Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 
  • Users Online: 533
  • Home
  • Print this page
  • Email this page

 Table of Contents  
Year : 2020  |  Volume : 17  |  Issue : 6  |  Page : 480-483

An unusual case of tricho–dento–osseous syndrome

1 Department of Oral and Maxillofacial Surgery, Dental Implants Research Center, School of Dentistry, Isfahan University of Medical Sciences, Kermanshah, Iran
2 Department of Oral and Maxillofacial Surgery, School of Dentistry, Isfahan University of Medical Sciences, Kermanshah, Iran
3 Department of Oral and Maxillofacial Radiology, School of Dentistry, Kermanshah University of Medical Sciences, Kermanshah, Iran
4 Department of Dermatology, Skin Diseases and Leishmaniasis Research Center, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

Date of Web Publication10-Dec-2020

Correspondence Address:
Dr. Maryam Ghazizadeh
22 Bahman Street, Behzisti Square, Razi Building, Kermanshah
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/1735-3327.302892

Rights and Permissions

Tricho–dento–osseous (TDO) syndrome is a multisystem congenital disorder that is known by bone, skin, and hair abnormalities. Primitive studies show different varieties of manifestations related to this disorder, which involve sclerotic bones, nail involvement, enamel hypoplasia, mandibular prognathism, and taurodontism. Although exploring different TDO cases revealed genetic mutations in all of them, they have many variations in phenotypic view. In this study, we report a case whose primary diagnosis was alopecia and came for extraction of her third molars, but after clinical and radiographic examination, it was found that the cause of her disease was something different.

Keywords: Alopecia, genetic diseases, tricho–dento–osseous syndrome

How to cite this article:
Haghighat A, Pourarz S, Ghazizadeh M, Talebzadeh Z. An unusual case of tricho–dento–osseous syndrome. Dent Res J 2020;17:480-3

How to cite this URL:
Haghighat A, Pourarz S, Ghazizadeh M, Talebzadeh Z. An unusual case of tricho–dento–osseous syndrome. Dent Res J [serial online] 2020 [cited 2021 Dec 9];17:480-3. Available from: https://www.drjjournal.net/text.asp?2020/17/6/480/302892

  Introduction Top

Tricho–dento–osseous syndrome is identified as a rare congenital syndrome, which manifests as autosomal dominant and is belonged to the group of diseases, named as ectodermal dysplasia.[1],[2] This disorder is mainly caused by DLX3 gene mutation on the 17q21 chromosome, which is associated with bone, hair, and nail development.[3] From phenotypic viewpoint, tricho–dento–osseous (TDO) clinical signs indicate many varieties, therefore may be missed and true diagnosis of this disorder is difficult. However, this hypothesizes that the clinical signs variety is because of genetic heterogeneity or phenotypical variety has not been proved yet.[1],[4] The most common clinical findings of TDO are thin hairs (curly at birth and stiffening with age increasing), enamel hypoplasia, taurodontism (especially molars), and increase in bone density (especially skull).[3],[5]

  Case Report Top

A 21-year-old female who visited her dentist, referred to department of surgery, School of Dentistry, Isfahan University of Medical Sciences, to extract her semi-impacted third molars. Investigating her medical background did not indicate any signs of systemic disease. The patient suffered only from severe hair losing, and the dermatologist's diagnosis was alopecia. Investigating familial history indicated no special sign. Clinical examination showed the head hair loss, but the body and face hairs were not lost. Further studies revealed that the patient had normal hair at childhood, but she lost them gradually [Figure 1].
Figure 1: Normal hair in childhood and hair loss in adulthood.

Click here to view

The nail and skin were normal, and it was observed no kind of abnormality [Figure 2]. In the examination of the neck, the lymph nodes were normal, and mandibular prognathism was observed in facial examination [Figure 3].
Figure 2: Normal nail and skin.

Click here to view
Figure 3: Prognathism of mandible and Class III relationship.

Click here to view

Oral mucus and tonsils were normal and there was no inflammation. The teeth of the patient did not have any special anomaly. The teeth color and shape were in a normal condition. Bilateral mandibular third molars were semi-impacted, and the first mandibular molar restoration and the second mandibular molar occlusal caries were observed [Figure 4]. In panoramic view, the roots of all teeth were very short [Figure 5]. Therefore, the TDO syndrome was considered, and the patient was referred to genetic investigation, due to available abnormalities in hair, teeth, and bone. Genetic analysis indicated a mutation in the DLX3 gene. Genetic linkage was observed on chromosome 17q21 and a 4 base-pair deletion has been identified in the DLX3 gene.
Figure 4: Intraoral photograph. The crowns of teeth are normal.

Click here to view
Figure 5: Panoramic and lateral cephalometric view. Severe shortening roots of all teeth and mandibular prognathism are observed.

Click here to view

  Discussion Top

Alopecia is the most frequent autoimmune disease with unknown etiology and pathogenesis, and rarely has the teeth origin.[6],[7] The autoimmune diseases such as vitiligo, thyroid disease, and atopic are along with alopecia; however, genetically bases exist for them.[7] A theory said the infection originated from fungus, bacteria, and virus or their toxins, which are originated from infection centers like oral cavity, tonsils, adenoid, and sinus, can be considered as the causes of this disease. Although there is no certain agreement about alopecia etiology and pathogenesis, immunologic base is the most popular hypothesis.[6] Teeth infection can rarely a source for alopecia.[6] Whereas, in this case systemic examination, no kind of infectious or autoimmune disease were observed.

TDO is a rare autosomal dominant systemic genetic disease, which is created as a result of heterozygous mutations in DLX3 and also has an unknown incidence rate.[8]

The disease diagnosis criteria are: generalized defects of enamel, sever taurodontism (especially in the mandible first permanent molars), autosomal dominant instinct, and one of the minor manifestations. These manifestations include nail defect, sclerotic bone, and wavy, kinky and curly hairs at childhood, which can be straighten out in the future.[1] Panoramic radiography needs to be prescribed routinely for the cases in which clinical signs of jaw dysfunction are observed.[9],[10] However, these signs and symptoms are frequent at different clinical manifestations.[3]

There are significant variety to describe this syndrome in pervious literature.[11],[12] The investigations of different families with TDO, demonstrated that there are various differences for TDO appearances even between members of a family.[13],[14] As a result, with respect to phenotypic variety, many subtypes were proposed for TDO (TDO I, TDO II, and TDO III).[13] The classical type of TDO or the mild version of the disease with different phenotypes can accompany DLX3 mutation. Amelogenesis imperfecta and taurodontism appear to be the general features of all the cases, and they have been reported. The skin, hair, bone, and nails are also reported.[8]

Although studies expressed that soft, hypoplastic, or pitted enamel is a hallmark for TDO, they acknowledged that the genetic heterogeneity and environmental factors, that caused TDO phenotypic variety, must not be ignored.[11] In this case, no enamel involvement was observed.

Another cephalometric study about the cranial parameter varieties of a 40-member family (struggling with TDO) demonstrated that increasing the mandibular body length might be the only bone parameter for TDO.[15] In fact, mutation of DLX3 gen in TDO syndrome is accompanied with significant increasing of the mandibular body length.[4] According to the terminal difference of each kind of cell, DLX3 indicates different effects on mineralized tissue. In addition, direct involvement of DLX3 was observed in the osteoprogenitor cells that express the bone matrix protein (e.g., collagen type 1), bone sialoprotein, osteocalcin, and alkaline phosphatase.[16] The bone thickening in TDO can increase either fracture risk or macrocephaly.[1]

Wright et al. in another study conducted on 33 patients reported that kinky/curly hairs were existed in 85% of patients at birth time. In 54% of patients, the kinky hairs disappear after the infancy period, but they remain as coarse thick in other patients.[17] Price et al. reported that the phonotype variety in Virginia and North Carolina revealed that clinical variation is not caused by genetic heterogeneity at the major locus, but can be considered as a result of genetic heterogeneity at other epigenetic loci and/or the environment factor collaboration.[12] Moreover, Mayer et al. reported an atopic dermatitis in a TDO case.[3]

Moghim Farooji et al. reported a 10-year-old case of TDO and consumer of immunosuppressive. Due to the late referring, some of the teeth had pulp lesion. They declared that regular follow-up and on time dental treatment especially in critical age, prevents pulp lesion in patients with TDO syndrome.[18]

Harbuz et al. reported a familial case of TDO with osteogenesis imperfecta and intellectual disability, which had heterozygous deletion of DLX3.[14] For dentists, the TDO importance is because of two reasons: severe hypoplastic defects of enamel and difficulty in the diagnosis of hypomature and hypoplastic amelogenesis imperfecta with taurodontism of this syndrome.[1] Among teeth abnormalities, thin enamel (0.125–0.25 of normal thickness) is observable in these patients, which are mostly appear in primary teeth and fewer in permanent teeth.[1],[2]

TDO syndrome management is team approach. Because the most frequent problem of this syndrome is associated with the teeth and longtime follow-up of these patients is quite needed, dental team plays an important role in this approach.[1]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

The authors of this manuscript declare that they have no conflicts of interest, real or perceived, financial or nonfinancial in this article.

  References Top

Al-Batayneh OB. Tricho-Dento-Osseous syndrome: Diagnosis and dental management. Int J Dent 2012;2012:514692.  Back to cited text no. 1
Atar M, Körperich EJ. Systemic disorders and their influence on the development of dental hard tissues: A literature review. J Dent 2010;38:296-306.  Back to cited text no. 2
Mayer DE, Baal C, Litschauer-Poursadrollah M, Hemmer W, Jarisch R. Uncombable hair and atopic dermatitis in a case of Trichodento-Osseous syndrome. J Dtsch Dermatol Ges 2010;8:102-4.  Back to cited text no. 3
Nguyen T, Phillips C, Frazier-Bower S, Wright T. Craniofacial variations in the Tricho-Dento-Osseous syndrome. Clin Genet 2013;83:375-9.  Back to cited text no. 4
De La Dure-Molla M, Garrec P. Dysmorphic patients: A review of minor clinical signs leading to a diagnosis. J Dentofac Anom Orthod 2014;17:1-18.  Back to cited text no. 5
Dinkova A, Kirova D, Gavasova G, Drangov M, Gospodinov DL. Case of alopecia areata originated from dental focus. J IMAB Annu Proc Sci Pap 2014;20:669-73.  Back to cited text no. 6
Anzengruber F, Maul JT, Kamarachev J, Trüeb RM, French LE, Navarini AA. Transient efficacy of tofacitinib in alopecia areata universalis. Case Rep Dermatol 2016;8:102-6.  Back to cited text no. 7
Whitehouse LL, Smith CE, Poulter JA, Brown CJ, Patel A, Lamb T, et al. Novel DLX3 variants in amelogenesis imperfecta with attenuated Tricho-Dento-Osseous syndrome. Oral Dis 2019;25:182-91.  Back to cited text no. 8
Sheikhi M, Ghazizadeh M, Salehi MM. Posttraumatic mandibular asymmetry presenting in a young adult. Radiol Case Rep. 2017;12:73-7.  Back to cited text no. 9
Ghazizadeh M, Sheikhi M, Salehi MM, Khaleghi A. Bilateral coronoid hyperplasia causing painless limitation of mandibular movement. Radiol Case Rep. 2018;13:112-7.  Back to cited text no. 10
Islam M, Lurie AG, Reichenberger E. Clinical features of Tricho-Dento-Osseous syndrome and presentation of three new cases: An addition to clinical heterogeneity. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005;100:736-42.  Back to cited text no. 11
Price JA, Wright JT, Kula K, Bowden DW, Hart TC. A common DLX3 gene mutation is responsible for Tricho-Dento-Osseous syndrome in Virginia and North Carolina families. J Med Genet 1998;35:825-8.  Back to cited text no. 12
Melnick M, Shields ED, El-Kafrawy AH. Tricho-Dento-Osseous syndrome: A scanning electron microscopic analysis. Clin Genet 1977;12:17-27.  Back to cited text no. 13
Harbuz R, Bilan F, Couet D, Charraud V, Kitzis A, Gilbert -Dussardier B. Osteogenesis imperfecta, Tricho-Dento-Osseous syndrome and intellectual disability: A familial case with 17q21.33-q22 (COL1A1 and DLX3) deletion and 7q32.3-q33 duplication resulting from a reciprocal interchromosomal insertion. Am J Med Genet A 2013;161A:2504-11.  Back to cited text no. 14
Kula K, Hall K, Hart T, Wright JT. Craniofacial morphology of the Tricho-Dento-Osseous syndrome. Clin Genet 1996;50:446-54.  Back to cited text no. 15
Jain P, Kaul R, Saha S, Sarkar S. Tricho-Dento-Osseous syndrome and precocious eruption. J Clin Exp Dent 2017;9:e494-7.  Back to cited text no. 16
Wright JT, Kula K, Hall K, Simmons JH, Hart TC. Analysis of the Tricho-Dento-Osseous syndrome genotype and phenotype. Am J Med Genet 1997;72:197-204.  Back to cited text no. 17
Moghim Farooji E, Kazemi Z, Moradi S. Endodontic therapy of the periapical lesion in the anterior mandibular in a patient with Tricho-Dento-Osseous syndrome and consumer of immunosuppressive drug: A case report. J Dent Mater Tech 2017;6:44-7.  Back to cited text no. 18


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)  

  In this article
Case Report
Article Figures

 Article Access Statistics
    PDF Downloaded252    
    Comments [Add]    

Recommend this journal