(covers information from several alternate timelines)
As was common in military culture of 19th , 20th, and 21st century Earth, Starfleet personnel maintained a quasi-uniform hairstyle. Sideburns were perhaps the most universal aspect of this, as many male officers stylized their sideburns to end in triangular points. It is possible that it was even required to do so. Many ships, including the USS Enterprise-D, had barbershops staffed by barbers onboard, where it was likely that this uniform sideburn style was administered. Some male personnel, William T. Riker being notable among them, chose to wear beards as well.
Many male performers who appeared on Star Trek had their "pointy" sideburns added on by make-up. A few of note include:
- Abdullah bin al-Hussein's appearance as a lieutenant of the sciences division aboard Voyager in VOY: "Investigations".
- Through several seasons of Star Trek: Deep Space Nine, sideburns were reportedly the only aspect of make up that Kenneth Marshall required for his portrayal of Michael Eddington. (The Official Star Trek: Deep Space Nine Magazine issue 15, p. 55)
- While portraying Phillip Green in the Star Trek: Enterprise episode "Demons", Steve Rankin reported the following about his make-up process: "They made me up, got my hair dark, gave me the pointy sideburns."