Orient can confirm the appointment of Andy Hessenthaler as assistant manager.
Hessenthaler has signed a two-year deal with the O’s and joins having completed his third spell with League One side Gillingham.
Hendon and his new assistant have enjoyed a good working relationship over the years, with Orient’s head coach having become Hessenthaler’s assistant at Priestfield in 2010.
The 49-year-old links up with Hendon once more and adds a wealth of experience to his backroom staff at Orient, in which Kevin Nugent remains firmly part of.
On the appointment, Hendon told www.leytonorient.com: “I am delighted to have someone with Andy’s experience and knowledge by my side.
“I have worked with him and he is a very good coach. I also played alongside Andy in the same team and know what attributes he will bring to the club.
“Andy will work alongside Kevin Nugent, who remains very much part of my coaching team.”
Hessenthaler became player-manager with Gillingham in 2000, having joined the club from Watford in 1996.
Born in Dartford, he was part of the successful Kent side when they won promotion to the then First Division in the 1999-2000 season.
After manager Peter Taylor left, Hessenthaler took up a player-manager role at Priestfield and guided them with three back-to-back mid-table finishes, before tendering his resignation as manager in 2004, but remaining as a player.
A loan move to Hull City followed before a return to the Gills side in the 2005-06 season.
Hessenthaler joined League Two side Barnet in January 2006 and after a one-and-a-half year spell at Underhill, he was appointed as manager of then Ryman Division One South side Dover Athletic, where he guided them to successive promotions, and narrowly missed out on a third after a Conference South play-off semi-final loss to Woking.
He resigned as boss at Dover in May 2010, and returned to Gillingham to take over as first-team manager for a two-season spell, which culminated with the Gills just missing out on a play-off spot in 2012, before taking up a director of football position at the club.
Having left in 2013, Hessenthaler returned as assistant manager to Peter Taylor a year later, and following the latter’s sacking in December last year, was part of a four-man caretaker managerial role alongside Darren Hare, Steve Lovell and Mark Patterson last season, before Justin Edinburgh was appointed as boss in February.