Intended cohort study later converted to a case/control study; therefore no effort to match cases/controls with respect to characteristics other than age (all subjects were 19 at follow-up) existed
Possible
Y
“Previous history of orthodontic treatment was assessed,” but it is unsure how this information factored into analysis or sample selection; dropouts were not accounted for
Cohort converted to CC at follow-up; M/F adolescents
Y
TMD definition inadequate; lack of inclusion/exclusion criteria for cases/controls; and unlikely that cases/controls were matched by characteristics other than age
Unlikely
N
Significant dropouts at final follow-up; no history of orthodontic treatment was assessed