--- title: "Over-Retained Baby Teeth UK | When to Extract 2026 Guide" url: https://virtualconsultant.online/guides/over-retained-baby-teeth-uk description: "Why primary teeth sometimes fail to shed in the UK — infraocclusion, ankylosis, when extraction is needed, and orthodontic effects." updated: 2026-09-29T00:00:00Z publisher: Virtual Consultant Online --- Baby Teeth Infraocclusion Paediatric Orthodontics # Over-Retained Baby Teeth UK Most children lose their baby teeth in a predictable sequence between ages 6 and 12. When a primary tooth remains in place well beyond the expected time, it is described as over-retained. This can affect how and whether the adult tooth erupts, and may require orthodontic or surgical intervention. [Start Photo Assessment](https://virtualconsultant.online/evaluations/quote) [Compare Costs](https://virtualconsultant.online/costs) ## What does over-retained mean? A primary (baby) tooth is described as over-retained when it remains in the mouth significantly beyond the age at which it would normally be shed and replaced by a permanent tooth. The term implies the tooth is present at a time when it is causing or is likely to cause a problem — either by blocking the eruption path of the adult tooth, by taking up space needed for permanent teeth, or because it has fused to the underlying bone and is no longer erupting normally alongside surrounding teeth. Over-retained teeth are not simply late-shedding teeth; they are teeth where a clinical decision about management is required. ## Normal and delayed eruption timeline Eruption timing varies considerably between children, but the general sequence in the UK follows predictable ranges. The lower central incisors are usually the first to be replaced, around age 6. Upper central incisors follow. Lateral incisors, first premolars, canines, and second premolars erupt in broadly predictable order through ages 7 to 12. Molars follow. A tooth that is more than 12 to 18 months outside the normal range for its type warrants investigation. A panoramic X-ray (OPG) and sometimes a cone beam CT allows the dentist or orthodontist to see whether the permanent successor is present, where it is positioned, and what may be delaying eruption. Not all delayed eruption represents a problem — some children are simply late developers — but investigation avoids missing a problem that worsens with time. ## Causes of over-retention The most common reason for a primary tooth to remain in place is the absence of a permanent successor. This condition — hypodontia — means there is no developing tooth beneath the baby tooth to resorb its roots and push it out. Without root resorption, the baby tooth simply stays. The second major cause is ankylosis — a process where the tooth root fuses directly to the surrounding alveolar bone, preventing the normal eruption mechanism from working. Ankylosis can develop in any primary tooth but is most commonly seen in the lower second primary molars. Where a successor is present but impacted — unable to erupt normally due to crowding, a cyst, or an abnormal eruption path — the primary tooth may also be retained well beyond its expected time. ## Infraocclusion: graded mild, moderate, and severe Ankylosed primary teeth often show a clinical sign called infraocclusion — the tooth appears to have sunk below the level of the surrounding teeth, though in reality the tooth has stopped erupting while neighbouring teeth and the alveolar bone have continued to grow vertically. Infraocclusion is graded by how far below the occlusal plane the tooth sits. Mild infraocclusion means the tooth is within 1 mm below the contact points of adjacent teeth. Moderate means it is between the contact points and the gumline. Severe means it is at or below the gumline. Severe infraocclusion is associated with a much higher risk of adjacent teeth tipping into the space, difficulty with extraction when required, and bone deficiency at the site. Monitoring with sequential X-rays helps track whether infraocclusion is progressing. ## Signs of ankylosis Clinically, an ankylosed tooth may sound different when tapped — a dull, solid sound rather than the normal slightly hollow percussion note. It does not respond to orthodontic forces and cannot be moved. On X-ray, the normal periodontal ligament space (a thin dark line around the root) may be partially or completely absent. In growing children and adolescents, the differential growth of surrounding teeth and bone makes the ankylosed tooth appear to progressively submerge. Ankylosis is not always obvious at an early stage, which is why sequential monitoring of suspected retained primary teeth — particularly lower second primary molars — is an important part of paediatric and orthodontic dental care. ## Orthodontic implications Over-retained primary teeth cause several orthodontic problems if left unmanaged. The space occupied by the baby tooth is needed by the permanent tooth. Adjacent teeth tip into the space over months and years, reducing available space and complicating future orthodontic alignment. Where the retained tooth is severely infraoccluded, the adjacent teeth may erupt to different heights, creating a step in the bite. If the retained tooth blocks eruption of the permanent successor, that tooth may become impacted, requiring surgical exposure and orthodontic traction to bring it into the arch. Where hypodontia is present, the retained primary tooth is sometimes intentionally preserved as a natural space filler for as long as possible before a longer-term plan — implant, bridge, or orthodontic space closure — is executed. ## When to extract a retained primary tooth The decision to extract a retained primary tooth depends on several factors: whether a permanent successor is present, the degree of infraocclusion, the age of the patient, and the overall orthodontic treatment plan. Extraction is generally recommended when a retained tooth is blocking eruption of the permanent successor, when infraocclusion has reached the moderate or severe grade, when the tooth is causing adjacent teeth to tip significantly, or when orthodontic treatment is being planned and the retained tooth would obstruct appliance placement or tooth movement. Early extraction — before moderate infraocclusion develops — allows more time for spontaneous drift of the permanent tooth and preserves the alveolar bone height. In cases of hypodontia where no successor exists, the extraction decision is made in the context of the long-term plan for the space. ## Options when no permanent successor is present When a primary tooth is retained because no successor exists, the long-term management options are: maintaining the retained tooth for as long as possible and planning a dental implant or resin-bonded bridge when the patient is an adult (typically after jaw growth is complete, usually around 18 to 20 years), or using orthodontic space closure to eliminate the gap entirely by moving the adjacent teeth together. The best option depends on the site, the patient's overall occlusion, age, and preferences. Retained lower second primary molars in hypodontia are a particularly common scenario in the UK; orthodontists frequently work with restorative colleagues to manage these cases as part of a multidisciplinary plan. A space maintainer appliance may be placed after early extraction to prevent space loss before the long-term treatment is ready to begin. ## Useful related pages [Space Maintainer Children UK](https://virtualconsultant.online/guides/space-maintainer-children-uk) [Hypodontia and Orthodontics UK](https://virtualconsultant.online/guides/hypodontia-orthodontics-uk) [Interceptive Orthodontics UK](https://virtualconsultant.online/guides/interceptive-orthodontics-uk) [Missing Lateral Incisors UK](https://virtualconsultant.online/guides/missing-lateral-incisors-orthodontics-uk) This guide is for general information only. It is not a diagnosis, treatment plan, or substitute for advice from a registered dentist or orthodontist. ### Compare next steps [Orthodontist Near Me](https://virtualconsultant.online/locations/orthodontic-treatment-near-me) [Clear Aligners Near Me](https://virtualconsultant.online/treatments/clear-aligners-near-me) [Invisalign Near Me](https://virtualconsultant.online/locations/invisalign-provider-near-me) [Browse Locations](https://virtualconsultant.online/locations) ### Ready for a clearer starting point? Upload guided photos and receive an indication of likely treatment options and pricing before booking appointments. [Get an Online Quote](https://virtualconsultant.online/evaluations/quote) ### Frequently Asked Questions Why has my child baby tooth not fallen out? A baby tooth that does not fall out on its own usually means one of two things: there is no adult tooth developing beneath it (hypodontia), or the baby tooth has fused to the bone (ankylosis) and cannot be pushed out by a developing tooth. In some cases, a permanent tooth is developing but is impacted or positioned abnormally and is not applying the root-resorbing pressure needed to loosen the baby tooth. A dental X-ray will show whether a successor tooth is present and what the root and bone situation looks like. If a baby tooth is more than 12 to 18 months beyond its expected shedding time, it is worth discussing with a dentist or orthodontist. What is infraocclusion? Infraocclusion is when a tooth appears to have sunk below the level of the surrounding teeth. In the context of retained primary teeth, it usually indicates ankylosis — the tooth has fused to bone and stopped erupting while adjacent teeth and bone have continued to grow downwards and outwards. The tooth has not actually moved down; it has stayed still while everything around it has moved up. Mild infraocclusion may be monitored; moderate to severe infraocclusion typically warrants extraction because the tooth is unlikely to recover and will worsen with growth. When should a retained baby tooth be extracted? Extraction is generally recommended when the retained tooth is blocking eruption of the permanent successor, when infraocclusion has progressed to a moderate or severe level, when adjacent teeth are tipping significantly into the space, or when orthodontic treatment is planned. Earlier extraction is usually better than later because it preserves bone height, allows more time for the permanent tooth to erupt naturally, and avoids increasingly difficult extractions as ankylosis deepens. Your dentist or orthodontist will advise based on X-rays and the specific clinical picture. Can a baby tooth be kept permanently? In some cases, yes — particularly where no permanent successor is present (hypodontia). A well-preserved retained primary tooth can function for many years into adulthood. The average lifespan beyond childhood is variable; some retained primary teeth survive into the 30s and 40s, while others fail much earlier due to root resorption, loss of bone support, or complications of ankylosis. When the retained tooth eventually fails, the patient will need a dental implant, bridge, or orthodontic closure of the space. The decision to keep or extract a retained primary tooth in hypodontia is made as part of a long-term multidisciplinary plan. How does an over-retained baby tooth affect orthodontic treatment? Retained primary teeth complicate orthodontic treatment in several ways. They occupy space needed for permanent teeth and may need to be extracted as part of pre-orthodontic planning. Adjacent teeth tipping around a retained tooth create additional alignment problems. An ankylosed retained tooth cannot be moved with orthodontic forces and therefore cannot be incorporated into an alignment plan — it must either be extracted or the treatment designed around it. In hypodontia cases, the retained tooth may be deliberately left as a temporary space holder while long-term plans are formulated, or extracted to allow orthodontic closure of the space. Does a retained baby tooth need an X-ray to diagnose? Yes, a dental X-ray is the standard way to confirm why a baby tooth has not been shed. A panoramic X-ray (OPG) shows whether a permanent successor tooth is present and developing normally, whether it is impacted or abnormally positioned, and whether the retained tooth shows signs of ankylosis such as a missing periodontal ligament space around the root. In more complex cases, a cone beam CT scan gives a three-dimensional view of tooth position and surrounding bone, which helps plan extraction or orthodontic management more precisely. 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Upload guided photos and get a tailored recommendation for your teeth and bite. [Start Photo Assessment](https://virtualconsultant.online/evaluations/quote) [Find an Orthodontist](https://virtualconsultant.online/locations) Citation details Title Over-Retained Baby Teeth UK | When to Extract 2026 Guide Publisher Virtual Consultant Online Published 2026-05-28 Updated 2026-09-29 URL [https://staging.virtualconsultant.online/guides/over-retained-baby-teeth-uk](https://staging.virtualconsultant.online/guides/over-retained-baby-teeth-uk)