International Journal of Oral Health Sciences

: 2015  |  Volume : 5  |  Issue : 1  |  Page : 45--48

Bilateral double mesiodentes in the ugly duckling stage

Salma Babiker Idris Elhag1, Ashraf Sidig Idris Abdulghani2,  
1 Department of Orthodontics, University of Khartoum, Khartoum, Sudan
2 Department of Oral and Maxillofacial Surgery, University of Khartoum, Khartoum, Sudan

Correspondence Address:
Salma Babiker Idris Elhag
Department of Orthodontics, University of Khartoum, Khartoum


The ugly duckling stage is a physiological stage characterized by a small median diastema and distally inclined incisors. A mesiodens is a supernumerary tooth found in the premaxilla between the two central incisors. It can be single or multiple, impacted, erupted, or inverted. We present a case of a 9-year-old nonsyndromic, asymptomatic male patient with bilateral double mesiodentes in the ugly duckling stage of the mixed dentition.

How to cite this article:
Elhag SB, Abdulghani AS. Bilateral double mesiodentes in the ugly duckling stage.Int J Oral Health Sci 2015;5:45-48

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Elhag SB, Abdulghani AS. Bilateral double mesiodentes in the ugly duckling stage. Int J Oral Health Sci [serial online] 2015 [cited 2021 May 14 ];5:45-48
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The mixed dentition phase is known as the ideal time to intercept orthodontic problems that interfere with the normal growth and development of the face and dentition. The ugly duckling stage in the mixed dentition is a physiological space which was first described by Broadbent in 1941.[1] It commences at approximately 8 years old and ends about 12 years of age with the eruption of the canines. Characteristics of this stage include presence of a small physiological diastema with distally tipped incisors due to the unerupted permanent canines that often lie superior and distal to the lateral incisor roots forcing the lateral and central incisor roots to converge toward the midline.[2] Normally, this physiological space is about 2mm and tends to close spontaneously when the canines erupt, and the incisor root and crown positions change. When a larger diastema (>2 mm) is present, a pathologic condition, for example, an unerupted supernumerary tooth or intrabony lesion may exist and requires further investigation by a maxillary occlusal view or a periapical view.[2]

A supernumerary tooth is one that is additional to the normal series.[3] It is more commonly found in the central region of the upper or lower jaw and its occurrence in the mandible is quite rare.[4] It has a higher predilection for males than females with a ratio of 2:1.[3],[5]

The description of a supernumerary tooth varies according to its position, for example, it is called a mesiodens when it is located between the two maxillary central incisors, a paramolar when presented beside a molar, a distomolar when found distal to the last molar, and a para premolar when positioned beside a premolar.[3]

Occurrence of a supernumerary tooth may be single or multiple, unilateral or bilateral, erupted or impacted, and in one or both jaws. Multiple supernumerary teeth are rare in individuals with no other associated diseases or syndromes. Conditions that are commonly associated with an increased prevalence of supernumerary teeth include cleft lip and palate, cleidocranial dysplasia, and Gardner syndrome.[6] Presence of double or multiple bilateral mesiodens in the midline creates a complicated clinical situation by displacing the incisor crowns more distally creating a larger than normal midline diastema. Consequently, the incisors obstruct the eruption path of the canines, and as a result, the canines ectopically erupt or become impacted. Moreover, if the patient is in the ugly duckling stage, the presence of the supernumerary teeth in the midline, prevents the canines from performing their physiological role of closing the diastema and correcting the incisor crown inclination.

The aim of this report is to describe a case of bilateral, conical and erupted mesiodentes in a 9-year-old nonsymptomatic and asyndromatic male patient in the ugly duckling stage of the mixed dentition.

 Case Report

A 9-year-old male patient reported to the Department of Oral Surgery, Khartoum Dental Teaching Hospital, with the chief complaint of two small irregular shaped teeth in the upper front region causing esthetic problems. The familial, medical and dental history was noncontributory. Extraoral examination did not reveal any abnormalities. Intra-oral examination [Figure 1] revealed two conical teeth which were smaller in size when compared with the adjacent normal dentition, bilateral to the midline, present between the maxillary permanent central incisors. The incisors were distally positioned and with distally inclined crowns. Panoramic radiograph [Figure 2] confirmed the presence of two mesiodentes in the midline with completely formed roots, the patient was in the ugly duckling stage of the mixed dentition period with a large diastema (8 mm), distally positioned and inclined incisors, and canines that were potentially impacted against the root of the lateral incisors due to lack of space for their eruption. Because of the aesthetic demand of the patient and consequences of retaining the mesiodentes, extraction of the mesiodentes was carried out under local anesthesia (2% lidocaine) [Figure 3] and [Figure 4].{Figure 1}{Figure 2}{Figure 3}{Figure 4}


Various theories exist to explain the occurrence of supernumerary teeth. One theory suggests that dichotomy of the tooth bud creates an extra tooth. Another theory, the hyperactivity theory, proposes that supernumeraries are produced as a result of local, independent, conditioned hyperactivity of the dental lamina. Finally, heredity may also play a role, as supernumeraries are more common in the relatives of affected children [6] Foster and Taylor [7] have pointed out that the conical mesiodens develops quite early with its root formation being at least as early as that of the permanent upper central incisor, and sometimes earlier.

The prevalence of mesiodens in the permanent dentition is estimated at approximately 2% of the general population and in the primary dentition to be <1%.[3] In India, it was found that among the total 2318 screened children 0.77% had mesiodens. Among 18 children, four had two mesiodentes and the rest had one mesiodens.

Different names have been designated to describe the supernumerary tooth according to its shape, this includes supplemental (tooth-like), conical, tuberculate, and odontome. The conical form is the most common type.[3] Other variations of the mesiodens also exist, for example, a mesiodens that resembles a molar coined a molariform mesiodens,[8] and a mesiodens with talon cusp which is an accessory cusp-like structure present on the lingual or the facial surface of maxillary or mandibular incisors have been reported in the literature.[9],[10]

Reported cases in the literature have shown different eruption patterns of paired mesiodens, where both can erupt palatally,[11],[12] be impacted labially,[13] erupt in the midline [14],[15] or one can be erupted, and another impacted and inverted.[16]

Clinical implications of supernumerary teeth include diastema, failure of eruption of the central incisors, displacement or rotation of an erupted permanent tooth, crowding, impaction, ectopic eruption, or it can cause no effect at all.[3] However, the occlusal problems caused by conical mesiodens are the rotation of the central incisors or development of a wide upper median diastema, but it rarely delays eruption.[6],[17]

Generally, treatment usually involves removal of the supernumerary tooth and local tooth alignment. Sometimes, the supernumerary tooth is unerupted and causes no occlusal problems. In such cases the tooth may be retained, especially if it is high in the jaw and inverted, or if its removal would endanger other teeth. However, it should be checked periodically.[17]

A diastema >2 mm is unlikely to close spontaneously and most probably requires bodily repositioning of the central and lateral incisors by fixed appliance to correct inclinations of the teeth and create sufficient space for the eruption of the canines. This patient had a very wide diastema (8 mm); therefore, the decision was made to extract the paired mesiodentes and refer the patient for orthodontic treatment to close the diastema by fixed appliance.

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Conflicts of interest

There are no conflicts of interest.


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