Evaluation of Upper Anterior Teeth Retraction Rate Assisted by Two Corticotomy Techniques
Condition: Class II Division 1 Malocclusion
MeSH terms: Malocclusion
Study type: Interventional

Summary: 
      This study aims to assess the dental changes, periodontal health and the pulp vitality in
      mini-screw supported en-masse retraction associated with traditional or flapless corticotomy
      techniques.

      40 adult patients exhibiting class II division 1 malocclusion requiring upper first premolar
      extractions followed by en-masse retraction will participate in the study. They will be
      randomly and equally distributed into two groups: traditional corticotomy (20 patients)
      versus flapless corticotomy (20 patients). The corticotomy procedure will be performed
      pre-retraction. The dental changes will be assessed using dental casts. The impressions will
      be taken after finishing the leveling and alignment phase and before starting the en-masse
      retraction (T0), 1 month (T1), 2 months (T2), 3 months (T3), 4 months (T4), and 5 months (T5)
      following the onset of en-masse retraction. The final impression will be considered at the
      end of the en-masse retraction (when the canines reach Class Ι relationship).
    

Detailed description: 
      One of the most important challenges in daily practice is prolonged orthodontic treatment
      duration. For that lots of therapeutic procedures have been introduced to minimize
      orthodontic treatment time such as surgical interventions. Even though the traditional
      corticotomy with flap elevation proved to be effective in accelerating different types of
      tooth movement, it has been deemed aggressive. Therefore, minimally invasive surgical
      techniques have been proposed and labeled 'flapless corticotomies'.

      In flapless corticotomy group, vertical soft-tissue incisions will be made on the buccal and
      palatal gingiva by using a blade N.15. 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 second
      premolars. The incisions will be 5 mm long and started 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.

      In traditional corticotomy group, a full-thickness mucoperiosteal flap will be elevated
      including the interdental papilla, and extended from the distal side of the second premolar
      on the right side to the same position on the left side without performing any vertical
      releasing incisions. The full-thickness flap will be extended 3 mm above the root apices,
      from the buccal and palatal sides, knowing that the incision in the incisal papilla region
      will be done around it with a (V) or (U) shape. Then, one vertical incision between the roots
      of upper anterior teeth and two vertical incisions in the site of first premolar extraction
      will be made by the piezosurgery knife. The vertical incisions will be connected by a
      horizontal incision using the piezosurgery knives. The vertical incisions will be 3 mm in
      depth, starting 2-3 mm apical to the alveolar crest, and extending 3 mm beyond the root
      apices. The interrupted technique of suturing will be done using a non-absorbent 3-0 black
      silk.

      The en-masse retraction will be begun 4 days after carrying out the corticotomy procedure
      using 0.019×0.025-inch SS archwires with 8-10-mm long soldered hooks located distal to the
      lateral incisors. NiTi closed coil springs with 9-mm long will be extended from the
      mini-screws to the soldered hooks and applied 250-g of force per side. The patients'
      follow-up appointments will be every 2 weeks. The force will be measured on every appointment
      and adjusted if needed. The endpoint of the monitoring period will be the session when
      canines reached a class Ι relationship.
    

Intervention name(s): Traditional corticotomy; Flapless corticotomy
Intervention type(s): Procedure; Procedure
Intervention description(s): A full-thickness mucoperiosteal flap will be elevated including the interdental papilla, and extended from the distal side of the second premolar on the right side to the same position on the left side without performing any vertical releasing incisions. Then, one vertical incision between the roots of upper anterior teeth and two vertical incisions in the site of first premolar extraction will be made by the piezosurgery knife.; Vertical soft-tissue incisions will be made on the buccal and palatal gingiva by using a blade N.15. 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.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: En-masse; retraction; corticotomy; flapless; miniscrew; upper anterior teeth