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PubMed This is a summary of 18 peer-reviewed journal articles Updated
Dentistry

Classification: Telling the Difference

At a Glance

Dentin Dysplasia Type I (DD-I) is a genetic dental condition causing short or missing roots, which leads to loose teeth. Doctors classify DD-I using X-rays and genetic tests to identify specific mutations, distinguishing it from similar conditions to plan the most effective dental care.

When you hear terms like “Type I,” “Type II,” or “Dentinogenesis Imperfecta,” it can feel like a lot of jargon. However, these categories help your dental team understand exactly how your child’s teeth are built and what to expect in the future. Accurate classification is essential because it helps predict how long teeth will stay in the mouth and which treatments will be most successful [1][2].

The Shields Classification

For decades, dentists have used the Shields Classification (established in 1973) to organize hereditary dentin disorders [3]. This system looks primarily at X-rays and the physical appearance of teeth.

Subtypes of DD-I

Within the “Type I” category, some specialists use a more detailed breakdown (subtypes DD-Ia through DD-Id) to describe how much of the tooth’s internal space (the pulp) has been filled in [4][2]:

  • DD-Ia: Complete absence of pulp chambers and roots (rootless teeth).
  • DD-Ib: Horizontal, crescent-shaped pulp remnants and very short roots.
  • DD-Ic: Half-moon shaped pulp remnants and slightly longer, but still short, roots.
  • DD-Id: Normal-sized pulp chambers but with large “pulp stones” that block the canals.

While this system is helpful, it has limitations. Because it was created before we understood the genetics of these conditions, some cases don’t fit perfectly into one “box” [5][6].

Telling the Difference: DD-I vs. Others

It is common for DD-I to be confused with other conditions that affect dentin. Here is how doctors tell them apart:

Feature Dentin Dysplasia Type I (DD-I) Dentin Dysplasia Type II (DD-II) Dentinogenesis Imperfecta (DI)
Crown Color Usually Normal [7] Baby teeth: Discolored; Adult teeth: Normal [8] Discolored (Amber, gray, or opalescent) [8]
Root Length Short, blunt, or absent [7] Normal [8] Usually shorter or thinner [8]
Pulp Shape Obliterated or Half-moon [7] Thistle-tube shape [8] Obliterated or very large “shell teeth” [9]
Genetics VPS4B, SSUH2, or SMOC2 [10] DSPP gene [11] DSPP gene [12]

Why the Distinction Matters

Distinguishing these conditions is vital for your child’s care. For example:

  • In DD-I, the primary concern is often tooth mobility and loose teeth because the roots are so short [13].
  • In DD-II or DI, the teeth may be more prone to wear and tear (attrition) or breakage because the dentin is softer, even if the roots are a normal length [14][15].

Modern Diagnosis

Today, doctors are moving beyond just looking at X-rays. Genetic testing is becoming a powerful tool to confirm a diagnosis [16][17]. Knowing if the mutation is in the DSPP gene (linked to DD-II and DI) or genes like VPS4B (linked to DD-I) gives your team a clear roadmap for your child’s dental journey [10][18].

Common questions in this guide

What are the subtypes of Dentin Dysplasia Type I?
There are four main subtypes of Type I (DD-Ia to DD-Id). These are categorized based on how much of the tooth's internal pulp space is filled in and the length of the roots, ranging from completely rootless teeth to teeth with normal-sized pulps but large pulp stones.
How is Dentin Dysplasia Type I different from Type II?
In Type I, teeth typically have a normal color but very short or missing roots, making them loose. In Type II, baby teeth are often discolored (amber or gray) and teeth are more prone to wear and tear, but root length is usually normal.
What is the main complication associated with Dentin Dysplasia Type I?
The primary concern is tooth mobility and early tooth loss. Because the roots are abnormally short or completely absent, the teeth are not anchored securely in the jawbone.
Can genetic testing confirm Dentin Dysplasia Type I?
Yes, genetic testing is increasingly used to confirm a diagnosis. Testing can identify specific gene mutations, such as VPS4B for Type I or DSPP for Type II, providing a clearer roadmap for your child's long-term dental care.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Does my child show signs of 'total' or 'partial' pulp obliteration, and which subtype (a through d) does that suggest?
  2. 2.Are there any signs of amber or gray discoloration in the baby teeth that might suggest DD-II instead of DD-I?
  3. 3.How does the 'rootless' appearance of my child's teeth change our long-term plan for tooth replacement or preservation?
  4. 4.Since DD-II and DI are linked to the DSPP gene and DD-I is not, would genetic testing help confirm the exact classification?

Questions For You

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References

References (18)
  1. 1

    Guided endodontic treatment of multiple teeth with dentin dysplasia: a case report.

    Krug R, Volland J, Reich S, et al.

    Head & face medicine 2020; (16(1)):27 doi:10.1186/s13005-020-00240-4.

    PMID: 33203420
  2. 2

    Type I Dentin Dysplasia: The Literature Review and Case Report of a Family Affected by Misrecognition and Late Diagnosis.

    Putrino A, Caputo M, Galeotti A, et al.

    Medicina (Kaunas, Lithuania) 2023; (59(8)) doi:10.3390/medicina59081477.

    PMID: 37629767
  3. 3

    Novel frameshift mutations in DSPP cause dentin dysplasia type II.

    Lee JW, Hong J, Seymen F, et al.

    Oral diseases 2019; (25(8)):2044-2046 doi:10.1111/odi.13182.

    PMID: 31454439
  4. 4

    Dentin dysplasia Type I: A rare case report.

    Akhil Jose EJ, Palathingal P, Baby D, Thachil JM

    Journal of oral and maxillofacial pathology : JOMFP 2019; (23(2)):309 doi:10.4103/jomfp.JOMFP_132_19.

    PMID: 31516254
  5. 5

    Dentin dysplasia: diagnostic challenges.

    Alhilou A, Beddis HP, Mighell AJ, Durey K

    BMJ case reports 2018; (2018()) doi:10.1136/bcr-2017-223942.

    PMID: 29895546
  6. 6

    A histological continuum between dentinogenesis imperfecta and dentin dysplasia: A case report with literature review.

    Gulati N, Juneja S, Singh A, Singh I

    Indian journal of dental research : official publication of Indian Society for Dental Research 2019; (30(4)):643-646 doi:10.4103/ijdr.IJDR_318_18.

    PMID: 31745067
  7. 7

    Endodontic treatment of dentin dysplasia type I D.

    Buchanan GD, Tredoux S, Nel C, Gamieldien MY

    Australian endodontic journal : the journal of the Australian Society of Endodontology Inc 2021; (47(2)):343-349 doi:10.1111/aej.12444.

    PMID: 32964546
  8. 8

    A rare case diagnosed as dentin dysplasia type II.

    Perlea P, Dragomir C, Bodeanu A, et al.

    Romanian journal of morphology and embryology = Revue roumaine de morphologie et embryologie 2018; (59(1)):359-365.

    PMID: 29940650
  9. 9

    A Novel Variant in Dentin Sialophosphoprotein (DSPP) Gene Causes Dentinogenesis Imperfecta Type III: Case Report.

    Wang Y, Xu X, Ding Y, Yuan G

    Molecular genetics & genomic medicine 2025; (13(3)):e70087 doi:10.1002/mgg3.70087.

    PMID: 40040554
  10. 10

    Dentin dysplasia type I-A dental disease with genetic heterogeneity.

    Chen D, Li X, Lu F, et al.

    Oral diseases 2019; (25(2)):439-446 doi:10.1111/odi.12861.

    PMID: 29575674
  11. 11

    [Clinical and genetic analysis of a Chinese pedigree affected with Hereditary dentin dysplasia type II due to a variant of DSPP gene].

    Li F, Yang Y, Liu Y, et al.

    Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics 2025; (42(11)):1329-1336 doi:10.3760/cma.j.cn511374-20241219-00668.

    PMID: 41645374
  12. 12

    Beyond the diagnosis: Unraveling DSPP genotype-phenotype correlations in dentin dysplasia and dentinogenesis imperfecta.

    Boonyakanog A, Sriwangyang K, Eamtanaporn T, et al.

    The Japanese dental science review 2026; (62()):46-56 doi:10.1016/j.jdsr.2026.01.001.

    PMID: 41583696
  13. 13

    Dentin dysplasia type I-novel findings in deciduous and permanent teeth.

    Ye X, Li K, Liu L, et al.

    BMC oral health 2015; (15()):163 doi:10.1186/s12903-015-0149-9.

    PMID: 26693824
  14. 14

    An unusual variation of radicular dentin dysplasia: A rare case report with review of literature.

    Patnana AK, Chugh VK, Chugh A

    Indian journal of dental research : official publication of Indian Society for Dental Research 2020; (31(5)):807-812 doi:10.4103/ijdr.IJDR_372_19.

    PMID: 33433525
  15. 15

    Endodontic Management of Dentin Dysplasia Type II in a Pediatric Patient: A Case Report.

    Saberi E, Rezvani S

    Iranian endodontic journal 2025; (20(1)):e17 doi:10.22037/iej.v20i1.47021.

    PMID: 40206783
  16. 16

    A novel DSPP frameshift mutation causing dentin dysplasia type 2 and disease management strategies.

    Yuan M, Zheng X, Xue Y, et al.

    Oral diseases 2023; (29(6)):2394-2400 doi:10.1111/odi.14494.

    PMID: 36597617
  17. 17

    Translated Mutant DSPP mRNA Expression Level Impacts the Severity of Dentin Defects.

    Kim YJ, Lee Y, Zhang H, et al.

    Journal of personalized medicine 2022; (12(6)) doi:10.3390/jpm12061002.

    PMID: 35743786
  18. 18

    Identification of DSPP novel variants and phenotype analysis in dentinogenesis dysplasia Shields type II patients.

    Du Q, Cao L, Yan N, et al.

    Clinical oral investigations 2023; (27(7)):3885-3894 doi:10.1007/s00784-023-05009-y.

    PMID: 37017752

This page explains Dentin Dysplasia Type I classifications for educational purposes only. Always consult your pediatric dentist or geneticist for an accurate diagnosis and treatment plan for your child.

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