"If the child is sick ... he has yellow hair, he doesn't eat, he's skinny, it's because of the bad teeth," says the 75-year-old Ali. "This is a treatment for malnutrition. No one has ever told me that this is bad."
By the time children do turn up at the United Nations-funded centers, they have already been through hell. Nearly every week, health workers here admit dangerously emaciated children with a foamy substance coming out of their mouths.
Malnutrition is the underlying cause for the deaths of 2.6 million children every year, according to a study published in the scientific journal, The Lancet. That's a third of the global total for children's deaths.
At the feeding center in the town of Mao, run by the French aid group Action Against Hunger, a mother has come in carrying a bundle in her arms. When she pulls back the sheet, the health workers gasp. It looks like she has brought in a skeleton.
The best predictor for the severity of malnutrition is the circumference of a child's upper arm, the World Health Organization has found over years of responding to famines in Africa. Less than 115 millimeters indicates the child is at risk of imminent death.
This child's arms measure just 80 millimeters around. She weighs 5.2 kilograms (11.4 pounds), slightly more than a healthy newborn. She is 3 years old.
It takes a moment for the health workers to realize that the little girl, Fatime, has been admitted before.
Fatime's short history is a litany of the well-meant customs that get in the way of a child's health, and possibly even her life.
She was born underweight. Women in Chad, including her mother, are discouraged from eating during pregnancy, in the hope that a small child will be easier to deliver.
Fatime's mother stopped breastfeeding her when she became pregnant with her youngest child. She was told that pregnancy tainted her milk and could poison the child still nursing.
Zara Seid, the mother, collected the bitter chaff left over when women pound millet into flour, mixed it with water and painted it on her breasts. The bitter taste repelled the toddler, and she was weaned overnight.
Yet in a place where food is hard to come by, it meant that Fatime began her precipitous fall into undernourishment.
Malnutrition and disease work in a deadly cycle, and soon Fatime got sick with diarrhea and a fever. The lack of a proper diet weakens the immune system and makes childhood diseases more severe. The sick child then loses more weight, making recovery more difficult.
More than a year ago, Fatime's mother brought her into the clinic.
Like many African women, though, her mother needed permission from her husband to leave her family and stay away. And she knew he was starting to get impatient.
Over the pleas of the health workers, she left the clinic only a week after she got there. And upon the advice of villagers, she went to the traditional healer, a one-day visit instead of a three-week hospital stay.
The medicine man diagnosed the child's illness as the result of her baby teeth. He heated a blade in the fire and pulled them out.
"I thought this would bring back my daughter's health, so I took heart from that, even if it was hard to see her in pain," says Seid. "After we took out the bad teeth, it seemed like she was getting better. ... Then she got seriously worse."
It took the death of Fatime's baby cousin from malnutrition for her father to finally give her mother the permission to make a second, 1.5-hour journey to the clinic.
By the time Fatime made it to the clinic the second time, she didn't look much bigger than a fetus. Zara Seid kept her daughter wrapped in a cloth, as if embarrassed to show her body, the frightening sight of a child on the knife's edge of starvation.
Her head is bald except for a few tufts of hair. Her mouth is infected with lesions, and stained purple with the antifungal wash the nurses use daily. When she tries to drink formula, she coughs until her tiny, doll-like chest heaves.
Her legs are insect-like, unable to hold her up. They dangle, lifeless. Her arms are no bigger than a shower rod.
Flies are attracted to her, as if she is already dead. They land on her face and crawl in and out of the corners of her eyes.
These mistakes lead here, to a set of humps in the sand. There's a burial ground in every village in this part of Chad, including in Djiguere, where Fatime's cousin lies under the newest hump of sand.
The big mounds are where the adults are buried. But the majority of the piles in the cemetery are small. Some are no larger than a loaf of bread.
Fatime may or may not make it. In the week since she arrived at the feeding center, she's gained 200 grams (7 ounces).
At home in the village, her father, Mahamat Ibrahim, says he has no regrets about having had his daughter's teeth extracted. Bad teeth are to blame for a child not growing, he says.
"This is something that everyone here knows," he says. "It's only the doctors at these foreign hospitals that don't know this. And that's why we avoid taking our children there."
His youngest child is five months old. In a few weeks, her baby teeth will start coming in.
If she falls sick, he plans to take her to the healer to yank them out.