A dislocated jaw should be put back as soon as possible as there is a risk of osteoarthritis setting in due to damage to the cartilage and other complications as following:
1) chronic recurrent dislocations,
2) ischemic necrosis of the condylar head,
3) traumatic damage to the articular disk,
4) mandibular osteomyelitis
5) permanent malocclusion
These complications are dependent on various factors;
a) Age of the patient
b) Duration of the dislocation
c) Severity of the dislocation (more severe dislocation can injure the blood supply)
d) Associated soft tissue injury
So a set rule for a duration cannot be assigned and this is absolutely dependent on the individual dislocation. But as soon as reduction means within 72 hours and not later than 7-10 days, which will increase the complication rate even in mild to moderate dislocation.
Please feel free for your follow up questions.