Adult Human Skull Bone Count
The adult human skull contains 22 bones, excluding the 6 auditory ossicles (3 in each middle ear), for a total of 28 bones when the ossicles are included. 1, 2
Standard Anatomical Count
- The 22 bones of the adult skull consist of 8 cranial bones and 14 facial bones 3
- When the 6 auditory ossicles are added (malleus, incus, and stapes bilaterally), the total reaches 28 bones 1
- The auditory ossicles are among the smallest bones in the human body and are located within the temporal bones 1
Historical Context and Variability
- Historical bone counts have varied significantly, with reports ranging from 197 to 307 bones throughout the body over past centuries 2
- The modern count of 206 total body bones (which includes skull bones) resulted from exclusion of teeth and sesamoid ossicles, and reassessment of structures like the hyoid, sacrum, coccyx, and sternum as unitary bones 2
- The number of skull bones specifically is higher in young adults and lower in elderly individuals due to fusion of cranial sutures over time 2
Clinical Considerations
- The adult cranium is viewed as a collection of 21 bones (8 cranial + 14 facial bones, excluding ossicles), though individual differences exist 2
- Skull bone fusion patterns vary between individuals, making a definitive count challenging in some cases 2
- The skull's 29 bones (including ossicles) contain all typical bony features and landmarks used for clinical and anatomical reference 1
Common Pitfall
Do not confuse the infant skull bone count with the adult count—infants have more separate bony elements that fuse during development, particularly in the cranial vault where fontanelles and unfused sutures are present 3. The 22-bone count (or 28 with ossicles) applies specifically to the mature adult skull after all developmental fusion has occurred.