Congenital absence of multiple primary teeth.

Sir

Hypodontia in the permanent dentition is considered a variant of normal. Its frequency ranges between 2% and 10%. Hypodontia in the primary dentition is uncommon with a prevalence of 0.1–0.9%.[1]

A 2.5-year-old girl child was referred to our outpatient department with a chief complaint of several missing teeth. On examination the child appeared to be physically normal, with no systemic abnormalities [Figure 1]. The child was born to nonconsanguineous parents. The mother stated that pregnancy was normal. Drug history was not significant. The family history did not reveal any missing teeth. Furthermore, the child had no siblings.

Figure 1

Front profile of the patient

An intra-oral examination showed the presence of only lower left first primary molar. The tooth was normal in shape, size, and color [Figure 2]. Panoramic radiograph revealed congenital absence of 14 primary teeth (maxillary right and left central incisors, lateral incisors, canines, and first primary molars. It also showed the absence of right and left lower central incisors, lateral incisors, right canine, and right first primary molar. It also revealed an unerupted mandibular left canine and maxillary and mandibular second primary molars) [Figure 3].

Figure 2

An intra-oral examination revealed the presence of lower left first primary molar

Figure 3

The panoramic radiograph revealed congenital absence of 14 primary teeth except maxillary right and left second primary molars, mandibular left canine, left first primary molar, and right and left second primary molars

This present case reports 14 missing primary teeth with no associated systemic abnormalities. In this case, a very rare agenesis pattern was observed, i.e., missing primary upper central incisors. Agenesis of primary central incisors is a rare condition seen in holoprosencephaly as a part of more extended midline malformation which also includes the brain.[2] Agenesis of several maxillary incisors is seen in Rieger syndrome.[3] In the present case, the child had no such associated abnormality.

Further intra-oral examination revealed the presence of the mandibular left first primary molar only. A radiographic examination showed bilateral agenesis of the maxillary first primary molars. In the mandibular arch, the right first primary molar was missing. The radiographic examination further revealed the embedded right mandibular canine, and maxillary and mandibular second primary molars. Idiopathic agenesis of first primary molars is extremely rare and in this patient there was observed agenesis of all the first primary molars except the mandibular left first primary molar, which has not been reported earlier.[4]

Several factors have been proposed for the etiology of oligodontia. Viral disease during pregnancy has been implicated as a causative factor. Gravely and Johnson concluded that most investigations demonstrated a genetic predisposition to oligodontia and the mode of transmission was uncertain.[5] Thomsen considered a Mendelian recessive gene to be responsible, whereas Grahnen suggested an autosomal dominant gene with varying expression acting possibly in a system involving more than one gene.[6]

Metabolic imbalances and developmental abnormalities may also be associated with oligodontia. Environmental factors especially maternal environment have been implicated in determining oligodontia. In the present case, there was an absence of a confirmatory family history and no associated developmental abnormalities.

Studies have shown that when the primary teeth are absent there is a high prevalence of the absence of succedaneous teeth. Ravn reported that patients with aplasia in the primary dentition showed a similar pattern in the permanent dentition in 80% of the cases.[7] By the age of 3 years, maxillary and mandibular central and lateral incisors, canine, and first molar tooth buds should be present. In the present case, the radiographic examination revealed the absence of the succedaneous tooth buds, except the first permanent molar tooth buds. This case needs to be followed up to determine the correlation between agenesis of the primary and permanent teeth.

According to Daugaard Jensen, agenesis in the primary dentition may be an isolated rare phenomenon, without consequence in the permanent dentition.[8] Oligodontia in the primary dentition with permanent successors was reported by Oshima et al.[9] There has been a reported case of idiopathic oligodontia in the primary dentition by Shashikiran et al. with nine missing teeth.[10]

A similar case of idiopathic oligodontia (14 missing primary teeth) was reported by us in which only the primary maxillary central incisors, and maxillary and mandibular secondary primary molars were present. OPG revealed corresponding succedaneous permanent maxillary anterior tooth buds and an absence of corresponding succedaneous lower tooth buds.[11]

Venkataraghavan et al. have reported one case of multiple missing primary teeth (n = 18). There is no mention as to whether this particular case is idiopathic or not. According to the author, thorough medical evaluation could not be carried out as a patient resided in a different state. OPG showed congenital absence of all primary teeth except the maxillary right and left primary second molars with the presence of all the developing permanent tooth buds showing defective formation of dentin, and roots of the permanent molars and lower central incisors.[12]

Treatment of oligodontia requires multidisciplinary management to improve function and esthetics. Numerous clinical reports have demonstrated the importance of prosthetic dental treatment in patients with oligodontia for physiological and psychological reasons. The prosthetic treatment of oligodontia varies and includes removable partial dentures, fixed partial dentures, and overdentures. In the present case, rigid fixed prosthesis is contra-indicated. A removable partial denture is recommended, keeping in view the growing age of the patient.

The rationale for the use of removable partial dentures is their easy care, acceptable cost, easy adjustment during growth, restoration of vertical dimension, and easy replacement of missing teeth. Dental implants can provide more support, retention, and stability and improve the function and esthetics of the prosthesis. In this case, because of the severe atrophy of the alveolar ridge and the age of the patient, dental implants were not suitable at this time. The use of dental implants in the future may be a possibility.