Dentin Dysplasia - A Rootless teeth

What Is the Cause of Dentin Dysplasia?

Dentin dysplasia (DD) is a rare dental anomaly. It has an autosomal dominant inheritance pattern. It is caused due to hereditary disturbance in the second layer of tooth (dentin) formation. This disorder affects the primary or permanent dentitions in a ratio of approximately one in every 100,000 individuals globally. Patients affected by this condition usually complain of discoloration in the tooth crown or premature exfoliation (tooth loss). Primary dentition or milk teeth get prematurely lost. Parental attention to the early loss of teeth is one of the reasons for the early diagnosis of dentin dysplasia in children. In adults as well as children, it holds an aesthetic concern.

What Are the Types of Dentin Dysplasia?

There are mainly two types of dentin dysplasia or DD:

• Type I Dentin dysplasia.

• Type II Dentin dysplasia.

Type I Dentin Dysplasia: In this type, the tooth crowns appear quite normal but might be slightly altered in color (amber-colored). The typical feature is no tooth root development or just rudimentary root development. There is observably a growth of the tooth dentin layer into the pulp chamber of the teeth. When the pulp space or the root canal space is reduced by this invasion of dentin especially in permanent teeth, there will be either partial or complete obliteration of the pulp chambers. Radiographically in dentin dysplasia type 1, the dentist observes periapical radiolucent areas around the tooth crown with a lack of root. When cysts are present around these tooth crowns, it causes tooth loss prematurely at times. Type 1 DD teeth show more resistance to dental caries attack or bacterial invasion than normal teeth. This condition is colloquially known in dental literature as rootless teeth.

Type II Dentin Dysplasia: In this type of dysplasia, the tooth crown color can range from yellowish brown to even gray or amber. The primary teeth appear translucent with complete obliteration of the pulp or root canal chamber. The permanent teeth may have a normal appearance or an amber color with normal roots. But the pulp or root canal chamber will have a 'thistle tube' shaped appearance and pulp stones. Obliteration of the pulp chambers happens at a later stage in life in this type II dentin dysplasia and does not occur before the eruption of teeth, unlike in type 1.

What Conditions Are Associated With Rootless Teeth Formation?

The pathogenesis of dentin dysplasia was thought to be unknown in the traditional dental literature. However, few studies have hypothesized the cause to be as follows:

• Abnormal interaction of odontoblasts with the ameloblasts or tooth crown-forming cells leads to an atypical differentiation or function of the odontoblasts or cells forming the dentin layer.

• Ehlers-Danlos syndrome (inherited connective tissue disorder).

• Goldblatt syndrome (bone dysplasia associated with skeletal abnormalities).

• Calcinosis (Abnormal calcium salt deposition).

• Osteogenesis imperfecta (inherited bone disorder).

• Immuno-osseous dysplasia (multisystem disorder associated with kidney disorder, short stature, and immune deficiency).

• Brachio-skeleton-genital syndrome (Genetic disorder associated with skeletal abnormalities).

Because these teeth are rootless or the roots are rudimentary with loss of normal tooth root functions (like support, anchorage, or attachment), the premature loss of teeth or mobile teeth is an issue encountered by most patients who suffer from this condition. The parent can notice this when the teeth exfoliate rapidly in the primary dentition and in the permanent dentition in adults; exfoliation or tooth mobility would be evident to the patient.

What Is the Diagnosis of Dental Dysplasia?

Diagnosing dental dysplasia can be done by:

• Clinical Examination: Interview the patient regarding oral hygiene, plus an assessment of the color and shape of the teeth.

• Radiographic Imaging:

  • Type I: From the radiographical analysis, patients present with short or no roots, obliterated pulp chamber, and well-defined periapical rarefaction that are not related to caries.

  • Type II: Conventional radiography reveals that the pulp chambers are relatively larger in permanent teeth and the pulp chambers are missing in primary teeth.

• Histopathology:

  • Type I: Irregular arrangement of dentine tubules and a scanty development of root dentine.

  • Type II: The root structure is normal but the coronal dentine is abnormally arranged with interglobular dentine areas.

What Are the Differential Diagnosis of Dental Dysplasia?

Dentinal dysplasia (DD) vs. dentinogenesis imperfecta (DI):

• DI: Has blue-gray or amber opalescent teeth; both the crown and the root show bulbous crowns, obliterated pulp chambers, and roots.

• DD Type I: A generally normal crown with an abnormally short root structure.

• DD Type II: It can be confused with DI because both have a similar appearance of primary teeth however, it can be distinguished from DI based on the radiographic features of the permanent teeth.

Other Considerations:

• Regional Odontodysplasia: Ghost teeth, dentine with low mineralization degree.

• Pulpal Dysplasia: Hyperdontia and hypodontia pulp stones and other pulpal anomalies that are not associated with generalized dentine anomalies as in DD.

• Odontogenesis Imperfecta: A more general term that may encompass dentine and enamel abnormalities.

What Is the Dental Management Protocol in Primary and Permanent Dentition Affected by Dentin Dysplasia?

• The most effective treatment the dentist can suggest to the patient is to practice good oral hygiene like brushing methods, effective control of dental plaque, regular dental follow-ups, and professional oral prophylaxis to maintain the teeth' health.

• When these patients avoid dental treatment, then the need for intervention becomes more invasive with time and further. As a result, tooth loss would be the natural consequence.

• Hence it's important to practice dental hygiene and follow up on dental visits. The dentist would decide on treatment in DD type 1 and 2 based on factors such as patient age, the severity of the issue, and the chief complaint to restore their functional and esthetic looks.

• In the case of primary dentition, the pedodontist will manage this condition of rootless or exfoliated teeth by maintaining the tooth with stainless steel crowns. This maintains not only occlusal dimensions but also prevents tooth wearout in the child. Composite fillings in the front-facing surfaces (the labial or buccal surface of the tooth) or composite strip crowns would be good options, too, for aesthetic reasons in the child.

• In adults with permanent dentition, conserving the existing teeth is a challenge. Endodontic intervention by root canal treatment would be required, and the success rate should be evaluated. This is because the obliterated root canal pulp chambers develop abscesses or pulp stones, making endodontic treatment access difficult for the dentist or endodontist.

• If this endodontic therapy is not possible, a periapical curettage with a retrograde filling is another alternative. This method, however, only applies to teeth with short roots.

• Teeth with short or very thin roots are unfavorable for crown fabrication. If the abscess develops further with a low prognosis for endodontic therapy, the dentist will consider removing the affected teeth and proceed with partial or complete oral rehabilitation. Overdentures and cast partial dentures are good treatment options for these patients.

• Dental implants should be only considered when bone growth is complete in adults. This is because they require complex ridge augmentation procedures for implant placement and a sinus lift technique in the maxillary posterior teeth.

Conclusion

To conclude, dentin dysplasia, either in primary or permanent dentition, should have an early diagnosis and regular dental treatment protocol for rehabilitation. This helps the affected patients to maintain their esthetics and function and minimize any associated nutritional or systemic deficits and social distress.