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ePaper created 2018-03-13, 09:28:55 | version 1.38.0
| research Six keys to effectively using alveolar corticotomy: A different perspective on surgically assisted tooth movement Dr Raffaele Spena, Italy Introduction Alveolar decortication (corticotomy) has long been used with orthodontic treatment in order to accelerate orthodontic tooth movement (OTM) while reducing the undesired effects of root resorption, loss of vitality, peri- odontal problems and relapse of the corrections. The acceleration of tooth movement should shorten the ther- apy. However, the scientific and clinical assumptions of the early days were totally different from the more recent ones: we moved from a pure mechanical approach to a biological and physiological one. In 1983, Suya1 proposed a great improvement of the surgical approach described in 1959 by Kole2 modifying the horizontal osteotomy in a corticotomy, avoiding the alveolar crest in the vertical cuts and eliminating the luxation of the blocks. He proposed this “corticotomy- facilitated orthodontics” to treat adult patients, anky- losed teeth and crowded malocclusions to avoid premo- lar extractions. Like Kole, Suya believed he was creating bony blocks and suggested accomplishing most of the movements in the first three to four months of treatment before the fusion of the blocks (healing of the bone). The concept of corticotomy-assisted OTM drastically changed in 2001 after the publication of Wilcko et al.3 In this key case report, two adult patients received a selec- tive corticotomy, along with alloplastic resorbable grafts, to increase the bone level and avoid the risk of reces- sions. An accurate evaluation with CT scans before and after treatment, and histological sections in one case, allowed the authors to formulate a new hypothesis about what really happens at the bone level after corticotomy. No movement of tooth–bone blocks, but a transient reduction of mineralisation of the alveolar bone and mod- ifications similar to those described by Frost4–7 during the healing of fractured bones and named “regional acceler- atory phenomenon” (RAP) most likely occur. The surgery - orthodontic protocol proposed by Wilcko et al.3 has been subsequently patented as Periodontally Accelerated Osteogenic Orthodontics (PAOO). The claims of PAOO are (a) accelerated tooth movement with reduction of the total treatment time; (b) osteogenic modifications with trans- portation of the bony matrix, and final improvement of hard- and soft-tissue support of the teeth treated ortho- dontically; (c) increase of the short- and long-term stabil- ity of the orthodontic treatment. So far, scientific evidence has been given only on the acceleration of tooth move- ment that is transient, and lasts as long as there is a RAP modification in the alveolar bone surrounding the teeth. After more than one and a half decades of clinical experience with alveolar corticotomy, in light of the cur- rent literature published on this topic, six rules have been established that should be taken into account when con- sidering using alveolar corticotomy in a complex ortho- dontic case. These keys are the best way to ensure effec- tiveness and reduce the risk of producing no positive effect or, worse, causing damage. The six keys are as follows: 1. Alveolar corticotomy is to facilitate OTM. 2. Alveolar corticotomy has limited effect in time. 3. Alveolar corticotomy has limited effect in space. 4. A proper surgical procedure must be followed. 5. Proper orthodontic management after corticotomy must be performed. 6. Proper patient selection for corticotomy is essential. A detailed description of each rule follows. 1. Alveolar corticotomy is to facilitate orthodontic tooth movement (Periodontally Facilitated Orthodontics) Speed is a fascinating issue in life. We like to go fast in cars, motorbikes, boats, airplanes and so forth. Speed in orthodontics is a different matter. It is one of the main objectives of modern orthodontics to reduce treatment time, but we must recognise that a great number of vari- ables may affect it.8–11 The initial difficulty of the malocclusion and tooth mal- position, the age of the patient, the variability of the indi- vidual response to the treatment, the quality of the end 20 ortho 1 2018