A Success Story in Treating Dentinogenesis Imperfecta

It can be hard when you’re different, especially for a teenager. And Mia McNinch of Rockford knew she was different in one key way: Her teeth were smaller than most people’s, and translucent instead of white.

“When I got my braces off in middle school,” she recalls, “people still thought I had them on, because they could see through my teeth to my permanent retainer.”

Then, in high school, her teeth began fracturing, one after another. This was in spite of excellent general health, superb oral hygiene and no caries history.

A rare condition

Mia used extra care because her dental difficulties weren’t a surprise. She has known since childhood that, like her mom, she has the genetic condition dentinogenesis imperfecta (DI), also known as hereditary opalescent dentin. It’s an autosomal dominant disorder, which means that there is a 50 percent chance of passing the disease to children. The mutations involve a gene called DSPP (dentin sialophosphoprotein), which is believed to play a role in the normal development of collagen, a key protein in dentin.

Dentists learn in dental school about DI, but they can go decades in practice without encountering it. One recent study of 96,000 Michigan children found a prevalence of 1 in 8,000.1 In some patients, DI affects only the primary teeth, but often, as in Mia’s case, it involves the permanent teeth as well. DI has three types. People with Type I also have osteogenesis imperfecta, while those with the other two types do not. Type III is a rare condition that has been seen in some individuals in southern Maryland and some of Ashkenazi Jewish descent; it features multiple pulp exposures and differences in radiographic appearance. Mia has Type II, the most common type; it’s sometimes accompanied by progressive hearing loss as patients grow older. Cases vary, but this type usually manifests in teeth that are smaller than average, translucent with gray-blue or yellow-brown overtones, and weak and especially vulnerable to fracture. Says one study: “Radiographically, the teeth have bulbous crowns with narrow roots, and a constriction at the cervix.”2

Masking the darkness

When Tara Meachum, DDS, of Greenville took over Mia’s care from a pediatric dentist in 2016, she recognized DI immediately—even though she’d never had a patient with the disorder. “When I first met her, I did quite a bit of research,” says Dr. Meachum.

She knew that, at the very least, multiple implants and crowns were in Mia’s future. But Mia was not yet 14 so her jaw had some growing to do. At this point, her teeth were still functional, but their dark, translucent appearance bothered and embarrassed Mia. “Whenever I knew my picture was being taken,” she recalls, “I always made sure I had my mouth closed and my teeth weren’t visible.”

Dr. Meachum addressed that situation in a marathon, eight-hour session with Mia in August 2016, applying composite veneers to all of her teeth. “We masked the darkness with composite,” she explains. To say that Mia was a cooperative patient would understate things. “She was a dream to work on,” says Dr. Meachum.

It was in Mia’s junior year of high school that her teeth began fracturing—and oral surgeon Rosie Noordhoek, DDS, FACS, of the Center for Oral Surgery and Dental Implants in Rockford and Grand Rapids, began extracting them as needed.

“Her deterioration happened really quickly,” Dr. Meachum recalls. It soon became apparent that a game of tooth-by-tooth whack-a-mole was not going to suffice; a more comprehensive remedy was needed.  “We were like, ‘Okay, we need to do something right now.’”

Dr. Noordhoek agreed, she says, noting that Mia “was coming in every two to four months with another fractured tooth.”

Deciding on a treatment plan 

Mia was also Dr. Noordhoek’s first DI patient. Due to Mia’s young age (18) and rapid loss of teeth, she went through multiple treatment plan options with Mia, her mother and Dr. Meachum. Then, on Zoom sessions with a laboratory technician, the two clinicians collaborated in developing the best treatment plan for Mia.

By this time, it wasn’t simply a matter of aesthetics. Yes, Mia’s teeth were small and worn down. “They looked like primary teeth in an adult person’s mouth,” recalls Dr. Noordhoek. But also, due to her loss of vertical dimension and her multiple edentulous spaces, a class III malocclusion had developed and her chewing was compromised. “We had to figure out if she needed corrective jaw surgery,” the oral surgeon says.

Mia’s mother hoped that a single ambitious treatment would correct things for Mia permanently. The two clinicians gently explained that a guaranteed “forever” fix wasn’t possible. It’s in the nature of DI that continued deterioration was likely in store. The hope was to leave Mia as many future options—and as much bone to work with—as possible.

Thus, the decision went against using a full arch implant hybrid prosthesis, for which Dr. Noordhoek would have needed to remove teeth that were still functional, and also against removable dentures. “The plan we chose was the least invasive one that still corrected her bite,” says Dr. Noordhoek. “She would be able to keep all of the remaining teeth that had not yet fractured. They’d be covered with full crowns to help keep them, hopefully for another decade or so while at the same time opening her vertical dimension of occlusion and placing her again in a class I position.” In a full-mouth dental reconstruction, she would receive implants with crowns for the missing teeth. “And we can still have a Plan B for later on. If Mia does end up needing to go to an all-on-4, we’ll still have some bone left to do that on.”

For timing, a balancing act

Dr. Meachum sent Mia’s STL files and CBCT scans to an aesthetic laboratory and had them remake her teeth in wax—“with full-coverage crowns and with implant teeth”—so that Mia could wear the resulting acrylic “mock-up” to make sure her jaw muscles could comfortably adapt to the new form. Because Mia had grown accustomed to her too-small teeth, the mockup teeth felt “noticeably larger than what I had,” she recalls. “It felt like a mouthful at first.” But fortunately, Mia was able to adapt, and orthognathic jaw surgery wouldn’t be necessary.

In early 2021, Drs. Meachum and Noordhoek faced a delicate balancing act in terms of timing. “When I started practicing a decade ago, it was considered okay to put anterior implants in 15- and 16-year-old girls,” Dr. Noordhoek explains. “But a lot of new literature shows that we’re really not finished with the micro-growth of our anterior jaws at those ages—and sometimes even into our 30s.”

Thus, one worry was whether Mia had enough maxillary maturity to accommodate the implants. Measured against that was pressure to act right away to relieve Mia’s already damaged chewing and give her a new smile in time for her freshman year at Michigan State University in the fall of ’21. The clinicians weighed the benefits against the risks and decided that her other teeth had to be given full-coverage restorations as quickly as possible, and posterior occlusion would be necessary to support this rehabilitation.

On July 1, 2021, using a comprehensive digital plan based on 3-D X-rays, Dr. Noordhoek employed fully guided technology to place five maxillary implants. When they had healed enough to accept crowns, Dr. Meachum—in another marathon eight-hour session in September 2021, and a further visit in January 2022—placed crowns on 20 existing teeth and on the new implants too.

“Normally I would have made the crowns on the regular teeth while we were waiting for the implants to heal,” Dr. Meachum explains. “But she would only have been biting on her front teeth, and they would have just broken. Plus, it would have looked terrible.”

A chance to ‘shine’

Unfortunately, Mia had no dental benefits coverage, and her family’s medical plan did not cover congenital dental conditions. Although Drs. Meachum and Noordhoek planned to donate their considerable time, there remained the substantial cost of the implant components and lab fees. But when Dr. Noordhoek mentioned Mia’s case to a representative of The Straumann Group, the Basel, Switzerland-based implant vendor she often uses, the rep said, “That sounds like a really good case for the ‘Let Them Shine’ program.”

Through that initiative, Straumann offers financial assistance to help provide implants to patients who can’t afford the treatment. Mia’s family isn’t poor, but the heavy treatment cost necessitated by her hereditary condition could have blown a vast hole in the budget of even the most solidly middle-class family. It would have equaled “definitely a couple years in college,” Mia says with a laugh.

So Dr. Noordhoek set about preparing an application for Mia to the “Let Them Shine” program. That required organizing the information she’d gained about DI, describing Mia’s history and writing up a detailed treatment proposal. (See “The Plan for Treatment,” below.) It was four or five months before she received a response, as evidently the pandemic had slowed the decision process. During that time Dr. Noordhoek had to proceed with the surgery to meet the timetable for Mia’s departure for college in the fall. But finally good news came—Mia was approved for the funding. In a thank-you letter to Straumann, Mia called the program “a blessing and a life-changer.”

As she turns 20 this October and ceases to be a teen, Mia is embarking on her second year at Michigan State, majoring in environmental biology and plant biology. She knows that her future will probably include further dental challenges. She’s still cautious about eating sticky things, she says, but less so than she was with her original teeth “because I know these ones are stronger than my teeth were naturally.”

“I’ve received so many positive comments on my smile that I never thought I would get,” Mia reports. While the difficulties caused by her DI have “kind of swayed me against having kids” because of the hereditary risk, she says that if she did have children, she would reassure them that “like, there’s ways to fix it.”

Both Dr. Meachum and Dr. Noordhoek look forward to years of being there for Mia when she needs them. Says Dr. Noordhoek: “I want Mia to still be my patient, if I’m still practicing, when she’s 40. At our office we’re always focused on collaboration with our referring doctors for the best outcome. And this case shows, when we work together, what a dramatic change we can make in someone’s life.”

1 Jeffrey Dean, DDS, MD, Acquired and developmental disturbances of the teeth and associated oral structures, in David R. Avery and Ralph E. McDonald, ed., Dentistry for the Child and Adolescent, 2022, downloaded via ScienceDirect.

2 Kawther Taleb, et al, Dentinogenesis imperfecta type II—genotype and phenotype analyses in three Danish families, Molecular Genetics & Genomic Medicine, 2018 May; 6(3): 339–349