Hi guest!
Great question. From my understanding, Class I, II, III & IV signify the level of compromise based on a few main categories:
Bone height, mandibular
Maxillomandibular relationship
Residual ridge morphology, maxilla
Muscle attachments
I have some additional information I would be happy to e-mail you if you would like to post your e-mail address or send me an e-mail to
courtney@dentalwriter.comBut basically, the dentist should be able to determine after examining the patient what class applies. If not, then "unspecified" should be used.
Hope this helps!