Dentinogenesis Imperfecta: A Deep Dive into the Mysteries of Genetic Dental Disorders

INTRODUCTION

In the world of dentistry, amidst the countless conditions that challenge clinicians and researchers alike, Dentinogenesis Imperfecta (DGI) emerges as a captivating anomaly, its complexities weaving a tapestry of genetic intricacies and clinical challenges. Characterized by the abnormal development of dentin, the substance that forms the bulk of our teeth, DI transcends mere cosmetic concerns, often presenting formidable hurdles to dental health and function. As researchers delve deeper into its genetic underpinnings and clinical manifestations, the quest to unravel DGI's mysteries becomes increasingly urgent. In this article, we embark on a journey through the intricate landscape of Dentinogenesis Imperfecta, exploring its genetic origins, clinical presentations, diagnostic approaches, and emerging treatment modalities."

DGI is an autosomal dominant disorder of tooth development. The presence of opalescent dentin is a characteristic feature of this condition. It is a localized mesodermal dysplasia that affects both permanent and primary dentition. Affected teeth are grey to yellowish-brown in color and have broad crowns with constriction of the cervical area resulting in a “Tulip” shape. Enamel is easily broken leading to accelerated attrition of exposed dentin.

TYPES OF DENTINOGENESIS IMPERFECTA

Shields classification

1. DGI Type I: Dentinogenesis imperfecta with Osteogenesis imperfecta. It affects both dentition ie: permanent and deciduous teeth.

2. DGI Type II: Dentinogenesis imperfecta without Osteogenesis imperfecta. It is the most common type of Dentinogenesis imperfecta and it affect both primary and permanent teeth.

3. DGI Type III: It is known as Brandywine isolate and was found in Maryland, Washington. It also affect both primary and permanent teeth.

Revised classification

1. Dentinogenesis Imperfecta I: DGI without Osteogenesis imperfecta: this corresponds to DGI Type II of Shields classification.

2. Dentinogenesis Imperfecta II: Brandywine type DGI: this corresponds to DGI III of Shields classification.

ETIOLOGY

Dentin is composed of 70% of inorganic materials or minerals, 20% of organic material and 10% of water. The organic materials are composed of collagenous and non-collagenous proteins.  Collagenous proteins is mainly type I collagen and the genes responsible for its production are COL1A1 and COL1A2 genes. The most abundant non-collagenous protein is derived from dentin silaophosphoproteins and the gene guiding the formation of these protein is dentin silaophosphoproteins (DSPP) gene. Mutation in COL1A1 and COL1A2 are responsible for DGI Type I. Mutation in DSPP genes leads to Type II and Type III DGI.

CLINICAL FEATURES

Extraoral features include:

• Blue sclera

• Short stature

• Brittle and fragile bones in Shields Type I DGI

• In rare cases, sensorineural hearing loss can be seen

Intraoral features:-

DGI Type I:

• Deciduous teeth are commonly affected

• Affected teeth are blue-grey to amber-brown in color and are opalescent.

• Severe attrition of teeth

• Obliteration of pulp chambers

DGI Type II:

• Affected teeth show bulbous crowns with cervical constriction.

• Radiograph shows teeth with bulbous crowns and narrow roots, small pulp chambers, and root canals as compared to normal teeth.

DGI Type III:

• Both primary and permanent teeth are affected

• Affected teeth are susceptible to fracture after eruption

• Multiple pulp exposures are seen

• Radiographs of the primary (deciduous) teeth reveal initially enlarged pulp chambers with thin enamel, dentin (Shell teeth) and root canals, which subsequently decrease in size with age.

• Pulp spaces of permanent teeth are smaller than normal and are sometimes obliterated.

TREATMENT

Dentinogenesis imperfecta may require a multidisciplinary approach involving prosthodontic, restorative and orthodontic treatments. The treatment may vary according to the age of the patient and the severity of the condition. Dentists mainly aim to prevent infection, restore aesthetics and function, and protect teeth from attrition and to maintain the occlusal vertical dimension.

Treatment for primary teeth:

• Pits and fissure sealant application to prevent the formation of dental caries.

• Stainless steel crown to protect the primary teeth from attrition

• Composite strip crowns to protect anterior teeth

• Extraction of affected teeth in case of abscess

• Overdentures in case of severe attrition

Treatment for permanent teeth:

• Cast occlusal onlays reduce teeth wear and help to maintain vertical occlusal dimension.

• Placement of porcelain veneers on anterior to improve aesthetics

• Dental implants or Dentures to replace missing teeth.

CONCLUSION

In conclusion, Dentinogenesis imperfecta presents a fascinating interplay of genetic predisposition and clinical manifestation. Rooted in mutations affecting dentin matrix proteins, this condition manifests in uniquely opalescent or translucent teeth prone to rapid wear and susceptibility to fractures. Treatment strategies, ranging from preventive measures to advanced restorative techniques like crowns and dental implants, aim to mitigate these challenges and preserve dental integrity. As research continues to uncover deeper insights into its genetic underpinnings and refine treatment modalities, the journey towards managing Dentinogenesis imperfecta remains a dynamic frontier in dental care and genetic medicine.

REFERENCES

1. Dentinogenesis imperfecta-Dr. Anuthanyaa R, 2022

2. Dentinogenesis imperfecta-Aetiology and Prosthodontic Management- Sushant K Garg, Sanjay Bansal, Sanjeev Mittal, Manumeet K Bathal, 2012

3. Dentinogenesis imperfecta-A Review and Case Report of A Family over Four Generation- Sudhir Bandari,Karneev Pannu, 2008

4. Shafer WG, Hine MK, Levy BM. Disturbances of Development and Growth. In: Rajendran R, Sivapathasundram B, editors. Shafer’s Textbook of Oral Pathology. Elsevier: A Division of Reed Elsevier India Private Limited; 2006.

By Dr. Amingold M J