Introduction

Mesiodens are the most common type of supernumerary teeth which is generally present in between the two central incisors in maxillary arch. It can be seen as single, multiple, unilateral or bilateral.1 When multiple supernumerary teeth is present, it is called ‘mesiodentes’.2 It is commonly seen in mixed dentition and permanent dentition but it is believed to be rare in deciduous dention.3 It is very rarely seen in mandibular anterior region.4 The prevalence of supernumerary teeth in permanent dentition for the general population has been reported between 0.1 and 3.8%,5 gender difference reported a sex ratio of around 2:1 to a higher ratio of 6.5:1.6, 7

Mesiodens usually erupts normally on the arch like the teeth but they can also be found as inverted, impacted or ectopically erupted. Impaction may lead to delayed eruption of the permanent teeth resulting in malocclusion.5, 6, 7 Morphologically, conical or peg shaped, tuberculate and supplemental tooth like shapes are the common types, out of which the conical form is the most common. Usually they erupts normally on the arch, but sometimes they remain impacted or in inverted position. Some cases of ectopic eruption has also been reported in the literature.5, 6, 8, 9 Supernumerary teeth can be seen associated with cysts like dentigerous cysts, or as odontomes or multilobed mesiodens with palatal talon cusp.

Treatment options may vary from normal extraction to surgical extraction depending upon the position of the mesiodens. 10 In order to ensure eruption and proper alignment of the erupting permanent teeth, surgical exposure and orthodontic treatment is indicated in case of delayed eruption of the permanent tooth following the extraction of mesiodens. 11 Fixed orthodontic therapy can create sufficient arch space and alignment before eruption of the permanent tooth.12 Therefore, an early diagnosis allows the most appropriate treatment, often reducing the extent of surgery, orthodontic treatment and possible complications

Materials and Methods

A longitudinal observational study was conducted on 1240 pediatric patients aged 4-12 years coming to department of pedodontics and preventive dentistry, Universal College of Medical Sciences, College of Dental Surgery, Bhairahawa, Nepal, after taking ethical clearance by institutional review board, for a period of 10 months (July 2023 to April 2024). Demographic data, the presence of mesiodens, their morphological charecteristics like type, position etc and associated complications were recorded. All obtained data were statistically analyzed with SPSS software by using descriptive statistics and cross tabulations.

Results

Out of 1240 samples under the age group 4-12 years, a total of 32 patients were diagnosed as having mesiodens. The prevalence rate was found to be 2.58% (Table 1). The majority of the cases were detected between 9-12 years of age out of all the age groups (Table 2). Out of the 32 patients diagnosed to have mesiodens, 30 were boys and 02 were girls showing a sex ratio of 15:1, favouring boys.

Regarding the position of the mesiodens, the majority of them were palatally placed (Table 3), most common types out of all was seen to be the conical type (Table 4) and most commonly caused complications were axial rotation or displacement of permanent incisors (Table 5).

Discussion

Although mesiodens are believed to have an unknown etiology however, it is also seen to be syndrome associated. Gardner’s syndrome, cleft lip and palate and cleidocranial dysostosis are few to be named. Heredity is also considered to be an etiologic factor for supernumerary teeth it is more common in family members however, it does not follow a simple Mendelian pattern but it has been suggested that environmental factors might have influence on genetic susceptibility.3

Few theories are also suggested, one of them is the Atavistic theory which states that mesiodens shows a phylogenetic relic of extinct ancestors who exhibited three central incisors; other suggests that the dichotomy of the tooth bud is the reason behind supernumerary tooth. 13, 14, 15, 16 The most acceptable etiological factor is the hyperactivity theory, which states the restricted increase in the local independent controlled hyperactivity of dental lamina results in the development of mesiodens. 17, 18, 19

The prevalence of mesiodens in this study was 2.58%, which is much greater than studies done by Stafne (0.41%), Thilander (1.2%), Faizal (0.71%) and Clayton 0.89%), but lower in comparison to that of Tay 5.8%) and Khandelwal V 3.8%).3

Mesiodens occurs more frequently in boys than in girls.^5,6 In the present study, a male:female ratio of 15:1 was observed, which in accordance with previous studies on gender difference showing a sex ratio of around 2:1 to a higher ratio of 6.5:1.6, 7

Impaction, crowding, diestema, root resorptions of adjacent tooth, ectopic eruption and displacement of permanent teeth are the commonest problems associated with mesiodens. Sometimes impacted mesiodens results in dentigerous cyst formation, sometimes even inside the nasal cavity.20 Palatally placed tuberculate mesiodens causes delayed eruption due to its position.21, 22, 23 Clinical and radiological examination dictates management of mesiodens, 18 as 63% of patients with unerupted incisors had hyperdontia.19 Early stages of mixed dentition is the best time for the treatment of mesiodens, as behaviour management will be easier at a younger age. Extraction should be planned as early as possible to avoid future complications of complex surgical and orthodontic treatment. 24 In case of surgical extraction the impacted mesiodens, the type, position, the space available and root development may influence the time of eruption. 25, 26

Conclusion

Routine check up during the primary dentition and mixed dentition stages helps for early detection of mesiodens and other anomalies. Early diagnosis and treatment helps in minimising future complications and prognosis are better. In case of any alteration in the eruption path of the central incisors or even asymmetric eruption, the clinician must evaluate the possibility of an extra tooth.

Source of Funding

None.

Conflict of Interest

None.