Effect of Corticotomy on the Orthodontic Tooth Movement
Condition: Tooth Crowding
MeSH terms: Malocclusion
Study type: Interventional

Summary: 
      Orthodontic therapy allows for the treatment of dental malpositions in order to produce an
      adequate relationship between teeth during occlusion. Conventional orthodontic therapy
      applies slight forces and moves teeth slowly. It is generally performed during a 2 year
      minimum of time. Recent studies seem to suggest that orthodontic therapy time can be
      shortened by surgical assistance (corticotomy). This investigation is aimed to determine the
      velocity of tooth movement and changes in periodontal clinical parameters between
      corticotomy-assisted orthodontic therapy and conventional orthodontic therapy.
    

Detailed description: 
      The use of surgical techniques to accelerate orthodontic tooth movement has been developed.
      By means of surgical burs, vertical grooves in the cortical plate (corticotomy) are produced
      mesial and distal to the roots of teeth that are being moved 3 mm below the marginal crest
      and extending beyond the apex. Animal studies showed that the rapid orthodontic tooth
      movement was due to increased cellular activity in the surrounding periodontal tissues, a
      regional acceleratory phenomenon (RAP). A high osteoclastic activity is observed in the
      compression side although is also observed in the tension side to a less degree. Histological
      analysis indicates that at day 21 the remodeling tissues are replaced by a fibrous tissue and
      later (60 days) by bone. Furthermore, the tissues immediately adjacent to the corticotomy are
      characterized by an increased width of the periodontal ligament, less calcified spongiosa
      bone surface and higher counts of osteoclasts. But not only the catabolic activity is
      increased (osteoclasts) but also the anabolic activity (osteoblasts) is increased 3-fold as
      well. This balances the rate of bone resorption and bone apposition. An interesting finding
      was the reduced rate of hyalinization at the compression site, which may be due to increased
      width of the periodontal ligament and thus facilitating tooth movement.

      As opposed to conventional osteotomy used in alveolar distraction, the preservation of the
      medullar vasculature during a corticotomy procedure provides and adequate blood supply and
      nutrition. This accelerates the rate of tissue healing and remodeling and hence orthodontic
      movement can start immediately after surgery. It has been calculated that the rate of tooth
      movement is doubled (2.5mm to 3mm at day 25) in comparison to standard orthodontics without
      any detrimental effects on periodontal tissues. This surgically assisted approach for
      improved tooth movement is beneficial for molar intrusion, space closure, de-crowding and
      open bite management.

      This investigation is aimed to determine the velocity of tooth movement and changes in
      periodontal clinical parameters between corticotomy-assisted orthodontic therapy and
      conventional orthodontic therapy. Periodontally and systemically healthy subjects in need of
      orthodontic therapy for the treatment of teeth crowding in the anterior segment. The rate of
      tooth movement will be assessed by radiographs and cast models and periodontal clinical
      parameters will be recorded at each visit during the 4 month follow-up.
    

Intervention name(s): Corticotomy; Conventional orthodontics
Intervention type(s): Procedure; Procedure
Intervention description(s): After a periodontal full flap is dissected, by using small round burs, vertical lines (2 mm depth corticotomy) parallel to each root of the teeth in the anterior segment (canines and incisors) are created 5 mm beyond the apex in the maxillary bones and interconnecting the lines at the apex by horizontal corticotomies. Marginal bone crest is not touched by the surgical procedure.; Conventional orthodontic treatment
Other intervention name(s): Osteotomy; Orthodontic treatment
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Tooth crowding; Teeth malpositions; corticotomy; orthodontics; tooth movement; periodontal parameters