Advertising his services with a huge poster of sparkling pearly whites on blood-red gums. He is one of thousands of low-cost, unlicensed dentists, whose small stores with their lurid signs can be found nestling in grimy alleys and wedged between red-tiled houses across the capital.
But after years of horror stories about people suffering terrible damage at the hands of unscrupulous practitioners with neither clean tools nor training, the government moved to ban them from all dental work in 2011.
The unlicensed dentists are fighting back, however, they have managed to get the ban overturned after challenging it in the constitutional court -- and are now demanding the right to practice.
"We demand to be granted a licence so we can operate legally. We will never give up our fight," said Dwi Waris Supriyono, chairman of the Informal Dentists' Association.
For Herman, 56, a ban would have destroyed his livelihood and stopped him from practising a trade passed down to him and his brothers by their father.
"The government wants to put us out of business," said Herman, dressed in a faded T-shirt and sarong, as he puffed on a clove cigarette waiting for his next patient at his central Jakarta shop.
"But I've been doing this since 1980, and I don't want to lose my job."
Wanting to protect their livelihoods, the informal dentists -- who can be found all across Indonesia -- argue that they are the only realistic option for many in a country where millions live in abject poverty.
Herman charges only 50,000 rupiah (around $4.50) for a simple scaling job, and 1,500,000 rupiah (around $140) to fit a brace -- four to five times lower than prices at professional, licensed dentists.
It is also much easier to find an informal dentist. The health ministry estimates there are 75,000 of them in Indonesia, compared to 35,000 licensed practitioners.
The government insists that numerous tales of dental disaster at the hands of unlicensed practitioners vindicates its drive to impose a ban.
One such case is that of cleaner Fitri Hayati, whose attempts to get her teeth straightened at two illegal dentists in Jakarta were far from successful.
The 24-year-old was fitted with braces but one tooth has been pushed down so it now looks longer than the others, and she said she suffers from "unbearable pain".
"I can't eat or sleep as my whole mouth is in pain since I started wearing these braces," she told AFP.
Senior health ministry official Untung Suseno Sutarjo accused unlicensed dentists of "putting our people at risk for their own gain."
"These practitioners have no qualifications. They use tools which have not been cleaned or sterilised properly."
Informal dentists, known as "Tukang Gigi" in Indonesian -- which translates as "Tooth Workers" -- have been plying their trade for generations.
In the late 1980s, authorities sought to crack down on them by ordering that they limit their work to making only dentures.
But the new law was largely ignored and they continued to perform many other procedures regardless.
So in 2011 the government sought to ban them from doing all dental work, a move the informal dentists countered by seeking a judicial review of the new legislation.
Earlier this year the constitutional court sided with them and declared the law against the constitution, which states that every Indonesian has the right to work.
Supriyono, of the Informal Dentists' Association, argues that despite a lack of formal training, unlicensed practitioners often have years of experience and skills passed down from generation to generation.
"Informal dentists have been around a lot longer than the professionals," he said.
"Earlier generations learnt their skills from the Chinese in the 1800s," he said, referring to Chinese dentists who travelled to Indonesia in the company of merchants.
The first dentist school, where licensed practitioners are trained, only opened in 1928, he added.
The association now wants unlicensed dentists to be given the right to officially perform procedures such as fitting crowns or putting in fillings, things many are already doing anyway.
And there is a hope that at least some of them may achieve this. In its ruling, the constitutional court ordered the health ministry to grant informal dentists a licence if they successfully pass a training course.
But ministry official Sutarjo predicted only a small number in the unlicensed sector would be able to take the course.
"Some are illiterate and many have not even graduated from high school," he said.
He added that only those who meet certain educational criteria would be allowed to attend courses and that the selection process "would eventually make them disappear".
He said that a plan to ensure all Indonesians have access to health care, which will start being rolled out next year, would help cover the cost of professional dentists for those on low incomes.
However that plan will not fully come in to effect for some years, meaning the cheap dental practices are likely to remain a common sight on Jakarta's colourful streets for years to come.