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Year : 2020  |  Volume : 32  |  Issue : 1  |  Page : 69-72

Early exfoliation as an indication for evaluation: A case report

1 Department of Oral Medicine and Radiology, Annamalai University, Chidambaram, Tamil Nadu, India
2 Oral and Maxillofacial Pathology, Rajah Muthiah Dental College and Hospital, Annamalai University, Chidambaram, Tamil Nadu, India

Date of Submission20-Nov-2019
Date of Decision05-Mar-2020
Date of Acceptance17-Mar-2020
Date of Web Publication17-Apr-2020

Correspondence Address:
Dr. J Reni Anjalin
Post Graduate, Department of Oral Medicine and Radiology, Rajah Muthiah Dental College and Hospital, Annamalai University, Chidambaram - 608 002, Tamil Nadu
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jiaomr.jiaomr_189_19

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Hypophosphatasia (HPP) is a rare genetic skeletal disorder that occurs due to mutation in the ALPL gene. It is characterized by defective bone and teeth mineralization. Odontohypophosphatasia is the mildest form of HPP that affects only the dental tissues, manifests as early exfoliation of teeth, defective cementum formation, reduced alveolar bone height, and enlarged pulp chamber. We report a case of an 8-year-old female who presented only with dental findings of HPP. HPP was suspected due to reduced serum alkaline phosphatase level, reduced alveolar bone height, and enlarged pulp chamber. The cemental defects were identified by the ground section of the exfoliated tooth and measured using Image J software. Thus, we arrived at the final diagnosis of Odontohypophosphatasia.

Keywords: Cementum, hypophosphatasia, odontohypophosphatasia, premature exfoliation

How to cite this article:
Anjalin J R, Ramasamy S, Nirmal R M. Early exfoliation as an indication for evaluation: A case report. J Indian Acad Oral Med Radiol 2020;32:69-72

How to cite this URL:
Anjalin J R, Ramasamy S, Nirmal R M. Early exfoliation as an indication for evaluation: A case report. J Indian Acad Oral Med Radiol [serial online] 2020 [cited 2022 Jan 27];32:69-72. Available from: https://www.jiaomr.in/text.asp?2020/32/1/69/282610

   Introduction Top

Hypophosphatasia is a rare genetic disorder, first described by John Campbell Rathbun in 1948.[1] Hypophosphatasia due to mutations in the ALPL gene encoding for tissue nonspecific alkaline phosphatase enzyme results in reduced enzymatic activity.[2] Decreased alkaline phosphatase activity affects osteogenesis and cementogenesis by increasing the accumulation of pyrophosphatase, an enzyme that inhibits mineralization.[3] Hence, hypophosphatasia causes defective mineralization resulting in abnormal development of bones and teeth, deformed and soft bones that are more prone to fracture, and premature loss of teeth.[4]

HPP is characterized by a decreased level of serum alkaline phosphatase, elevation of phosphoethanolamine in urine, increased serum pyridoxal-5-phosphate which are used as diagnostic markers[5] with skeletal abnormalities, and premature loss of teeth. It is classified according to the age of first appearance of clinical manifestations: [Table 1][2],[6],[7]].
Table 1: Classification of Hypophosphatasia[2],[6],[7]

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   Case Report Top

An 8-year-old female patient [Figure 1] came to the outpatient department complaining of missing teeth in the upper and lower jaw for the past 7 years. In history, her parents noticed shedding of the baby teeth from the age of one, till the last year. The patient had consulted at various hospitals, routine blood investigations and radiographs were taken, and provisionally diagnosed as Hypophosphatasia.
Figure 1: Profile picture of the patient

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The clinical examination revealed the presence of hypertelorism and intraoral examination showed multiple missing primary teeth (51,52,53,54,55,61,62,63, 72,73,74,75,82,83,84,85); preshedding mobility of 64 was evident. Permanent teeth 31,41,16,26,36,46 were present.[Figure 2]a, [Figure 2]b,[Figure 2]c No other mucosal abnormalities were present with good oral hygiene. Investigations were carried out; orthopantamograph revealed widening of pulp chamber in erupted permanent teeth [Figure 3]; long bone X-rays showed mild decalcification without any symptoms of bone deformities. Normal serum calcium, phosphate, and thyroid profile was present; serum alkaline phosphatase level was 66 U/L which was contrary to the patient's previous reports, where the serum alkaline phosphatase level was 24 U/L.
Figure 2: (a-c): Intraoral image showing multiple missing teeth

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Figure 3: OPG of the patient showing widening of pulp chamber in erupted permanent molars

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Hence, to confirm the diagnosis of hypophosphatasia, the histopathologic study of the exfoliated teeth in relation to 64 [Figure 4] was done to check the cementum thickness, as it is affected in HPP.[8] Ground section was done and the cementum thickness of the diseased tooth was measured and compared with a healthy tooth using imageJ software (version 2006.02.01).
Figure 4: Exfoliated 64, showing no root resorption

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The average cementum thickness in the diseased tooth was 16.24 μm, whereas the thickness in the normal tooth was 36.19 μm [Figure 5],[Figure 6]. Thus, the cementum thickness was reduced and the diagnosis of hypophosphatasia was confirmed. As the patient did not show any bone abnormalities other than dental findings, the diagnosis was refined as milder form of hypophosphatasia—”Odontohypophosphatasia.”
Figure 5: Ground section of the diseased tooth showing reduced cementum thickness

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Figure 6: Ground section of the normal healthy tooth showing the cementum thickness

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   Discussion Top

Loss of primary dentition is a physiologic process. However, the loss of teeth in children below age of 5 years suggests genetic or systemic diseases in the absence of trauma— Hartsfield JK.[3] [Table 2].
Table 2: Differential diagnosis for premature exfoliation of primary teeth[3]

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Hypophosphatasia is an uncommon inherited disorder with an incidence of 1:100,000.[1] Premature deciduous teeth exfoliation is the major manifestation of hypophosphatasia. The case described here shows premature exfoliation of primary teeth. There was low alkaline phosphatase level (24 U/L) when the patient was first examined before one year but now increased to 66 U/L. Hence, the ground section study was done to measure the cementum thickness which revealed the presence of hypoplastic cementum.

The literature has shown that the level of alkaline phosphatase may approach a normal value as the patients grow older.[9] In addition, patients with an isolated dental manifestation of hypophosphatasia in childhood later in life may develop the adult or childhood forms of the disease.[5] However, there is a subset of patients who do not develop other bone manifestations of HPP and thus likely are considered as true odonto-HPP.[5]

Therefore, the patients with the dental symptoms of HPP should be followed for a long term and monitored for skeletal and other systemic symptoms; hence, other symptoms of HPP can be identified and treated at their earliest symptom.[5]

The management of hypophosphatasia includes supportive and symptomatic treatment that includes dietary supplements with calcium restriction in case of hypercalcemia,[10] vitamin-D supplements, phosphate or combination of vitamin D and fluoride, but none of these were successful.[8] Recently enzyme replacement therapy with asfotase alfa had been employed for severe forms of HPP (currently approved for perinatal/infantile/childhood forms in United States, Canada, and European Union; and all forms of HPP in Japan).[5] As the present case showed only dental changes, the major concern was to maintain the arch length until the eruption of permanent teeth, with periodic follow-up.

   Conclusion Top

Hypophosphatasia is characterized by a wide spectrum of skeletal and dental manifestation, in which dental findings may be the most common and sometimes the only presentation, termed as odontohypophosphatasia. The proper diagnostic route for odonto-HPP may be complicated by normal biochemical findings as seen in the present case; hence, other investigations become important to rule out odonto-HPP, like assessing the cementum thickness in deciduous tooth.

Premature loss of teeth always caused anxiety and frustration in patients and parents; hence, counseling and assurance should be given to prevent psychological trauma. Long term follow-up is important to prevent the patients from adverse effects of later forms of HPP.

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

There are no conflicts of interest.

   References Top

Manohar B, Mathur L, Pillai R, Shetty N, Bhatia A, Mathur A. Odontohypophosphatasia - A case report. J Carcinog Mutagen 2010;1:105-7.  Back to cited text no. 1
Bloch-Zupan A. Hypophosphatasia: Diagnosis and clinical signs - a dental surgeon perspective. Int J Paediatr Dent 2016;26:426-38.  Back to cited text no. 2
Hartsfield JK. Premature exfoliation of teeth in childhood and adolescence. Adv Pediatr 1994;41:453-70.  Back to cited text no. 3
Bishop N. Clinical management of hypophosphatasia. Clin Cases Miner Bone Metab 2015;12:170-3.  Back to cited text no. 4
Mori M, DeArmey SL, Weber TJ, Kishnani PS. Case series: Odontohypophosphatasia or missed diagnosis of childhood/adult-onset hypophosphatasia? - Call for a long-term follow-up of premature loss of primary teeth. Bone Reports 2016;5:228-32.  Back to cited text no. 5
Duffus S, Thrasher B, Calikoglu AS. Brief clinical report: Hypophosphatasia - Diagnostic considerations and treatment outcomes in an infant. Case Rep Pediatr 2018;2018:5719761. doi: 10.1155/2018/5719761.  Back to cited text no. 6
Mornet E. Hypophosphatasia. Orphanet J Rare Dis 2007;2:40-7. Available from: http://www.OJRD.com/content/2/1/40.  Back to cited text no. 7
Cheung WS. A mild form of hypophosphatasia as a cause of premature exfoliation of primary teeth: Report of two cases. Pediatr Dent 1987;9:49-52.  Back to cited text no. 8
Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and Maxillofacial Pathology. Philadelphia: Saunders; 2008. p. 984.  Back to cited text no. 9
Horimo H. Pathophysiology of hypophosphatasia and the potential role of asfotasealfa. Ther Clin Risk Manag 2016;12:777-86.  Back to cited text no. 10


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]

  [Table 1], [Table 2]


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