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Year : 2013  |  Volume : 16  |  Issue : 3  |  Page : 269-271
Asyndromic hypodontia associated with tooth morphology alteration: A rare case report

1 Department of Conservative Dentistry and Endodontics, Teerthanker Mahaveer Dental College and Research Centre, Teerthanker Mahaveer University, Moradabad, India
2 Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India
3 Private practice, Moradabad, India

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Date of Submission12-Sep-2012
Date of Decision08-Oct-2012
Date of Acceptance04-Mar-2013
Date of Web Publication4-May-2013


Clinicians frequently encounter hypodontia in their practice. It can be associated with any syndrome or more commonly it is asyndromic. This asyndromic form is commonly familial and can be followed in heredity of the patient. The patient referred in this report presented with a rare anomaly of hypodontia with altered morphology where the patient had all the teeth single rooted and single canalled. Studies have indicated several genes that affect the tooth morphology and number. A genetic correlation of hypodontia with altered permanent teeth morphology may be explored further in studies.

Keywords: Hypodontia; mandibular molar; maxillary molar; single rooted

How to cite this article:
Agarwal A, Gundappa M, Miglani S, Nagar R. Asyndromic hypodontia associated with tooth morphology alteration: A rare case report. J Conserv Dent 2013;16:269-71

How to cite this URL:
Agarwal A, Gundappa M, Miglani S, Nagar R. Asyndromic hypodontia associated with tooth morphology alteration: A rare case report. J Conserv Dent [serial online] 2013 [cited 2020 May 26];16:269-71. Available from:

   Introduction Top

Hypodontia refers to a condition where few teeth are congenitally missing or when some of the teeth do not form. [1] Frequently missing teeth include mandibular second premolars, maxillary lateral incisors, and maxillary second premolars (excluding third molars). [2] Genetic studies suggest both genetic and environmental etiology toward this anomaly. [3] Various experimental studies show that genes control the number and region of missing teeth. Hypodontia and oligodontia may be inherited as autosomal dominant trait and mutation of genes such as MSX1 and PAX9 have been implicated in a few studies. [4],[5],[6],[7] Occasional environmental factors (such as trauma in the dental region such as fractures, surgical procedures on the jaws, and extraction of the preceding primary tooth) may also contribute toward hypodontia. Other environmental factors affecting tooth development may be multiagent chemotherapy and radiation therapy depending on the age of patient and dosage [8] with radiation having more serious effects as compared with chemotherapy. [9] Hypodontia has also been reported in children where mothers have taken thalidomides during pregnancy. [9] But by and large it has got more genetic predilection than environmental. It has been observed that hypodontia occurs in individuals related to patients with hypodontia (genetic or hereditary predilection). [4],[10]

Hypodontia may be associated with any syndrome or may be asyndromic. [11] The present case presented with hypodontia associated with altered tooth morphology and was not associated with any other anomaly.

   Case Report Top

A 24-year-old male reported to the department of conservative dentistry and endodontics with the chief complaint of pain in right lower back tooth region. On intra-oral examination, the patient had multiple carious lesions and multiple missing teeth with retained deciduous teeth. Intraoral periapical radiographs were done for mandibular molars and left maxillary molar. Single rooted morphology of molars was observed on the intraoral periapical radiographs. OPG was taken after the completion of root canal treatment. The OPG depicted an interesting picture [Figure 1]. It revealed altered morphology of all permanent teeth and numerous missing teeth. Realizing the importance of the findings of this case, a computed tomograph for upper and lower jaw was advised. Since only high resolution computer tomography (HRCT) facility was available at the university hospital, HRCT was undertaken [Figure 2] and the findings of HRCT confirmed the diagnosis. HRCT and OPG images suggested that right maxillary lateral incisor, second premolars, and third molars were congenitally missing. Deciduous second molars were retained and showed normal anatomy and all permanent teeth had single roots [Figure 2] and [Figure 3].
Figure 1: OPG after the root canal treatment

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Figure 2: High resolution computed tomography images of maxilla and mandible clearly show the single rooted anatomy of all permanent teeth

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Figure 3: Pictures clearly suggest altered morphology and retained deciduous molars and missing second premolars

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Since hypodontia along with altered morphology of teeth was observed, thorough medical examination was advised. The medical examination and checkup revealed no contributory finding. So it was concluded that there was no association with any medical condition and could not be kept under the category of any known syndrome. The patient is a single child and oral examination of his parents revealed nothing significant. So a familial correlation, at least for now, could not be established.

The importance of this case lies in the fact that all permanent teeth were single canalled including all molars, which is a rare finding. [12] Also the condition presented with no additional anomaly other than dental, so could not be associated with any syndrome.

   Discussion Top

Hypodontia can either occur with accompanying genetic disease as part of a recognized clinical syndrome, or as a nonsyndromic, familial form, which occurs as an isolated trait, affects variable numbers of teeth and appears either sporadically or in a familial fashion within a family pedigree. [13]

There are over 60 different syndromic conditions that include hypodontia as part of their phenotypic spectrum of anomalies. However, familial or the nonsyndromic form of hypodontia is of more concern to the dental practitioner. This condition can follow autosomal dominant, [5],[14],[15],[16] autosomal recessive [17],[18] or sex-linked [19] patterns of inheritance, with considerable variation in both penetrance and expressivity.

Although mouse studies have suggested a number of factors and genes responsible for hypodontia, but mutations in very few human genes have been identified that result in hypodontia of specific teeth and associated tooth morphology. [20] It has been suggested that epithelial signals such as bone morphogenetic proteins (BMP), fibroblast growth factor (FGF), sonic hedgehog gene (Shh) and wingless integration (Wnt) molecules determine the generation of distinct tooth shapes/classes. [19],[20] Reports suggest BMP4 directs the shape of incisors, whereas FGF8 directs the shape of molars. [19],[20],[21] BMP4 induces expression of home box proteins Msx1 and Msx2, affecting incisor patterning. FGF8 induces expression of barx homebox1 genes (Barx1), distal less homebox1 (Dlx1), distal less homebox2 (Dlx2), lim homebox6 (Lhx6), and lim homebox7 (Lhx7) genes, which affect molar morphogenesis. Thus, we can understand that the complementary expression of the genes affects or induces the formation of the various teeth.

The importance of reporting this case lies in the fact that this case has a rare presentation of having all permanent teeth to be single rooted including maxillary first permanent molar and a single rooted mandibular first permanent molars. Moreover, this anomaly presents in conjunction with missing lateral incisor, second premolars, and third molars. However, retained deciduous molars present a normal morphology. The nonsyndromic hypodontia is not uncommon and genetic predisposition of hypodontia is known to an extent, but this case highlights a correlation of hypodontia with altered morphology of permanent teeth.

Hereby, it can be conclude that the genes and factors responsible for the development of teeth also have a bearing on the morphology of the teeth as already discussed. Whatever knowledge we have today for this association, this report may prove to be helpful in understanding the morphological patterning and its association with different factors of development.

Clinically, such cases are important adjuncts that help in advancing our knowledge of various anomalies that may be seen in clinical practice. Dentists come across cases of hypodontia and altered morphology very frequently, a clearer understanding of the defects may be useful for a better treatment.

   References Top

1.Nville BW, Damm DD. Oral and Maxillofacial Pathology. 3 rd ed. Philadelphia: W.B. Saunders; 2009. p. 77-82.  Back to cited text no. 1
2.Mcdonald RE, Avery DR, Dean JA. Dentistry for the child and adolescent. 8 th ed. USA.: Mosby; 2004. p. 52-129.  Back to cited text no. 2
3.Vastardis H. The genetics of human tooth agenesis: New discoveries for understanding dental anomalies. Am J Orthod Dentofacial Orthop 2000;117:650-6.  Back to cited text no. 3
4.Burzynski NJ, Escobar VH. Classification and genetics of numeric anomalies of dentition. Birth Defects Orig Artic Ser 1983;19:95-106.  Back to cited text no. 4
5.Vastardis H, Karimbux N, Guthua SW, Seidman JG, Seidman CE. A human MSx1 homeodomain missense mutation causes selective tooth agenesis. Nat Genet 1996;13:417-21.  Back to cited text no. 5
6.Stockton DW, Das P, Goldenberg M, D'Souza RN, Patel PI. Mutation of PAX9 is associated with oligodontia. Nat Genet 2000;24:18-9.  Back to cited text no. 6
7.Van den Boogaard MJ, Dorland M, Beemer FA, van Amstel HK. MSX1 mutation is associated with orofacial clefting and tooth agenesis in humans. Nat Genet 2000;24:342-3.  Back to cited text no. 7
8.Näsman M, Forsberg CM, Dahllöf G. Long-term dental development in children after treatment for malignant disease. Eur J Orthod 1997;19:151-9.  Back to cited text no. 8
9.Maguire A, Craft AW, Evans RG, Amineddine H, Kernahan J, Macleod RI, et al. The long-term effects of treatment on the dental condition of children surviving malignant disease. Cancer 1987;60:2570-5.  Back to cited text no. 9
10.Brook AH. A unifying aetiological explanation for anomalies of human tooth number and size. Arch Oral Biol 1984;29:373-8.  Back to cited text no. 10
11.Cobourne MT. Familial human hypodontia-is it all in the genes? Br Dent J 2007;203:203-8.  Back to cited text no. 11
12.Gopikrishna V, Bhargavi N, Kandaswamy D. Endodontic management of a maxillary first molar with a single root and a single canal diagnosed with the aid of spiral CT: A case report. J Endod 2006;32:687-91.  Back to cited text no. 12
13.Nieminen P, Arte S, Pirinen S, Peltonen L, Thesleff I. Gene defect in hypodontia: Exclusion of MSX1 and MSX2 as candidate genes. Hum Genet 1995;96:305-8.  Back to cited text no. 13
14.Alvesalo L, Portin P. The inheritance pattern of missing, peg-shaped, and strongly mesio-distally reduced upper lateral incisors. Acta Odontol Scand 1969;27:563-75.  Back to cited text no. 14
15.Arte S, Nieminen P, Apajalahti S, Haavikko K, Thesleff I, Pirinen S. Characteristics of incisor-premolar hypodontia in families. J Dent Res 2001;80:1445-50.  Back to cited text no. 15
16.Goldenberg M, Das P, Messersmith M, Stockton DW, Patel PI, D'Souza RN. Clinical, radiographic, and genetic evaluation of a novel form of autosomal-dominant oligodontia. J Dent Res 2000;79:1469-75.  Back to cited text no. 16
17.Ahmad W, Brancolini V, ul Faiyaz MF, Lam H, ul Haque S, Haider M, et al. A locus for autosomal recessive hypodontia with associated dental anomalies maps to chromosome 16q12.1. Am J Hum Genet 1998;62:987-91.  Back to cited text no. 17
18.Pirinen S, Kentala A, Nieminen P, Varilo T, Thesleff I, Arte S. Recessively inherited lower incisor hypodontia. J Med Genet 2001;38:551-6.  Back to cited text no. 18
19.Erpenstein H, Pfeiffer R A. Sex-linked-dominant hereditary reduction in number of teeth. Humangenetik 1967;4:280-93.  Back to cited text no. 19
20.Arte S, Nieminen P, Pirinen S, Thesleff I, Peltonen L. Gene defect in hypodontia: Exclusion of EGF, EGFR, and FGF-3 as candidate genes. J Dent Res 1996;75:1346-52.  Back to cited text no. 20
21.Tucker A, Sharpe P. The cutting-edge of mammalian development; how the embryo makes teeth. Nat Rev Genet 2004:5:499-508.  Back to cited text no. 21

Correspondence Address:
Abhinay Agarwal
Department of Conservative Dentistry and Endodontics, Teerthanker Mahaveer Dental College and Research Centre, Teerthanker Mahaveer University, Moradabad
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0972-0707.111332

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  [Figure 1], [Figure 2], [Figure 3]


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