Saltwater crocodiles will often swallow stones to help grind up food in their stomach. Their teeth are like sharp spikes and each one is replaced by a new one every time one wears out, so the saltwater crocodile never looses it's teeth which one of the reasons these crocs live so long.
The saltwater crocodile has a wide snout compared to most crocodiles. However, it has a longer muzzle than the mugger crocodile; its length is twice its width at the base. The saltwater crocodile has fewer armour plates on its neck than other crocodilians. On this species, a pair of ridges runs from the eyes along the centre of the snout. The scales are oval in shape and the scutes are either small compared to other species or commonly are entirely absent. In addition, an obvious gap is also present between the cervical and dorsal shields, and small, triangular scutes are present between the posterior edges of the large, transversely arranged scutes in the dorsal shield. The relative lack of scutes is considered an asset useful to distinguish saltwater crocodiles in captivity or in illicit leather trading, as well as in the few areas in the field where sub-adult or younger saltwater crocodiles may need to be distinguished from other crocodiles. The adult saltwater crocodile's broad body contrasts with that of most other lean crocodiles, leading to early unverified assumptions the reptile was an alligator. The head is very large. The largest skull sized that could be scientifically verified was for a specimen in the Muséum national d'Histoire naturelle sourced to Cambodia, the skull length for this specimen was 76 cm (30 in) (female skull lengths of over 45 cm (18 in) are exceptional), with a mandibular length of 98.3 cm (38.7 in) and a maximum width across the skull (near the base) of 48 cm (19 in). The length of the specimen this came from is not known but based on skull-to-total-length ratios for very large saltwater crocodiles its length was presumably somewhere in the 7 m (23 ft 0 in) range. Although it is the largest overall living crocodilian and reptile, other crocodilians may have a proportionately longer skull, namely the gharial (Gavialis gangeticus) and the false gharial (Tomistoma schlegelii), skull lengths in the latter have been verified up to 84 cm (33 in) (the largest crocodilian skull verified for a living species), although both of these thin-snouted species have less massive skulls and considerably less massive bodies than the saltwater crocodile. The teeth are also long, with the largest teeth (the fourth tooth from the front on the lower jaw) having been measured at up to 9 cm (3.5 in) in length. If detached from the body, the head of a very large male crocodile can reportedly weigh over 200 kg (440 lb) alone, including the large muscles and tendons at the base of the skull that lend the crocodile its massive biting strength.