Introduction

In this article, we will discuss how teeth are affected in individuals affected by Dentin Dysplasia, and whether orthodontic treatment can be considered as a treatment. 

Overview of dentin dysplasia type I (DDI)

Definition and characteristics

Dentin Dysplasia Type I (DDI) consists of normal crowns, alongside poorly formed or missing roots in primary and permanent teeth. Affected teeth may erupt normally, but can be loose and may be lost sooner than expected. Radiographs show obliterated pulp chambers and roots that lack normal structures, and histologically, their dentin is disorganised. The enamel is also characterised as being intact, or potentially more caries-resistant than normal enamel, even if affected teeth do end up being lost.^1,2

Genetic aetiology and prevalence

DDI is generally inherited in an autosomal dominant pattern; however, recessive forms also exist. DDI is rare, but it has been described as similar to other disorders. Unlike these other disorders, DDI exhibits genetic variability, with known mutations arising from the VPS4B, SSUH2, and SMOC2 genes. While they each share similarities, all of them interfere with normal dentin development. Moreover, the genetic variability complicates the diagnosis of DDI, particularly since there are potentially many genetic pathways that can influence root dentin development.¹

DDI is estimated to occur in 1 in every 100,000 persons, making this condition a rare disorder. DDI occurs in both males and females equally and can affect any set of teeth.^1,2

Importance of orthodontic management

Impact on dental and oral health

Dentin Dysplasia Type I (DD-I) can result in tooth mobility, premature loss, delayed eruption, and periapical radiolucencies in primary and permanent teeth, affecting their dental function and aesthetic. These conditions predispose the patient to malocclusion and severely affect the quality of life. Early diagnosis and treatment are required for effective management and long-term stability.³

Necessity of customised orthodontic treatment

Orthodontic treatment of a patient diagnosed with DD-I requires careful planning and individualised treatment. Careful movement of the teeth should be performed, using the least amount of force to avoid unacceptable root damage. A multidisciplinary approach may be required, including surgical procedures, tooth extractions, and restorative treatment. Rigorous follow-up is required to review the integrity of the teeth, and prosthetic options may be indicated if early tooth loss is experienced.³

Clinical presentation 

Morphological features

DDI is characterised by gross shortening, malformations, or absence of root(s), and is sometimes referred to as "rootless teeth". The pulp chamber is obliterated with occasional remnants or pulp stones. The dentin is thin with an irregular contour, and generally, multiple periapical radiolucencies can be seen on the radiographs. Histologically, the junctions of the enamel surfaces may have large scalloped shapes with teardrop lacunae.¹

Clinical complications

Patients experience early tooth loss commonly from the instability of roots and periapical pathologies, such as abscesses or cysts, which occur very frequently even in the absence of trauma. It is difficult to apply restorative treatment as endodontic work; if possible, it must be attempted with obliterated canals. This tooth loss and periapical pathologies with severe shape defects are an issue with malocclusion, functional problems, and aesthetics.¹

Orthodontic challenges in DDI patients: tooth anchorage and stability

Due to malformed and shortened roots, DD-I severely limits tooth anchorage, increasing the risk of mobility during orthodontic treatment. Customised anchorage methods, like trans-palatal arches and force distribution across multiple teeth, help reduce stress on individual units.⁴ 

Treatment planning considerations

Orthodontic plans must use very light, intermittent forces to prevent root resorption. Each case requires a personalised risk assessment, frequent imaging, and clear communication with patients. In severe cases, limited or alternative treatments may be safer for long-term tooth survival.⁴

Risk of root resorption

DD-I patients face a high risk of root resorption, even with minimal orthodontic force. Since root damage is already a concern in healthy individuals, the compromised root structure in DD-I significantly increases the risk of tooth or root loss during treatment.⁴

Diagnostic approaches

Radiographic evaluation

Teeth affected by DD-I typically appear normal, and a visual diagnosis is not reliable. The most typical signs of DD-I include unexplained tooth mobility, premature tooth loss, and abscess formation in non-carious teeth. A thorough family health history is crucial for confirming a diagnosis, and systemic conditions must also be ruled out.^1,5

Clinical assessment

Radiographs are essential for the diagnosis of DD-I; they should reveal classic indications of DD-I, such as short roots, absent roots, obliterated pulp chambers, and multiple periapical radiolucent lesions. Determining the subclassification of DD-I into the specific types, such as 1a, 1b, 1c, and 1d, can help to refine the diagnosis.^1,5 Standard dental radiographs include panoramic X-ray; micro-CT can be helpful for radiographic evaluation.⁶

Orthodontic treatment options

Braces and appliances

For DD-I, fixed appliances are helpful, but only if it is possible to apply very light forces with patient-specific mechanics (e.g. trans-palatal arches) to limit damage to the root. Successful treatment can be accomplished with careful monitoring of the DD-I case; results will vary depending on the root structure and how each individual responds.^1,4

Space management

Space management is the process of balancing the ability to retain the remaining tooth structure versus the need to extract teeth, particularly with impacted teeth or early loss. In these situations, removable prosthetic appliances play an important role in maintaining preserved space and function in young patients or for those who are missing multiple teeth.^1,4

Extraction protocols

Extractions will vary by case in DD-I, with extraction often being appropriate when the teeth are not root-supported or when pathology is evident. In severe cases of DD-I, complete extraction (and extraction if there is a possibility of movement) may end in eventual implant-based rehabilitation in the young adult patient. Early diagnosis, monitoring, and treatment will inform the supporting team to extract teeth and minimise any related risks.^1,4

Post-treatment considerations

Retention phase

Retention in DD-I becomes essential because of poor root retention and to reduce recollection risks. Removable retainers are preferred, as they alleviate the pressure off the teeth and allow clinicians to monitor. Fixed retainers are still used, but they are limited. Retention protocols must be adjusted on an individual basis, and retention may be required far longer than planned.^1,4

Follow-up and monitoring

Patients should be followed up every 3-4 months to monitor tooth stability, any root resorption, and periapical health. Ranch radiographs can help identify issues early on, which will allow family members time to replace missing teeth with prosthetics (if the tooth is missing).^1,4

Collaboration with other dental specialists

Collaboration with special consultants can provide comprehensive treatment, as part of a multidisciplinary team. Periodontists can work to manage teeth and gums, prosthodontists manage tooth replacement, and endodontists manage the infection as best they can, although some may be unwilling to manage previously treated teeth. Genetic counselling may be suggested for families. ^1,4

Summary

Orthodontic therapy for Dentin Dysplasia Type I (DD-I) takes extreme care because the roots are shortened or completely absent, ultimately compromising stability. Treatment options typically utilise light, intermittent forces and/or an appliance (similar to a transpalatal arch), to minimise damage to the roots and lessen complications associated with increased mobility. Radiographs should be taken to monitor progress and the detection of complications; if minimal, they should take precedence. Space management may involve selective extractions and will typically require the use of removable appliances or prosthetics to maintain function for the patient long-term. With the significant risk of root resorption, treatment plans will need to be very individualised in conjunction with the patient's understanding of the risks involved. Most commonly, retainers post-treatment will be removable; this is to minimise stress on teeth and allow for continued monitoring of the dentition and treatment completion. A careful, multidisciplinary approach is important to maximise tooth preservation, while demonstrating some improvement to the patient's dental function and aesthetics.