy procedure will be performed, followed by final orthodontic correction. Before initiating the treatment, the treatment protocol was explained and informed consent was signed by the patient. Periodontal therapy consisting of scaling was performed.

Presurgical orthodontic treatment phase

Strap-up of the patient was carried out using preadjusted edgewise appliance system (MBT 0.022"). Initial alignment and leveling was started with preformed 0.016” NiTi archwires (3M unitek, Ca, USA) followed by 0.016” × 0.022” NiTi archwires and sequentially 0.017” × 0.025” NiTi archwires (3M Unitek, CA, USA) and finally shifted to 0.017” × 0.025” stainless steel. This orthodontic phase of treatment was continued till all the teeth were aligned. The archwires were also coordinated so that the teeth were in good occlusion. The time interval required for this presurgical orthodontic phase was 3 months. After which the patient was scheduled for piezosurgical corticotomy.

Piezosurgical corticotomy phase

Before surgery, the orthodontic wire placed for presurgical alignment was removed to facilitate the surgical procedure in the maxillary arch [Figure 2]. Aseptic surgical protocol was followed throughout the surgical procedure. Before surgery, patient's face was painted with povidone-iodine solution (Troydine, Troikaa Pharmaceuticals Ltd.). Presurgical mouthrinse with 0.2% chlorhexidine gluconate (Rexidine® Indoco Remedies Ltd.) solution was advocated for a minute. Local anesthesia was obtained with bilateral infraorbital nerve block and nasopalatine nerve block using 2% xylocaine (Ligno-Ad Local Anesthetic, Proxim Remedies, India) with 1:80,000 concentration epinephrine. Using a surgical blade no. 15 (Glassvan® Niraj Industries Pvt. Ltd., India), which has a small curved cutting edge with the sharpest point at the rounded tip and has the most popular blade shape for making short and precise incisions, an initial horizontal incision was given at a distance of 5 mm apical to the tip of interdental papilla, extending from maxillary left to right canine, preserving the gingiva over the cervical region and avoiding unnecessary exposure of alveolar bone, which may cause undue bone resorption [Figure 3]. To facilitate adequate exposure of the alveolar bone, vertical releasing incisions were given extending up to the depth of the vestibule at both ends of the horizontal incision [Figure 3]. A full-thickness flap was reflected, buccally and palatally, with the help of a periosteal elevator [Figure 4], avoiding vertical releasing incisions, palatally [Figure 5].

Figure 2

Presurgical clinical view

Figure 3

Horizontal and vertical releasing incisions given

Figure 4

Labial mucoperiosteal flap reflected

Figure 5

Mucoperiosteal flap reflected on palatal aspect

After reflection of the flaps, the markings of vertical bone cuts extending apically, 5 mm from apices of anterior teeth, were made in the interdental cortical bone [Figures 6 and 7]. The greatest mesiodistal width of the roots of anterior teeth as determined using orthopantamograph and the elevations formed on the alveolar process by the convexity of the root were taken as a guide to mark the vertical cuts. On the palatal aspect, the markings were slightly convergent toward the center of palate as they followed the alignment of the roots of teeth in accordance to the shape of palate [Figure 7].

Figure 6

Markings done for corticotomy on labial aspect

Figure 7

Schematic presentation of marking on palatal side

Vertical bone cuts were then given in the cortical bone on the markings with Piezosurgical Unit (Mectron Piezosurgery®) using osteotomy insert 7 (OT 7 insert) [Figure 8]. The Piezosurgery® handpiece used was vibrating with a amplitude of 60–210 μm and frequency range of 25 and 30 kHz utilizing power exceeding 5 W. To increase cooling effectiveness, physiological sodium chloride solution at a temperature of approximately 4°C was used for irrigation. The vertical cuts with a depth of 1.5–2 mm (the thickness of cortical bone) were made [Figures 9 and 10] and were joined using the horizontal cuts 2–3 mm apical to the root apex. The flaps were approximated with interrupted sutures (Silk 3-0, Ethicon, Johnson and Johnson Ltd) [Figure 11].

Figure 8

Corticotomy cuts being given with OT 7 insert of Piezoelectric unit

Figure 9

Clinical view after completion of corticotomy cuts

Figure 10

Immediate postoperative radiograph

Figure 11

Flaps approximated with simple interrupted sutures

Postoperative care

One of the advantage of using Piezosurgery® device is lesser postoperative pain;[4] therefore, after surgery, only mild analgesic tablets of acetaminophen 500 mg, thrice daily for 5 days and an antibiotic, amoxicillin 500 mg thrice daily for 5 days were prescribed. Furthermore, rinsing with 0.12% chlorhexidine gluconate mouthwash (Rexidine® Indoco Remedies Ltd.) twice daily for a period of 1 month was prescribed. The patient was refrained from brushing in the treated area. External ice pack on the first postsurgical day to minimize postoperative swelling was advised. Suture removal was done 1 week postsurgery.

Postsurgical orthodontic treatment phase

After a healing span of 15 days, 0.019” × 0.025” SS wires (3M Unitek, CA, USA) with e-chains were placed, and with activation period of 15 days, activation was followed. The 7 mm of residual spacing left after presurgical orthodontic phase was closed in a span of 45 days with well-aligned crown and root positions [Figure 12].

Figure 12

Clinical view two months after corticotomy showing complete closure of spacing between maxillary anterior teeth

After final active orthodontic therapy, the average treatment time to achieve esthetic, functional results was reduced to one-third the average, i.e., in 5 months (presurgical orthodontics 3 months, postsurgical orthodontics 2 months). After 1-year follow-up, stability in the periodontal parameters such as the gingival margin position with no evidence of periodontal pocket formation was seen. On radiographic evaluation in the follow-up phase, there were no evidences of loss of neither crestal bone nor apical root resorption [Figures 13 and 14]. There were no postoperative complications such as mobility or loss in vitality of any tooth.

Figure 13

Preoperative radiograph

Figure 14

One-year postoperative radiograph showing no significant root or bone pathology

DISCUSSION

Patients today are very much conscious about their appearance, especially smile. Therefore, there has been an increased demand for alignment of the malposed teeth using orthodontic treatment, even in older adults. The guidelines of the American Association of Orthodontists defines a orthodontic treatment time between approximately 1.5–2.5 years taking into consideration the treatment options and individual characteristics.[5]

Oral surgical procedures such as corticotomy can modify the biology of bone thus influencing tooth movement and reducing the treatment duration. Corticotomy procedures are based on a complex physiologic process involving increased rate of bone turnover known as the RAP.[2] RAP accelerates tissue reorganization by temporary increase in localized tissue remodeling, whose initial phase is characterized by increased osteoclastic activity leading to cortical bone porosity, promoting rapid orthodontic tooth movement. It has been observed that RAP in humans starts within few days of surgical procedure, have maximum effect at 1–2 months, and may take 6 months to 24 months to subside.[1] Another important principle of corticotomy procedure is that it decorticates the bone which results in transient osteopenia resulting in temporary decrease in the mineral content. The osteogenic cells start laying down abundant deposits of calcium followed by bone mineralization within a period of about 20–55 days. During this transient state, orthodontic brackets help in moving the teeth more rapidly because the immature bone offers decreased resistance to the orthodontic forces. All these findings had a clinical translation in the reduced period required for orthodontic treatment in the present case. PAOO also facilitates orthodontic tooth movement to a greater distance without undue complications, thereby making it a better treatment option in selected cases, which would otherwise require orthognathic surgery.[6]

In the present case, Piezosurgery® was used for corticotomy procedure. Numerous advantages of Piezosurgery® over conventional corticotomy devices were evident like precise cutting and safety as it is an ultrasonic device that enables micrometric cutting depending on micro-oscillation of the handpiece which resulted in width of the cuts smaller than the width achievable with rotary instruments. It also resulted in minimal surgical invasion as ultrasonic frequencies used (25-30kHz), preferentially cut mineralized tissues.[7] Piezosurgery® requires lesser force (0.5 kg)[3] as compared to conventional drills which needs to be loaded with a force of 2–3 kg, which provided greater surgical control to achieve the desired efficiency. Almost bleeding-free surgical site was observed which is due to cavitation effect that creates bubbles, from physiologic salt solution, leading to implosion, generating shock waves causing microcoagulation, and thereby resulting in better visualization of surgical site.[8] Various studies[7] on Piezosurgery® have shown rapid regeneration and reduced healing period, which was also evident in the present case, due to an antiseptic effect provided by the release of oxygen molecules and rapid metabolic rate of cells stimulated by the piezoelectric vibrations. Various other benefits of Piezosurgery® include no risk of emphysema due to the aerosol effect that the ultrasonic device produces unlike the effect of air-water spray generated with rotary instruments, reduced postoperative pain due to less invasive nature and reduced traumatic stress to the patient due to the noise-less nature of the microvibration,[3479] all of which were well appreciated by the patient as well as operator in the present case.

Use of bone grafts as a part of PAOO has been advocated in literature, which aids to increase alveolar housing around teeth, to reshape the morphology of bone, especially in cases with reduced amount of total bone volume around teeth and in cases with preexisting bone defects such as fenestrations and dehiscences.[6] However, in the present case, use of bone grafting was not done as the alveolar housing around the teeth was adequate and no preexisting bony defects were present intraoperatively. The outcome of the case was in accordance with the results found by Vercellotti and Podesta[10] where Piezosurgery® microsaw was used to eliminate cortical bone resistance to achieve faster orthodontic tooth movement reducing treatment time by 60%–70%.

Thus, by the findings of the present case, taking into consideration the limitations, it can be inferred that the availability of advanced surgical devices such as the Piezosurgery® has not only reduced greatly the time period of orthodontic treatment but also has helped in overcoming the limitations of conventional corticotomy techniques. However, further clinical studies should inculcate larger sample size with longer posttreatment follow-up to further clarify the longevity of the results achieved.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understand that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.