|Year : 2015 | Volume
| Issue : 6 | Page : 289-293
Cone-beam computed tomography exploration and surgical management of palatal, inverted, and impacted mesiodens
Mounir Omami, Abdellatif Chokri, Hajer Hentati, Jamil Selmi
Department of Medicine and Oral Surgery, University Dental Clinic, Monastir, Tunisia
|Date of Web Publication||8-Oct-2015|
Department of Medicine and Oral Surgery, University Dental Clinic, Monastir
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Supernumerary teeth are extra teeth or toothlike structures which may have either erupted or unerupted in addition to the 20 deciduous teeth and the 32 permanent teeth. Mesiodens is one of these located in the midline between the two central incisors. Their presence may give rise to a variety of clinical problems. This paper describes a rare case of palatal placed, inverted and impacted mesiodens associated to two supernumerary teeth which were detected during a radiographic examination for delayed eruption of permanent central incisors in the case of a healthy 8-year-old girl monitored at the oral surgery service while discussing the usefulness of cone beam computed tomography for accurate diagnosis and management.
Keywords: Cone-beam computed tomography, inverted, mesiodens, palatal impaction, supernumerary tooth
|How to cite this article:|
Omami M, Chokri A, Hentati H, Selmi J. Cone-beam computed tomography exploration and surgical management of palatal, inverted, and impacted mesiodens. Contemp Clin Dent 2015;6, Suppl S2:289-93
|How to cite this URL:|
Omami M, Chokri A, Hentati H, Selmi J. Cone-beam computed tomography exploration and surgical management of palatal, inverted, and impacted mesiodens. Contemp Clin Dent [serial online] 2015 [cited 2019 Jul 20];6, Suppl S2:289-93. Available from: http://www.contempclindent.org/text.asp?2015/6/6/289/166815
| Introduction|| |
A supernumerary tooth is a development anomaly of number characterized by the presence of tooth in addition to the normal series., Its prevalence rates of reported in the literature vary between 0.1% and 3.6% in the permanent dentition depending on the respective population. However, in deciduous teeth, prevalence is lower amounting to 0.3–0.8%. Males are affected approximately twice as often as females. Supernumerary teeth can occur as singles, multiples, unilaterally, or bilaterally and in the maxilla, the mandible, or both., According to Alberti, the mesiodens is the most common type of supernumerary tooth. It is locateda between the two central incisors. Only 25% of all mesiodentes spontaneously erupt into the oral cavity. In general, they remain impacted and asymptomatic; and are commonly discovered during the routine radiographic examination., There are several hypotheses which have been proposed to explain the occurrence of supernumerary teeth, and their etiology remains unclear. A combination of environmental and genetic factors has been proposed to explain supernumerary tooth occurrence. A range of complications varying from crowding to cyst formation can be caused by supernumerary tooth. Though, it is clear that early treatment can possibly prevent further complications.
Several studies have applied cone-beam computed tomography (CBCT) to accurately diagnose supernumerary teeth with the potential to overcome most of the technical limitations of the plain film projection and the capability of providing a high-resolution three-dimensional (3D) representation of the maxillofacial tissues in a cost and dose efficient manner., For the treatment, it depends on the type, position of supernumerary teeth, and the possibility to produce complications which are identified both clinically and radiographically.
The aim of this article was to describe a rare case of palatal placed, inverted, and impacted mesiodens associated to two supernumerary teeth delaying the eruption of permanent central incisors in the case of a healthy 8-year-old girl monitored at the oral surgery service while discussing the outcomes of using CBCT to diagnose the accurately position of supernumerary teeth and to choose the appropriate management technique.
| Case Report|| |
An 8-year-old female patient visited the university hospital due to delayed eruption of her right permanent maxillary central incisor. Her medical history revealed no systemic diseases, and the dental history proved no facial trauma or other tooth abnormalities have occurred. She avowed that she was operated on, at the age of seven years, for a supernumerary tooth delaying the eruption of the left permanent maxillary central incisor. A previous panoramic radiograph (one year ago) revealed the presence of a mesiodens associated to two supernumerary teeth [Figure 1].
|Figure 1: Panoramic radiograph shows the impacted permanent upper central incisors and the presence of two supernumerary teeth and a mesiodens|
Click here to view
Clinical examination revealed a mixed dentition and the absence of the right maxillary permanent central and lateral incisors [Figure 2]. The left ones have already erupted.
|Figure 2:Intraoral photograph shows mixed dentition, clinical absence of the maxillary right central and lateral incisors|
Click here to view
The patient was referred to CBCT examination of the maxilla to assist the localization and orientation of the mesiodens. CBCT images were requested for diagnosing accurately the morphology and exact location of the mesiodens and the radicular formation of the permanent maxillary central incisors. The images were created and viewed interactively using a dental computed tomography (CT) software program.
The 3D CBCT panorex showed the impaction of the right permanent maxillary incisor and the presence of a supernumerary tooth; moreover, the axial slice image of CBCT revealed the palatal position of the impacted and inverted mesiodens and the sagittal slices showed that the supernumerary tooth was in palatal position over the impacted permanent maxillary central incisor [Figure 3].
|Figure 3: The panoramic reconstruction (a), axial (b) and sagittal (c) slices of cone beam computed tomography show an impacted, palatal placed, and inverted mesiodens associated to a supernumerary tooth|
Click here to view
A comprehensive treatment plan was formulated, which included surgical extraction of the mesiodens and the supernumerary tooth [Figure 4]. The patient was administered local anesthesia. Using a mucoperiosteal elevator, a full thickness palatal flap was raised. The supernumerary tooth was exposed, luxated, and removed. Hemostasis was achieved and the flap was replaced back and sutured. For the mesiodens, a simple palatal anteroposterior incision was done and the extraction followed. Postchirurgical instructions were explained to the patient along a prescription of antibiotic and analgesic treatment. The recall visits were scheduled for the following week to remove suture and evaluate the healing process. The patient was kept under the observation until the successful eruption of permanent central and lateral incisors.
|Figure 4: Progress photographs: Surgical removal of the supernumerary tooth and the mesiodens. (a) A palatal mucoperiostal flap was reflected and the bone overlying the impacted supernumerary tooth was removed. (b) Anteroposterior incision to remove the mesiodens (indirect vision). (c) The mesiodens and the supernumerary tooth. (d) Suture removal and control after 1-week (indirect vision)|
Click here to view
| Discussion|| |
Supernumerary teeth or hyperdontia can be defined as teeth that exceed the normal dental complement, regardless of their locations and morphologies. It is more common in the central region of the upper or lower jaw; however, its occurrence in the mandible is rare. Mesiodens is the most common type of supernumerary teeth and is located in the midline between the two upper central incisors. Its prevalence in general population ranges between 0.15% and 1.9% and it is reported to be more common in males rather than females., The frequency of mesiodens has been estimated to be 0.45% in Caucasians, 0.4% in Finnish, 1.43% in Norwegians, and 2.2% in Hispanic populations. Variations due to differences in demographic and environmental susceptibilities may have an impact on the reported prevalence.
Supernumerary teeth are classified based on morphology (conical, tuberculate, and supplemental), location (mesiodens, paramolar, distomolar, and parapremolar), position (buccal, palatal, and transverse), and orientation (vertical or normal, inverted, transverse, or horizontal). In our case, it was a conical, palatal, and inverted mesiodens.
The present case is unique in several aspects:First, the occurrence of mesiodens is very rare in the mid palatal region. It seems that due to the erupting force of the central incisor the tooth might have shifted to the mid-palatal region. Second, the presence of two supernumerary teeth delaying the eruption of upper permanent central incisors.
Although the abundant information is available on normal tooth development, the genetic etiology and molecular mechanisms that lead to congenital deviations in tooth number have not been clearly understood. The literature reports three theories concerning the cause of mesiodentes, but this subject remains controversial. The first one was a phylogenetic relic of extinct ancestors who had three central incisors known as phylogenetic reversion (atavism).,, The second theory known as dichotomy suggests that the tooth bud is split to create two teeth, one of which is the mesiodens., The third theory involving hyperactivity of dental lamina which was the most widely supported., Although no investigation proved the hereditary condition of mesiodens, genetics are also thought to contribute to its development, as such occurrence has been diagnosed in twins, siblings, and sequential generations of a single family., Sedano and Gorlin proposed a genetic theory in which mesiodens is an autosomal dominant trait with the lack of penetrance in some generations. It has been suggested that the environmental factors might have an influence on genetic susceptibility which could probably be a cause for negative family history in our case. A sex-linked pattern has also been proposed, as males are affected twice as frequently as females. Mesiodens is frequently associated with several craniofacial disturbances, including cleft lip and palate, and cleidocranial dysostosis; and to a lesser extent with Gardner's syndrome or chondroectodermal dysplasia.
However, various complications might occur as a result of the presence of supernumerary teeth. A retrospective analysis showed 10% of cases with supernumerary teeth cases exhibited midline diastema. In addition, the supernumerary tooth is the common reason for the delayed or failure of eruption of permanent teeth in the premaxillary region., It can cause also crowding, displacement, and rotation of the adjacent teeth (28–60%)., Furthermore, they may lead to dilaceration or root resorption in permanent teeth., Secondary alveolar bone grafting may be compromised due to the supernumerary teeth in patients with cleft lip and palate., Moreover, the presence of supernumeraries in a potential implant site may compromise implant placement., Occasionally, dentigerous cyst formation may occur (11% of the cases in an 11-year retrospective study of Asaumi et al.) or the extra tooth might erupt into the nasal cavity., In our case, the presence of supernumerary teeth had caused the failure of eruption of maxillary central incisors.
For preoperative examination, intraoral and panoramic radiography has been used. However, alone, they are insufficient for determining the exact location of supernumerary and impacted teeth, due to the image superimposition. In the present case, CBCT provided valuable information that helped us to determine the morphology and the exact 3D position of the mesiodens, supernumerary tooth, and the permanent maxillary impacted right central incisor. In fact, standard radiographs (periapical radiograph and orthopantomograph) could not provide information about the 3D relationship of these supernumeraries to the associated teeth and neighboring structures, which is important in making decisions about treatment options. In the past decade, detailed information has been obtained by CT which can provide highly detailed 3D information either directly or with the aid of dental software, avoiding superposition of bony and dental structures. However, the disadvantages of its relatively high cost and high radiation dose outweigh these advantages in the context of impacted and supernumerary teeth. Furthermore, CBCT provides a picture of supernumeraries in 3 planes and in relation to neighboring structures at a significantly lower radiation dose when compared with traditional spiral CT., Therefore, we recommend that CBCT be used routinely for the treatment of supernumerary teeth, especially for those cases with multiple impaction, those with local malocclusions, or with high-situated supernumeraries. For those supernumeraries that should be removed, the comprehensive pictures in 3 planes provided by CBCT can assist surgeons in choosing the appropriate surgical approach, identifying the tooth that should be extracted, and reducing the amount of surgical trauma on the adjacent hard and soft tissues.,
For the treatment, it depends on the type and location of the supernumerary teeth and on its potential effect on the adjacent hard and soft tissue structures. The management of a supernumerary tooth should form part of a comprehensive treatment plan and should not be considered in isolation. The timing of surgical removal of supernumerary teeth is contentious and two alternatives exist. First, to remove the supernumerary tooth as soon as it has been diagnosed and the second to leave the supernumerary tooth as such till the root development of adjacent teeth is complete in order to prevent damage to their root apices. If teeth are causing no complications and are not likely to interfere with orthodontic tooth movement, they can be monitored with the yearly radiographic review. The patient should be warned of complications, such as cystic change and migration with damage to nearby roots. If the patient does not wish to risk such complications, it is acceptable to remove supernumerary teeth. However, If supernumerary teeth are associated with complications, it is usual to extract such teeth, which usually involves a surgical procedure. Early extraction of supernumeraries, causing incisor impaction, may have the benefit of minimizing loss of eruptive potential, space loss, and centerline displacement. Rotberg recommended the removal of the supernumerary tooth as soon as it has been discovered and ideally before the age of 5 years so that root formation of the associated permanent incisors is incomplete. However, Koch stated that no immediate removal of supernumerary teeth is necessary if no pathology is present, no orthodontic treatment involving the region of supernumerary tooth is planned, and the child is seen regularly by a dentist: “Wait and see” behavior. Omer et al. reported based on a retrospective analysis the ideal age of removal of a supernumerary tooth is 6–7 years., Hogstrom and Andersson suggested two different opinions where the supernumerary tooth should be removed as early as upon identification or should wait until complete root formation of adjacent teeth. However, the potential disadvantages associated with this deferred surgical plan include loss of eruptive force of adjacent teeth, loss of space and crowding of the affected arch, and possible midline shifts. In the present case, surgical extraction of supernumerary teeth and mesiodens was made as soon as it was diagnosed, without any damage to adjacent teeth.
The majority of delayed permanent incisors erupt spontaneously if sufficient space is created at the time of removal of the supernumerary tooth and maintenance of postoperative space is needed. However, if there was not space for delayed tooth, we have to re-establish it by orthodontic treatment. A spontaneous eruption of the impacted permanent maxillary central incisor following supernumerary removal is suggested to be in the range of 54–75% and within 16–18 months of the removal of the supernumerary tooth., Smailiene et al. have suggested that spontaneous eruption of impacted maxillary incisor has an advantage over its surgical-orthodontic treatment., A recent study revealed that if the supernumerary tooth was of conical form then the associated permanent incisor was almost twice as likely to erupt spontaneously as when the supernumerary was of the tuberculate form. A retrospective analysis of factors influencing the eruption of delayed permanent incisors after supernumerary tooth removal revealed that spontaneous eruption occurred in 89.4% of delayed permanent teeth. The mean time to eruption was 9.2 months (median = 7 months). However, there was no statistically significant association between tooth eruption and root maturity or the degree of vertical impaction. there was an association between eruption and the degree of the angle of impaction of the permanent incisor. Research data indicate that the spontaneous eruption of impacted maxillary incisor may take up to 3 years and sometimes orthodontic treatment is necessary to achieve adequate alignment of the erupted tooth in the dental arch. In the present case since the root was not completely formed it was desirable to wait for a spontaneous eruption.
Because children are more prone to vagal stimulation, bradycardia should be a consideration when palatal flaps are reflected for procedures such as removal of a mesiodens. It is caused by the stimulation of the trigeminovagal reflex: The afferent impulses are caused by the stimulation of the nasoplatine nerve and the efferent pathway is the vagus nerve. Therefore, the infiltration with local anesthesia of the nasopalatine nerve should block the response. Thus, bradycardia thought to be attributed to the trigeminovagal reflex. Management includes halting the procedure until normal sinus rhythm returns and administration of atropine and/or glycopyrrolate.
| Conclusion|| |
Supernumerary teeth are extra to normal complement in both dentitions. Males are predominantly affected by supernumeraries which are common in permanent dentition. Supernumerary teeth may occur unilaterally or bilaterally, single or multiple, and at any region of the dental arch. Mesiodentes are a common type of supernumerary teeth. A variety of complications was associated with their presence which range from crowding to cyst formation. CBCT yielded accurate 3D information relative to the orientation, sagittal position, local disorders, and neighboring anatomic structures. All these were of great significance for pretreatment evaluation of supernumeraries. Therefore, we suggest routine use of CBCT in cases of supernumeraries to choose the accurate diagnosis and management.
Source of Support:
Conflict of Interest:
| References|| |
Vecchione Gurgel C, Soares Cota AL, Yuriko Kobayashi T, Moura Bonifácio Silva S, Aparecida Andrade Moreira Machado M, Rios D, et al.
Bilateral mesiodens in monozygotic twins: 3D diagnostic and management. Case Rep Dent 2013;2013:193614.
Liu JF. Characteristics of premaxillary supernumerary teeth: A survey of 112 cases. ASDC J Dent Child 1995;62:262-5.
Proff P, Fanghänel J, Allegrini S Jr, Bayerlein T, Gedrange T. Problems of supernumerary teeth, hyperdontia or dentes supernumerarii. Ann Anat 2006;188:163-9.
Shah A, Gill DS, Tredwin C, Naini FB. Diagnosis and management of supernumerary teeth. Dent Update 2008;35:510-2, 514-6, 519-20.
Rajab LD, Hamdan MA. Supernumerary teeth: Review of the literature and a survey of 152 cases. Int J Paediatr Dent 2002;12:244-54.
Sulabha AN, Sameer C. Association of mesiodentes and dens invaginatus in a child: A rare entity. Case Rep Dent 2012;2012:198032.
Canoglu E, Er N, Cehreli ZC. Double inverted mesiodentes: Report of an unusual case. Eur J Dent 2009;3:219-23.
Mallineni SK. Supernumerary teeth: Review of the literature with recent updates. Conf Pap Sci 2014;2014:6.
Kim KD, Ruprecht A, Jeon KJ, Park CS. Personal computer-based three-dimensional computed tomographic images of the teeth for evaluating supernumerary or ectopically impacted teeth. Angle Orthod 2003;73:614-21.
Indira M, Dhull KS, R S, Kumar Ps P, Devi Bm G. Molariform mesiodens in primary dentition: A case report. J Clin Diagn Res 2014;8:ZD33-5.
Meighani G, Pakdaman A. Diagnosis and management of supernumerary (mesiodens): A review of the literature. J Dent (Tehran) 2010;7:41-9.
Van Buggenhout G, Bailleul-Forestier I. Mesiodens. Eur J Med Genet 2008;51:178-81.
Kazanci F, Celikoglu M, Miloglu O, Yildirim H, Ceylan I. The frequency and characteristics of mesiodens in a Turkish patient population. Eur J Dent 2011;5:361-5.
Nagaveni N, Shashikiran N, Reddy VS. Surgical management of palatal placed, inverted, dilacerated and impacted mesiodens. Int J Clin Pediatr Dent 2009;2:30-2.
Gharote HP, Nair PP, Thomas S, Prasad GR, Singh S. Nonsyndromic double mesiodentes – Hidden lambs among normal flock! BMJ Case Rep 2011;2011. pii: Bcr0720114420.
Yagüe-García J, Berini-Aytés L, Gay-Escoda C. Multiple supernumerary teeth not associated with complex syndromes: A retrospective study. Med Oral Patol Oral Cir Bucal 2009;14:E331-6.
Brook AH. A unifying aetiological explanation for anomalies of human tooth number and size. Arch Oral Biol 1984;29:373-8.
Sedano HO, Gorlin RJ. Familial occurrence of mesiodens. Oral Surg Oral Med Oral Pathol 1969;27:360-1.
Garvey MT, Barry HJ, Blake M. Supernumerary teeth – An overview of classification, diagnosis and management. J Can Dent Assoc 1999;65:612-6.
Liu DG, Zhang WL, Zhang ZY, Wu YT, Ma XC. Three-dimensional evaluations of supernumerary teeth using cone-beam computed tomography for 487 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;103:403-11.
Ludlow JB, Davies-Ludlow LE, Brooks SL. Dosimetry of two extraoral direct digital imaging devices: NewTom cone beam CT and Orthophos Plus DS panoramic unit. Dentomaxillofac Radiol 2003;32:229-34.
Rallan M, Rallan NS, Goswami M, Rawat K. Surgical management of multiple supernumerary teeth and an impacted maxillary permanent central incisor. BMJ Case Rep 2013;2013. pii: Bcr2013009995.
Patchett CL, Crawford PJ, Cameron AC, Stephens CD. The management of supernumerary teeth in childhood – A retrospective study of practice in Bristol Dental Hospital, England and Westmead Dental Hospital, Sydney, Australia. Int J Paediatr Dent 2001;11:259-65.
Omer RS, Anthonappa RP, King NM. Determination of the optimum time for surgical removal of unerupted anterior supernumerary teeth. Pediatr Dent 2010;32:14-20.
Kumar A, Namdev R, Bakshi L, Dutta S. Supernumerary teeth: Report of four unusual cases. Contemp Clin Dent 2012;3 Suppl 1:S71-7.
Smailiene D, Sidlauskas A, Bucinskiene J. Impaction of the central maxillary incisor associated with supernumerary teeth: Initial position and spontaneous eruption timing. Stomatologija 2006;8:103-7.
Bryan RA, Cole BO, Welbury RR. Retrospective analysis of factors influencing the eruption of delayed permanent incisors after supernumerary tooth removal. Eur J Paediatr Dent 2005;6:84-9.
Webb MD, Unkel JH. Anesthetic management of the trigeminocardiac reflex during mesiodens removal – A case report. Anesth Prog 2007;54:7-8.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]