Hi,
Welcome to sdn forums!!
Since u r a foreign trained dentist u shld 1st have ur credentials evaluated..then prepare for ur toefl and part 1 nbde....These are the basic requirements u shld 1st fulfil in order to be eligible to apply in a school here..However, in some schools u need a part 2 score too..and in some GRE too[ sice u said u want to become an orthodontist]..U can go for an Adv. Standing program ..and then do PG in ortho..or go for MS..
Try going thro' all the links given in "links of interest for foreign trained dentist" here on sdn. It will be of gr88 help to you.
Also, try getting study material for part 1...U can buy from ebay or even from someone on sdn...try searching for it. I got my for 60-70$..dont recall exactly now..Get the 2006 decks too. I have heard tht from 2007 part 1 will have more of clinical ques..get this confirmed from others too...
When u r done wit ur part 1 prep..u can send all ur documents to ada and register for the test...thts it...
As u search thro' so many threads on sdn..u will get an answer to all ur ques..Since u r new here, I thought i might just give u a basic understanding of how things work...
PArt 1 has become ver competitive these days....so study hard..
all the best!!