When a Baby Tooth Comes Back: A Rare Dental Case in an Adult Patient
A Hidden Dental Problem That Lasted Into Adulthood
Most people assume that baby teeth are a thing of childhood once they fall out, they’re gone for good. However, a recently published case report challenges this assumption by describing an extremely rare condition: a deciduous (primary) tooth that re-impacted and remained hidden until adulthood.
The case, reported in Annals of Medicine & Surgery, documents a 25-year-old woman with a fully re-impacted primary molar discovered during routine dental evaluation. This unusual finding highlights the importance of early diagnosis and long-term monitoring of tooth eruption, even beyond childhood
What Is Tooth Re-Impaction?
Re-impaction refers to a condition in which a tooth that once erupted normally becomes submerged again beneath the gum and bone. This phenomenon is most commonly seen in children during the mixed dentition stage, when baby teeth and permanent teeth coexist.
In adults, however, re-impaction of a primary tooth is exceptionally rare. Most documented cases involve children, making this report particularly noteworthy
The Case: An Unexpected Finding in a Young Adult
The patient visited an oral surgery clinic for the removal of impacted teeth related to orthodontic treatment. During imaging examinations, clinicians identified an unusual impacted tooth located near the maxillary sinus.
Advanced imaging using cone-beam computed tomography (CBCT) revealed:
A tooth with three divergent roots
Close proximity to the maxillary sinus
An anatomy inconsistent with a permanent premolar
After surgical removal, the tooth was confirmed to be a deciduous molar, based on crown shape, root morphology, and the presence of occlusal decay clear evidence that the tooth had erupted in the past before becoming re-impacted
Why Did This Happen?
The exact cause of tooth re-impaction remains unclear, but it is believed to be multifactorial. Several local factors may contribute, including:
Ankylosis (fusion between tooth and bone)
Missing permanent successor teeth
Trauma
Developmental disturbances of eruption
Among these, ankylosis is considered one of the most significant contributors and is often associated with infra-occlusion, where a tooth gradually sinks below the normal bite level
Clinical Risks and Surgical Challenges
Re-impacted teeth can lead to several complications if left untreated, such as:
Malocclusion
Tipping of adjacent teeth
Ectopic eruption of permanent teeth
Increased risk during surgical removal due to proximity to anatomical structures
In this case, surgical extraction resulted in a large bone defect and temporary exposure of the maxillary sinus, illustrating the high surgical risk associated with late discovery of re-impacted teeth in adults
Why Early Detection Matters
This case reinforces a crucial clinical message: early diagnosis can prevent serious complications. In children, monitoring infra-occluded or submerged deciduous teeth allows timely intervention, often avoiding complex surgery later in life.
The authors emphasize that any missing tooth whether primary or permanent should always be investigated carefully, especially if there is no history of extraction
Key Takeaway for Clinicians
Although rare, re-impaction of deciduous teeth can persist into adulthood and cause significant clinical problems. Dentists, orthodontists, pediatric dentists, and oral surgeons should remain alert to eruption anomalies and use appropriate imaging techniques, such as CBCT, when conventional radiographs are inconclusive.
Conclusion
This rare case demonstrates that dental developmental disturbances can remain hidden for decades. Awareness, careful radiographic evaluation, and early management are essential to avoid invasive procedures and long-term complications. Sometimes, even a “baby tooth” can return with serious consequences.
Original Article Reference
Soualem H, Chami B. Severe re-impacted deciduous tooth in a 25-year-old female with permanent dentition associated with high-risk oral-sinus communication surgery: A rare case report. Annals of Medicine & Surgery. 2024;86:1664–1668.
DOI: 10.1097/MS9.0000000000001685