Indian Journal of Dental Research

: 2012  |  Volume : 23  |  Issue : 5  |  Page : 700-

Concomitant hypo-hyperdontia: Report of two cases

Amita Sharma 
 Department of Pedodontics, Seema Dental College and Hospital, Rishikesh, Uttarakhand, India

Correspondence Address:
Amita Sharma
Department of Pedodontics, Seema Dental College and Hospital, Rishikesh, Uttarakhand


Concomitant hypo-hyperdontia is a rare condition of coexisting missing teeth and supernumerary teeth in the same subject. Its etiology is still not exactly known. Permanent dentition is usually affected. Presented here are two uncommon cases of bimaxillary concomitant hypo-hyperdontia during the mixed dentition period. Early diagnosis of the condition and multidisciplinary approach for management of such cases is recommended.

How to cite this article:
Sharma A. Concomitant hypo-hyperdontia: Report of two cases.Indian J Dent Res 2012;23:700-700

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Sharma A. Concomitant hypo-hyperdontia: Report of two cases. Indian J Dent Res [serial online] 2012 [cited 2021 Sep 23 ];23:700-700
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Hypodontia or congenital absence of teeth may be regarded as an opposite dental developmental anomaly to hyperdontia or supernumerary teeth. However, their simultaneous presence in the same individual is a rare condition. It has been found more often in the permanent dentition rather than in primary or mixed dentition. [1]

The etiology of coexisting hypodontia and hyperdontia is unknown. Disturbances in migration, proliferation and differentiation of the neural crest cells and interactions between the epithelial and mesenchymal cells during the initiation of odontogenesis have been suggested. [1],[2] This rare condition was found in fucosidosis patient. [3] Whether this means that a specific enzyme defect has a profound role in the development of the dentition is uncertain.

Anthonappa and co-workers have provided a comprehensive review on this condition. [4] This paper reports two unusual cases of bimaxillary concomitant hypo-hyperdontia in mixed dentition stage.

 Case Reports

Case 1

A nine-year-old female child reported to the department of Pedodontics with the complaint of irregular front teeth. The family and dental histories were noncontributory. Intraoral examination revealed a mixed dentition stage. An erupted supplemental supernumerary tooth was seen palatal to the maxillary right permanent lateral incisor [Figure 1]. Radiographic examination of the case with the help of an occlusal x-ray film and orthopantomogram was done [Figure 2] and [Figure 3]. A well developed supplemental supernumerary tooth in relation to maxillary right permanent lateral incisor was seen. Both the right and left mandibular second premolars were missing. The deciduous mandibular second molars of both sides were firm and healthy. The palatally erupted supplemental supernumerary lateral incisor was extracted. The patient was kept on recall visits for reassessment of the case and further treatment.{Figure 1}{Figure 2}{Figure 3}

Case 2

An eight-year-old male child reported with the complaint of an odd looking tooth in upper anterior region. The family, medical and dental histories were non-contributory. General physical/extra oral examination did not show any abnormality. Intraoral examination revealed mixed dentition with a palatally erupted conical shaped mesiodens. The mandibular deciduous lateral incisor and canine on both sides were fused. Radiographic examination [Figure 4] and [Figure 5] revealed a well formed conical shaped mesiodens and bilateral fusion of the mandibular deciduous lateral incisor and canine. Congenital absence of the mandibular right and left permanent lateral incisors was noted. The fused teeth were firm and caries free. However, prophylactic sealing of the deep labial and lingual grooves was done. The palatally erupted mesiodens was extracted.The patient was further kept under observation.{Figure 4}{Figure 5}


The combined defect, hypo-hyperdontia is usually mentioned in the literature as individual case reports. [3],[4],[5],[6],[7] However, the surveys done by Mercer estimated the probability of the combined defect, hypo-hyperdontialay between 8 and 15 per 10,000 patients. [5] Rose and Brook reported a frequency of 13 and 9 respectively in 10,000 patients. [8],[9] Gibson gave an average probability of 41 per 10,000 orthodontic patients. [10] Its prevalence has been reported to be 0.3 percent in patients with cleft lip and palate, 0.4 percent in Chinese school children and 0.45 percent in an Irish population. [1],[11],[12]

A thorough clinical and radiographic examination is essential for early diagnosis of the coexisting hypo-hyperdontia. During the mixed dentition years, treatment planning should be based on the dental age rather than the chronological age of the patient.

The bilateral type of fusion in primary dentition (Case 2) occurs less frequently than unilateral type. When fused primary teeth are found, the application of fissure sealants on the grooves between the two components is recommended to prevent dental caries (as done in Case 2). [13] Several clinical problems in the permanent dentition follow fused primary teeth, such as physiological root resorption of fused deciduous teeth being reported, leading to delayed or ectopic eruption of the permanent successors. Anomalies in the permanent dentition like impaction of successors, supernumerary teeth, permanent double teeth or aplasia of teeth may occur. Radiographic examination in Case 2 revealed bilateral absence of mandibular permanent lateral incisors as a sequel to bilaterally fused teeth involving primary lateral incisor and canine. Radiographs should also be taken to check the development of successors. Careful examination and surgical intervention at anappropriate time are necessary to prevent delayed exfoliation and eruption of the successors. [14]

Most clinical complications of supernumerary teeth are associated with interference of normal eruption and position of adjacent teeth which may cause cosmetically objectionable mal alignment of dentition. Therefore, supernumerary teeth should be extracted, if any complications are found during the examination. [15] Supernumeraries encountered in the presented cases were extracted as they caused displacement of adjacent teeth and crowding in the upper anterior region.

For the treatment of hypodontia, decision should be based not only on which tooth is missing, but also on facial profile, incisor position, space requirements and status of the primary teeth. The treatment option is either accomplished by spontaneous/orthodontic space closure or by maintaining the primary tooth, space maintenance and eventual conventional prosthodontics, implant placement or auto transplantation. [16]

The patient and parent must be fully informed about the condition, the aims and objectives of potentially extensive dental treatment and financial considerations. Care requires a team approach, including pediatric, orthodontic, restorative and prosthodontic specialists.


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