Introduction

Overview of Dentin Dysplasia Type I (DD-I)

Dentin Dysplasia Type I (DD-I) is a rare hereditary dental condition that fundamentally affects the root structure of both the permanent and primary dentitions. It is part of the spectrum of dentin abnormalities alongside dentinogenesis imperfecta, but is distinguished by the fact that affected teeth typically present with a clinically normal crown appearance. This can make early diagnosis challenging, particularly without radiographic assessment.¹ The main pathological findings in DD-I are extremely short, conical, or absent roots, which severely affect the long-term prognosis of the teeth. Many patients may not present with functional issues immediately, as the coronal enamel and dentin appear normal; however, the underlying structural defects create a risk for early exfoliation and tooth mobility. Due to the rarity of DD-I, most of the available literature is based on case reports and small case series rather than large-scale studies; nevertheless, these consistently highlight the challenges of maintaining oral health over a patient’s lifetime.

Clinical relevance and long-term implications

The clinical implications of DD-I are significant. Adolescents may exhibit early primary tooth exfoliation, and inadequate root support can cause teeth to become mobile shortly after eruption, placing patients at risk of early edentulism and functional impairment. Furthermore, periapical disease typically develops even in the absence of dental caries, a characteristic that can lead to unnecessary extractions when clinicians are unfamiliar with the condition.² Early tooth loss can also have psychological consequences, including reduced self-esteem and social difficulties, further underscoring the importance of preventive management.

Importance of consistent follow-up and preventive strategies

Given its complex and long-lasting effects, DD-I requires a shift in clinical focus from curative to preventive and supportive care. As there is no definitive treatment to regenerate or repair the damaged dentin structure, the primary objectives are to preserve function, prolong the survival of existing teeth, and plan for eventual prosthetic rehabilitation. Long-term follow-up enables early identification of pathology, more predictable extraction planning, and timely introduction of prosthetic or implant-based therapies.³ For these reasons, maintenance regimens tailored to childhood, adolescence, and adulthood are essential to achieving the best possible outcomes for affected individuals.

Pathophysiology and Clinical Features

Genetic and hereditary background

DD-I is typically inherited in an autosomal dominant pattern; if one parent has the condition, the child has a 50% chance of inheriting it. The condition involves disturbances in dentin matrix development during odontogenesis, although the precise genetic pathways have not yet been fully elucidated.³ Whilst coronal dentin is retained, odontoblasts, the cells responsible for dentin production, appear unable to form properly organised dentin in the root region. No single widely accepted causative gene for DD-I has been established, although some publications have implicated mutations affecting the collagen and dentin sialophosphoprotein (DSPP) pathways. The hereditary nature of the condition underscores the value of early screening in at-risk children and genetic counselling for affected families.

Radiographic and clinical characteristics

Radiographs provide the most conclusive diagnostic evidence in DD-I. Characteristic findings include exceptionally short, blunted, or absent roots, and obliterated pulp chambers that may appear as crescent-shaped remnants parallel to the enamel-dentine junction. Periapical radiolucencies are commonly observed even in teeth that are otherwise free of decay, most likely as a result of pulpal necrosis and periapical inflammation caused by atypical dentin architecture. As clinical crowns often appear normal in size, shape, and colour, DD-I may be overlooked in the absence of radiographic evaluation. Teeth may occasionally erupt but become mobile shortly afterwards, leading to functional difficulties.

Follow-Up Strategies

Recommended intervals for clinical and radiographic assessments

Consistent clinical follow-up is essential in the management of DD-I. Assessments are generally recommended every six to twelve months; however, accurate timelines should be determined under clinical guidance, as younger children and individuals with active pathology may require more frequent review.⁵

Each appointment should include evaluation of patient comfort, gingival health, occlusion, and tooth mobility. Regular monitoring enables clinicians to time extractions strategically, minimise disruption to occlusion, and plan for prosthetic replacement when necessary.

Monitoring for root resorption, periapical pathology, and mobility

Radiographs provide essential diagnostic information that cannot be obtained from clinical examination alone. Bitewing and periapical radiographs should be taken at baseline and repeated at regular intervals according to the patient’s risk profile. These images allow for the early identification of periapical disease, root resorption, and changes in bone support, enabling prompt management.⁶ In cases with known pathology, follow-up intervals should be shortened to ensure close monitoring.

Importance of a multidisciplinary approach

Due to the multifaceted nature of DD-I, care must be provided by a coordinated multidisciplinary team. Paediatric dentists oversee preventive and early management strategies, orthodontists assess occlusion, prosthodontists provide transitional prosthetics, and oral surgeons assist with extractions and eventual implant placement. This collaborative approach ensures that the patient’s care plan adapts appropriately as they develop, balancing immediate functional needs with long-term rehabilitation goals.

Maintenance Protocols

Preventive measures: oral hygiene reinforcement, fluoride therapy, and dietary counselling

Preventive care is a cornerstone of DD-I management. Daily plaque control combined with fluoride toothpaste helps maintain gingival health and delay the onset of caries. Professional fluoride applications and dietary counselling are also important adjuncts. In this patient group, complete caries prevention is of greater importance than in the general population, as restorative and endodontic options are more limited. Families should receive thorough oral hygiene instruction to support consistent adherence at home.⁶

Restorative interventions: conservative restorations versus prosthetics

Where caries lesions develop, conservative restorative approaches should be prioritised to maximise tooth survival. Composite restorations are preferred, and excessive tooth preparation should be avoided to preserve remaining structure.⁷ Crowns may be considered in selected cases, although their longevity may be limited by inadequate root support.

Orthodontic management: limitations due to root fragility

Orthodontic intervention in DD-I patients must be approached with considerable caution. Root fragility means that even light orthodontic forces may accelerate tooth loss and root resorption. Orthodontic treatment is often contraindicated; however, space management and interceptive measures may still have a role.⁸ In these cases, the orthodontist’s contribution is typically more consultative than therapeutic.

Summary

Dentin Dysplasia Type I (DD-I) is a rare genetic dental condition characterised by clinically normal-appearing crowns but severely malformed roots, resulting in tooth mobility, periapical disease, and early tooth loss. Conventional endodontic and orthodontic procedures are frequently contraindicated, and management therefore centres on preventive care, regular follow-up, and staged rehabilitation. Clinical and radiographic surveillance every six to twelve months is essential for early detection of pathology and timely intervention. Preventive measures, including plaque control, fluoride therapy, and dietary counselling, are prioritised to reduce caries incidence, while space maintainers and functional appliances support children experiencing early tooth loss. Prosthetic devices such as overdentures and removable prostheses offer interim solutions until implant therapy becomes appropriate in adulthood. Successful care requires a multidisciplinary team approach and careful consideration of the patient’s psychosocial well-being.