After my Invisalign treatment I notice my temples and cheeks have sunken. Is this normal?

Although a significant change in external face form in these areas is unlikely as a result of invisalign movements, you definitely want to have your treating invisalign dentist check this.  If significant narrowing of the arches is not part of the plan, then there has to be another reason.  Have you lost weight recently?  This can definitely cause these kinds of changes, and if your not purposely trying to lose weight, then a doctor should be consulted.  Good Luck!