After Vidal Sassoon changed the look of women’s hair with his radical geometric cuts in the early 1960s, variants of his original shapes prevailed. Short cuts kept close to a head’s profile, longer bobs swung in movement but dropped straight as a curtain at rest.

Then in 1974, Sassoon’s young artistic director, Trevor Sorbie, saw how a model’s locks fell full and chunky as he pulled a brush through them, and, impromptu, cut that shape into her hair. This was 3D geometry. Voila, the Wedge, so striking that Vogue allotted it an unprecedented double-page spread. The cut was imitated worldwide, an emblem of the 70s like the platform soles and wide flares it balanced.

Sassoon’s original passion had been architecture, and his cuts were planned grand designs. Sorbie, who has died aged 75, was a craftsman in hair, by descent, training and curiosity about his raw material and what could be done with it: he described his work as “cutting from the gut”, with sweeps of sharp scissors in one hand and a rat tail comb in the other, releasing his anxiety through creation.

Unusually, he did not regard texture – waves, kinks – as an intrusion on a high concept of line, but as an individual quality to explore. Even more than the Wedge, Sorbie was proud of the Scrunch, invented ad hoc in 1979 when three salon customers awaited him to finger-dry their wavy hair, a time-consuming no-heat process. He scrungled up the first client’s hair handful by handful, and blowdried each.

Result, the massy, mussy whorls that became the dominant look of the 80s. The easy technique is still standard for curlyheads.

That responsiveness to the individual – for Sorbie assessed a customer’s personality and overall manner as well their follicles before a cut – brought him waiting lists of up to a year, with clients from Boy George to Queen Elizabeth II (he was appointed MBE for services to hairdressing in 2004), Helen Mirren, Torvill and Dean, Grace Jones, Annie Lennox, Kylie Minogue, Sting, Paul McCartney, and other pop celebs and models through the 80s and 90s; he won Hairdresser of the Year four times.

Sorbie formed a company for his own-name products, especially those to sustain that big-volume look, in 1986, later sold profitably to L’Oréal, and became a regular onscreen in early lifestyle television from the mid-90s.

Hair was his heritage as well as vocation. Born in Paisley, Renfrewshire, Trevor was son of a barber, Robert Sorbie (himself the son of a barber) and his wife, Edna (nee Saxby). When he was 11 the family moved to Ilford in Essex, where Robert’s barber shop had just two chairs. Trevor, who had dreamed of being an artist, went to work in the shop on leaving school at 15, and his father was a tough master – even on Sundays, he set him to hone razors with a stone until they severed hair at a touch.

Sorbie swapped to women’s hairdressing, did six months at the Richard Henry school, which sent him on to intern briefly, unpaid, for Sassoon. Then he moved between suburban salons and central London until he rejoined Sassoon in 1972, and became a star there.

Sorbie transferred to guest at John Frieda’s establishment, where an investor with a chain of hairdressing businesses phoned to offer him his own salon, with 50% ownership: Sorbie, always a financial innocent, agreed, and by 1979, had opened in a tiny venue in Russell Street, Covent Garden.

The venture had an iffy start – he wept when his partner warned its door must soon close unless business bucked up. But it then flourished for 22 years before moving to bigger premises nearby, and other salons followed in Britain and Dubai. When Sorbie was present, rather than travelling the world to demonstrate his craft and products or attend clients, he often mucked in to sweep the floor.

His skills were used as purposefully when his elder brother Michael’s wife, Jackie, shed her hair after chemotherapy for cancer. Sorbie supplied a wig and cut it, as he said, to humanise it and comfort her. It was a right turn for his career, and in 2006 he set up a charity, My New Hair, to establish a network of, by now, more than 1,000 stylists trained to provide technical skills to personalise NHS-supplied wigs, and salon sympathy for their wearers. He also advised on related NHS policy. Sorbie was very aware of the profound psychological power of human hair.

His commitment to his craft anywhere, anytime, made for a rocky private life. He first married Sue Harre, who had been his model when they were teenagers, and they had a daughter, Jade. After that marriage’s dissolution, he met Kristine Szewczyk, a trainee on one of his courses, and they wed in 1985. The relationship was de facto over by 1999, later ending in a complex divorce, when Sorbie was exposed in the tabloids as being involved with a sex worker; in a reversal of salon practices, he told her celeb gossip when he styled her hair as part of the payment.

Kristine, Jade and his salon staff supported him through a resultant attempt to take his own life and a breakdown. He met his third wife, Carole, in 2007, and they married soon afterwards. Late in life he was impressively frank about his anxiety, stress and the bowel cancer from which he eventually died.

He is survived by Carole, Jade and his brother, Michael.