According to Gram Research analysis, specific genetic variations significantly influence whether baby teeth stay too long or permanent teeth erupt late in children. A 2026 systematic review of 6 studies identified genetic variations in RANKL, COX2, MMP8, and vitamin D receptor genes, plus four additional genetic locations, that were more common in people with delayed or retained teeth. These findings suggest tooth eruption timing is controlled by multiple genes involved in bone breakdown and mineral metabolism, not just environmental or local factors.
A new systematic review analyzed research on why some children’s baby teeth stay in longer than normal or their permanent teeth come in late. Scientists found that specific genes may play a bigger role than previously thought in tooth eruption timing. The study identified several genetic variations linked to delayed tooth eruption and retained baby teeth, including genes that control bone breakdown and tooth development. While environmental factors still matter, this research suggests that genetics significantly influence when teeth come in, opening new possibilities for understanding and treating tooth eruption problems in children.
Key Statistics
A 2026 systematic review of 6 studies found that specific variations in the RANKL gene (rs9594738) and COX2 genes (rs5275 and rs689466) were more frequent in individuals with over-retained baby teeth, indicating a genetic contribution to tooth eruption timing.
A genome-wide association study identified four genetic locations (HMGA2, TNP1, CACNA1S/TMEM9, and ADK) associated with permanent tooth eruption timing, demonstrating the polygenic nature of tooth eruption according to a 2026 systematic review.
Among 6 studies reviewed in 2026, genes involved in bone resorption, extracellular matrix remodeling, and mineral metabolism showed repeated associations with delayed tooth eruption and over-retained deciduous teeth.
A 2026 systematic review found that vitamin D deficiency was associated with tooth eruption disturbances, though genetic variations in the vitamin D receptor gene did not consistently predict eruption delays across studies.
The Quick Take
- What they studied: Whether genes and genetic variations cause baby teeth to stay too long or permanent teeth to come in late
- Who participated: The review analyzed 6 previous studies that looked at children and adults with tooth eruption problems, comparing their genes to people without these issues
- Key finding: Specific genetic variations in genes like RANKL, COX2, MMP8, and vitamin D receptor were found more often in people with delayed or retained teeth, suggesting genetics plays an important role
- What it means for you: If your child’s baby teeth won’t fall out or permanent teeth are delayed, genetics may be partly responsible—not just local problems. This could help doctors predict and treat these issues better in the future, though more research is needed
The Research Details
This was a systematic review, which means researchers searched through scientific databases to find all existing studies about genes and tooth eruption problems. They looked at studies published up until March 2025 across 13 different databases. The researchers used strict rules to decide which studies to include—they only selected studies that directly examined genetic factors in people with delayed permanent tooth eruption or over-retained baby teeth.
The team followed international guidelines called PRISMA to make sure they did the review properly and fairly. They looked at case-control studies (comparing people with the problem to those without), cross-sectional studies (looking at groups at one point in time), and cohort studies (following people over time). They also checked how reliable each study was using a standard quality assessment tool.
A systematic review is important because it brings together all the best available evidence on a topic rather than relying on single studies. This approach helps identify patterns across multiple research projects and gives us a clearer picture of what the science actually shows. By reviewing all available genetic studies on tooth eruption, the researchers could identify which genes appear most important and which findings are most reliable.
The review included only 6 studies that met strict quality standards, which is a small number. This suggests the research area is still developing and more studies are needed. The studies used different methods and looked at different populations, which makes it harder to draw firm conclusions. The researchers noted that larger, more diverse studies with consistent diagnostic criteria are needed to confirm these genetic links.
What the Results Show
The systematic review identified several genes with variations linked to tooth eruption problems. Two case-control studies found that specific variations in the RANKL gene (rs9594738) and COX2 gene (rs5275 and rs689466) were more common in people with baby teeth that wouldn’t fall out. These genes are involved in bone breakdown, which is necessary for baby teeth to loosen and fall out naturally.
Another important finding came from a large genome-wide association study, which scanned the entire genetic code. This study identified four genetic locations associated with permanent tooth eruption timing: HMGA2, TNP1, CACNA1S/TMEM9, and ADK. This discovery shows that tooth eruption is controlled by multiple genes working together, not just one or two genes.
The research also examined vitamin D’s role, since vitamin D is important for bone and tooth development. While vitamin D deficiency was linked to tooth eruption problems, the specific genetic variations in the vitamin D receptor gene didn’t consistently predict eruption delays. This suggests vitamin D levels matter more than the genetic variations in how your body uses vitamin D.
Additional studies found connections between delayed tooth eruption and variations in the MMP8 gene (rs17099443), which controls enzymes that break down the tissue around teeth. The vitamin D receptor gene also appeared in multiple studies, though with mixed results. These findings highlight that genes involved in bone remodeling and mineral metabolism are particularly important for normal tooth eruption.
Previous research focused mainly on local factors (like crowding or missing teeth) and systemic factors (like hormonal problems or nutritional deficiencies) as causes of delayed tooth eruption. This review adds important evidence that genetic factors deserve equal attention. The identified genes align with what scientists already know about bone and tooth biology, making the findings more credible. However, this is among the first comprehensive reviews connecting specific genes to these tooth eruption problems.
The review included only 6 studies, which is a small number for drawing firm conclusions. The studies used different methods and looked at different populations, making it hard to combine results. Most studies were relatively small, and some genetic variations were only found in one study. The researchers didn’t have enough information to determine exactly how much genes versus environment contribute to these problems. They emphasized that larger, more diverse studies with consistent ways of diagnosing tooth eruption problems are urgently needed.
The Bottom Line
If your child has baby teeth that won’t fall out or permanent teeth that are delayed, ask your dentist about genetic factors as a possible cause (moderate confidence). Genetic testing might eventually help predict who will have these problems, but it’s not yet a standard recommendation. Treatment should still focus on addressing local factors like crowding while considering that genetics may play a role (moderate confidence).
Parents of children with delayed tooth eruption or retained baby teeth should know genetics may be involved. Orthodontists and pediatric dentists should consider genetic factors when evaluating these problems. People with family histories of tooth eruption problems may have increased genetic risk. This research is less relevant for people with normal tooth eruption patterns.
Genetic factors influence tooth eruption timing from early childhood, but the effects develop gradually over months and years as teeth naturally erupt. If genetics are involved, the delayed eruption pattern typically continues unless treated. Seeing results from treatment may take several months to years depending on the specific situation.
Frequently Asked Questions
Can genes cause baby teeth to not fall out?
Yes, according to a 2026 systematic review, specific genetic variations in RANKL and COX2 genes were more common in people with over-retained baby teeth. These genes control bone breakdown needed for teeth to loosen naturally.
What genes affect when permanent teeth come in?
A 2026 systematic review identified variations in RANKL, COX2, MMP8, and vitamin D receptor genes, plus four additional genetic locations (HMGA2, TNP1, CACNA1S/TMEM9, and ADK) associated with permanent tooth eruption timing.
Is delayed tooth eruption always genetic?
No, tooth eruption depends on both genetic and environmental factors. A 2026 review shows genetics plays an important role, but local factors like crowding and systemic factors like vitamin D deficiency also matter significantly.
Should my child get genetic testing for tooth eruption problems?
Genetic testing for tooth eruption isn’t yet standard practice. A 2026 systematic review supports genetic involvement but notes more research is needed. Discuss with your dentist whether testing might help guide treatment decisions.
If my family has late tooth eruption, will my child too?
Family history suggests increased genetic risk, but it’s not guaranteed. A 2026 review found multiple genes influence eruption timing, so inheritance patterns are complex. Environmental factors also play important roles.
Want to Apply This Research?
- Track your child’s tooth eruption timeline by recording the date each baby tooth falls out and each permanent tooth appears. Compare this to normal eruption charts to identify delays. Note any family patterns of late tooth eruption.
- Use the app to set reminders for regular dental checkups every 6 months to monitor eruption progress. Document any concerns about retained baby teeth or delayed permanent teeth to discuss with your dentist. Keep a photo record of tooth eruption patterns over time.
- Create a long-term eruption timeline in the app showing expected versus actual eruption dates. Track whether interventions (like orthodontic treatment) affect eruption timing. Monitor for complications like crowding or misalignment as permanent teeth come in. Share this data with your dental care team to inform treatment decisions.
This article summarizes research on the genetic basis of tooth eruption problems and is for educational purposes only. It is not medical advice. If your child has delayed tooth eruption or baby teeth that won’t fall out, consult with a pediatric dentist or orthodontist for proper evaluation and treatment. Genetic factors are one of many contributors to tooth eruption timing. Individual cases vary significantly, and professional dental evaluation is essential for diagnosis and treatment planning.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.