Sixty patients who need extraction-based treatment of the maxillary first premolars with subsequent retraction of the maxillary anterior teeth will be divided randomly into three groups: piezocision group, piezocision with low-level laser therapy group, and control group. In each group, after the levelling and alignment phase is completed, the rectangular stainless steel archwires (0.019" × 0.025") will be inserted, then after two weeks, the en masse retraction will be started via closed nickel-titanium coil springs applying 250 g of force per side. For anchorage, mini implants will be inserted between the second premolars and the first molar on each side.
Regarding the Piezocision, vertical soft-tissue incisions will be made on the buccal and palatal gingiva. One incision will be made between the roots of the six upper anterior teeth, and two incisions will be made between the upper canines and the second premolars. The incisions will be 5 mm long and start 4 mm apical to the interdental papilla. Then a piezosurgery knife will be inserted to perform the cortical alveolar incisions with 3-mm in-depth and 8 mm in length. No suturing will be needed. Regarding the piezocision with the later application of low-level laser therapy (LLLT): After six weeks of piezosurgery, a diode laser (wavelength: 810 nm and exposure time of 10 seconds\\point) 10 seconds per point will be applied on each tooth of the six maxillary anterior teeth according to this protocol: the root will be divided theoretically into two halves; gingival and cervical, and the laser will be applied in the center of each half from both buccal and palatal sides which means four application points and total energy of 16 Joules per tooth. LLLT irradiation will be performed in the sixth week after the onset of mass retraction (day 0). After that, irradiation is repeated on days 3, 7, and 14, then every two weeks, until the class I canine relationship is achieved and/or spaces lateral to incisors are closed
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
63
One incision will be made between the roots of the six upper anterior teeth, and two incisions will be made between the upper canines and the second premolars. The incisions will be 5 mm long and start 4 mm apical to the interdental papilla. After six weeks of piezosurgery, GaALAs diode laser (wavelength: 810 nm and exposure time of 10 seconds\\point) 10 seconds per point will be applied.
One incision will be made between the roots of the six upper anterior teeth, and two incisions will be made between the upper canines and the second premolars. The incisions will be 5 mm long and start 4 mm apical to the interdental papilla.
After the levelling and alignment phase is completed, the rectangular stainless steel archwires (0.019" × 0.025") will be inserted, then after two weeks, the en masse retraction will be started via closed nickel-titanium coil springs applying 250 g of force per side.
University of Damascus
Damascus, Syria
The rate of en-masse retraction of upper anterior teeth
The rate of en-masse retraction of upper anterior teeth (mm/month) in each group will be calculated. This outcome will be measured by the following steps: Drawing a projection from the upper canine apex to the middle palatal bone line. Drawing a projection from the upper central incisor edge to the middle palatal bone line. Drawing a projection from the mesial ending of the third palatal rugae to the middle palatal bone line. Measuring the distance (mm) between the canine apex and third palatal rugae projections. Measuring the distance (mm) between the central incisor edge and third palatal rugae projections. The rate of en-masse retraction will be measured by dividing the distance between the canine apex/central incisor edge projections and the third palatal rugae projection by the time elapsed between assessment times.
Time frame: This will be assessed at the end of the active treatment, which is expected to occur within five months
Change in the anteroposterior movement of the molar
The anteroposterior movement of the molar (mm/month) in each group will be calculated. This outcome will be measured on the dental casts by drawing two projections from the central groove of the first maxillary molar and the mesial ending of the third palatal rugae to the middle palatal bone line. The anteroposterior movement of the first maxillary molar (mm) will be measured by dividing the distance between the two projections by the time elapsed between assessment times.
Time frame: Time 0:1 day before the beginning of the retraction phase (baseline). Time 1: after 1 month from the beginning. Time 2: after 2 months. Time 3: after 3 months. Time 4: after 4 months. Time 5: immediately after the end of the retraction phase
Change in the inter-canine width
The change in the inter-canine width (mm/month) in each group will be calculated. Assessment will be performed by measuring the distance between the cusp tips of the two upper canines. This variable will be measured on dental casts.
Time frame: Time 0:1 day before the beginning of the retraction phase (baseline). Time 1: after 1 month from the beginning. Time 2: after 2 months. Time 3: after 3 months. Time 4: after 4 months. Time 5: immediately after the end of the retraction phase
Change in the inter-molar width at 5 months
The change in the inter-molar width (mm/month) in each group will be calculated. Assessment will be performed by measuring the distance between the central groove of the two first maxillary molars. This variable will be measured on dental casts.
Time frame: Time 0:1 day before the beginning of the retraction phase (baseline). Time 1: after 1 month from the beginning. Time 2: after 2 months. Time 3: after 3 months. Time 4: after 4 months. Time 5: immediately after the end of the retraction phase
Change in molar antero-posterior position
The amount of distance being travelled by the first molars is going to be measured on study models taken at monthly intervals until the end of the retraction phase.
Time frame: Time 0:1 day before the beginning of the retraction phase (baseline). Time 1: after 1 month from the beginning. Time 2: after 2 months. Time 3: after 3 months. Time 4: after 4 months. Time 5: immediately after the end of the retraction phase
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