Department of Pediatric and Preventive Dentistry; Department of Dentistry, Jamia Millia Islamia, Jamia Nagar, New Delhi-110025, IndiaIndia
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Congenitally missing teeth are a common developmental abnormality. It is defined as the developmental absence of teeth excluding the third molars. It is more commonly seen in permanent dentition but rarely in primary dentition. Second premolars are the most commonly missing teeth after the third molars. This paper reports a case of non-syndromic bilaterally congenitally missing second premolars in the mandibular region and its management.
Keywords: Congenitally missing teeth; Mandibular region; Second premolars
True anodontia or congenital absence of teeth can be found in almost any region of the dental arch and in both primary and permanent dentitions. According to the most accepted theory hypodontia is multifactorial and results from a combination of genetics and environmental influences.1 True anodontia or congenital absence of teeth can be classified into two types, total and partial. Many cases of congenitally missing teeth have been reported in the literature, but this case report presents a unique case of management of bilaterally missing second premolars in the mandibular region without extraction.
Missing teeth are associated with trauma, infection,
radiation, chemotherapeutic medications, endocrine disturbances, and severe intrauterine disturbances.1 Somatic diseases like syphilis, rickets and scarlet fever have also been associated with tooth agenesis.7 Tooth agenesis has been associated with a lot of syndromes and dental anomalies like orofacial clefts, Downs syndrome (trisomy 21), Book syndrome, Coffin-Lowry syndrome, Goldenhar syndrome, Ellis-van Creveld syndrome, Marshall-White syndrome, Johanson-Blizzard syndrome, Gorlin-Chaudhary-Moss syndrome, Progeria, Tooth-and-Nail syn- 1,7,8 drome, Witkop syndrome.
Recently it has been reported that tooth agenesis in humans is caused by mutations in gene encoding low-density lipoprotein receptor-related protein (LRP6).9
Hypodontia may lead to abnormal spacing of teeth, delayed tooth formation and deciduous tooth exfoliation, late permanent tooth eruption and altered dimension of the associated gnathic regions.8 Tooth agenesis can result in dental malpositioning, periodontal damage, and lack of development of maxillary and mandibular bone height.10
The treatment of congenitally missing mandibular premolars pose a challenge for the pediatric dentist as lot of therapeutic options are available with their innate advantages and disadvantages. Selection of the right treatment plan is of utmost importance for long term aesthetic results. Therapeutic options most commonly used to resolve the problem include either extraction of second deciduous molar or retention of the deciduous molar. Extraction of deciduous second molars can be planned if second premolars are missing due to pulpal pathology, crowding in permanent dentition, ankylosis and differences in tooth sizes between deciduous and permanent teeth.11 However if crowding of teeth is associated with bilaterally congenitally missing second mandibular premolars, then the case can be managed with a multi-specialty approach in which deciduous second molars are sectioned, prepared for full coverage crown followed by correction with fixed orthodontics.12 Hemisection or controlled slicing technique can also be used which is based on slicing the second primary molar and removing the mesial half allowing the mesial drift of the first permanent molar with less anterior tipping and loss of anchorage.13 Hemisection technique not only preserves the buccolingual ridge but also prevents the formation of a lateral buccal bony depression.14 It was also noted that late decisions on extraction or hemisection of second deciduous molars increased the likelihood of average to poor 14,15 results.
A multidisciplinary approach can also be used to ensure functional occlusion and aesthetics at the same time. Genetic counselling may play an imperative role in children with multiple missing teeth.
In the present case the left deciduous second molar was retained and since the right deciduous molar was already extracted, the first permanent molar was allowed to drift mesially.
The child patient was kept under follow-up to observe the pattern of eruption of teeth.
Congenitally missing teeth is a dental anomaly with multifactorial etiology, occurring with greater frequency in females and in the permanent dentition. It can occur in both the maxilla and the mandible.
Retaining a deciduous mandibular second molar can be a viable treatment option in cases where anterior crowding is not present. As very few studies have been done regarding the risk factors and severity of congenitally missing teeth, future studies are recommended.
The patient has provided written permission for publication of the case details.