Most supernumerary teeth are located in the anterior maxillary region. They are classified according to their number, form, and location. Their presence may give rise to a variety of clinical problems. Detection of supernumerary teeth is best achieved by thorough clinical and radiographic examination. Their management varies according to the different clinical presentations.
This is a case report of a 9-year-old boy with an unerupted UR1 due to supernumerary teeth in the anterior maxilla. The treatment consisted of a surgical excision of the supernumeraries followed by interceptive orthodontic treatment to align the impacted UR1.
Clinical relevance: the importance of interceptive orthodontic treatment in preventing the development of more complex
malocclusion with space loss of the unerupted teeth and upper centerline shift.
Supernumerary teeth are those that are additional to the normal series and can be found in almost any region of the dental arch.  They are classified according to their morphology, location and number (Fig. 1). [2,3]
The prevalence of their occurrence varies between 0.1 and 3.8%.  The male-to-female ratio has been reported as 2:1.  The literature reports that 80% – 90% of all supernumerary teeth occur in the maxilla.  Half are found in the anterior region.  Extra teeth may present in both the permanent and the primary dentitions but are 5 times less frequent in the primary dentition.  In a survey of 2,000 schoolchildren, Brook found that supernumerary teeth were present in 0.8% of primary dentitions and in 2.1% of permanent dentitions. [6,7]
Occasionally, supernumerary teeth are asymptomatic and may be detected as a chance finding during radiographic examination. Supernumerary teeth can be managed by either removal, or maintaining them in the arch with frequent observation. The removal of the supernumerary teeth is recommended where: [7,8]
– Permanent tooth eruption has been delayed due to the presence of supernumerary tooth
– Altered eruption or displacement of adjacent tooth is evident
– There is associated pathology
– Increased risk of caries due to the presence of supernumerary teeth which makes the area inaccessible to maintain oral hygiene
– Orthodontic treatment needs to be carried out to align the teeth
– Its presence would compromise alveolar bone grafting and implant placement
– There is compromised aesthetic and functional status
K.A is a 9-year-old boy presented to the dental clinic accompanied by his parent, complaining of the appearance of his front teeth. He presented in the early mixed dentition stage with unerupted/missing upper left central incisor. He had fair oral hygiene and heavily restored primary dentition.
Extra Oral Examination
K has oval face shape with normal skin tone and color, slightly convex facial profile with apparently normal vertical dimension and lip support. His lips are competent with slight asymmetry and average smile line (Fig. 2).
K has U- shaped average sized dental arches. He presented in the mixed dentition stage with a Class I incisor relationship and delayed eruption of UR1, drifting of UR2, UL1 into the space of UR1. Upper midline was shifted to the right by 2 mm. In occlusion, he had a unilateral posterior cross bite on the right side without mandibular shift on closure (Fig.3). Palpation of the buccal sulcus in the area of UR1 shows a bulge of the buccal mucosa. In addition, palpation of the palatal mucosa showed prominent bulge in the palate.
Panoramic, occlusal, and periapical radiographs revealed the presence of an impacted UR1 with normal shaped crown and incomplete root formation with two mesiodens supernumeraries obstructing its eruption (Fig. 4). The buccolingual position of unerupted supernumeraries can be determined using parallax technique. Whereas an occlusal film together with a panoramic view are routinely used for vertical parallax. If the supernumerary moves in the same direction as the tube shift, it lies in a palatal position, but if it moves in the opposite direction then it lies buccally. 
On the basis of the clinical and radiographic findings, diagnosis of mesiodens supernumerary was established.
1st: Tuberculate mesiodens, superimposed on the unerupted central incisor which rarely erupts and are frequently associated with the delayed eruption of the incisors. 
2nd: Conical inverted mesiodens, which had a significantly higher rate of eruption, compared to the tuberculate type. 
Arch expansion to correct the crossbite and create space for the impacted UR1 followed by surgical removal of supernumeraries under local anesthesia and orthodontic interceptive treatment for alignment of the impacted incisor was planed. The possibility of UR1 being ankylosed or needed to be extracted during the surgery both discussed with the patient previously and agreed up on, then informed consent was signed by the parents.
The treatment started with oral hygiene instructions including tooth brushing by using fluoridated dentifrices, dental floss and dietary advice. Once the oral hygiene was improved an upper alginate impression was taken to construct a quadhelix appliance in the dental laboratory to correct the unilateral cross bite and to gain more space for the impacted UR1 (Fig. 5a). At the following visit, the quadhelix was cemented active and an upper sectional fixed readjusted Edgewise appliance was bonded (APC II 3M victory series twin 0.018’’ MBT). The orthodontic bracket were bonded on the fully erupted permanent maxillary teeth; UR5, UR4, UR2, UL1, UL2, UL4 and UL5 (Fig. 5b). Once enough space was gained for the impacted UR1 (Fig. 5c), surgical removals of the supernumeraries were done under local anesthesia.
A palatal flap was raised (Fig. 6a) and both tuberculate and conical supernumeraries were extracted (Fig. 6b and 6c). The impacted UR1 was exposed from the buccal aspect and bonded with a gold chain. The area was irrigated and the flap was sutured back in position. The gold chain extending from the impacted UR1 was tied to the arch wire passively (Fig. 6d). The patient was recalled at 4-week intervals for tightening the gold chain; Thereby causing forced extrusion of the impacted UR1 (Fig. 7a and 7b). After three visits, the UR1 erupted into the oral cavity, 0.014” nickel titanium wire was engaged piggy back on the erupting incisor with a 0.016”x0.022” stainless steel base wire (Fig. 7c).Eight weeks later the impacted UR1 was properly aligned in the arch (Fig. 7d) with the final finishing and detailing followed few weeks later (Fig. 8a and 8b). Retention was by means of upper Howley’s retainer.
The patient completed the treatment within one year. The unerupted UR1 was aligned successfully (Fig. 8) and all the objectives of the treatment plan were achieved. The patient requires continued monitoring of the growth and the development of the dentition in case a comprehensive orthodontic treatment is required once all the remaining permanent teeth erupt.
The etiology of supernumerary teeth is not completely understood.  Various theories exist for the different types of supernumerary. One theory suggests that the supernumerary tooth is created as a result of a dichotomy of the tooth bud. [7,8] Another theory, well supported in the literature, is the hyperactivity theory, which suggests that supernumeraries are formed as a result of local, independent, conditioned hyperactivity of the dental lamina.  Heredity may also play a role in the occurrence of this anomaly, as supernumeraries are more common in the relatives of affected children than in the general population.  However, the anomaly does not follow a simple Mendelian pattern.  A mesiodens should be suspected when there is asymmetry in the eruption pattern of the maxillary incisors.  Early diagnosis of a mesiodens minimizes the treatment required and prevents development of associated problems. Extraction of the mesiodens in the early mixed dentition stage may facilitate spontaneous eruption and alignment of incisors, while minimizing intervention. In this case the patient presented in late mixed dentition stage, with space loss, midline shift and delayed eruption of the right central incisor, which required surgical and orthodontic intervention. Extraction is not always the treatment of choice for supernumerary teeth. unerupted supernumerary teeth that are asymptomatic, do not appear to be affecting the dentition in any way and are found by chance sometime best left in place and kept under observation. 
The fixed appliance phase was indicated to align the unerupted UR1 and to correct the appearance of his front teeth.
As outlined above, in most cases the incisors will erupt spontaneously or can be orthodontically erupted following extraction of the mesiodentes. In the rare case that a central incisor cannot be erupted orthodontically because of its position or ankylosis, 2 treatment options exist: surgical repositioning or extraction and placement of an implant. Replacing an ankylosed tooth with an implant may be a better option, as the risks of root resorption, discolouration and periodontal compromise associated with repositioning may be reduced. However, treatment options must be considered individually in each case. 
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by Dr. Tasneem AL Farhan, Dr. Kholoud Al-Foudari, Dr. Nour AL Hasan