Tore Sinus Membrane: How Long Should I Wait for Re-Entry and What Complications Should I Expect?

Dr. R asks:
I attempted a maxillary sinus lift through a lateral window approach and unfortunately I tore the membrane. I closed up the surgical site and am allowing the membrane to heal before I attempt a re-entry. How long should I wait for the sinus membrane to heal before I attempt the re-entry? Is there any way I can determine if the membrane has healed? Should I expect any complications with the membrane when I re-enter the surgical site?