Fouad S. Salama, BDS, MS*, Faika Y. Abdel-Megid, BDS, MS**
* Department of Preventive Dental Sciences
** Department of Biomedical Dental Sciences,
King Saud Univer­sity College of Dentistry, P.O. Boxb0169, Riyadh 11545, Saudi Arabia

 
Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stages. The presence of a supernumerary tooth often results in a variety of complications particularly aesthetics and malocclusion. This report describes three cases of supernumerary teeth at different locations in the oral cavity and their management. The importance of radiographic interpretation and the implications of early diagnosis are discussed.

 
Hyperdontia or supernumerary teeth describe an excess in tooth number which can occur in both the primary and the permanent dentitions.1 The etiology is unknown, but hyperactivity of the dental lamina is the most widely accepted theory.1,2 In some cases, there appears to be a hereditary tendency for the development of supernumerary teeth.1 There are two morphologic types of supernumerary teeth, supplemental and rudimentary.1,2 Supplemental refers to supernumerary teeth that closely resemble normal teeth in shape and size.1,2 Rudimentary supernumerary teeth bear little resemblance to normal teeth in size or shape and include conical, tuberculate, and molariform types.1,2 Conically shaped supernumerary teeth situated between the maxillary central incisors [mesiodens], are the most common type.1,3 The second common supernumerary tooth is the maxillary fourth molar [distomolar] and is situated distal to the third molar.1 A mandibular fourth molar also is seen occasionally, but this is much less common than the maxillary fourth molar.1 Other supernumerary teeth seen with some frequency are maxillary paramolars situated bucally, lingually, or interproximaly in molar areas, mandibular premolars and maxillary lateral incisors.1 Mandibular central incisors and maxillary premolars are found on occasion.1 In contrast to the permanent dentition, the most common supernumerary teeth in primary dentition is the maxillary lateral incisors, although both supernumerary maxillary and mandibular primary canines have also been reported.4 Approximately, 90 to 98 percent of all supernumerary teeth occur in the maxilla, with a strong predilection for the anterior region.1,2,3,5 Supernumerary teeth in the primary dentition are less common than in the permanent dentition.1 The prevalence of supernumerary teeth in the permanent dentition in Caucasian population ranged between 0.15 and 3 percent.1,3 In the Swedish population a prevalence of 2 to 3 percent6 was reported and among Hispanics, the range is from 2 to 2.65 percent.7,8 In primary teeth, the prevalence was 0.3 percent in Swedish children4 and 0.4 percent in Finnish children.9 At the same time, an association between supernumerary teeth in the primary and the permanent dentitions has been reported.9,10
Complications associated with the presence of supernumerary teeth include enlarged follicular sacs, cystic degeneration, nasal eruption, malposition of adjacent teeth, over retention of primary teeth, delayed eruption of permanent teeth, loss of space, impaction, diastema, loss of vitality, and root resorption.1,2,5,7,8,11,14 Supernumerary teeth are characteristically found in cleidocranial dysostosis, Gardner's syndrome, orofacial digital syndrome 1, Rothmund-Thomson syndrome, hypertelorism-Hypospadias syndrome, and cleft palate.1,2,15

Case Reports

Case 1:

A thirteen-year old Saudi female presented for a routine dental care at the College of Dentistry King Saud University. Medical history was unremarkable. Dental history includes temporary filling and amalgam restoration. Occlusion was within normal limits with no deviation of the midline. No abnormal habits were reported. Clinical examination revealed fully erupted permanent dentition except the third molars and some carious teeth. Panoramic view [Fig. 1] revealed the presence of bilateral mandibular fourth molar's tooth buds. Patient and parent were unaware of their presence. The patient reported no symptoms related to the presence of bilateral mandibular fourth molars. Oral surgery consultation recommended follow-up and future re-evaluation.

Case 2:

A well-developed eleven year-old Saudi male was brought to the College of Dentistry King Saud University for dental examination. Medical and dental history were unremarkable. Clinical examination revealed numerous carious lesions and crowded teeth in the mandibular anterior region [Fig. 2]. Five mandibular permanent incisors and the right mandibular primary canine were present between the mandibular first premolars. The mandibular incisors were all of normal size and shape. The mandibular left central incisor was labially inclined with gingival recession [Fig. 3j. A panoramic view [Fig. 4] revealed the presence of unerupted mandibular canines and confirmed the presence of a supernumerary tooth. The family was not aware of the condition until it was brought to their attention. Orthodontic and Periodontic consultations recommended extraction of the left central incisor involved with gingival recession as well as right primary canine. Extractions for both teeth were done. A follow-up appointment showed improved alignment of the mandibular permanent incisors [Fig. 51. The permanent canines are expected to erupt later without any difficulty.

Case 3:

A six-year-old Saudi female referred to Pedodontic Division King Saud University by a general dentist after four appointments in which the patient was uncooperative and had refused dental treatment. Clinical examination of the patient revealed multiple carious teeth. Maxillary left primary central incisor was loose while right primary central incisor was intact. Evaluation of the panoramic view [Fig. 6] taken by the general dentist revealed presence of a supernumerary tooth in the maxillary left primary central incisor area. Patient's father was unaware of the condition and he reported negative history ofthe family for presence of supernumerary teeth. This supernumerary tooth was not diagnosed by the genera! practitioner. The father was informed about the need to follow-up the patient for possible eruption of the supernumerary tooth. One month later, clinical examination revealed loss of maxillary left primary central incisor and partial eruption of the supernumerary tooth [Figs. 7 & 8]. Foilow-up of the patient was recommended to allow extraction of the supernumerary tooth at the proper time before any complication arises. After approximately three months, the supernumerary tooth was partially erupted enough to allow nonsurgical extraction [Fig. 9]. A follow-up visit showed normal eruption of the left maxillary permanent central incisor, normal exfoliation of the adjacent teeth [Fig. 10] and the outline of the soon-to-erupt right maxillary permanent incisor.

 
Supernumerary permanent teeth are most common in the anterior region of the maxilla and occasionally reported in mandibular central incisors and fourth molar areas.1,3 In this article, three case reports of maxillary anterior supernumerary tooth, mandibular fourth molars, and mandibular central incisor are presented. Supernumerary permanent teeth have been reported with marked predilection in males.3,9 In this report two cases were in females and one case in male.
Most supernumerary primary teeth are asymptomatic and erupt into good arch alignment.10-16 It is likely that many such teeth exfoliate without being recognized as supernumerary. In contrast, the presence of supernumerary permanent teeth often results in a variety of irregularities and complications.1,2,11-14 The presence of a supernumerary tooth in the primary dentition should not be ignored. It should however, alert the clinician for a thorough examination since there is an increased chance of supernumerary teeth in the permanent dentition.9,10
Early diagnosis of supernumerary teeth is important so that proper treatment procedures at the proper time can be done. In case 2, late diagnosis resulted in malposition of the adjacent teeth. Early recognition could permit an interceptive orthodontic approach and allow early correction of arch crowding.
Radiographic examination and interpretation of the presence of supernumerary teeth are impor­ tant. A careful radiographic survey of both dental arches and accurate diagnosis of supernumerary teeth can be made from panorex or full-mouth series. However, a complete interpretation of each film is necessary to avoid diagnostic errors. Turner et al17 reported a case of mandibular premolar supernumerary which was asymptomatic and positioned in the apical area of the premolars below the range of a mounted bitewing film. In case 3, the supernumerary tooth was not diagnosed by the general practitioner probably due to the lack of a thorough radiographic interpretation.
It has been reported that approximately 75 percent of anterior supernumerary teeth remain unerupted while 25 percent are partially or fully erupted.2,5,18 In case 3, the supernumerary tooth erupted approximately three weeks following loss of the primary central incisor. Also, the presence of the supernumerary tooth resulted in premature exfoliation of the left primary central incisor compared to the right central incisor. Not all supernumerary teeth cause immediate complications. In case 1, patient was asymptomatic and there was no effect on occlusion. When any complication occurs or is anticipated, surgical removal of the supernumerary tooth is indicated.2,19 However, immediate removal is not necessary, if no orthodontic treatment involving the region of the supernumerary tooth is planned and if the child is seen regularly by a dentist.20 The optimal time for surgical removal of a supernumerary tooth is controversial - immediate versus delayed removal. Immediate intervention calls for removal of the supernumerary tooth soon after diagnosis.11,12 On the other hand, delayed intervention indicates removal should not occur until adjacent root formation is complete.2,19

 
This study was supported by the Research Center, College of Dentistry, King Saud University in Riyadh, with Grant No. NF1134.