Odontomas and supernumerary teeth: is there a common origin?

Epidemiological and CBCT characterizations of odontomas: A retrospective study of 87,590 subjects

OBJECTIVES

This study aimed to assess the epidemiological and three-dimensional (3D) radiological characterizations of odontomas, as well as the spatial relationship between odontomas and gubernaculum tracts (GT).

MATERIALS AND METHODS

We retrieved the cone-beam computed tomography (CBCT) data of 87,590 patients. Dentition, location, type, diameter of the odontomas, width of the dental follicle (DF), the spatial relationship between the odontoma and GT, and the influence on adjacent teeth were evaluated.

RESULTS

Significant differences were found in age, dentition, location, Max/Min diameter, width of DF, impaction, retention, and root bending of adjacent teeth among different spatial relationships between the odontoma and GT (all p < 0.05), as well as in age, type and size, absence, impaction, malposition, and retention of adjacent teeth among different locations of odontomas (all p < 0.05). Compared to the odontomas without impaction, those with impaction had larger diameter (p < 0.05 in all directions). This statistically significant association was consistent for odontomas with malposition, while no similar result was observed in the maximum diameter.

CONCLUSION

Our findings provide the preliminary data for clinicians to comprehensively understand the incidence, radiographic characterizations and symptoms of odontoma in Chinese population.

Odontome and its pathological effect on surrounding teeth

Odontoma is the most common odontogenic tumour derived from both epithelial and mesenchymal components of the tooth-forming apparatus. It is commonly diagnosed in the second and third decades of life when a radiograph is taken for some other purpose, as most cases are asymptomatic. This case involves a young boy, with the chief complaint of pain and swelling in the lower left back region. An intraoral examination revealed a carious and hypoplastic left permanent mandibular first molar. Although the molar was suspected as the source of his symptoms, radiographic imaging revealed multiple odontomas and missing second and third molar tooth buds. This case highlights the pathological effects of odontomas on surrounding teeth, including the malformation of the first molar and aplasia of the second and third molars. The sole management depends on the early diagnosis, histopathological examination to rule out malignancy and conservative surgical excision of these tissues.

Criteria for Treatment of Intranasal Supernumerary Teeth: A Comprehensive Literature Analysis

Objectives: Among oral surgical conditions, supernumerary teeth of the dental arch is quite common. However, supernumerary teeth in the nasal cavity is a rarity and their diagnosis and treatment have not yet been systematized. We therefore examined the literature on intranasal supernumerary teeth to establish systematic methods for their diagnosis and treatment. Methods: Using the PubMed database, we searched for literature on intranasal supernumerary teeth, published from 1990 to 2019. We combined 131 cases identified in the literature with 1 case that we experienced and summarized the characteristics of 132 cases. We recorded data on sex, age, reason for consultation (chief complaint), reporting department, impact classification, surgical approach, and anesthesia. Results: Males outnumbered females in all decades evaluated. The median age of patients was 10 years. The characteristics of these cases resembled those of maxillary anterior supernumerary teeth. The most common reason for consultation in earlier years was nasal symptoms; however, over time, an increasing number of patients sought consultation due to indications in diagnostic imaging. The most common reporting department in all decades was Otolaryngology. However, reports from Departments of Oral Surgery became increasingly common over time. General anesthesia was applicable for all impaction positions and surgical methods used. Local anesthesia was performed only with the nasal method. Of the 132 patients, 4 experienced no effect from local anesthesia, which was then changed to general anesthesia. Intranasal supernumerary teeth were found to possess the same characteristics as impacted maxillary central supernumerary teeth. Conclusions: The increased use of computed tomography has enabled early detection in asymptomatic cases. Classifying intranasal supernumerary teeth by their vertical and horizontal impaction positions provides an accurate grasp of supernumerary tooth impact classification and the selection of suitable methods of surgery and anesthesia, thus enabling systematic diagnosis and treatment of intranasal supernumerary teeth.

Heterozygous Variants in FREM2 Are Associated with Mesiodens, Supernumerary Teeth, Oral Exostoses, and Odontomas

BACKGROUND

Supernumerary teeth refer to extra teeth that exceed the usual number of dentitions. A mesiodens is a particular form of supernumerary tooth, which is located in the premaxilla region. The objective of the study was to investigate the genetic etiology of extra tooth phenotypes, including mesiodens and isolated supernumerary teeth.

METHODS

Oral and radiographic examinations and whole-exome sequencing were performed on every patient in our cohort of 122 patients, including 27 patients with isolated supernumerary teeth and 94 patients with mesiodens. A patient who had multiple supernumerary teeth also had odontomas.

RESULTS

We identified a novel (c.8498A>G; p.Asn2833Ser) and six recurrent (c.1603C>T; p.Arg535Cys, c.5852G>A; p.Arg1951His, c.6949A>T; p.Thr2317Ser; c.1549G>A; p.Val517Met, c.1921A>G; p.Thr641Ala, and c.850G>C; p.Val284Leu) heterozygous missense variants in FREM2 in eight patients with extra tooth phenotypes.

CONCLUSIONS

Biallelic variants in FREM2 are implicated in autosomal recessive Fraser syndrome with or without dental anomalies. Here, we report for the first time that heterozygous carriers of FREM2 variants have phenotypes including oral exostoses, mesiodens, and isolated supernumerary teeth.

Tooth number abnormality: from bench to bedside

Tooth number abnormality is one of the most common dental developmental diseases, which includes both tooth agenesis and supernumerary teeth. Tooth development is regulated by numerous developmental signals, such as the well-known Wnt, BMP, FGF, Shh and Eda pathways, which mediate the ongoing complex interactions between epithelium and mesenchyme. Abnormal expression of these crutial signalling during this process may eventually lead to the development of anomalies in tooth number; however, the underlying mechanisms remain elusive. In this review, we summarized the major process of tooth development, the latest progress of mechanism studies and newly reported clinical investigations of tooth number abnormality. In addition, potential treatment approaches for tooth number abnormality based on developmental biology are also discussed. This review not only provides a reference for the diagnosis and treatment of tooth number abnormality in clinical practice but also facilitates the translation of basic research to the clinical application.

A Rare Case of Peripheral Compound Odontoma and Review of the Literature

Peripheral or extraosseous odontogenic tumors are rare oral soft tissue enlargements which demonstrate the same histologic features of their intraosseous counterparts but emerge in gingiva and mucosa. In this paper we report a case of peripheral odontoma in a 12-years-old female patient presented asymptomatic swelling in the palatal site. After the clinical and radiographic examination, excisional biopsy was applied to the lesion located entirely in the soft tissue of maxillary incisors. Histopathologically presence of tooth-like structures containing dentin with regular canals and partly enamel matrix were observed. Our aim is to present the extremely rare case of peripheral odontoma and to review the literature for demonstrating the frequency and clinicopathologic features of this entity.

Pattern and prevalence of dental anomalies among a paediatric population in Lagos, Nigeria

BACKGROUND

Dental anomalies are craniofacial abnormalities in the size, structure or number of the teeth. This study was conducted to assess the prevalence of dental anomalies among children aged 0-16 years attending the Paediatric Dental Clinic at the Lagos University Teaching Hospital, Lagos, Nigeria.

METHODS

A cross-sectional design was used and data were obtained from the dental records of the Dental Clinic from January 2014 to August 2019 by two calibrated examiners, who are co-authors of the manuscript. To test for statistical differences, Chi-squared test was utilised for the categorical variables. The prevalence of the different dental anomalies was estimated and presented with frequencies. P < 0.05 was considered statistically significant.

RESULTS

Among the 6175 patients' dental records reviewed, 50.85% (n = 3150) were male and the highest proportion of 45.4% (n = 2807) were aged between 6 and 10 years, with a mean age of 8.62 ± 3.85 years. A total of 1090 (17.52%) had dental anomalies; 465 (7.53) anomalies were in the maxilla, 263 (4.6) were in the mandible while 360 (5.83) were in both. The most common anomaly was hypoplasia 550 (9.06%), followed by retained primary tooth 546 (8.84%) and hypodontia 84 (1.36%). Dentinogenesis imperfecta 1 (0.02) and transposition 1 (0.02) were the least prevalent anomalies. Retained primary teeth (5.8%) and the cusp of Carabelli (0.4%) were slightly more prevalent among males. However, females had a higher prevalence of natal/neonatal teeth (0.4%), fusion/germination (0.4%), hypodontia (1.5%) and peg-shaped lateral incisors (0.9%).

CONCLUSION

Dental anomalies' prevalence in this study was 17.52%, with a higher occurrence of anomalies in the maxilla. Hypoplasia was the most prevalent anomaly, after which was retained primary tooth, then hypodontia. Prompt diagnosis and preventive interventions are crucial for the appropriate management of these dental anomalies.

Management of the Two Dental Developmental Anomalies in Two Maxillary Incisors for Improved Esthetic Appearance: A Case Report

Introduction:

The presence of a developmental dental anomaly in maxillary incisors usually affects esthetic appearance. Therefore, gemination and supernumerary teeth are considered anomalies and need a careful and comprehensive diagnosis and treatment.

Case Description:

This clinical report presents a 10-year-old girl complaining of the esthetic appearance of her anterior maxillary teeth. Clinical and radiographical examinations revealed a maxillary geminated permanent left central incisor and a supplemental supernumerary permanent right lateral incisor. The treatment has been performed in different stages, including preventive, conservative, surgical, and orthodontic treatments. Thus, the large geminated incisor has been restored to its normal shape, and the problem of anterior incisor crowding resolved through alignment.

Conclusion:

Dental anomalies in the anterior segment are common and need time during treatment. Selective grinding for the large geminated incisor and the extraction of the supplemental tooth followed by orthodontic treatment may be the right decisions that a dental practitioner may consider during the management of such cases.

Acanthomatous Ameloblastoma: An Early Stage Case Report with Difficult Management

A case of a mandibular acanthomatous ameloblastoma, with an admixed little component of follicular type, is reported. The epidemiological features of the present case agree with those reported in the international literature. Clinico-radiographic differential diagnostic difficulties existed with several other noncystic osteolytic lesions of the mandible. Recurrence was diagnosed early 1 year after the initial excisional biopsy, and a definitive rim resection was therefore performed. No further recurrence occurred in the following 4-year follow-up.

Practical Approach to Radiopaque Jaw Lesions

Radiopaque lesions of the jaw are myriad in type and occasionally protean in appearance. In turn, the radiologic analysis of these lesions requires a systematic approach and a broad consideration of clinical and imaging characteristics to enable reliable radiologic diagnosis. Initially categorizing lesions by attenuation pattern provides a practical framework for organizing radiopaque jaw lesions that also reflects important tissue characteristics. Specifically, the appearance of radiopaque lesions can be described as (a) densely sclerotic, (b) ground glass, or (c) mixed lytic-sclerotic, with each category representing a distinct although occasionally overlapping differential diagnosis. After characterizing attenuation pattern, the appreciation of other radiologic features, such as margin characteristics or relationship to teeth, as well as clinical features including demographics and symptoms, can aid in further narrowing the differential diagnosis and lend confidence to clinical decision making. The authors review the potential causes of a radiopaque jaw lesion, including pertinent clinical and radiologic features, and outline a simplified approach to its radiologic diagnosis, with a focus on cross-sectional CT. An invited commentary by Buch is available online. ^©RSNA, 2021.

Phenotypic heterogeneity of non-syndromic supernumerary teeth: genetic study

BACKGROUND

Numerical dental anomalies, through their phenotypic diversity and etiological complexity, represent a very topical chapter in dental practice. In Romania, there is no recent complex genetic study, regarding supernumerary teeth (ST), as a whole.

PATIENTS, MATERIALS AND METHODS

In this research, through the specific genetic study of the phenotypic variability of ST, completed with clinical examinations and paraclinical investigations, to which statistical determinations were added, we performed a complex genetic-clinical and statistical analysis of ST, within a representative group, consisting of 574 patients, who came for specialized dental treatment, between 01/01/2018-05/30/2019, at the private dental offices (Lucky Dental), in Bucharest, Romania.

RESULTS

Following this study, it was possible to characterize the phenotypic variability of ST, to analyze the pattern of abnormality genetic transmission in the families of investigated patients, to identify people at risk, and specify the therapeutic conduct of choice, specific to each case.

CONCLUSIONS

We consider this paper to be of interest for medical practice by bringing new, recent data on the current prevalence of non-syndromic ST, their clinical phenotypes, and the specifics of their genetic determinism in the studied population group.

Developing complex odontoma in a 4-year-old child with active ameloblastic follicles: A case report

The World Health Organization (WHO) classification of odontogenic tumors, in its different iterations, has seen several modifications in benign mixed odontogenic tumors. Odontoma is a benign mixed odontogenic tumor that shows dental hard tissue formation to varying degrees. Although odontomas are the most common odontogenic tumors, they are mostly seen in the form of compound odontomas, where the dental hard tissues resemble tooth-like structures. Complex odontoma shows a haphazard mass of dental hard tissues and is generally identified at an older age (mean age of around 20 years). Incidence of complex odontoma in very young children is quite rare, with only around 10 cases associated with the primary dentition being reported in the literature till date. Unlike other odontomas, our case showed an active epithelial component in the form of tooth buds and ameloblastic follicles along with the hard tissues, which made it difficult to distinguish from other similar lesions like ameloblastic fibroma with hard tissue formation and ameloblastoma arising from an odontoma. This article reports the 11th case of complex odontoma associated with the primary dentition, and the youngest such case to be reported in the Indian population.

Peripheral compound odontoma: A rare case report and literature review

Peripheral odontoma is a very rare odontogenic hamartoma arising in soft tissues. Here, we report a case of peripheral odontoma in a pediatric patient and review the cases published in the literature. An 11-year-old male patient presented a nodular lesion in the anterior region of the palate for over 1 year. Under the clinical hypothesis of fibroma, an excisional biopsy was performed. Histopathological examination revealed the presence of tooth-like structures, formed by enamel, and dentin matrix, occasionally associated with the dental papilla and surrounding pulp tissue, thus, the histopathological diagnosis of peripheral odontoma was established. The patient has been undergoing follow-up for 6 months without any signs of lesion recurrence. Peripheral odontomas are uncommon lesions that usually affect young patients and display a preference for the maxilla and limited growth potential. The recognition of the clinical and histopathological features of the peripheral odontoma is indispensable for the establishment of its diagnosis.

Dental anomalies and orthodontic characteristics in patients with pseudohypoparathyroidism

Background

Pseudohypoparathyroidism (PHP) is a rare and inherited disease caused by mutations in the GNAS-gene or upstream of the GNAS complex locus. It is characterized by end-organ resistance to PTH, resulting in hypocalcemia and hyperphosphatemia. We aimed to investigate the dental anomalies according to tooth types and the orthodontic characteristics of patients with PHP.

Methods

Using a cross-sectional design, 29 patients (23 females) with PHP, living in Denmark, were included, and their clinical intraoral photos and radiographs were examined.

Results

Pulp calcification was found in 76% of the patients. Blunting of root apex was present in 55% and shortening of root in 48% of the examined patients. Blunting and shortening of roots were seen more often in premolars than in other tooth types (p_both < 0.01). Crowding of lower anterior teeth was frequently observed (36%) as well as diastema in the upper arch (25%), midline diastema (18%), and Class III malocclusion (11%).

Conclusion

In the present study population, the teeth were frequently affected by pulp calcification and/or deviation of the root morphology. Blunting and shortening of root(s) were more often seen in premolars than in other tooth types. Class III malocclusion was relatively prevalent. It is important to pay attention to dental anomalies and occlusion in order to provide adequate care for patients with PHP.

Supernumerary teeth of permanent dentition in patients with neurofibromatosis type 1

PURPOSE

The purpose of the study was the investigation of supernumerary teeth (ST) in the permanent dentition of patients with neurofibromatosis type 1 (NF1).

MATERIAL AND METHODS

The panoramic radiographs of 200 NF1 patients were analysed for ST. The potential impact of certain neurogenic facial tumours on the measured variable was investigated separately. The results were compared to dental findings in panoramic radiographs of 200 age- and sex-matched controls.

RESULTS

The total number of ST in all individuals was 23 in 12 patients (3% of total population). However, all ST had developed in the group of NF1 patients (6%), (p = 0.0004). ST were particularly common distal to the molar region. Although ST occur in the region of facial plexiform neurofibroma, the numerical aberrations of the dentition are independent of specific type of facial nerve sheath tumour.

CONCLUSION

The unusual accumulation of ST in the terminal sections of molar development could be an indicator of preferred points of developmental disorder, in which the genetic predisposition of the patient is involved. Reviewing the results of other NF1 patient collectives is desirable.

Two Rare Cases of Non-Syndromic Paramolars with Family Occurrence and a Review of Literature

Supernumerary teeth (or hyperdontia) are teeth that exceed the normal number of deciduous or permanent teeth in the oral cavity. The occurrence of supernumerary teeth without any associated syndrome has been frequently reported and many case reports have been published. This article reports two rare cases of familial occurrence of multiple paramolars without the presence of any other syndrome for two consecutive generations. Limited cases of bilateral maxillary or mandibular paramolars have been reported. In addition, prevalence, classification, etiology, complications, diagnosis and therapeutic strategies that may be adopted when supernumeraries occur are discussed. A review of similar cases published in the literature is included as well.

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.

Wnt/β-catenin signaling, which is activated in odontomas, reduces Sema3A expression to regulate odontogenic epithelial cell proliferation and tooth germ development

Odontomas, developmental anomalies of tooth germ, frequently occur in familial adenomatous polyposis patients with activated Wnt/β-catenin signaling. However, roles of Wnt/β-catenin signaling in odontomas or odontogenic cells are unclear. Herein, we investigated β-catenin expression in odontomas and functions of Wnt/β-catenin signaling in tooth germ development. β-catenin frequently accumulated in nucleus and/or cellular cytoplasm of odontogenic epithelial cells in human odontoma specimens, immunohistochemically. Wnt/β-catenin signaling inhibited odontogenic epithelial cell proliferation in both cell line and tooth germ development, while inducing immature epithelial bud formation. We identified Semaphorin 3A (Sema3A) as a downstream molecule of Wnt/β-catenin signaling and showed that Wnt/β-catenin signaling-dependent reduction of Sema3A expression resulted in suppressed odontogenic epithelial cell proliferation. Sema3A expression is required in appropriate epithelial budding morphogenesis. These results suggest that Wnt/β-catenin signaling negatively regulates odontogenic epithelial cell proliferation and tooth germ development through decreased-Sema3A expression, and aberrant activation of Wnt/β-catenin signaling may associate with odontoma formation.

Patients with SATB2-associated syndrome exhibiting multiple odontomas

Special AT-rich sequence-binding protein 2 (SATB2)-associated syndrome (SAS) is characterized by alterations of SATB2. Its clinical features include intellectual disability and craniofacial abnormalities, such as cleft palate, dysmorphic features, and dental abnormalities. Here, we describe three previously undiagnosed, unrelated patients with SAS who exhibited dental abnormalities, including multiple odontomas. Although isolated odontomas are common, multiple odontomas are rare. Individuals in families 1 and 3 underwent whole-exome sequencing. Patient 2 and parents underwent targeted amplicon sequencing. On the basis of the hg19/GRCh37 reference and the RefSeq mRNA NM_001172517, respective heterozygous mutations were found and validated in Patients 1, 2, and 3: a splice-site mutation (chr2:g.200137396C > T, c.1741-1G > A), a nonsense mutation (chr2:g.200213750G > A, c.847C > T, p.R283*), and a frame-shift mutations (chr2:g.200188589_200188590del, c.1478_1479del, p.Q493Rfs*19). All mutations occurred de novo. The mutations in Patients 1 and 3 were novel; the mutation in Patient 2 has been described previously. Tooth mesenchymal cells derived from Patient 2 showed diminished SATB2 expression. Multiple odontomas were evident in the patients in this report; however, this has not been recognized previously as a SAS-associated phenotype. We propose that multiple odontomas be considered as an occasional manifestation of SAS.

The mineral content of the hard dental tissue of mesiodens

OBJECTIVE

Mesiodens is the most common form of supernumerary tooth mainly located between the maxillary central incisors. Its etiology is not completely understood but both genetic and environmental factors are assumed. The degree of mineralization and inorganic element content in hard tooth tissues is poorly understood as well as is the durability and suitability for allo- and auto-transplantation. Therefore aim of this study was to examine the content of inorganic elements.

MATERIALS AND METHODS

This study included 26 mesiodens teeth and 26 normal central incisor teeth as controls. All specimens were prepared for SEM/EDS analysis which was aimed at specific sites on the enamel, dentine and cementum in order to evaluate the weight percentage and ratio of important inorganic elements.

RESULTS

and Conclusion. The results showed that there was a difference in the weight percentage of selected inorganic elements (calcium, phosphorus, oxygen, carbon, magnesium and sodium) in all three types of dental hard tissues but the differences were mostly expressed in the cementum tissue. The statistical analysis showed that the differences were marginally significant especially for calcium and phosphorus values and ratio in the enamel and dentine. The carbon and magnesium content in all three hard tissues showed the most differences, but overall, the hard tissues mineral content of the mesiodens did not differs significantly from healthy teeth.

Gingival complex odontoma: a rare case report with a review of the literature

Odontomas are odontogenic tumors composed of a mixture of dental tissues. They are very common hamartomas of the jaws. However, their peripheral or gingival counterparts are extremely uncommon. The objective of this article is to report a rare case of gingival complex odontoma in an 11-year-old patient, and also to review all published cases of this type of lesion.

A novel mutation of adenomatous polyposis coli (APC) gene results in the formation of supernumerary teeth

Supernumerary teeth are teeth that are present in addition to normal teeth. Although several hypotheses and some molecular signalling pathways explain the formation of supernumerary teeth, but their exact disease pathogenesis is unknown. To study the molecular mechanisms of supernumerary tooth‐related syndrome (Gardner syndrome), a deeper understanding of the aetiology of supernumerary teeth and the associated syndrome is needed, with the goal of inhibiting disease inheritance via prenatal diagnosis. We recruited a Chinese family with Gardner syndrome. Haematoxylin and eosin staining of supernumerary teeth and colonic polyp lesion biopsies revealed that these patients exhibited significant pathological characteristics. APC gene mutations were detected by PCR and direct sequencing. We revealed the pathological pathway involved in human supernumerary tooth development and the mouse tooth germ development expression profile by RNA sequencing (RNA‐seq). Sequencing analysis revealed that an APC gene mutation in exon 15, namely 4292‐4293‐Del GA, caused Gardner syndrome in this family. This mutation not only initiated the various manifestations typical of Gardner syndrome but also resulted in odontoma and supernumerary teeth in this case. Furthermore, RNA‐seq analysis of human supernumerary teeth suggests that the APC gene is the key gene involved in the development of supernumerary teeth in humans. The mouse tooth germ development expression profile shows that the APC gene plays an important role in tooth germ development. We identified a new mutation in the APC gene that results in supernumerary teeth in association with Gardner syndrome. This information may shed light on the molecular pathogenesis of supernumerary teeth. Gene‐based diagnosis and gene therapy for supernumerary teeth may become available in the future, and our study provides a high‐resolution reference for treating other syndromes associated with supernumerary teeth.

The epidemiology of supernumerary teeth and the associated molecular mechanism

Supernumerary teeth are common clinical dental anomalies. Although various studies have provided abundant information regarding genes and signaling pathways involved in tooth morphogenesis, which include Wnt, FGF, BMP, and Shh, the molecular mechanism of tooth formation, especially for supernumerary teeth, is still unclear. In the population, some cases of supernumerary teeth are sporadic, while others are syndrome-related with familial hereditary. The prompt and accurate diagnosis of syndrome related supernumerary teeth is quite important for some distinctive disorders. Mice are the most commonly used model system for investigating supernumerary teeth. The upregulation of Wnt and Shh signaling in the dental epithelium results in the formation of multiple supernumerary teeth in mice. Understanding the molecular mechanism of supernumerary teeth is also a component of understanding tooth formation in general and provides clinical guidance for early diagnosis and treatment in the future.

Clinical, pathological, and genetic evaluations of Chinese patient with otodental syndrome and multiple complex odontoma: Case report

Otodental syndrome is a rare autosomal-dominant disease characterized by globodontia, associated with sensorineural, high-frequency hearing loss. Here, we describe the clinical, pathological, and genetic evaluations of a 9-year-old girl with otodental syndrome and multiple complex odontoma.The patient presented with a draining sinus tract in her left cheek, globodontia, and hearing loss. The odontomas which caused the cutaneous sinus tracts were extracted because of the odontogenic infection. The extracted odontoma and primary tooth was studied by micro-CT and further observed histopathologically. The micro-CT findings revealed that the primary tooth had three crowns with two separated pulp chambers, and their root canals were partially fused. The histological findings showed abnormal morphologies of odontoblasts and dentin, hyperplasia of enamel, and malformation of odontogenic epithelium. Furthermore, DNA sequencing and analyze of deafness associated gene GJB2, GJB3, and PDS had not revealed any SNP or mutation; but exon 3 of the causative gene FGF3 could not be amplified, which may be associated with the microdeletion at chromosome 11q13.3. Three month after surgery, the patient was found to be asymptomatic and even the evidence of the extra-oral sinus had disappeared.The dental abnormality of otodental syndrome included congenital missing teeth, globodontia, and multiple complex odontoma. Globodontia exhibited characteristic features of fusion teeth. In addition, gene FGF3 haploinsufficiency was likely to be the cause of otodental syndrome. The report provides some new information in the field of otodental syndrome, which would make dentists more familiar with this disease.

Clinical parameter of odontoma with special emphasis on treatment of impacted teeth-a retrospective multicentre study and literature review

OBJECTIVES

Odontoma-separated into complex (CxOD) and compound (CpOD) subtypes-represents the most frequent odontogenic malformation. Retention of permanent teeth is a common symptom. Therefore, in a series of odontomas, an analysis of the management of retained teeth was conducted.

MATERIALS AND METHODS

In a retrospective multicenter study of two University Medical Centers and one private praxis in Germany, demographic and clinical data regarding odontomas from 01/2000-03/2015 were obtained. In particular, the influence of operative therapy on the dentition and on the treatment of impacted teeth was analyzed.

RESULTS

Forty-five patients with 15 CxOD and 30 CpOD were included. Initial symptoms were delayed eruption of permanent teeth (n = 11), pain (n = 4), and swellings (n = 2); 28 cases were discovered by incidence, all of them via panoramic radiographs. The mandible/maxilla ratio was about 1:0.55 (29/16). Thirty-five out of 45 odontomas were in close proximity of at least one tooth (n = 16 at molars). A total of 14 teeth were extracted (CxOD: n = 5; CpOD: n = 9). Extractions had to be conducted more often in older patients (mean age 39.8 vs. 25.6 years). Of the non-extracted teeth, 8 teeth were displaced and retained. Of those, 4 teeth were aligned in the dental arch via orthodontic help and 2 teeth erupted spontaneously after operation during the follow-up period. In all cases, no relapse was seen.

CONCLUSION

Odontomas can cause displacement as well as malformation and resorption of the adjacent teeth.

CLINICAL RELEVANCE

Mostly, removal of odontomas is conducted. Extirpation of odontoma can allow for normal tooth eruption, often rendering extractions avoidable. Orthodontic alignment, though sometimes challenging, is a reasonable therapeutic option. These findings underline the value of the panoramic radiograph in preventive dentistry in younger patients.

Cone beam CT as an aid to diagnosing mixed radiopaque radiolucent lesions in the mandibular incisor region

We present two cases where the identities of mixed radiopaque radiolucent lesions in the lower incisor region were unclear, although the position of the lesions and positive pulp sensitivity tests were suggestive of periapical osseous dysplasia. In the first case, the lesion presented as a solitary round mixed radiopaque radiolucent periapical lesion, suggestive in some images as periapical osseous dysplasia. Cone beam CT (CBCT) provided clear images, which confirmed the diagnosis and, additionally, the images showed evidence of initial lesions associated with other anterior teeth and some destruction of the labial plate, not evident on the conventional radiographs. In the second case, radiopacities were identified within the lesion on conventional radiographs, but CBCT imaging also showed extensive and unexpected perforation of the lingual plate. Such destruction of cortical plates may be a feature of periapical osseous dysplasia, which is not visible in conventional radiography.