Patients

Here are all the patients that visited Dr. Philip Sherman's office in Finding Nemo:

Mr. Tucker
Alan Tucker is a patient of Dr. Sherman's in the film Finding Nemo.

He is seen after Nemo is put into Dr. Sherman's fish tank as he is getting an anterior crown. He flinches and screams in pain whenever Dr. Sherman does operations on his teeth.

The Prime Minister of Australia
Prime Minister John Howard can be seen getting his checkup during the Tank Gang's second attempt at clogging the filter. When Nigel the pelican crashes into the window overlooking the harbor before being let in to tell Nemo about Marlin and Dory's journey to Sydney to find him. The noise startles Dr. Sherman so much that he accidentally forcefully yanks out the prime minister's bad tooth, causing him to scream in pain.

Davey Reynolds


Davey Reynolds appears in the scene where the tank is very dirty. Davey Reynolds' name is most likely a reference to Pixar employee David Reynolds, who wrote Finding Nemo.

Unnamed Boy and Mother


This boy and mother can be seen in the waiting room three times near the end of the film during Darla's checkup: The first time when the Tank Gang mistake them for Darla resulting in a "false alarm" after mocking the AquaScum 2003 for ruining their escape plan, but before Dr. Sherman scoops Nemo out of the tank; and the second and third times where they are sitting on a couch facing the fish tank where they notice the commotion between Dr. Sherman, Darla, Marlin, Dory, Nigel, and Gill while attempting to get Nemo away from Darla (the second time they appear, the boy is surprised, and the third the mother gets surprised as well), since the fish tank is located inside a rectangular hole in the wall separating the waiting room from the dental office.

They have the most screentime of all of Dr. Sherman's patients seen in the film, and are the ones seen in the most detail (and even more so in the fullscreen version, see Trivia below): the boy is presumably 8-10 years of age, has short brown hair, and wears a dark blue T-shirt, tan shorts, and brown sandals (implied, since his lower legs were cut off by the bottom of the screen in his and his mother's first appearance and by the coffee table in their last two); while his mother appears to be in her 30s, also has brown hair styled into a flip, and she wears a light blue jacket over a light green shirt (presumably a T-shirt judging by the shape of the collar. Although she did not remove the jacket, it's implied that the shirt has short sleeves underneath.), a calf-length light blue skirt (the hem, which features a faint stitching represented by two thin lines, extends down to where an electrical socket near the door would be) concealing her long, thin legs (see Trivia below), and gray tennis shoes. In their last two appearances, the boy is reading an Incredibles comic (again, see Trivia below) while his mother is reading a newspaper showing the current weather at Sydney, Australia.

Darla
See here.

Unnamed Brunette-haired Woman
This second brunette haired woman can be seen being surprised by the above commotion in the dental office with the boy and mother. Unlike the mother, she is a teenager instead of an adult.

Unnamed Balding Man
This balding, middle-aged man can be seen also being surprised by the above commotion in the dental office with the boy and mother.

Trivia

 * During the boy and mother's last two appearances, the boy can be seen reading an Incredibles comic, foreshadowing the release of The Incredibles, which was already released the following year.
 * Because of the reframing process Pixar uses for its fullscreen home releases, in the fullscreen version of Finding Nemo (exclusive the 2003 US original home release, the 2012 Blu-ray release and the international versions of both releases only contains the widescreen release), when the boy and his mother enter the waiting room, the mother's skirt billows upward for a split second, revealing the visible portion of her legs underneath. However, we still see the mother's legs in the widescreen version, but she and her son were sitting. It happens at 1:14.57 in the film.
 * The mother resembles either Ms. Davis, Helen Parr, adult Ellie Fredricksen, or a modernized Queen Elinor.
 * The mother's wardrobe is one of Pixar's first attempts at animating realistically-animated flowing skirts and/or dresses on women.
 * When we see the dentist's office from the boy and mother's perspective from inside the fish tank (it's located inside a rectangular hole in the wall separating the office from the waiting room), when Dr. Sherman is trying to get Nigel, Marlin, and Dory away from Nemo, he looks like if he is bouncing back and forth in front of Darla while Darla is screaming.