Non-Syndromic Oligodontia: A Case Report

Introduction

The congenital non-existence of either one or multiple teeth, with the exception of 3rd molars is known as hypodontia.¹ Absence of all teeth is named as anodontia, which is quite infrequent, but the common and frequent types are hypodontia and oligodontia. If one to six teeth are absent, it is known as hypodontia; whereas, if more than six teeth are congenitally missing excluding 3rd molars, it is oligodontia.2 Oligodontia is relatively an infrequent condition, developed genetically and in all likelihood affects about 0.1 to 1.2% of human beings.³ The rate of occurrence of non-syndromic type of oligodontia in Danish school children was 0.16%. A study conducted in Indore city of India has shown an occurrence rate of 0.36% oligodontia.⁴ The cause for tooth agenesis is unknown and it is associated with certain genetic factors.³ A study reported in the literature has shown that the homeobox gene MSX1, paired domain transcription factors PAX9 and EDA have been involved with nonsyndromic type of oligodontia.⁵ Oligodontia is found to be associated with other ectodermal abnormalities and syndromes.⁶ Oligodontia may be seen as a distinct characteristic of a specific disease such as Anhidrotic Ectodermal Dysplasia, Pierre Robin syndrome, Ehler Danlos syndrome, Down’s syndrome, Incontinentia pigmenti- which is an X-linked genetic disorder that affects the ectodermal derivatives along with agenesis of teeth and abnormal shape of teeth.³ The present report is a case of non-syndromic type of oligodontia involving agenesis of 19-teeth from permanent dentition in a 13-year old girl. 

Case Report

A 13-year old girl patient reported to the Pediatric dentistry department, with a chief complaint of pain in the upper left back tooth region and multiple retained deciduous teeth. History revealed consanguineous marriage of her parents. Medical and family histories were non-contributory. This girl had four siblings and none of them presented with any retained or missing teeth. Extra-oral examination (Figure 1) revealed no gross asymmetry of face. No soft tissue abnormalities were found on intraoral examination. Hard tissue examination (Figure 2, 3 & 4) showed absence of multiple permanent teeth by birth. Abnormalities in tooth size were also observed namely microdontia with 36 and 46. Abnormalities in tooth shape included multiple cusps on 35, 36, 45, 46 and enamel pearls with 36 and 46. The teeth 51, 52, 61, 62, 64, 71, 72, 81, 82 were retained. Permanent teeth present were 13, 14, 15, 23, 25, 33, 34, 35, 36, 43, 44, 45, 46.

Orthopantomogram (OPG) (Figure 5) examination revealed the presence of a total of 22 teeth (9-retained primary teeth and 13 permanent teeth). Absence of 19-teeth from permanent dentition namely, 11, 12, 16, 17, 18, 21, 22, 24, 26, 27, 28, 31, 32, 37, 38, 41, 42, 47, 48 was evident on OPG (Figure 5). The permanent molars 36 and 46 present in this patient were single rooted. Dental caries involving pulp was seen with 25 and all the remaining teeth were non-carious. Lateral skull view (Figure 6) showed diffuse radiolucency with multiple radiopacities in the occipital bone. However, this finding was insignificant.

To rule out any associated syndromes and medical conditions, the child patient was sent to a Paediatrician. Radiographs of knee joints, dorso-lumbar spine, both hands, pelvis with both hip joints were done. No significant and noteworthy abnormalities were detected on these radiographs. The pediatric, opthalmological, dermatological and radiological evaluations showed no systemic abnormalities. Thus, by history, clinical and radiological findings, a diagnosis of non-syndromic type of oligodontia was made. Conventional root canal treatment was done with tooth 25. The patient was scheduled for periodic follow up visits to evaluate growth and development of jaws.

Discussion

The term oligodontia describes an entity of agenesis of six or more teeth and it excludes the 3rd molars. Types of oligodontia includes isolated or non-syndromic type and syndromic type. Oligodontia can occur in association with more than sixty different syndromes. Nevertheless, it can occur without any systemic disease or syndrome. Familial or non-syndromic oligodontia is seen more often than syndromic form.²

Familial or non-syndromic type of oligodontia is inherited as an autosomal dominant trait. Genetic changes seen in MSX1 gene and PAX9 gene which encode transcription factors are associated with isolated or non-syndromic type of oligodontia. Oligodontia cannot be neglected in child patients as it will produce malocclusion, altered facial looks, psychological distress/anxiety, difficulty in masticatory function and speech.⁷ Oligodontia can occur due to the factors associated with environment like trauma, thalidomide drug exposure, rubella infection, hormonal changes, tumours or post radiation therapy.⁸ Thus, early investigations, diagnosis and treatment of oligodontia is very important. Isolated oligodontia may occur or it can occur as a part of syndrome. Ectodermal dysplasia is a serious systemic disturbance and oligodontia is usually associated with this syndrome. If oligodontia occurs with any syndrome, then there are usually changes in the skin, eyes, nails, ears or skeleton.⁴ However, in this child patient, the paediatric, opthalmological, dermatological and radiological evaluations ruled out any associated syndromes/medical conditions.

Edentulous areas, atrophic alveolar bone ridge, thinner attached gingiva and downward extended maxillary sinus must be taken into account in oligodontia cases.³ The case reported here was advised to maintain the remaining deciduous teeth properly till their normal exfoliation to prevent bone loss. Subsequently, advised to consider a removable or fixed partial denture. To improve aesthetics and also to restore function and psychology in oligodontia patients, a team of dentists involving Pedodontist, Orthodontist, Oral and maxillofacial surgeon and Prosthodontist are mandatory based on the severity of the condition and patient’s perceived needs. The goal of the management consists of improvement in phonetics and chewing efficiency resulting in psychological improvement, which in turn regains patients self-confidence and social perception.^9,10

Conclusion

The issues associated with agenesis of teeth and related consequences are countless, based on the number and type of missing teeth. The most common disturbance is seen in growth as well as in the development of orofacial structures that affects speech, masticatory function and aesthetics. A dental team approach is often required for the management of children with oligodontia.

Conflict of Interest

None.