Mouth Cam

More a framing device than an actual camera technique, the "Mouth Cam" is a shot taken from a position that appears to be inside the mouth of one character as he, she or it faces or approaches another character. Most of the time, it is used when someone or something is about to or even is in the process of being eaten. Almost a Discredited Trope these days, although it has been used (apparently in all seriousness) as recently as the Jaws movies.

Sister trope to Binocular Shot and Trunk Shot.

Not to be confused with Eat the Camera.

Examples of Mouth Cam include:

Anime and Manga

Shown in one scene in an episode of Gigantor from inside Dr. Katzmeow's mouth.
Episode 1 of Kujibiki Unbalance (which is the Show Within a Show in the anime Genshiken) has a Mouth Cam shot with a bit of Innocent Innuendo as one characters waits expectantly for another to feed her a mushroom, stem-first.
Inside the jaws of a lizardman in Rosario + Vampire.
Used in Fullmetal Alchemist: Brotherhood at one point within Gluttony's mouth.
This trope is used sometimes in Bleach usually inside the Hollows mouths. It was also used with Nel when she pulls her Uvula.
Used in episode 3 of Puella Magi Madoka Magica. HEADCHOMP

Film

The Jaws films, as noted above.
- Averted in the first one, but it was however used in the trailer.
The "Dentist!" musical number from Little Shop of Horrors includes a sequence shot from inside a dental patient's mouth.
The 2005 film Madagascar has a sequence where a clueless lion is trying to be friendly with a tiny primate, with a Mouth Cam shot used to show just how threatening he is unintentionally being.
The very bad film Ice Grill does a particularly unsavory variation, with a shot meant to appear as if it had been filmed through a character's fly.
Used more or less seriously in the 2005 film Charlie and The Chocolate Factory.
In The Simpsons Movie, we get a Mouth Cam shot of him eating a burger
One appears in Stranger Than Fiction to show Harold Crick brushing his teeth.
This does happen in the An American Tail movies but only because Fievel is actually inside the mouth at the time.
In Anaconda we get a mouth shot of the villain being swallowed by the titular creature.
This trope is used in a rather squicky way in the low budget film Scar 3D. The shot is within a teen girl's mouth while a knife cuts her cheek open.
One Crazy Summer parodies the Jaws angle with a view from the mouth of the "rabid killer dolphin" submarine as it attacks the villain.

Live-Action TV

Edina's liposuction nightmare in Absolutely Fabulous.

Music

Inverted in the video for Huey Lewis and the News's song "Hip to Be Square". The video is composed almost entirely of extreme closeups on Lewis, his bandmates and various instruments. Twice in the video a shot actually starts out with a focused on the back of Lewis's mouth, but before the viewer can quite register what he's looking at, the camera pulls out until Lewis's face fills the frame.

Video Games

Present in some video games with playable toothy monsters, such as skulks in Natural Selection and the Kabuto in Giants: Citizen Kabuto. Ostensibly being first-person views, it does seem to imply that their eyes actually are within their mouths.
- Also pops up in Ghouls vs. Humans for most of the Ghoul classes (they're huge floating heads who usually attack by biting/screaming/breathing something out of their mouths).
The Cave Of Bad Dreams level in Rayman 2 uses this when the Guardian of the Cave catches up to Rayman and chases him down a slippery slide, with the camera switched to a POV shot of the Guardian's mouth, sharp teeth dripping with saliva and all. It's very effective.
In Ratchet and Clank 3, during the boss fight against the Mother Tyrrhanoid, there is a sequence where the camera takes up residence inside her head. It's very definitely not her POV, because all her eyes are on eyestalks. It's not a typical Mouth Cam either, as no teeth or lips are visible at the edge of the screen. On the other hand, her mouth is probably big enough that you wouldn't see them... Unusual also in that she's not trying to eat Ratchet, she's trying to shoot him.
If you're playing as an Alien in the Aliens vs. Predator video games, teeth will appear on the top and bottom of the screen if you've lined up a headbite on an unlucky victim.
Two of them (in the mouths of manatees), both in Tales of Monkey Island Chapter 3: Lair of the Leviathan: one when Guybrush is approaching the cave guarded by a female manatee, and one near the end of the chapter, as the Giant Manatee approaches to swallow De Cava and his crew in the Howler Monkey.

Western Animation

Codename: Kids Next Door, "Op TEETH", has a Mouth Cam shot of Numbuh Three licking a lollipop within a plaque filled mouth.
One Bill Plympton short or another sees a date progress, from the viewpoint of the back of the mouth. It ends well.
Happens in Justice League Unlimited in "The Once and Future Thing" part 2-- we get a nice shot of the inside of the hyena-man's toothy maw.
Almost every episode Rugrats would use this trope. Sometimes a shot would be used when characters are crying, eating or even simply talking.
There are a few in Avatar: The Last Airbender, usually of Appa's mouth. There also some within Sokka's mouth, once where a spider has made its web while he was asleep and another when he insists that there was a wart on his "throat flap."
In one of the episodes of Ed, Edd 'n' Eddy, where they're filming a video, Ed randomly swallows the camera (shouting "Man the helms! DIVE, DIVE!"), ending up in a shot from inside his stomach as Edd digs it back out.
The Ursa Minor from "My Little Pony: Friendship Is Magic" in episode 6 exhibits this shot.
Happens in Disney's Pinocchio, through Monstro's mouth as he swallows the raft with Pinocchio and Geppetto
Used in Wolves, Witches, and Giants whenever the wolf ate someone.