External Occipital Protuberance: The Origin of Human Horns

In 3023, a new morphology appears in the human cranium, specifically the occipital bone. The occipital bone of the cranium covers the back portion of the head and houses the cerebellum (Sieroslawska 2022, 1). On the occipital bone, there is a portion of the bone called the external occipital protuberance (EOP) which varies in volume and is a trait considered sexually dimorphic (Figure 1) (Gülekon and Turgut 2003, 1). Enthesophytes are bony projections from sites from ligaments, tendons, or joint capsules attached to bone (Shahar and Sayers 2016, 286). Rarely seen in young adults, these projections usually need a long amount of time to develop, however, they are increasingly found as enlarged external occipital protuberance (Shahar and Sayers 2016, 286). The manufacturing and popularity of smartphones swept the globe and changed the course of history. Now, humankind has the ability to access a wealth of information that has accumulated over hundreds of years.

The global average time spent using smartphones in 2023 was 3 hours and 34 minutes (Howarth 2023). In different countries around the globe, the average time spent has only increased, for instance in the Philippines where the average was 5 hours and 47 minutes in 2023 (Howarth 2023). Society questioned the long-term impacts of a heavily relied-upon technology, however, there was not enough data to begin the study of smartphones and their impact on human health. Enlarged external occipital protuberances EEOPs were found to be most frequent in the millennial generation and thus smartphones were thought to be to blame (Jacques et al. 2020, 5). Figure 1 shows the variations of volume that EOPs can reveal. As time continued, the implications of modern technology made its statement on the health of humankind.

EOPs were studied in 2019 and 2011 in young French individuals who likely used a smartphone (Jacques et al. 2020, 1). Jaques et al. (2020, 1) obtained their data through CT scans on young individuals (205 individuals from 2011 and 240 from 2019) that were compared with ancient craniums and considered the effects smartphones may have on the occipital bone. However, they found there was not sufficient data on the use of smartphones due to their then-recent introduction (Jacques et al. 2020, 5). Figure 2 depicts an individual from the 2019 data set and the pronounced EOPs that have a relatively unknown driver (Jacques et al. 2020, 1).

Jaques et al. compared their data with ancient samples, particularly a young Egyptian female mummy with a pronounced EOP (2016, 5) (Figure 3). The comparison between the two samples demonstrated the longevity and commonality of the EOP to varying degrees in different populations. EOPs were not new in expression in humans, however, the millennial generation saw the most EOPs recorded(Jacques et al. 2020, 6). Jacques et al. noted that ancient craniums had EOPs with volumes similar to the upper range of today's measurements (2020, 5). However, data supporting smartphones as the cause of EOPs was not far along enough to rule it out entirely as a potential driver in the increased amount of EOPs in modern populations (2020,7).

Shahar and Sayers (2016, 1) have researched the biomechanical drivers associated with EEOP. Multiple kinds of skeletal dysplasias and syndromes, such as Occipital Horn Syndrome (OHS), fibrodysplasia ossificans progressiva, proteus syndrome, or radiation-induced exostosis exhibit EOPs (Takamine et al. 2004, 530), however there are some individuals who do not share these diseases and still demonstrate this particular variation. Shahar and Sayers (2016, 289) found that a higher percentage of EEOP cases were male, thus suggesting the possibility that it could be associated with OHS which is commonly found in males but this explanation does not explain why some women exhibit EEOP (Shahar and Sayers 2016, 286). OHS is associated with Menkes Disease in that they are both disorders related to copper transport (Kaler 1998, 85). OHS involves abnormal neurodevelopment in infancy, connective tissue problems, and sometimes early death (Kaler 1998, 85).

A high percentage (41%) demonstrating EEOP from the selected sample in the study by Shahar and Sayers (2016, 289) suggested an external excessive force was affecting young people and causing a bony projection to occur much earlier than it should. Previous literature suggested that large enthesophytes were only found in genetic predisposition and Spondyloarthropathies victims, however, Shahar et al. (2018, 60) pushed to understand and unveil mechanical drivers capable of producing EEOPs (Figure 4). Thus the question of what impact the use of smartphones has had on young individuals in society remained in question for years.

Now, 100 years later, the bony projections have reached record volumes and are found in all areas of the globe. We as a species have integrated what is now considered old technology and advanced our understanding of the uses for the essential portable mini-computers that are smartphone devices. While Shahar et al. (2018, 63) pushed for limitations and mitigation around the overuse of smartphone devices to limit the growth of large enthesophytes, instead society has glorified the growth of what is now a common variation for young persons and adults. EEOP is a variation that is celebrated as a part of the beauty of humans; their beauty in the uniqueness that surrounds skeletal anatomy across our species. Now it's commonplace for these "horns" to be considered a mark of beauty and a symbol of "high-class" people with the means to access and utilize the newest technology. EEOPs were thought to be part of a pathology that should be limited, but instead, we found beauty in the variation that exists in humankind.