Efficacy of Modified Piezocision Corticotomy Procedure to Accelerate Orthodontic Tooth Movement

Seven to ten days after first premolar extraction, experimental group received fixed orthodontic appliances of the pre-adjusted edgewise McLaughlin Bennett Trevisi (MBT) prescription brackets and buccal tube of the 0.022-inch slot (Natural orthodontic product) were bonded from the first molar to the first molar teeth, with light cure bonding kit, i.e., Transbond XT (3M Unitek, Monrovia, Calif), and curing was performed by using a light-emitting diode (Dentsply International, York, Pa). To initiate the levelling and alignment phase a first archwire 0.012-inch nickel-titanium (3M Unitek) was inserted and tied to each bracket in the maxillary and mandibular arch using an elastic module just immediate after the bonding of each brackets completed. After that, the archwire sequences were maintained 0.016-inch, 0.017 × 0.025–inch, and 0.019 × 0.025–inch nickel-titanium used for ideal alignment. The approximate amount of time taken to bond the fixed orthodontic appliance and placement of first archwire together was 20-25 minutes. The follow up visit to activate the orthodontic appliance was performed every 4-5 weeks until complete the leveling and alignment. Each number of archwires was replaced only when the possibility for full engagement into the brackets slot with a minimal amount of bending and without expressing excessive force on anterior teeth. Hence, it could produce an adequate amount of force for the tooth movement and achieved ideal leveling and alignment. There was also used lace back ligature from the first molar to second premolar tooth to prevent the anchorage loss and proclination of the anterior tooth. During each appointment, the position of all the brackets was evaluated, and if required, the bracket was re-bonded to the correct position to achieve the ideal alignment. The completion of leveling and alignment of the teeth was considered finished when Little’s Irregularity Index (LII) of the anterior teeth show 0 mm, and the feasibility of inserting the final archwire 0.019 x 0.025 SS passively into all brackets as the bracket slot used 022-inch. Experimental subjects received piezocision corticotomy procedure 5-10 minutes after the bonding of fixed orthodontic appliances on same day. Before surgery proper aseptic technique was maintained, all instrument used for this surgery purpose was sterilized by autoclave, and before start surgery patient was advised to rinse the mouth with 0.2% chlorhexidine mouth wash. A panoramic radiograph was used to assess the root proximity and the long axis of the teeth before starting the procedure. Local anaesthesia was administered using 2 percent Lidocaine with 1:100000 epinephrine. After given local anaesthesia, seven vertical interproximal incisions were made by using a 15C surgical scalpel blade through the gingiva on the labial aspect of the maxillary and mandibular six anterior teeth. In cases of root proximity, this procedure was not performed in that particular area. The scalpel blade was positioned on the inter radicular attached gingiva at an inclination of 45– 60 degree to the long axis of the maxillary and mandibular six anterior teeth. The vertical incisions were made 3mm below from the interdental papilla to preserve the papillary gingival margin and to preserve the alveolar crest, and extended the incision line up to 4-5mm long. Once the incisions were made, the gingiva was slightly elevated laterally to check out the bone and roots. A piezosurgical blade (BS1 insert, Satelec Acteon Group) was inclined at 45– 60 degree to the long axis of the tooth to perform the cortical alveolar incisions 3mm below from the alveolar crest at a depth of 3mm to reach the medullary bone. The depth of piezotome cutting was measured by millimeter marking on the blade itself and maintained the cutting depth continuously during the operation. The piezoelectric device setting was adjusted to deliver low-frequency ultrasonic waves (28–36 kHz) with the power button one that is required for cutting the cortical bone, including continuous irrigation of 60% saline. Under these conditions, the micro-vibrations that are creating in the piezoelectric hand piece cause the inserts to vibrate linearly between 30 and 60µm; also used high-speed suction to remove any excess fluid. After surgery, no subsequent sutures were required as it is a minor surgery, and no bone grafts were required. Hemostasis was maintained by cotton gauze and thumb pressure. The patients were advised to take analgesics (paracetamol) only if necessary and careful tooth brushing and use 0.2% chlorhexidine mouthwash twice a day for one week were recommended. All experimental subjects were advised to contact immediately to the Orthodontic Clinic of HUSM if any complications arise after surgery and get ensure normal healing. The approximate time taken to complete the piezocision corticotomy procedure was 30-40 minutes. All the piezocision procedure and orthodontic procedure was performed by the principal investigator who is a Orthodontist.