A dentist would know that asking about dentures is always required for general anesthesia. A tube is pushed into the patient's mouth and down the trachea so the patient can be respirated. Dentures must be removed so they will not interfere with the work of the anesthesiologist.
When Dr. Pincus is taking an impression of a female patient, he has her bite down into a tray of alginate. That material is not supposed to be bitten into but instead it is seated and held with hand pressure. Biting into an alginate impression can distort the impression or push the teeth into the tray, also distorting the impression.
When Gwen comes to visit Dr. Pincus in his office, the doctor was just finished with a patient, who then left the room. The doctor picked up a few of the now unsterile and contaminated instruments with his bare hands which would not be done without gloves on. Furthermore, he invited Gwen to sit in the chair so he could look at her sore tooth without first cleaning the room and putting out sterile instruments.
At the exhibition, when Gwen is conversing with Bertram, Gwen accidentally and briefly looks at Frank (standing in the foreground), realizes then turns away giving the appearance of an act of embarrassment.
When Richard came, unscheduled, to Dr. Pincus' office at the end of a day, Dr. Pincus started to examine the bothersome tooth Richard indicated. Dr. Pincus did not first put on gloves before picking up the mirror or explorer and looking in Richard's mouth.
The doctor asks if his hallucinations are "visual or oral" (possibly "aural"). No doctor uses "oral" or "aural" to describe auditory hallucinations. She would say "hearing voices" for a non-medically trained patient. For a dentist, the term "auditory" would surely be used.
Dr. Pincus pours the contents of the left-most bottle of laxative into a glass and drinks it. Firstly, the level of laxative in the glass drops by about an inch between pouring and drinking, presumably due to a missing shot. Then, when the camera returns to the three bottles on the counter, all three bottles appear full.
In the view down from the apartment that the air conditioner falls from, there are at least four air conditioners in other windows, directly below that apartment. When the air conditioner actually falls all those air conditioners are gone, and the air conditioner falls straight down.
There is an ice storm outside the day Dr. Pincus decides to start helping the ghosts. Assuming he gets to work right away, there should be still be cold, wet weather outside when he visits each of the mourners, but instead it is mild, autumn weather.
In a closeup of the bottle of colyte laxative the prescription label says "TAKE ONE TABLET DAILY WITH 8OZ GLASS OF WATER". However, when he takes the medicine, it's a liquid not a tablet. Also the red label that says "WARNING LAXATIVE AGENT" seems to disappear the second time the bottles are all three in a row.
In the elevator talking to Gwen, Dr. Pincus told her to check the mummy for something he saw on the slide show: "...some bone loss on the upper left mandibular gumline." If there was bone loss on the upper jaw, it would be the maxilla. The correct verbiage should be "...some bone loss on the upper left maxillary gumline." The mandible is the lower jaw. Additionally, upon examination of the mummy in a later scene, the upper right side of the mouth was examined.
When the close-up of the label is shown on the laxative agent Dr. Pincus is supposed to take, it shows the directions as: TAKE 1 TABLET DAILY WITH 8 OZ GLASS OF WATER, when it is a liquid solution. Also, it shows that the Colyte solution is 100mg per dose and that there are qty 50 doses, which if this were truly Colyte, one dose is 240 grams per 1 bottle which is 4000 ml. Even if it was 100 mg per dose and he had 50 doses, that would be the equivalent of almost 21 bottles of the 240 gram solution. So he would have almost a full 21 4000ml bottles sitting in front of him instead of just 3.
When Dr. Pincus is asked to take a look at the mummy because of his expertise as a dentist, he takes out his pocket calendar and opens it to the very beginning of the book near January or maybe February. However, the very next scene shows the bright colors of fall in Central Park which would be near September. However, he may be using an academic diary, which begins in August or September.
When Dr. Pincus first leaves his office, his apartment building is directly to the left. After the ghosts show up in his apartment and he goes to work in the early morning he goes left out of his building instead of right to his office. However, he is just trying to get away from the ghosts at this point, and Frank's dialogue seems to suggest he's trying to find a hotel.
While sitting a the bar Pincus orders a sapphire martini. The bartender is shown shaking it up. A sapphire gin martini shaken would appear cloudy (bruised) when poured into the glass. Pincus is next seen with a perfectly clear martini which would have to have been stirred.
When Gwen invited Pincus over for dinner, her fiancée Richard is called into work and leaves the apartment. As he is leaving, his reflection is in the photograph behind Gwen. He opens the door, but when he does he just stands still.