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OBJECTIVE Patients with oligodontia frequently show different types of malocclusions. However, how oligodontia affects the maxillofacial growth remains uncertain. This study aimed to investigate the maxillofacial morphological characteristics in growing patients with oligodontia. SETTING AND SAMPLE POPULATION The study subjects included 33 Japanese children with non-syndromic oligodontia (14 boys and 19 girls; mean age: 10.2 years) who visited the orthodontic clinic of Fukuoka Dental College Medical and Dental Hospital from 1999 to 2019. MATERIALS AND METHODS Cephalometric analyses were performed, and the variables measured in each subject were converted into Z scores in relation to the mean and standard deviation of the Japanese norms matched for growth stage. The one-sample t-test or Wilcoxon signed-rank test was performed to compare the mean scores in the patients with oligodontia with those of the Japanese norms. RESULTS Compared with the Japanese norms, patients with oligodontia showed a smaller convexity and larger A-B plane and SNB angles. The Frankfort-mandibular plane and gonial angles were smaller, whereas the height of the ramus was larger. The vertical height of the alveolar bone in the maxillary and mandibular incisors and molar areas was smaller in patients with oligodontia. CONCLUSIONS Patients with oligodontia showed Class III skeletal tendency with mandibular prognathism and flattened mandibular plane with a smaller gonial angle. These maxillofacial morphological features can be induced by a deficiency in the vertical growth of the alveolar bone in the maxillary and mandibular molar areas due to the lack of tooth germs.

Odontomas and ameloblastic fibro-odontomas (AFOs) are the result of a developmental anomaly of odontogenic tissues. A literature review of proteins immunoexpressed in odontomas and AFOs was conducted in order to determine which proteins are involved in the pathogenesis of these lesions. AFO was changed to early odontoma in the 2017 WHO classification and will also be discussed in this article. A literature search was performed in the following electronic databases: PubMed/MEDLINE, Web of Science, Scopus, EMBASE, Lilacs, Cochrane Collaboration Library, and Science Direct. The research question was developed according to the population, intervention, comparison, and outcome (PICO) framework: Which proteins are related to the differentiation of odontomas and what is their interrelationship with AFOs? Thirty articles met all inclusion criteria and were selected for this systematic review, totaling 355 cases of odontomas and 43 cases of AFO. Similar immunoexpression was observed in odontomas and AFOs. Immunoexpression of proteins involved in cell differentiation was higher in compound odontomas than in complex odontomas. Proteins involved in histodifferentiation and enamel formation were more frequent in odontomas. The immunoexpression of enamel matrix proteins differs between odontomas and tooth germs, with their persistence being related to the development of odontomas. Compound odontomas exhibit the highest immunoexpression of proteins involved in cellular histodifferentiation and the Wnt/beta-catenin pathway is involved in tumor formation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s12105-020-01260-x) contains supplementary material, which is available to authorized users.

The aim of the study.To reveal tooth germs structural changes induced by low doses of ionizing radiation in the experiment using light-microscopic examination. Objects and methods. The experiments were carried out on albino rats mongrel gregarious breeding. Gravid female rats were exposed to chronic irradiation on “Gammarid 192/120 unit” at 110 mR/h power of exposition for 18 days at the Institute of Radiobiology of the National Academy of Sciences of the Republic of Belarus. The total dose absorbed by the fetuses was 0.42 Gy. Results and discussion. The experiment showed a significant decrease of proliferative activity of tooth germ cells. It resulted in the decrease in size and in the number of cell layers, shape change up to the appearance of deformed tooth germs. Reducing the intensity of mitotic division also led to the lack of “concentric structures” and cell cushion-shaped thickenings in the enamel epithelium in the experiment. Conclusion. These series of experiments revealed such odontogenesis disorders that cannot be explained only by the decrease of proliferative activity.

Delayed tooth development (DTD) is the development progress of a tooth germ that takes place later due to local or general causes. This case report reviews a 16-year-old Asian adolescent whose bilateral upper second premolar germs were at Nolla’s 6 stage as shown on a panoramic radiograph. It is unusual that tooth germs of the maxillary second premolar are developed after 11 years of age. To reduce the chance of misdiagnosis, clinicians should consider the possibility of DTD if a tooth germ does not present in radiographs.

When a traumatic dental injury affects the deciduous teeth, the main management is to regularly review the patient until the successor permanent tooth erupts to avoid further consequences to the affected tooth and, especially, sequelae in the tooth germs of the successor permanent tooth. This report describes a case of a tooth extrusion in a 4-year-old male treated with a minimally invasive approach. After 4 years of follow-up, there was a mild disturbance (demarcated opacity in the vestibular surface) and a satisfactory result with normal eruption of the permanent successor tooth.

Introduction Nomads move from one settlement to another, thus it has been difficult to have adequate documentation about their oral health and that of their children. Aim To investigate the perception and practices of nomadic Fulani women toward their children’s oral health. Methodology A cross-sectional study was conducted among 197 Fulani women using a structured interviewer administered questionnaire. Results Perceived causes of tooth decay included tooth germs/worms (23.9%) and sugar (5.1%), and 32.0%, 15.2%, and 5.1%, respectively, self-medicated children with antibiotics, traditional concoctions/herbs, and analgesics for tooth decay. Two fifths (40.1%) attributed bleeding gums to tooth germs/worms. Polyurethane foam (46.7%), toothbrush (32.0%), finger (18.8%), and wooden twigs (2.5%) were aids used for cleaning children’s teeth. Conclusions These mothers have suboptimal oral health knowledge, attitudes, and practices toward their children’s oral health. There is a need for urgent intervention among this group of people.

Ectodermal dysplasia (ED) is an anomaly determined by genetic factors that alter ectodermal structures such as skin, hair, nails, glands, and teeth. Children affected by this condition require extensive, comprehensive, and multidisciplinary treatment. An 8-year-old female patient visited the Dentistry Clinic of the Federal University of Santa Catarina with the chief complaint of multiple missing teeth. The mother reported that the patient had ED. Clinical and radiographic examination revealed the congenital absence of several primary and permanent teeth and tooth germs. Subsequent oral rehabilitation comprised the application of a maxillary denture and mandibular implant-supported fixed prosthesis. The child was also supplied with a wig for further enhancement of esthetics aimed at improving her emotional wellbeing. Psychological follow-up and speech therapy were also provided. After 4 years of follow-up, implant-supported oral rehabilitation has proved to be a satisfactory treatment option, allowing restoration of masticatory, phonetic, and esthetic function, as well as an improvement in the patient's self-esteem and social wellbeing.

The presence of bilateral fusion of teeth in permanent dentition is an unusual and rare condition. It is a developmental anomaly characterized by the union of two separate tooth germs during formation. The case of a 9 year old boy with fusion of permanent maxillary central incisors with associated bilateral disto-palatal rotation was examined. The fused maxillary incisors were treated conservatively using an aesthetic restorative material. The purpose of this report is to review the literature related to bilateral fused maxillary permanent teeth and its aesthetic treatment. Keywords: Bilateral fusion, fused teeth, maxillary incisors, treatment

섬유성이형성증은 정상적인 골조직이 섬유성 조직으로 대체되는 특징을 가진 질환으로 해면골 내에 불규칙한 골소 주가 형성되며 상악과 하악을 포함하여 두개 안면골에 흔하 게 나타난다. 골의 크기와 모양 변화를 초래하는 양성 섬유골성 병소이며 체세포의 Gsα유전자 변이와 연관되어 나타 나는 것으로 알려져 있다. 1938년 Lichtenstein과 1942 년 Jaffe에 의해 보고되었으며 양성 골 종양의 5-7% 정도 를 차지하고 어느 연령에서나 발병할 수 있으나 특히 3세15세 사이에서 가장 많이 발병하는 것으로 알려져 있다. 섬유성이형성증의 임상적 특징으로는 우연히 발견되는 경우가 많으며 대부분 통증이 없어 환자가 병소를 인지하지 못하는 경우가 많다. 그러나 병소가 진행되면서 기형, 골 통 증, 피로 골절 및 병적 골절이 발생할 수 있으며 피부에 cafe′-au-lait 반점이 발견되기도 한다. 방사선학적으로 경 계가 불분명한 방사선 투과상과 불투과상이 혼재되어 있으 며 간유리 모양의 패턴을 나타내는 것이 특징이다. 조직학 적으로 미성숙한 골소주가 중국문자모양으로 관찰된다. 본 증례는 만 7세 여환이 하악 좌측 유구치 부위 잇몸이 부었다는 주소로 연세대학교 치과대학병원 소아치과에 내 원한 환아로 섬유성이성형증에 의한 안면비대칭이 관찰되 어 보고하고 그에 따른 합병증을 논의해보고자 한다.

Objective: This study aimed to determine changes in odontogenesis arising from prenatal and postnatal protein-calorie malnutrition. Materials and methods: Twelve adult Wistar rats were selected; 8 females and 4 males. The females were divided into two groups, one of which received a normoproteic diet (NG) and the other received a hypoproteic diet (HG). After the birth of the litters, 24 pups were randomly separated from each group. The animals were sacrificed, 12 at five-days old and 12 at eight-days old, and their jaws were subjected to histological preparation to obtain cuts of tooth germs. Forty-eight slides were selected that presented the germs properly cut (24 from each group), which were analyzed by microscopy and measured by a calibrated examiner. The differences between means were verified by the nonparametric Mann-Whitney test. Results: The results showed that at 5 days the differences in thickness of enamel and dentin were statistically significant between NG (84.08 ± 28.9 and 141.51 ± 33.2; p = 0.026) and HG (47.26 ± 43.8 and 91.19 ± 54.7; p = 0.006). At 8 days of life there were no significant differences between the groups. Conclusion: The results showed evidence of the impact of malnutrition on the thickness of dental tissues. It is suggested that further work is carried out in this line of research with more complex designs.

Objective: The purpose of this study was to estimate the feasibility and accuracy of mesio-distal width measurements with magnetic resonance imaging (MRI) in comparison to conventional 3D imaging techniques [multi-slice CT (MSCT), cone-beam CT (CBCT), and µCT]. The measured values of the tooth widths were compared to each other to estimate the amount of radiation necessary to enable orthodontic diagnostics. Material and Methods: Two pig skulls were measured with MSCT, CBCT, µCT, and MRI. Three different judges were asked to determine the mesio-distal tooth width of 14 teeth in 2D tomographic images and in 3D segmented images via a virtual ruler in every imaging dataset. Results: Approximately 19% (27/140) of all test points in 2D tomographic slice images and 12% (17/140) of the test points in 3D segmented images showed a significant difference ( P ≤ 0.05). The largest significant difference was 1.6mm ( P < 0.001). There were fewer significant differences in the measurement of the tooth germs than in erupted teeth. Conclusions: Measurement of tooth width by MRI seems to be clinically equivalent to the conventional techniques (CBCT and MSCT). Tooth germs are better illustrated than erupted teeth on MRI. Three-dimensional segmented images offer only a slight advantage over 2D tomographic slice images. MRI, which avoids radiation, is particularly appealing in adolescents if these data can be corroborated in further studies.

Fusion is a common dental anomaly affecting both primary as well permanent dentitions. Fusion is the union between two normally separated tooth germs. The problems associated with fused teeth are esthetics, arch symmetry, spacing, and malocclusion. These problems require cosmetic and orthodontic consideration.

Pediatric mandibular fracture needs special consideration by clinicians. The management of pediatric mandibular fracture differs from that in adults considering the presence of tooth germs and the potential for mandibular growth. One of the most common forms of conservative management for pediatric mandibular fractures is the use of cap splint along with circummandibular wiring. The conventional workflow prior to performing surgery with this technique is impression taking and dental model fabrication. Additionally, it is also recommended that mock surgery should be performed to achieve proper reduction before acrylic splint fabrication. However, these procedures are effortful and time consuming when performed under general anesthesia during surgery and require additional sedation if performed prior to surgery. The aim of this case report is to describe a simpler preoperative digital workflow for the treatment of pediatric mandibular fractures, in which closed reduction is achieved with a three-dimensional printed cap splint stabilized with circummandibular wiring under general anesthesia.

Objective: To test the reliability of some cephalometric measurements in unilateral cleft lip and palate patients. Measurements with A, ANS, and PNS, were compared to measurements performed with alternatives for point A, ANS, and PNS: A1, A2, ANS1, ANS2, and PNS1. Patients: One hundred sixty-four children with complete unilateral cleft lip and palate (UCLP), with a lateral head film taken at age 4 to 6 years. Mean Outcome Measures: Intraobserver and interobserver reliability for cephalometric measurements including A, ANS, PNS or their alternatives: Dahlberg errors, systematic errors, and Pearson correlation coefficients were calculated. Results: The measurements using ANS and PNS or their alternatives, were comparable. The systematic error between observers for measurements using A2 was less than for measurements using A or A1. The scatterplot of point A showed a slightly better distribution of the points than the plots of A1 and A2. Conclusions: Although the landmarks A, ANS, and PNS are hard to trace in UCLP patients with tooth germs in the anterior maxilla, no better landmarks were found in this study. Cephalometric studies using A, ANS, and PNS in UCLP patients should be interpreted with caution.

The maxillofacial skeleton is different from the bones elsewhere in the body in several aspects. Embryologically, it is unique as parts of it develop from cells migrating from the embryonal neuroectoderm. Furthermore, they house the tooth germs. Due to these special features, diseases occur in this area that are not seen in any other part of the skeleton. Moreover, bone diseases with a more generalized distribution are connected with entirely different differential diagnostic problems when located in the maxillofacial area because of specific clinical, radiological, and histological details at this site. To put these issues in the right perspective, both bone disorders that are restricted to the head and neck and diseases that also occur in the extragnathic skeleton are discussed in this chapter.

Forensic research requires the application of reliable identification methods for unidentified individuals, among which the dental analysis has prime importance. The most significant source of dental evidence is oral autopsy applications, which consist of an examination and evidence collection from the oral cavity of a deceased individual. Oral autopsies show variations depending on the age of the person due to rigor mortis. The oral autopsy of a child may require an easier operation than adults, and thus, the procedures are usually simpler for fetus or infant cases. The aim of this study is to propose the theoretical and experimental aspects of an oral autopsy protocol for a special age group of fetus or infant cases, which is a method for extracting tooth germs in their developmental stages for identification purposes and entitled by the authors’ names as the “Aka-Canturk Oral Autopsy Method”.

We examined whether tooth eruption would occur normally in grafted allogeneic mandibular bone.Using vascularized composite tissue transplantation, we extracted portions of immature mandibles including the tooth germs from young beagle dogs and transplanted them into unrelated immature or mature beagle dogs. In addition, we prepared vascularized gingival flaps from mature dogs and grafted them onto the mandibles of unrelated immature dogs. Mandibular bone including tooth germs without covering gingiva from immature dogs was also transplanted either to immature or mature recipient dogs, and the grafted bones were covered with recipients' gingiva. Then, we examined tooth eruption in these grafted mandibular bones.Normal tooth eruption was observed only in the mandibles transplanted to the young recipient dogs. In the mature dogs, tooth eruption from the gingiva was delayed; the whole crown was covered with a cap of gingival tissue, which was not a gingival overgrowth.It is suggested that tooth eruption depends on the age of the recipient, regardless of the overlying gingival tissues transplanted.

This study presents the treatment courses in three impacted cases of mandibular second premolars caused by distal inclination of the tooth germs. In all cases, the second premolars were surgically exposed, but the traction periods until oral emergence differed. The reasons for the differences may be the variation in the severity of the distal inclinations of the tooth germs and the calcified development of the affected germs at fenestration.

Fusion is the union of two normally adjacent tooth germs resulting in the formation of a single large tooth. The incidence of fused teeth is 0.1% in the permanent and 0.5% in the primary dentitions and it may be unilateral or bilateral. The purpose of this article is to report a rare case of unilateral fusion of permanent mandibular lateral incisor and canine with two pulp chambers and a single root canal.

The tooth is an ectodermal organ that arises from a tooth germ under the regulation of reciprocal epithelial-mesenchymal interactions. Tooth morphogenesis occurs in the tooth-forming field as a result of reaction-diffusion waves of specific gene expression patterns. Here, we developed a novel mechanical ligation method for splitting tooth germs to artificially regulate the molecules that control tooth morphology. The split tooth germs successfully developed into multiple correct teeth through the re-regionalisation of the tooth-forming field, which is regulated by reaction-diffusion waves in response to mechanical force. Furthermore, split teeth erupted into the oral cavity and restored physiological tooth function, including mastication, periodontal ligament function and responsiveness to noxious stimuli. Thus, this study presents a novel tooth regenerative technology based on split tooth germs and the re-regionalisation of the tooth-forming field by artificial mechanical force.

Fusion of the teeth is a developmental anomaly that may occur due to joining of the two separated tooth germs. It may be complete or incomplete based on which stage of development the fusion occurred. Physical forces or pressure may cause fusion. It can be seen between the two primary teeth or permanent teeth or between normal and supernumerary teeth, commonly mesiodens.1 In this case, an …

Supernumerary teeth need to be removed because they can cause various complications. Caution is needed because their removal can cause damage to permanent teeth or tooth germs in the local vicinity. Surgical guides have recently been used in maxillofacial surgery. Because surgical guides are designed through preoperative analysis by computer-aided design software and fabricated using a 3-dimensional printer applying computer-aided manufacturing technology, they increase the accuracy and predictability of surgery. This report describes 2 cases of removal of a mesiodens-1 from a child and 1 from an adolescent-using a surgical guide; these would have been difficult to remove with conventional surgical methods.

Missing teeth are one of the most common developmental problems in children. The adult teeth are more frequently affected than the baby teeth. Fusion defined as the merger of two adjacent tooth germs producing one tooth. These teeth may be fused by enamel, dentin, or both. The fused crown is broader than non fused adjacent teeth and thus resembles gemination. However, tooth counting reveals decreased numbers. Fused teeth are rare in the permanent dentition. A case of simultaneous missing upper incisors and fused lower incisors is reported.

Four clinical cases are presented to demonstrate the self-correcting potential of aberrant tooth germs after the elimination of eruption obstacles (in 2 cases cysts, in 2 other cases severely infraoccluded primary teeth). In the case of the submerging deciduous teeth, the tilted adjacent teeth were orthodontically uprighted after the surgical procedure. Possible causative mechanisms are discussed.

Microcomputerized tomography (micro‐CT) allows discriminating very small changes in dental hard tissue volumes. The aim of the present study was to create a new method for obtaining high‐resolution, three‐dimensional images of dental hard tissue development using micro‐CT, and to observe the changes in dental hard tissue development and composition in growing rat pups. Tooth germs from rats at the end of the 20‐day embryonic period (E20) and during the neonatal period (D1‐14) were subjected to micro‐CT. Three‐dimensional reconstructions were analyzed to compare dental hard tissue formation and mineralization during the different development periods. Scanning electron microscopy and energy dispersive spectroscopy were used to confirm mineral density (MD). Dental hard tissue began to form during the E20, but the process was slow and resulted in minimal deposition. Hard tissue volume increased by approximately 0.040 mm3/day from E20 to D3, and by 0.12‐0.42 mm3/day after D3, peaking at 0.42 mm3/day at D12. This increase in hard tissue volume resulted in continuous increases in hard tissue thickness, from 90.0 ± 20.7 μm at E20 to 545.2 ± 14.1 μm by D14. MD was 298 ± 3.1 mg HA/cm at E20 and increased to 678.2 ± 6.1 mg HA/cm by D14. The degree of calcification also progressively increased during the first 14 days of development. Dental MD was strongly associated with calcification. This study indicates that micro‐CT is a nondestructive, high‐resolution, reliable, and innovative tool for the evaluation of volume and MD of dental hard tissues during development. Micro‐CT minimizes artifacts caused by sample preparation. PACS number: 87

Fusion Tooth due to the union of two separated tooth germs, it may be complete or incomplete tooth fusion depending on the time of union and stages of tooth development. It may be between two normal teeth or sometimes between normal tooth and supernumerary tooth germ. Here we report a rare case of fusion between right mandibular primary central and lateral incisors in a six year old girl.

Introduction Regenerating a tooth completely in human oral cavity is not achieved by current studies yet. Here, we have conceived a man-induced method to construct a teeth germ which might be used to regenerate a tooth in vivo. This idea was generated by traits of the development of the compound odontoma, a benign tumour of tooth malformation. This is a kind of developmental tooth malformation, characterised by several small teeth inside the entity. Those scattered denticles/daughter teeth germs, formed in the early stage of odontoma morphogenesis, show similar layers as in a normal tooth, and could grow into tooth-like shapes. In consideration with recent report that mouse tooth germ constructed in vitro could develop into a fully functioned tooth in adult mouse jaws. We hope this hypothesis helps generate tooth germs for in vivo implantation. Hypothesis Tooth germ of wisdom tooth might be separated into small daughter germs by bone trabecular using tissue-engineering method, to provide more than one tooth germ for tooth regeneration. Evaluation of hypothesis By reconstruction existing dental tissues during tooth organgenesis in the jaw, this hypothesis shows advantage than generating tooth from single stem cell or artificial tooth graft. Conclusion Proving this hypothesis not only facilitates the acquirement of numerous homologous and immunological rejection-free teeth germs to treat tooth loss and deficit, but also helps afford an alternative lesson that merits attention in other human organ regeneration fields.

Recently, sonography of the fetal face has gained increasing importance in prenatal diagnosis. It is not yet clear whether sonographic depiction of fetal tooth germs would have an influence on the prenatal diagnosis of ectodermal dysplasia syndromes. During routine malformation screening, horizontal sections of fetal jaws were visualized and examined for tooth germs in 124 pregnant women following sonographic 'facing'. Histological jaw sections of fetuses that had died in utero at various gestational ages were produced in order to examine the degree of correspondence between the sonographic and histological findings. At least four tooth germs were found in the jaws of all fetuses between 19 and 34 gestational weeks (n = 104). Although jaw visualization was possible between 14 and 18 gestational weeks (n = 20), the exact number and location of the tooth germs could not be determined. Assessment of tooth germs may become increasingly important, as aplasia of the tooth germs is one of the principal signs of various hereditary ectodermal diseases.

Crown dilaceration of permanent teeth occurs due to the non-axial displacement of the already formed hard tissue portion of the developing crown at an angle to their longitudinal axis due to trauma to the primary predecessors. This is a rare condition, representing only 3% of the total of injuries to developing teeth and usually occurs in permanent maxillary incisors because of the close proximity of their tooth germs to the primary incisors, which are more susceptible to trauma. This alteration frequently results from the intrusion of a primary tooth when the child is around 2 years of age, at which time half of the crown of the permanent successor is already formed. Teeth with dilacerated crowns may either erupt with buccal or lingual displacement or remain impacted. The treatment may involve endodontic, orthodontic, restorative and prosthetic procedures. This paper reports the restorative treatment proposed to reestablish the esthetics and function of the affected teeth in three cases of crown dilaceration in permanent maxillary incisors after trauma to their primary predecessors.

Congenital absence of tooth germs and presence of supernumerary teeth (CHH) are anomalies which are classified as embryologically determined disorders. Both disorders can occur together (CHH), but relatively rarely.The aim of the present study was to present and analyze nine cases collected during the past 24 years, where congenitally missing teeth occurred with supernumerary teeth in the same patient.Dental records, radiographs and casts of nine patients, six boys and three girls (aged 9-29 years, mean age: 19 years) were examined. All the family members of the patients were also investigated regarding the presence of tooth disorders.The boys showed hypo-hyperodontia twice as often as the girls (6:3). Congenital absence of tooth germs was more common than the presence of supernumerary teeth (25:11). CAP were not present in the other family members.The full diagnosis of hypo-hyperodontia is only possible on the basis of radiographic examination, because some teeth may remain unerupted or missing. The results of this study showed that concomitant hypo-hyperodontia is rare and sex-related, with predominance of hypodontia. The genetic influence seems unclear.

Objective This study was undertaken to describe 2 cases of localized Langerhans cell histiocytosis (LLCH) of the mandible that healed quickly following intralesional infiltration of corticosteroids. Study Design Two patients with LLCH of the mandible were treated in a 1-stage procedure with intralesional injection of methylprednisolone. Symptoms of pain were quickly relieved and the swelling receded. Periodic orthopantomogram and computerized tomography after corticosteroid injection revealed continuous regression of mandibular osteolysis and a favorable osseous consolidation in the lesions. Conclusions The results of this report suggest that intralesional injection of corticosteroids should be the initial choice of treatment of LLCH of the mandible, especially in children to preserve tooth germs.

Odontogenic tumours are considered to be relatively rare; however, several histologically distinct types have been identified in dogs. The more common canine odontogenic tumours are peripheral odontogenic fibroma and canine acanthomatous ameloblastoma. The expression of cytokeratins (CKs) has been established for the human dental germ and odontogenic tumours. The aim of the present study was to describe the immunohistochemical expression of a panel of CKs in the epithelium of the canine dental germ, normal gingiva and odontogenic tumours arising in this species. Samples from 20 odontogenic tumours, 12 tooth germs and three normal gingival tissues were obtained. Each sample was stained with haematoxylin and eosin and subjected to immunohistochemistry for CK expression. The typical expression pattern of CKs in the odontogenic epithelium and gingiva of dogs was CK14 and CK5/6. CKs 7, 8, 18 and 20 were generally absent from the canine dental germ, gingiva and odontogenic tumours. Dogs and man therefore exhibit similar CK expression in the odontogenic epithelium.

The purpose of this article is to report the orthodontic treatment of a patient with extremely delayed development of the maxillary lateral incisors. At 7 years of age, the boy's permanent maxillary lateral incisors had not erupted. A radiograph showed no tooth germs in place, although well-defined radiolucent areas were evident. Removal of the radiolucent areas was contemplated, but it was rejected in favor of a conservative approach. At age 13, peg-shaped maxillary lateral incisors erupted; they were positioned during orthodontic treatment and reshaped with composite restorations, providing good esthetics and function.

The replacement of teeth by implants is usually restricted to patients with completed craniofacial growth. Implant insertions in children or adolescents are circumvented due to several unfavorable potential effects including trauma to tooth germs, tooth eruption disorders and multidimensional restrictions of skeletal craniofacial growth. Moreover, the functional and esthetic results of the oral rehabilitation are only temporary acceptable. However, to a small number of pediatric patients suffering congenitally from severe hypodontia caused by syndromes such as ectodermal dysplasia, conventional prosthodontic rehabilitations are insufficient. We report the case of a boy with ectodermal dysplasia who exhibited a severe hypodontia and who was treated with implants inserted into the anterior mandible at the age of 8 years. The implants were functionally loaded and resulted in a high patient satisfaction. We recommend the early insertion of dental implants in children with severe hypodontia. Reviewing the current literature, several aspects of syndromic hypodontia, patient selection and implant planning are discussed.

International audience; The present study proposes equations for age determination both in living and dead children, obtained with the help of stepwise ascending multiple linear regression. The equations should be applied, based on the number of erupted teeth and tooth germs, which were detected on radiographs, during clinical examination and in infant skeletal remains. The proposed equations proved to be efficient just like Demirjian's method used as a reference today, and permit age estimation till 20 years of age.

Odontogenic anomalies can occur as a result of conjoining or twinning defects. The phenomenon of tooth fusion arises through the union of two normally separated tooth germs and depending upon the stage of development of the teeth at the time of union, it may be either complete or incomplete. Fusion is the union of two normally separated tooth germs resulting in the formation of a single large tooth. The prevalence of this anomaly is

Purpose Central giant cell granulomas of the jaws are classified and treated according to their biologic behaviour. The most common therapy is curettage. The aggressive type of these lesions frequently require wide resections and may damage vital structures (tooth germs, inferior alveolar nerve, etc.) resulting in fuctional and aesthetic problems. The purpose of this report is to present alternative medical treatment in aggressive GCGC of the jaws either as monotherapy or in combination with surgical treatment in order to eliminate functional problems and aesthetic defects and minimize the reccurence rate. Materials and methods A 15-year retrospective review of the literature emphasizing in non-surgical therapies such as calcitonin, intralesional corticosteroids, interferon-a, bisphosphonates and monoclonal antibodies. Results In aggressive GCGC of the jaws surgical therapy has a a high reccurence rate. Calcitonin, intralesional corticosteroids, interferon-a and bisphosphonates can be used either as monotherapy in aggressive GCGC, or when there is partial response these therapies can be combined by surgical treatment. Conclusions Because of the rareness of the tumor there are no randomized clinical trials, except from calcitonin. Although surgical excision remains the treatment of choice, alternative therapies are promising but still require further investigation.

Double tooth is a term used to describe connate tooth and includes both dental fusion and gemination. Fusion refers to the union of two tooth germs resulting in a single large tooth. Owing to its irregular morphology, this anomaly can cause unpleasant aesthetic appearance. The diagnosis is based on the clinical findings and radiographic examination. We hereby discuss a case of fusion in a 30-year-old woman.

Fusion is the union of two normally separated tooth germs resulting in the formation of a single large tooth. The prevalence of this anomaly is less than 1% and most common in the primary dentition, in the incisor-canine region. Fusions are almost always unilateral, but few cases of bilateral fusions have been reported. The purpose of this article is to report a rare case of bilateral fusion of mandibular second premolar with supernumerary tooth.

Fusion is a developmental anomaly of dental hard tissues characterized by the union of two adjacent teeth. It may be complete with the formation of an abnormally large tooth or incomplete with the union of crowns or roots only. Exact etiological factors are still enigmatic. It is more common in deciduous than in the permanent dentition with higher frequency in anterior maxillary region. We present a case of fusion in permanent maxillary incisor region in a 35-year-old male who presented with the complaint of pain in same region. Early diagnosis is important to avoid various complications such as compromised aesthetics, space loss, midline shift, and carious exposure.

Summary 92 children with mandibular fracture were treated at our hospital between 1980 and 1989. Distribution and treatment of the fractures focus on a new classification based upon the stage of the dentition, site of the fracture and displacement of the tooth-bearing part of the mandible. The treatment rationale includes intermaxillary fixation by specially designed mini-arch bars with acrylic resin stiffening in cases with undisplaced fractures in the early stages of the dentition. With the help of this technique, invasive procedures for fracture immobilization become less common. The indication for miniplate osteosynthesis is limited to displaced or multiple fractures of the tooth-bearing part of the mandible. The combination of miniplates and monomaxillary splinting with mini-arch bars allows a shorter duration of intermaxillary fixation and hence early functional treatment of additional condylar fractures. Correctly applied miniplates neither injure the tooth germs nor lead to growth disturbances of the mandible. The classification and treatment of mandibular fractures in children are discussed.

A case is described of a seven year-old boy in whom root formation continued following the premature extraction of both maxillary first premolars.