Rogel McMorris, Jason Brew and Hector Muaimba were convicted of rape
Three men who raped a 16-year-old girl and then threw caustic soda on her are to have their sentences reviewed to decide if they were "unduly lenient".
The girl, who had a mental age of eight, was left disfigured following the attack in a flat in Tottenham, north London, in January 2008.
Rogel McMorris, 18, Hector Muaimba, 20, and Jason Brew, 19, were jailed for nine, eight and six years respectively.
The case has been referred to the Court of Appeal by the attorney general.
The trial at Wood Green Crown Court heard the girl agreed to meet a man she knew in the disused flat for sex there because she thought it would make her popular.
But during a two-hour ordeal she was repeatedly raped by a group of men. Before they left they threw caustic soda on her hoping it would destroy forensic evidence.
The girl was in a coma following the attack and has been left permanently disfigured. She has undergone treatment, including surgery and skin grafts.
In January, McMorris, 18, from Tottenham, was jailed for nine years for rape and grievous bodily harm.
Brew, 19, from Tottenham, was jailed for six years for rape and Muaimba, 20, from Walthamstow, east London, was given eight years for rape and robbery.
After the trial, the girl's uncle read a statement on behalf of her family, including her parents, saying: "We know the sentence imposed on the perpetrators of this hideous crime against our daughter, whatever and however we feel about it, will not bring sufficient justice and healing to our daughter."
Charities representing people with learning difficulties condemned the sentences as too short.
Attorney General Baroness Scotland sent the case to the Court of Appeal for it to consider if the sentencing had been "unduly lenient".