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Problems, obstacles and complications with transpalatal distraction in non-congenital deformities.

INTRODUCTION
The transpalatal distractor is a bone-borne device that eliminates negative orthodontic effects during and after maxillary expansion. It produces virtually parallel expansion in the coronal plane. Orthodontic appliances can be installed at an earlier date than when tooth-borne expanders are used. Our aim was to improve the technique by reviewing the difficulties encountered during applications in the past.


PATIENTS AND METHODS
The files of 57 patients were analyzed for problems (difficulties requiring surgical intervention), obstacles (difficulties requiring surgical intervention but not interfering with the result), and complications (difficulties not resolved at the end of the treatment).


RESULTS
Twenty-nine difficulties occurred. In 25 cases they were considered to be a 'problem'. Nine problems were surgery related and 16 problems were related to the distraction device itself (14 episodes of loosening of the module, two instances of loss of one osteosynthesis screw). 'Obstacles' occurred in three cases, i.e. loosening of an abutment plate. There was only one 'complication': unilateral infraorbital hyposensibility in a case of a high level corticotomy.


CONCLUSION
The expansion goal was achieved in all patients. Loosening of the module proved to be the major cause of discomfort. The incidence of difficulties has lead to a change in the design of the hardware and in the surgical protocol.