Supernumerary deciduous teeth with multiple maxillary impacted mesiodens: A case report

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1 PEDIATRIC DENTAL JOURNAL 22(2): , 2012 Case Report Supernumerary deciduous teeth with multiple maxillary impacted mesiodens: A case report Shinnosuke Nogami 1, *, Ikuya Miyamoto 1, Kensuke Yamauchi 1, Yoshihiro Kataoka 1, Yasuhiro Morimoto 2, Katsura Saeki 3, Kenshi Maki 3 and Tetsu Takahashi 1 1 Division of Oral and Maxillofacial Reconstructive Surgery, Department of Oral and Maxillofacial Surgery, Kyushu Dental College 2 Division of Diagnostic Radiology, Department of Oral Diagnostic Science, Kyushu Dental College 3 Division of Developmental Stomatognathic Function Science, Department of Growth and Development of Functions, Kyushu Dental College Abstract Maxillary impacted mesiodens are frequently encountered in pediatric dentistry. Much research has been conducted concerning their incidence, position, and form. Supernumerary teeth erupting in the primary dentition with maxillary impacted mesiodens are very rare. In January 2011, a nine-year-old boy presented for dental treatment and was found to have supernumerary deciduous teeth. Upon panoramic radiography, multiple impacted mesiodens were found; therefore, computed tomography (CT) was performed for further examination. One month later, the boy was referred to our department for extraction of the deciduous supernumeraries and impacted mesiodens. We suspected that these supernumeraries, mesiodens, and remaining primary teeth would lead to problems with the eruption of the permanent teeth. Therefore, by ascertaining the exact position of the mesiodens and the successional permanent teeth using CT, extraction was performed under general anesthesia in March 2011 without any error. Six months postoperatively, panoramic radiographs showed no superfluous structure that appeared to be a tooth. We suggest that when multiple maxillary impacted mesiodens are found, their exact positions can be located using CT before extraction. Key words Computed tomography, Multiple maxillary impacted mesiodens, Supernumerary deciduous teeth Introduction Supernumerary teeth are generally found less often in the primary dentition compared to the mixed or permanent dentition. Since primary teeth degenerate slower than permanent teeth and often maintain a primitive form, abnormalities of form occur less frequently. Supernumerary teeth erupting in the primary dentition are almost always maxillary impacted mesiodens. However, such eruption is in fact very * Correspondence to: Shinnosuke Nogami r09nogami@fa.kyu-dent.ac.jp Received on January 12, 2012; Accepted on March 29, 2012 rare. Grahnen reported this occurrence in only three out of 1,173 four- and five-year-olds in Sweden 1), and Luten reported 11 supernumerary primary teeth in 1,558 children 2). This report describes a rare case of supernumerary deciduous teeth involving multiple maxillary impacted mesiodens. Case Report In January 2011, a nine-year-old Japanese boy with a chief complaint of mobility of the primary central incisors was referred to the pediatric dental department of our college hospital for dental treatment. 193

2 194 Nogami, S., Miyamoto, I., Yamauchi, K. et al. Figs. 1a, b Intraoral photographs obtained at the first examination Anterior and upper occlusal views showing supernumerary primary teeth bilaterally between the primary central incisors and the primary lateral incisors. Fig. 1c Orthopantomographs obtained at the first examination A panoramic radiograph showing multiple maxillary impacted mesiodens. He presented with an eruption of supernumerary deciduous teeth in the primary dentition (Figs. 1a, b). Intra-oral and panoramic radiographs revealed multiple maxillary impacted mesiodens (Fig. 1c); hence computed tomography (CT) was performed for further examination. A pedodontist suspected that problems would arise with the eruption of his permanent teeth. The patient was referred to our department for extraction of the supernumerary teeth in February He had no significant medical history and his general condition was good. Family history included extraction of maxillary impacted mesiodens in his sister, but no supernumerary primary teeth were present in her. The patient was of medium build and his nutritional state was good. There were no significant extraoral findings. Intraoral examination revealed that the following teeth were present: (16, 55, 54, 53, <S52>, 51; 61, <S62>, 63, 64, 65, 26; 31, 32, 73, 74, 75, 36; 41, 42, 83, 84, 85, 46) 6EDC<SB>A 6EDC21 A<SB>CDE6 12CDE6 In the maxilla, there was bilateral eruption of supernumerary primary teeth between the primary central and lateral incisors. The right primary central and lateral incisors and the left primary central incisor showed grade 2 mobility. A torus near the frenulum of the upper lip was evident on touch that we suspected to be a maxillary impacted mesiodens. We did not find any torus or inflammation on the palatine mucosa.

3 Supernumerary deciduous teeth with multiple maxillary impacted mesiodens 195 Figs. 1d, e CT obtained at the first examination showing three tooth-like high-density structures visible on the palatal side of the crowns of the upper central incisors and another high-density tooth-like structure between the primary dentition and the floor of the nasal cavity. Fig. 2 Extracted teeth CT revealed few high-density tooth-like structures (Figs. 1d, e). Three tooth-like high-density structures were visible on the palatal side of the crowns of the upper central incisors on the CT image. The middle one of the three was invertedly and impacted. Another high-density tooth-like structure was visible between the primary dentition and the floor of the nasal cavity. This structure was also invertedly and impacted. Two maxillary impacted mesiodens were in contact with the incisive foramen. We suspected that one of the maxillary impacted mesiodens, seen between the crowns of the left upper central and lateral incisors, was touching the two incisors. Another maxillary impacted mesiodens on the labial side did not appear to be in contact with the nasal cavity. Our diagnosis was late-stage remaining bilateral upper central and lateral incisors, supernumerary deciduous maxillary teeth, and multiple maxillary impacted mesiodens, and we decided to extract them under general anesthesia (Fig. 2). At six months postoperatively, radiography showed no superfluous

4 196 Nogami, S., Miyamoto, I., Yamauchi, K. et al. Figs. 3a, b Post-operative intraoral photographs Anterior and upper occlusal views at six months postoperatively showing rotation of the left upper central incisors. structure that appeared to be a tooth (Figs. 3a c). Discussion In humans, the number of each type of a tooth is pre-determined but can be occasionally more than usual. In such rare cases, the extra teeth are described as supernumerary teeth. Supernumerary teeth are generally found less often in the primary dentition compared to the mixed or permanent dentitions. Even when supernumerary teeth are found in the deciduous dentition, they are almost always mesiodens. Bolk stated that when distinguishing supernumerary permanent teeth from supernumerary primaries, firstly, in almost all cases, the form of the primary supernumeraries is normal, and, secondly, they appear in the primary dentition 3). However, supernumerary teeth can be difficult to distinguish on this basis alone. All related factors, such as position, and timing of eruption, tooth form, condition of the pulp cavity, tooth color, progress of caries, occlusal wear, formation and absorption of the root, degree of calcification, and age of the patient must be taken into consideration. In our case, the form, color, and root formation of the right upper supernumerary primary teeth were similar to those of the left upper primary lateral incisor, and the form and color of the left upper supernumerary primary teeth were similar to those of the right upper primary lateral incisor. The left upper supernumerary primary teeth were longer than the right upper primary lateral incisor, but the root forms were similar. Further, since both of the upper supernumeraries had erupted at the same time as both Fig. 3c Post-operative periapical radiograph Periapical radiograph showing the absence of any superfluous structure that appears to be a tooth. primary lateral incisors in the primary dentition, we diagnosed them as supernumerary primary teeth. The incidence of supernumerary primary teeth is very low. Miyoshi et al. studied the difference in incidence between Japanese and non-japanese patients using epidemiology reports of supernumerary primary teeth 4). They reported that while the incidence of supernumerary teeth in Japan is 0.01% to 0.11%, in other countries it is 0.23% to 0.64%; thus, the reported incidence is lower in Japan than in other countries. Further, they reported significant differences between Japanese and Caucasians, and between Japanese and Chinese. Since it is difficult to distinguish between supernumerary primary and permanent mesiodens in the primary dentition, they excluded mesiodens from their study. There are many

5 Supernumerary deciduous teeth with multiple maxillary impacted mesiodens 197 reports concerning supernumerary primary lateral incisors with the incidence of supernumerary primary teeth ranging widely from 0.005% to 0.156%, but the occurrence of supernumerary primary teeth is rare 4 6). Supernumerary primary teeth almost always appear as maxillary incisors between the primary central and lateral incisors or between the lateral incisor and canine. They tend to appear more often on the right side than on the left. In our case, the patient had supernumerary primary upper lateral incisors bilaterally present between the primary lateral incisors and canines. In addition, we found maxillary impacted mesiodens and used CT to establish their exact positions. When there are only one or two maxillary impacted mesiodens, it is possible to ascertain their approximate position using occlusal radiography, but in cases with multiple maxillary impacted mesiodens and tooth buds, their exact positions need to be established using CT. Further, since the colors of erupted teeth in the primary dentition and maxillary impacted mesiodens are similar, using CT to locate their exact positions should help to avoid erroneous extractions. Grahnen reported the existence of tooth buds of the permanent successors of supernumerary primary teeth, also present in our case, in 30% of cases 1). They were also present in our case. There are numerous reports describing the effects of supernumerary teeth on the dentition. These effects include malocclusion, median diastema, rotation or displacement of incisors, delay in eruption, and cyst formation. In particular, it is well known that supernumerary teeth cause diastema; however, this was not observed in the present case. It is also well known that the presence of supernumerary teeth can cause difficulties with brushing and cleansing, leading to caries, but there were no such difficulties in this case. There is much variation in reports concerning the timing of extraction of supernumerary teeth. Sanders and Vermeeren suggested waiting until after permanent root formation 7,8). We believe that if supernumerary teeth do not lead to rotation or displacement of permanent incisors and delay in eruption of permanent teeth, it is not necessary to extract them. In our case, we were concerned that the remaining primary teeth, supernumerary teeth, and multiple impacted mesiodens would lead to problems with the eruption of permanent teeth and therefore decided to extract them. In addition, using this method, we were able to avoid damage to the tooth buds of the permanent successors during extraction. Conclusion We suspected that the remaining primary teeth and mesiodens would lead to difficulties in the eruption of permanent teeth and decided to extract them. By ascertaining the exact position of the mesiodens and the successional permanent teeth using CT, we were able to extract without error. We suggest that when multiple maxillary impacted mesiodens are found, their exact positions can be located using CT before extraction. Acknowledgments We are grateful to the mother of the patient for allowing reporting of the present case for academic purposes. References 1) Grahnen, H.: Numerical variations in primary dentition and their correlation with the permanent dentition. Odont Revy 12: , ) Luten, J.R.: The prevalence of supernumerary teeth in primary and mixed dentitions. J Dent Child 34: , ) Bolk, L.: Die uberzahkigen oberen inzisive des menschen. Dtsch Mschr Zahnheilk 35: , ) Miyoshi, S., Tanaka, S., Kunimatsu, H., Kunimatsu, H., Murakami, Y., Fukami, M. and Fujisawa, S.: An epidemiological study of supernumerary primary teeth in Japanese children: a review of racial differences in the prevalence. Oral Dis 6: , ) Stafne, E.C.: Supernumerary upper central incisors. Dent Cosmos 73: , ) Boyne, P.J.: Supernumerary maxillary incisors. Oral Surg Oral Med Oral Pathol 7: , ) Sanders, B.: Pediatric oral and maxillofacial surgery. C.V. Mosby Co., St. Louis, 1979, pp ) Vermeeren, J.: Surgical treatment of mesiodentes. Ned T Tandheelk 82: , 1975.