The management of supernumerary teeth in childhood--a retrospective study of practice in Bristol Dental Hospital, England and Westmead Dental Hospital, Sydney, Australia

Interventions to facilitate the successful eruption of impacted maxillary incisor teeth due to the presence of a supernumerary: A systematic review and meta-analysis

INTRODUCTION

A failure of maxillary incisor eruption is commonly attributed to the presence of a supernumerary tooth. This systematic review aimed to assess the percentage of impacted maxillary incisors that successfully erupt after surgical removal of supernumerary teeth with or without other interventions.

METHODS

Systematic literature searches without restrictions were undertaken in 8 databases for studies reporting any intervention aimed at facilitating incisor eruption, including surgical removal of the supernumerary alone or in conjunction with additional interventions published up to September 2022. After duplicate study selection, data extraction, and risk of bias assessment according to the risk of bias in nonrandomized studies of interventions and Newcastle-Ottawa scale, random-effects meta-analyses of aggregate data were conducted.

RESULTS

Fifteen studies (14 retrospective and 1 prospective) were included with 1058 participants (68.9% male; mean age, 9.1 years). The pooled eruption prevalence for removal of the supernumerary tooth with space creation or removal of the supernumerary tooth with orthodontic traction was significantly higher at 82.4% (95% confidence interval [CI], 65.5-93.2) and 96.9% (95% CI, 83.8-99.9) respectively, compared with removal of an associated supernumerary only (57.6%; 95% CI, 47.8-67.0). The odds of successful eruption of an impacted maxillary incisor after removal of a supernumerary were more favorable if the obstruction was removed in the deciduous dentition (odds ratio [OR], 0.42; 95% CI, 0.20-0.90; P = 0.02); if the supernumeraries were conical (OR, 2.91; 95% CI, 1.98-4.28; P <0.001); if the incisor was in the correct position (OR, 2.19; 95% CI, 1.14-4.20; P = 0.02), at the level of the gingival third (OR 0.07; 95% CI, <0.01-0.97; P = 0.04) and had incomplete root formation (OR, 9.02; 95% CI, 2.04-39.78; P = 0.004). Delaying removal of the supernumerary tooth 12 months after the expected eruption time of the maxillary incisor (OR, 0.33; 95% CI, 0.10-1.03; P = 0.05) and waiting >6 months for spontaneous eruption after removal of the obstacle (OR, 0.13; 95% CI, 0.03-0.50; P = 0.003) was associated with worse odds for eruption.

CONCLUSIONS

Limited evidence indicated that the adjunctive use of orthodontic measures and removal of supernumerary teeth might be associated with greater odds of successfull impacted incisor eruption than removal of the supernumerary tooth alone. Certain characteristics related to supernumerary type and the position or developmental stage of the incisor may also influence successful eruption after removal of the supernumerary. However, these findings should be viewed with caution as our certainty is very low to low because of bias and heterogeneity. Further well-conducted and reported studies are required. The results of this systematic review have been used to inform and justify the iMAC Trial.

Study protocol for the management of impacted maxillary central incisors: a multicentre randomised clinical trial: the iMAC Trial

Background

Failure of eruption of the maxillary permanent incisor teeth usually presents in the mixed dentition between the ages of 7 and 9 years. Missing and unerupted maxillary incisors can be regarded as unattractive and have a potentially negative impact on facial and dental aesthetics. The presence of a supernumerary tooth (or odontoma) is commonly responsible for failed eruption or impaction of the permanent maxillary incisors. The primary objective of this trial is to investigate the success of eruption associated with maxillary incisor teeth that have failed to erupt because of a supernumerary tooth in the anterior maxilla.

Methods

This protocol describes an interventional multicentre two-arm randomised clinical trial. Participants meeting the eligibility criteria will be randomised (unrestricted equal participant allocation [1:1]) to either space creation with an orthodontic appliance, removal of the supernumerary tooth and application of direct orthodontic traction or space creation with an orthodontic appliance, removal of the supernumerary tooth and monitoring. The primary outcome of this trial is to determine the prevalence of successfully erupted maxillary central permanent incisors at 6 months following removal of the supernumerary tooth. Secondary outcome measures include (1) the effect of initial tooth position (assessed radiographically) on time taken for the tooth to erupt, (2) time taken to align the unerupted tooth to the correct occlusal position, (3) gingival aesthetics and (4) changes in the self-reported Oral Health Related-Quality of Life (OHRQoL) (pre-and post-treatment).

Discussion

There is a lack of high-quality robust prospective studies comparing the effectiveness of interventions to manage this condition. Furthermore, the UK national clinical guidelines have highlighted a lack of definitive treatment protocols for the management of children who present with an unerupted maxillary incisor due to the presence of a supernumerary tooth. The results of this trial will inform future treatment guidelines for the management of this condition in young children.

Trial registration

ISRCTN Registry ISRCTN12709966. Registered on 16 June 2022.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06711-0.

Oncostatin M enhances osteogenic differentiation of dental pulp stem cells derived from supernumerary teeth

Supernumerary tooth (ST) may arise from uncertain developmental abnormalities or underlying genetic causes, and the extraction at the early age is recommended. Dental pulp stem cells (DPSCs) are the valuable resource for the regeneration of tooth and related craniofacial structures. DPSCs isolated from ST (sDPSCs) have not been fully characterized despite the potential in the applications. The objectives of this study are the efficient isolation of sDPSCs and the analysis of the properties as stem cells. sDPSCs were established by hammer-cracking and separation of the intact pulp from ST. sDPSCs in the culture were examined by light microscope and flow cytometer for the morphology and the surface marker expression. sDPSCs exhibited the cellular morphology of typical mesenchymal stem cells and expressed CD44, CD73, CD90, CD105 and CD166, but not CD14, CD34 or CD45. sDPSCs showed the differentiation potential toward osteogenic, chondrogenic and adipogenic lineages. During osteogenic differentiation, the stimulation by Oncostatin M enhanced the differentiation and significantly increased the expression of genes involved in the hard tissue repair, such as BMP2, BMP4, BMP6 and RUNX2. sDPSCs can be effectively derived from ST and displays the characteristics of mesenchymal stem cells in the maintenance and the differentiation. sDPSCs satisfies the quality as DPSCs thus provide the valuable resource to the regenerative therapy.

Spontaneous eruption of impacted maxillary incisors after surgical extraction of supernumerary teeth: a systematic review and meta-analysis

OBJECTIVES

To evaluate the spontaneous eruption potential of impacted human permanent teeth localized in the anterior part of the maxilla, after the surgical extraction of obstacles in their eruption pathway, by means of a systematic review and meta-analysis.

MATERIALS AND METHODS

A systematic literature search was carried out to locate studies reporting on the percentage of anterior permanent teeth erupting after surgical removal of the obstacle, without other interventions. Eruption potential of impacted teeth was calculated using a random-effects meta-analysis. Information about the sex proportion, follow-up duration, age and years during which the study was carried out was used for subgroup analyses.

RESULTS

A total of twelve studies were included, with a total sample size of 960 cases and a follow-up period of up to 36 months. The results show that more than 65.5% of impacted teeth erupt spontaneously following surgical extraction of the obstacle, with an odds ratio of 4 (95% CI 1.9, 8.2) (p < 0.001) favouring spontaneous eruption.

CONCLUSIONS

When faced with an impacted maxillary anterior tooth, surgical extraction of the obstacle can lead to spontaneous eruption of the impacted tooth in the majority of cases, with better success with a longer follow-up for up to 3 years.

CLINICAL RELEVANCE

Based on the present meta-analysis, clinical recommendation would be to surgically remove the obstacle impeding the eruption of a maxillary anterior permanent tooth and wait for the eruption of the tooth for a period of 12-36 months, depending on the age of the patient.

Complications associated with specific characteristics of supernumerary teeth

OBJECTIVES

The purpose of this study was to identify the characteristics of supernumerary teeth, analyze the associated complications, and to present new clinical knowledge on surgical interventions for supernumerary teeth.

STUDY DESIGN

This retrospective cohort study was based on the medical records and radiographic records of patients who underwent surgical extraction of supernumerary teeth. The relationships among the patient's age, gender, anatomic features of supernumerary teeth, and presence and type of complications (i.e., spacing, rotation, delayed eruption of the adjacent tooth, cyst formation.) were investigated. The groups were compared by using the Mann-Whitney U test, the Kolmogorov-Smirnov test, and multiple logistic regression analysis (P < .05).

RESULTS

The study population consisted of 705 participants who underwent extraction for 1036 supernumerary teeth. The mean age of the participants was 11.5 years, and 73.5% of the participants were males. The complication rate was 55.6%. Variables associated with an increased risk of complications were the patient's age, dentition, tuberculate shape, and horizontal direction of eruption (P < .05).

CONCLUSIONS

An increase in the patient's age or abnormalities in the shape and direction of eruption of supernumerary teeth was associated with complications. These parameters should be considered while formulating the treatment plan.

Rotated mesiodens in children. An immediate surgical removal or active monitoring?

Rotated mesiodentes impaction is a rare variant of dental anatomy which may cause a cluster of symptoms damaging nearby structures. Although some recommend a delayed approach, after the end of teeth development, it seems that an immediate surgical removal would be of great benefit for the patients involved.

National clinical guidelines for the management of unerupted maxillary incisors in children

This article summarises recently updated guidelines produced by the Clinical Governance Directorate of the British Orthodontic Society through the Clinical Standards Committee of the Faculty of Dental Surgery, Royal College of Surgeons of England (FDSRCS) on the management of unerupted maxillary incisor teeth in children. The maxillary incisor teeth usually erupt in the early mixed dentition but eruption disturbances can occur and are often attributable to local factors. A failure of eruption will affect the developing occlusion and potentially influence psychological development of the child. The general principles of management for delayed eruption or impaction of these teeth is to ensure that adequate space exists in the dental arch and to remove any obstruction to eruption. Consideration should also be given to further promoting eruption through surgical exposure of the incisor, with or without subsequent orthodontic traction. A number of factors influence the decision-making process, including patient age, medical history, potential compliance, aetiology and position of the unerupted incisor. Treatment planning should be complemented by careful clinical assessment and the use of appropriate special investigations. To optimise the treatment outcome a multidisciplinary specialist approach is recommended.

Fourth molar: A retrospective study and literature review of a rare clinical entity

Purpose

The prevalence of supernumerary teeth has been reported to be between 0.1% and 3.8%. The aim of this study was to determine the prevalence, clinical significance, and associated pathologies of fourth molars based on a retrospective study and a literature review.

Materials and Methods

A 5-year retrospective prevalence study was conducted at the Department of Oral Diagnosis and Dentomaxillofacial Radiology of Okayama University Hospital, Okayama, Japan. The study involved extracting data from the digital records of patients from January 1, 2013 through December 31, 2017. The sampling frame included all patients who had panoramic radiographs, cone-beam computed tomography (CT), and multislice CT images during the period under review.

Results

A total of 26,721 cases were reviewed and 87 fourth molars were identified. The prevalence of fourth molars in the 5-year study at Okayama was calculated as 0.32%. The mean age of patients with a fourth molar was 30.43 years, and the male-to-female ratio was 1:0.98. The vast majority of cases were in the maxilla (92%) and had normal shapes (89.7%); furthermore, 82.8% of cases were unerupted.

Conclusion

The prevalence of fourth molars in the study population was found to be 0.32%, and fourth molars occurred with approximately equal frequency in males and females. Fourth molars were more common in the maxilla and were predominantly unerupted and small.

Investigation of impacted supernumerary teeth: a cone beam computed tomograph (cbct) study

Purpose:

The purpose of this study was to investigate the impacted supernumerary teeth which were initially detected on panoramic radiographs by using cone beam computed tomography (CBCT).

Materials and Methods:

In this retrospective study, supernumerary teeth diagnosed on panoramic radiographs taken from patients who had admitted for routine dental treatment were evaluated using CBCT. Patients’ age, gender, systemic conditions as well as number of supernumerary teeth, unilateral-bilateral presence, anatomical localization (maxilla, mandible, anterior-premolar-molar, mesiodens-lateral-canine, parapremolar-paramolar-distomolar) shape (rudimentary, supplemental, tuberculate, odontoma), position (palatal-lingual-buccal-labial-central), shortest distance between the tooth and adjacent cortical plate, complications and treatment were assessed.

Results:

A total of 47 impacted supernumerary teeth in 34 patients were investigated in this study. Of these, 33 (70.2%) were unilateral and 14 (29.8%) were bilateral. Only 1 supernumerary tooth was found in 27 patients (79.4%) whereas 7 patients (20.6%) had 2 or more supernumerary teeth. Most of the teeth located in the anterior region (74.4%) of the jaws and maxilla (74.4%). Twenty teeth (42.5%) were mesiodens, 11 (23.4%) were lateral or canine, 14 (29.7%) were parapremolar and 2(4.4%) were distomolar. Twenty-seven teeth (57.4%) were rudimentary, 15 (31.9%) were supplemental and 5 (10.7%) were odontoma in shape. The shortest distance between the supernumerary tooth and adjacent cortical plate varied between 0 to 2.5 mm with a mean of 0.66 mm. The most common clinical complaint was the non-eruption of permanent teeth (42.5%). All supernumerary teeth were removed under local anesthesia. Orthodontic traction was performed for those impacted permanent teeth if necessary.

Conclusion:

Impacted supernumerary teeth are usually in close proximity to cortical bone. Although this may facilitate surgical access, there is a risk of damaging surrounding anatomical structures. Therefore, CBCT evaluation of impacted supernumerary teeth for accurate planning is recommended.

The effects of impacted premaxillary supernumerary teeth on permanent incisors

Purpose

The aim of this study was to examine the radiographic features associated with impacted premaxillary supernumerary teeth, to determine the relationship between their characteristics and their effects on permanent incisors, and to investigate the types of orthodontic treatment that patients received after the extraction of impacted supernumerary teeth.

Materials and Methods

The clinical records and radiographs of 193 patients whose impacted premaxillary supernumerary teeth were removed were retrospectively reviewed, and 241 impacted supernumerary teeth were examined. Cone-beam computed tomographic images and panoramic radiographs were examined to determine the number, location, sagittal position, orientation, and morphology of the supernumerary teeth. Their effects on permanent incisors and the orthodontic treatment received by patients after the extraction of the supernumeraries were also investigated.

Results

Supernumerary teeth were most frequently observed in the central incisor region, in the palatal position, in the inverted orientation, and were most commonly conical in shape. The most common complication was median diastema, followed by displacement and delayed eruption of the adjacent incisors. Ten (71.4%) of the 14 odontomas showed delayed eruption of the adjacent incisors. Displacement of the incisors was more frequently observed in association with supernumerary teeth with tuberculate or supplemental shapes. Orthodontic traction was most frequently performed after the removal of odontomas. In 32 cases (13.3%), permanent incisors erupted after the orthodontic creation of sufficient space.

Conclusion

Median diastema was most common complication. The delayed eruption of incisors was common in supernumerary teeth with a vertical orientation and an odontoma shape.

Characteristics and sequelae of erupted supernumerary teeth: A study of 218 cases among Sri Lankan children

AIM

In the present study, we investigated the characteristics and sequelae of erupted supernumerary teeth (ST) in a sample of Sri Lankan children.

METHODS

Data were recorded from patients' clinical records, radiographs, models, and extracted teeth.

RESULTS

The sample consisted of 239 ST from 218 patients. The mean age of the sample was 9.08 ± 2.47 years. The male-to-female ratio was 2.8:1. The majority (42.66%) of patients with ST were in aged 8-10 years. Many (94.94%) of the ST were located in the premaxilla (incisor), followed by the canine (4.22%), premolar (0.42%), and molar (0.42%) regions. The most common shape of ST teeth was conical. Malocclusion (59.83%) was the major problem associated with ST, and the clinical impact was highest on the 8-10-year age group. A strong association was observed between patients' age and clinical impact to the dentition (χ² =42.09, P=.000).

CONCLUSION

Because the majority of ST can lead to malocclusion, especially in mixed dentition, awareness, early detection, and timely clinical intervention of ST are recommended.

Cone-beam computed tomography exploration and surgical management of palatal, inverted, and impacted mesiodens

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.

Εvaluation of a treatment protocol for unerupted maxillary central incisors: retrospective clinical study of 46 children

AIM

To evaluate the clinical outcome of a treatment protocol performed in children with unerupted permanent maxillary central incisors, including surgical removal of any related obstruction and traction initiation in one stage, under fully repositioned flap, combined with pre- and post-operative orthodontics for space creation and final alignment.

METHODS

Forty-six patients aged 7.3-12.7 years (mean = 9.44 ± 1.36) having 54 impacted maxillary central incisors were reviewed. The study group included 37 patients fully treated by us and nine referrals with eruption failure of impacted incisors following previous surgical removal of various obstructions. Detailed patient's clinical and radiographic data were recorded.

RESULTS

Aetiology of unerupted incisors included 9 patients with odontomas, 24 with supernumerary teeth, 1 with skeletal lack of space, 1 with a dentigerous cyst, 4 with dilaceration, 1 with severe incisor MIH, 5 with luxation injuries to primary predecessors and 1 with coexisting dilaceration and odontoma. The total treatment time following the standardised protocol ranged from 5 to 21 months (mean 9.88 ± 3.10), while the time needed using different approaches (no pre-operative orthodontics or obstruction removal and then to wait over an assessment period) ranged from 12 to 18 months (mean 15 ± 2.12) and 17 to 30 months (mean 23.73 ± 5.14), respectively (p < 0.05). The time needed for full alignment depended on the inclination, the height of the impacted tooth (p = 0.001) and the patient's age (p = 0.002). Additionally, the absence of pre-operative orthodontics for space creation dramatically increased treatment time (p = 0.018). In contrast, the maturity of the impacted tooth and the developmental stage of the anterior teeth did not affect treatment time. Finally, when the location of the impacted tooth and the space availability allowed waiting for spontaneous eruption, treatment time was not statistically different from that of the main treatment protocol (p = 0.545).

CONCLUSIONS

The studied treatment protocol appears ideal for successful results and minimum treatment time. Space creation followed by surgical removal of any obstruction together with orthodontic traction initiation produces excellent results, while waiting for spontaneous eruption is indicated only in cases of favourable patient's age and tooth location. Treatment initiation with operation in the absence of the required eruption space is not recommended, whereas in unfavourable cases obstruction removal without simultaneous orthodontic traction increases dramatically the total treatment time and requires an unnecessary second operation for traction.

Prevalence, etiology, diagnosis, treatment and complications of supernumerary teeth

The aim of this article was to review the literature on supernumerary teeth, analyzing their prevalence, etiology, diagnosis, treatment and possible complications. An electronic search was made in the Pubmed-Medline database up to January 2014 using the key search terms “multiple supernumerary teeth” (n=279), “prevalence supernumerary teeth” (n=361), and “supernumerary teeth” (n=2412). In addition to the articles initially identified, others were included in the review proceeding from a manual search and from any references considered of relevance. Supernumerary teeth are those that exceed the normal dental formula. They are more common in men, more common in the upper maxilla, and more prevalent in permanent dentition. Complications associated with supernumerary teeth include dental impaction, delayed eruption, ectopic eruption, overcrowding, spacing anomalies and the formation of follicular cysts. The treatment of supernumerary teeth depends on their type, position, and possible complications, detected clinically and radiographically. No clear consensus exists as to the best time to extract unerupted supernumerary teeth.

Key words:Hyperdoncia, supernumerary teeth, impacted teeth, treatment, permanent teeth, deciduous teeth.

Prevalence and characteristics of non-syndromic distomolars: a retrospective study

AIM

Distomolars are defined as the supernumerary teeth that erupt distal to the third molar. The aim of the present study was to evaluate the prevalence of distomolars in permanent dentition in a non-syndromic Turkish subpopulation.

METHODS

A total of 10 111 panoramic radiographs of patients aged 18 years and over, who had no systemic diseases and syndromes, and who had not undergone any extractions in the third molar area, were examined to determine the presence, location, shape, and laterality of distomolars. The patients' age and sex were noted.

RESULTS

The results showed that distomolars were observed in 0.26% of the investigated population. Distomolars were seen in 0.29% of male patients and in 0.23% of female patients. In total, 30 distomolars were observed in 26 patients. Maxillary distomolars were more frequently encountered than mandibular teeth. Bilateral distomolars were found in three male patients. Of the 30 distomolars, 25 were impacted and five were erupted.

CONCLUSIONS

Although the frequency of distomolars is low, early diagnosis and treatment are important to minimize or prevent complications, such as delayed eruption, tooth displacement, crowding, root resorption of the adjacent tooth, and cystic formations.

Clinical recommendations for management of mesiodens and unerupted permanent maxillary central incisors

BACKGROUND

Un-erupted maxillary incisors may result secondary to supernumerary teeth. Despite the removal of such mesiodentes, orthodontic traction of a permanent un-erupted maxillary incisor may be required.

REVIEW

The literature regarding the impacted maxillary central incisor(s) was reviewed and all pertinent publications on the subject assessed. The review specifically relative to mesiodentes, surgical exposure and orthodontic management was interpreted together with the clinical experience of a number of the authors' cases. From this analysis a set of recommendations was developed.

RECOMMENDATIONS

(1) A sufficient arch space has to be ensured or orthodontically created for permanent maxillary central incisor(s). (2) Early surgical extraction of a mesiodens or mesiodentes (ideally before 7 years of age), with simultaneous closed surgical exposure of the permanent impacted maxillary incisor with bonding of an attachment with gold chain. (3) Re-evaluation after 2-3 months to assess for any natural eruption of the maxillary central incisor. (4) Application of orthodontic traction in the event of non-eruption.

CONCLUSION

Early diagnosis of the presence of mesiodentes is imperative. Appropriate surgical and/or orthodontic traction is often indicated with regular post-surgical follow-up assessments.

Characterization of mesenchymal progenitor cells in crown and root pulp from human mesiodentes

OBJECTIVE

Mesiodentes are usually found in the central position of the upper or lower jaw as supernumerary teeth. Here, we obtained 10 mesiodentes and three permanent teeth (PT) and separated the dental pulp (DP) from these into crown and root portions. We then characterized and compared the isolated crown portion-derived cells (crown cells) with root portion-derived cells (root cells) using a range of in vitro assays.

MATERIALS AND METHODS

Crown cells and root cells were examined for cell surface marker expression, colony-forming unit-fibroblast (CFU-F), cell proliferation, cell cycle characteristics and markers, and osteogenic and adipogenic differentiation.

RESULTS

The proportion of CD105-positive cells (CD105(+) cells) in the crown cells vs the root cells varied among the mesiodentes, but not among the PT. When there were more CD105(+) cells in the root cells than in the crown cells, the root cells showed higher CFU-F, proliferation capacity, and osteogenic differentiation capacity. In contrast, when the crown cells contained more CD105(+) cells than the root cells, the crown cells showed the higher CFU-F, proliferation capacity, and osteogenic differentiation capacity. In addition, the sorted CD105(+) cells showed higher CFU-F and proliferation capacity than the sorted CD105(-) cells.

CONCLUSION

These results indicated that proportion of CD105(+) cells is an effective means of characterizing DP-derived cells in mesiodentes.

Supernumerary lateral incisor

Supernumerary teeth are common in general population and occur frequently in patients with familial trait. However, it is rare to find supernumeraries in individuals with no associated disease or syndrome. Supernumerary teeth are found in any region of maxilla and mandible, with a predisposition for anterior maxilla. A case of endodontically involved supernumerary lateral incisor is described.

Molecular genetics of supernumerary tooth formation

Despite advances in the knowledge of tooth morphogenesis and differentiation, relatively little is known about the aetiology and molecular mechanisms underlying supernumerary tooth formation. A small number of supernumerary teeth may be a common developmental dental anomaly, while multiple supernumerary teeth usually have a genetic component and they are sometimes thought to represent a partial third dentition in humans. Mice, which are commonly used for studying tooth development, only exhibit one dentition, with very few mouse models exhibiting supernumerary teeth similar to those in humans. Inactivation of Apc or forced activation of Wnt/β(catenin signalling results in multiple supernumerary tooth formation in both humans and in mice, but the key genes in these pathways are not very clear. Analysis of other model systems with continuous tooth replacement or secondary tooth formation, such as fish, snake, lizard, and ferret, is providing insights into the molecular and cellular mechanisms underlying succesional tooth development, and will assist in the studies on supernumerary tooth formation in humans. This information, together with the advances in stem cell biology and tissue engineering, will pave ways for the tooth regeneration and tooth bioengineering.

Supernumerary teeth in a Turkish population

INTRODUCTION

Our aim in this study was to investigate the frequency, distribution, sex differences, and characteristics of supernumerary teeth in a referred Turkish population.

METHODS

A total of 2599 patients' panoramic radiographs (1360 girls, 1239 boys) were evaluated, including children in both the mixed and the permanent dentitions. Their mean age was 8.6 +/- 0.23 years. Number, location, classification, side, and impaction of supernumerary teeth were evaluated. Furthermore, the development of these teeth was evaluated.

RESULTS

Eighty-four supernumerary teeth were found on 69 radiographs; 9 were deciduous and 75 were permanent teeth. Most supernumerary teeth were in the premaxillary region (67%). Mesiodens (n = 43) was the most frequent supernumerary tooth (51.2%). This was followed by the maxillary lateral incisor (15.5%), the mandibular premolar (14.3%), the maxillary canine (9.5%), the maxillary premolar (6%), the mandibular lateral incisor (2.4%), and the mandibular canine (1.2%). Sixty-two (73.8%) supernumerary teeth were impacted. The male-female ratio was 1.13:1, which was not statistically significant.

CONCLUSIONS

The prevalence of supernumerary teeth in Turkish children was 2.7% in this study.

Postoperative prognosis of unerupted teeth after removal of supernumerary teeth or odontomas

INTRODUCTION

Impacted teeth do not always erupt spontaneously after removal of supernumerary teeth or odontomas. The purpose of this study was to examine the effect of several variables on eruption of impacted teeth in children with supernumeraries or odontomas.

METHODS

The sample consisted of 53 patients with 69 impacted teeth; the supernumeraries or odontomas were removed without other interventions. The patients were identified retrospectively and followed until the impacted teeth erupted to their correct positions or until orthodontic traction was started.

RESULTS

Loss of space, a second surgical procedure, a third surgical procedure, and orthodontic treatment were recorded in 77.6%, 53.8%, 9.4%, and 85% of the patients, respectively. Spontaneous eruption occurred in 83%, 75%, 46%, 19%, and 32% of the impacted teeth with normal and small size superlative, conical, tuberculated, and odontoma forms, respectively. In the univariate analysis, spontaneous eruption correlated with apex distance of the impacted tooth relative to its estimated position (P <.001), extent of vertical impaction (P <.001), obstacle form (P <.019), stage of root development of supernumerary tooth (P = .006), angle of impaction relative to the midline (P = .015), and time of surgery (P = .05). In the multivariate logistic regression analysis, higher distraction of the apex of the impacted tooth relative to its estimated correct position and the obstacle form (tuberculated and odontomas) were independently associated with impediment of spontaneous eruption (P = .03 and P = .04, respectively).

CONCLUSIONS

Spontaneous eruption of impacted teeth correlated mostly with lower distraction of the impacted tooth apex and obstacle form (conical and superlative). Immediate orthodontic traction is recommended concomitantly with the first surgery to remove supernumerary teeth.

A case of bilateral supplemental maxillary central incisors

A case of bilateral supplemental maxillary central incisors is presented. Treatment comprised of extraction of one supplemental and two lateral incisors, preservation of one supplemental incisor, finishing with a 'Cyclops' arrangement of the teeth. The handling of supernumerary teeth in general is discussed.