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Revista de Odontologia da Universidade de São Paulo

Print version ISSN 0103-0663

Rev Odontol Univ São Paulo vol. 11 no. 4 São Paulo Oct./Dec. 1997 





Laura Guimarães PRIMO **
Roberto Schirmer WILHELM ***
Eliana Pinheiro dos Santos BASTOS ****



PRIMO, L. G. et al. Frequency and characteristics of supernumerary teeth in Brazilian children: consequences and proposed treatments. Rev Odontol Univ São Paulo, v. 11, n. 4, p. 231-237, out./dez. 1997.

The study had the objective of identifying the frequency of supernumerary teeth on patients attended at the Pediatric Dentistry Clinic at the School of Dentistry of the Universidade Federal do Rio de Janeiro (FO-UFRJ), from 1981 to 1990, relating the frequency to the sex and dentition of the patients. Some characteristics relating to and consequential upon the pathology, as well as the proposed treatments, are also part of this work. To achieve the proposed objectives, 1,907 files of patients with full mouth radiographs were examined. Children who had disturbances such as cleft lip or palate, cleidocranial dysostosis or Gardner's Syndrome were excluded from the study. The age of the patients who comprised the sample varied from 2 to 14.
UNITERMS: Tooth, supernumerary * consequence; Tooth, supernumerary * treatment; Diagnosis; Malocclusion * etiology.




There is a series of factors which can influence the development of the normal occlusion, damaging the correct alignment of the teeth and their harmonious relationship with adjacent and antagonist elements. This becomes more important because the majority of disturbances in the occlusion start during mixed dentition. The pediatric dentist must be capable of recognizing intrinsic and extrinsic factors which can influence the growth and development of the dentofacial complex, and in this way interfere with the process, preventing the installation of malocclusion.

Among the factors which can interfere with this dynamic process are the dental anomalies in number or, as they are more specifically called, supernumerary teeth. Sometimes the presence of this extra element does not cause pathological alterations. However, the occurrence of this anomaly is usually associated with problems of aesthetics, malocclusion and even formation of cysts and tumors.

The previous literature generally relates to clinical cases. Rarely can there be found analysis of the frequency of the pathology and substantial information as to the pathology's characteristics, diagnosis, consequences and treatment in relation to children's teeth. With the use of complete X-ray examination as part of the oral examination it is possible to ascertain the real incidence of supernumerary teeth in human beings.

The Pediatric Dentistry Clinic of the School of Dentistry of the Federal University of Rio de Janeiro is considered a reference center for children's dental treatment and, for several years, it has accumulated substantial documentation and information about its clientele. Because of this, it is important to carry out detailed studies of these anomalies in the files of children of both sexes attended in the Clinic. The present work involved identifying the frequency of supernumerary teeth among the patients of this Clinic over a period of ten years, relating the frequency to sex and dentition; verifying the forms of occurrence, number of elements per patient, localization in relation to the arch and hemiarch, clinical presence and the axial inclination of supernumerary teeth which were found. The objective of the work is also to list the influences caused by the presence of the anomaly in the dentofacial complex amongst the patients who have this anomaly, and enumerate the forms of treatment proposed by the Department of Pediatric Dentistry of FO-UFRJ.



From 1981 to 1990 the Department of Pediatric Dentistry of FO-UFRJ accumulated clinical documents relating to 4,951 patients. For the study of supernumerary teeth in this group, patients were selected only if they had at least one of the following radiographic examinations: complete periapical or panoramic X-ray with or without complement. These X-rays had to be of good quality and reveal clearly all the teeth, erupted or not, and their adjoining structures.

The sample excluded anyone with disturbances such as cleft lip or palate, cleidocranial dysostosis or Gardner's Syndrome. This procedure was followed because such patients have a tendency for dental anomalies in number9,13.

In accordance with the above procedure, 1,923 files of patients from 2 to 14 years old were selected. Forty-two files were excluded from the study because their X-rays were not clear enough to allow an evaluation.

The X-rays were examined using an illuminator covered with a black cardboard mask, and under ideal illumination conditions, i. e., in a room with the illuminator as the sole light source.

By reading the clinical files and examining the X-rays, the sex and the dentition were identified and the presence or not of supernumerary elements was confirmed. It was accepted that the patients had the anomaly only when the presence of the extra tooth was confirmed by the X-rays. In this way, 1,907 patients were registered as follows: 969 females, 938 males. The files of the patients of this Department included 301 cases with deciduous dentition and 1,606 cases with permanent dentition.

To achieve the proposed objectives the files of the patients as well as X-rays of their supernumerary teeth, adjacent teeth and the adjoining tissue were examined.

To classify the supernumerary teeth found according to their form, the terminology proposed by HOWARD7 (1967) was used:

  • mesiodens or conoidal - small teeth, pear-like or conical in form;
  • incisiform - resembling normal incisors;
  • invaginate - small teeth, with a barrel-form;
  • odontome - teeth without any regular form.

The classification related to the number is represented by the quantity of extra elements present in each X-ray examination.

With regard to location of the supernumerary teeth in the arches, they were found: in the upper arch; in the lower arch; and also in both arches. With regard to the hemiarch, the classification varied between right hemiarch, left hemiarch and middle line. The specific location of the supernumerary teeth, i. e., the position which they occupy in the hemiarch, was classified according to the group of normal teeth with which they were associated: mesiodens, central, lateral, canines, premolars and molars. This classification was used in the study by LUTEN10 (1967).

To evaluate the clinical presence, LUTEN's10 criterion was used (1967), according to which the supernumerary teeth were classified in relation to their clinical presence as erupted or non-erupted teeth.

The classification of the axial inclination was based on the study by BODIN et al.2 (1981), in which the authors estimated 8 axial inclinations in relation to the frontal plan. The information relating to the axial inclination was obtained by superimposing on the X-rays of the patients a circle printed on celluloid, divided into 8 sections (Figure 1). The numbers in the figure represent the position in which the root apex appears in the 8 sections.

Image58.gif (3251 bytes) Image58b.gif (3244 bytes)
Figure 1 - Schematic drawings of the circles used to classify the upper supernumerary teeth (A) and lower (B), in relation to the axial inclination in the frontal plan (BODIN et al.2, 1981).


The consequences arising from the presence of supernumerary teeth amongst the cases of the sample were classified according to the following names: late eruption of the permanent tooth; non-eruption of the permanent tooth; prolonged retention of the primary tooth; displacement of the teeth; formation of diastemas; mal-positioning of the adjacent teeth (including displacement, cross bite etc.); ectopic eruption, that can occur in the nasal cavity; pain; and no consequences to the dentofacial complex. The list of consequences described above matches with the findings of several authors1,4,8,14,17.

The treatment proposed for the patients can be grouped as follows: follow-up visits to the dentist for clinical and radiographic examinations; extraction of the supernumerary teeth; referral to surgery; maintenance of the space in the region; restoring of the space in the region; application of orthodontic force; closing of the diastema; alignment of the adjacent teeth; and referral to corrective orthodontic treatment. The group of treatments proposed is in accordance with the proposals of various authors1,14,17 found in the researched literature.

Statistical evaluation was made using the test X2 adopting a level of significance of 5% of probability (p < 0.05).



Amongst the patients of the sample, 56 showed supernumerary teeth with a frequency of 2.96%. There was a significant statistical difference between males (3.84%) and females (2.06%). With regard to the dentition, two patients (0.66%) had deciduous dentition, whereas the other fifty-four patients (3.36%) had permanent dentition. With regard to the number of teeth present in each patient, 80.36% of the sample had simple cases, 16.08% double, and 3.56% multiple (3 or 4 teeth), making a total of 70 supernumerary teeth. The conoidal type (55.71%) predominated over the incisiform (32.86%), invaginate (8.57%), and odontomes (2.86%). The most frequent were in the upper arch (82.86%) and in the middle line (60.00%).

Table 1 shows the distribution of teeth found in the sample associating them with the normal series teeth.


TABLE 1 - Distribution of seventy supernumerary teeth found in the sample, associating them with the group of the normal teeth series.

Specific location Number of teeth %
Mesiodens 42 60.00
Central incisors 4 5.71
Lateral incisors 16 22.86
Canines 1 1.43
Premolars 5 7.14
Molars 2 2.86
Total 70 100.00


The information regarding the clinical presence shows no statistical difference between erupted elements (47.14%) or non-erupted elements (52.86%).

Of the 70 teeth of the sample group of patients, four were in the anteroposterior position, thus not allowing an evaluation in the frontal plan. In this way, Figure 2 shows the distribution of 66 teeth in relation to the axial inclination in the frontal plan, according to the method of BODIN et al.2 (1981).

Image59.gif (4347 bytes)

FIGURE 2 - Distribution of sixty-six supernumerary teeth of the sample in relation to the axial inclination in the frontal plan. Note: Of the seventy teeth, four were in the anteroposterior position, not permitting an evaluation of the frontal plan. The method used was proposed by BODIN et al.2 (1981).


Tables 2 and 3 respectively show the distribution of the consequences derived from the presence of this pathology and the forms of treatment proposed by the Department of Pediatric Dentistry of FO-UFRJ.


TABLE 2 - Distribution of the patients who had supernumerary teeth and the consequences which result from the presence of this pathology.

Consequences Patients %
Later eruption of permanent teeth 1 1.79
Non-eruption of permanent teeth 3 5.35
Non-eruption of permanent teeth + prolonged retention of primary teeth 8 14.29
Non-eruption of permanent teeth + mal-positioning of adjacent teeth 3 5.35
Prolonged retention of primary teeth 2 3.57
Formation of diastemas 8 14.29
Formation of diastemas + mal-positioning of adjacent teeth 4 7.14
Mal-positioning of adjacent teeth 12 21.43
Ectopic eruption 1 1.79
Pain 1 1.79
No consequences for the dentofacial complex 13 23.21
Total 56 100.00


TABLE 3 - Distribution of the forms of treatment proposed for the 42 patients who had supernumerary teeth.

Treatments proposed Patients %
Clinical/radiological follow-up visits 1 2.38
Clinical/radiological follow-up visits/Extraction of the supernumerary teeth 1 2.38
Extraction of the supernumerary teeth 16 38.09
Extraction of the supernumerary teeth + recuperation of the space 3 7.15
Extraction of the supernumerary teeth + application of orthodontic force 1 2.38
Extraction of the supernumerary teeth + closing of the diastema 4 9.52
Extraction of the supernumerary teeth + alignment of the adjacent teeth 10 23.81
Extraction of the supernumerary teeth + referral to corrective orthodontics 3 7.15
Referral to extend surgery 2 4.76
Alignment of adjacent teeth 1 2.38
Total 42 100.00

Note: From the 56 patients who had supernumerary teeth, 14 did not have any form of treatment proposed in the clinical file. So, the information relating to the forms of treatment proposed could only be computed in relation to 42 patients.



The development of intra-oral structures suffers influence from natural tendencies. The mechanism can be altered by adverse conditions, such as congenital dental anomalies. Recognition of these abnormal factors, during the phases of the primary dentition and mixed dentition, may allow treatment with a more favorable prognosis. In certain cases it can minimize the need for extensive intervention. However, the professional can only develop his diagnostic capacity properly if he has complementary examinations. Especially in the case of supernumerary teeth, where the majority is of unerupted teeth2,3,14,15, X-rays covering all the teeth and adjacent structures are essential for diagnosis. Therefore, it was necessary to select the cases which had complete X-rays, to be able to study the frequency of the supernumerary teeth in patients attended at the Pediatric Dentistry Department of the School of Dentistry of UFRJ, over a period of ten years.

It was verified through the literature that the frequencies relating to supernumerary teeth vary considerably, depending on different materials and methods of investigation. The researches used to produce this work showed that the frequencies of studies using material including radiographic examinations varied from 0.45% to 25.16%1,6,8,10,15.

The frequency obtained in this work is slightly above the average of the frequencies of the studies in the researched literature. This fact could have been determined by the place where the analysis was done. Being the Department of the Pediatric Dentistry at FO-UFRJ a reference point for children's dental treatment, some of the patients of the sample were sent to the institution already with suspicions of the pathology. This fact did not constitute bias as suggested by ISSÁO; KATHALIAN8 (1968), because the cases referred for treatment were diluted in the total number of the sample, i. e., children who looked for treatment by chance.

Some authors12,16 state that there is a tendency for the supernumerary teeth to be present with more frequency in males. The results shown reveal greater frequency for males, with a significant statistical difference.

The majority of dental anomalies rarely occur during the first dentition. In the sample with 56 cases studied, the frequency for the first dentition was of 0.66%, compared to 3.36% of the secondary dentition.

The incidence of the supernumerary can be simple or multiple1,4,9. However, there is a predomination of single supernumerary tooth2,11,14,16. Such predilection became clear in this work where 80.36% of the patients only showed one extra element.

There is unanimity amongst the researchers2,8,11,12,14 with regard to the most frequent form of supernumerary teeth, which is the conoid, with a lower percentage of the others being found. In the present study the conoid form was found in 55.71% of the cases, followed by 32.86% of the incisiform. Such results support the view that the predominant form is the conoid.

According to the results, 58 supernumerary teeth, 82.86% of the sample, were found in the upper arch. This result is in total agreement with the literature6,15.

The majority of authors concentrate in showing the predominance of these teeth in the middle line1,4,11,13. In the results of the present study there was no difference between the affected hemiarches, and a strong preference for the middle line could be observed.

The authors of this work attempted to find an association between the supernumerary element and normal teeth. They found a tendency of the extra elements to be located in the anterior region. This fact had already been mentioned in the literature4,8,16.

Some authors2,3,14,15 showed a variation of 77.6% to 93.7% of the supernumerary teeth with the tendency of not erupting. However, amongst the extra teeth found on the present work, there was no significant statistical difference between the teeth that erupted and those which did not.

Few studies were found in the literature showing a detailed classification of the axial inclination of the supernumerary teeth. The authors of this work opted to research the axial inclination in relation to the frontal plan, in accordance with the work of BODIN et al.2 (1981). Based on Figure 2, the authors of this work could observe the predominance of the teeth in the normal position (59.90%), followed by the oblique positions (30.03% - summary of the position 2, 4, 6 and 8), different percentages from those found by the authors who proposed the method. Only 9.09% were inverted and 1.52% were horizontal. This preference for the normal position could explain the high percentage of erupted teeth (47.14%).

There are few studies in the consulted literature which evaluated the complications derived from the presence of supernumerary teeth. The consequences found in the researched literature were listed and in some cases associations appeared between more than one of them. Individually, 23.21% of the supernumerary teeth did not cause alterations in the dentofacial complex, and 21.43% of the patients showed bad position of the adjacent teeth to the extra elements. Alteration in the eruption of permanent teeth, associated or not to other complications, affected 30.35% of the patients. The formation of diastemas associated or not with the mal-positioning of adjacent teeth appeared in 21.43% of the patients. Resorption of the roots of adjacent teeth and formation of cysts and tumors were not observed in this study. This could be attributed to the young age of the patients who composed the sample. Less frequently, complications such as ectopic eruption and pain were noted.

In the researched literature, the authors of this work did not find studies showing the percentage of treatments proposed or carried out in patients who had supernumerary teeth; only reports of clinical activities on which the authors of this work based themselves to establish a list of proposed treatments. The extraction of the supernumerary tooth associated or not with other forms of treatment were proposed in 88.1% of the cases. This fact is shown by WEBER17 (1964) and FOLIO et al.5 (1985). Clinical/radiographic follow-up visits was proposed for 4.76% of the patients.



Based on the results here presented, the authors of this work conclude that the frequency of supernumerary teeth amongst the patients attended at the Pediatric Dentistry Clinic at the School of Dentistry of the Federal University of Rio de Janeiro, from 1981 to 1990, is of 2.94%. Regarding the sex there was a significant statistical difference favouring males, and, regarding the dentition, the frequency of this pathology in the secondary dentition is remarkable. The most common form of the pathology is the conoid.

Patients having only one supernumerary element are the most common. Regarding location, there is a strong preference for the upper arch, for the anterior region of the arches, more specifically, for the middle line. The percentage related to the clinical presence showed no significant statistical difference between the elements, erupted or not. The normal axial inclination in relation to the frontal plan constitutes the predominant pattern amongst the patients in the sample who have supernumerary teeth. The influence of the presence of supernumerary teeth on the dentofacial complex is related to alterations of the eruption of the permanent teeth, which could be associated or not with other complications. The extraction of supernumerary teeth, related or not with other therapies, constitutes the most commonly proposed treatment for patients with this anomaly.

The obtaining of information based on the correct filling out of clinical forms and on the use of complete documentation of the patient enables the Pediatric Dentist to make an early diagnosis and institute adequate treatment for the patients. Hence, the necessity of extended and traumatic treatment is minimized, not only in private and institutional clinics but also in places where pediatric dentistry is taught.



PRIMO, L. G. et al. Freqüência e características dos dentes supranumerários em crianças brasileiras: conseqüências e tratamentos propostos. Rev Odontol Univ São Paulo, v. 11, n. 4, p. 231-237, out./dez. 1997.

Este estudo teve como objetivo identificar a freqüência de dentes supranumerários em pacientes atendidos na Clínica de Odontopediatria da Faculdade de Odontologia da Universidade Federal do Rio de Janeiro (FO-UFRJ), entre 1981 e 1990, relacionando-a com o sexo e a dentição dos pacientes. As conseqüências da presença dessa patologia, bem como os tratamentos propostos, também fizeram parte deste trabalho. A fim de atingir os objetivos propostos, 1907 fichas de pacientes com radiografias de boca total foram examinadas. As crianças que apresentavam distúrbios, tais como fenda labial ou palatina, disostose cleidocraniana ou Síndrome de Gardner, foram excluídas do estudo. A idade dos pacientes que compuseram a amostra variou de 2 a 14 anos.
UNITERMOS: Dente supranumerário * conseqüências; Dente supranumerário * tratamentos; Diagnóstico; Maloclusão * etiologia.



1. BAYSAL, M. C. Supernumerary teeth in children. Dent Dig, v. 70, n. 11, p. 506-509, Nov. 1954.

2. BODIN, I. et al. Hyperdontia: III. Supernumerary anterior teeth. Dentomaxillofac Radiol, v. 10, n. 1, p. 35-42, Jan. 1981.

3. BUENVIAJE, T. M.; RAPP, R. Dental anomalies in children: a clinical and radiographic survey. J Dent Child, v. 51, n. 1, p. 42-46, Jan./Feb. 1984.

4. DAY, R. C. B. Supernumerary teeth in the premaxillary region. Br Dent J, v. 116, n. 4, p. 304-308, Apr. 1964.

5. FOLIO, J. et al. Clinical management of multiple maxillary anterior supernumerary teeth: report of case. J Dent Child, v. 52, n. 5, p. 370-373, Sept./Oct. 1985.

6. GRAHNÉN, H.; LINDAHL, B. Supernumerary teeth in the permanent dentition. Odontol Revy, v. 12, n. 3, p. 290-294, July/Sept. 1961.

7. HOWARD, R. D. The unerupted incisor. A study of the postoperative eruptive history of incisors delayed in their eruption by supernumerary teeth. Dent Pract Dent Rec, v. 17, n. 5, p. 332-342, May 1967.

8. ISSÁO, M.; KATHALIAN, L. Y. Dentes supranumerários na região ântero-superior na dentição mista.  Rev Fac Odontol Univ São Paulo, v. 6, n. 2, p. 137-145, abr./jun. 1968.

9. LEVINE, N. The clinical management of supernumerary teeth. J Can Dent Assoc, v. 28, n. 5, p. 297-303, May 1962.

10. LUTEN, J. The prevalence of supernumerary teeth in primary and mixed dentitions. J Dent Child, v. 34, n. 5, p. 346-353, Sept. 1967.

11. PARRY, R. R.; IYER, V. S. Supernumerary teeth amongst orthodontic patients in India. Br Dent J, v. 111, n. 7, p. 257-258, Oct. 1961.

12. SAARENMAA, L. The origin of supernumerary teeth. Acta Odontol Scand, v. 9, Suppl. 6, p. 293-303, 1951.

13. SPYROPOULOS, N. D. et al. Simultaneous presence of partial anodontia and supernumerary teeth. Oral Surg Oral Med Oral Pathol, v. 48, n. 1, p. 53-56, July 1979.

14. STAFNE, E. C. Supernumerary upper central incisors. Dent Cosmos, v. 73, n. 10, p. 976-980, Oct. 1931.

15. STAFNE, E. C. Supernumerary teeth. Dent Cosmos, v. 74, n. 7, p. 653-659, July 1932.

16. TAY, F. et al. Unerupted maxillary anterior supernumerary teeth: report of 204 cases. J Dent Child, v. 51, n. 4, p. 289-294, July/Aug. 1984.

17. WEBER, F.N. Supernumerary teeth. Dent Clin North Am, v. 9, n. 2, p. 509-517, July 1964.



Recebido para publicação em 22/02/97
Aceito para publicação em 19/05/97


*  Thesis presented at Universidade Federal do Rio de Janeiro - UFRJ.
** Assistant Professor of Pediatric Dentistry at Universidade Federal do Rio de Janeiro.
*** Chairman of Orthodontics at Universidade Federal do Rio de Janeiro.
**** Associate Professor of Pediatric Dentistry at Universidade Federal do Rio de Janeiro.

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