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Concept: Hyperdontia


BACKGROUND: Cleidocranial dysplasia (CCD) is a rare congenital autosomal dominant skeletal disorder. The disorder is caused by heterozygosity of mutations in human RUNX2, which is present on the short arm of chromosome 6p21. The incidence of CCD is one per million births. CCD appears spontaneously with no apparent genetic cause in approximately 40% of affected patients, and one in three patients has unaffected parents. The most prevalent features associated with CCD are aplastic or hypoplastic clavicles, supernumerary teeth, failed eruption of permanent teeth, and a hypoplastic maxilla. CASE PRESENTATION: A 13-year-old Caucasian boy presented with a chief complaint of delayed eruption of the permanent anterior teeth. The patient was subsequently diagnosed with CCD based on the clinical examination, panoramic X-ray, anterior-posterior and lateral cephalogram, and chest radiograph findings. The details of this case are herein reported because of the extremely low incidence of this disorder. CONCLUSIONS: CCD is of clinical importance in dentistry and medicine because it affects the bones and teeth and is characterized by many changes in skeletal patterning and growth. Particularly in dentistry, CCD is of great clinical significance because is associated with delayed ossification of the skull sutures, delayed exfoliation of the primary teeth, lack of permanent teeth eruption, multiple supernumerary teeth, and morphological abnormalities of the maxilla and mandible. Patients with CCD seek treatment mainly for dental problems. Knowledge of the pathogenesis, clinical characteristics, and diagnostic tools of CCD will enable clinicians to render the appropriate treatment to improve function and aesthetics. Early diagnosis of CCD is crucial for timely initiation of an appropriate treatment approach.

Concepts: Medical terms, Medical statistics, Chromosome, Teeth, Hyperdontia, Dental anatomy, Cleidocranial dysostosis, Permanent teeth


In this review, we aimed to depict the clinical, radiological, and genetic features of cleidocranial dysplasia (CCD) and to suggest management guidelines, based on our experience of 8 cases, with an emphasis given to dental complications.The most common craniofacial features of CCD that stand out are a patency of the anterior fontanelle, an inverted pear-shaped calvaria, a hypertelorism, a general midface retrusion, and a mandible prognathism, associated with an excessive mobility of the shoulders, a short stature, and teeth abnormalities such as supernumerary teeth and failure of eruption, in particular. RUNX2 is the only gene in which mutation is known to cause CCD, but mutations are detected in only 65% of all patients with a clinical diagnosis of CCD. Panoramic radiography is a valuable adjunct in confirming the diagnosis of CCD.Our experience allowed us to conclude that orthodontically aided eruption should always be attempted. However, to stabilize the occlusion and to improve facial esthetics, we recommend associated orthognathic surgery. When orthodontic treatment is partially efficient, prosthetic treatment options bring satisfactory results, in terms of occlusion. Nevertheless, when orthodontic treatment fails, we recommend to preserve as many native teeth as possible, and to combine orthognathic preprosthetic surgery and implant-supported prosthesis.In any case, an individualized treatment protocol, depending on the needs and demand of the patient, the age at diagnosis and social and economic circumstances, should be put forward.

Concepts: Genetics, Cancer, Oral and maxillofacial surgery, Orthodontics, Haploinsufficiency, Hyperdontia, Fontanelle, Cleidocranial dysostosis


Mesiodentes are the most frequently encountered supernumerary teeth. Recently, reports of double mesiodens have increased, which may be due to the availability of better diagnostic methods. This article discusses 2 cases of double mesiodens with varying clinical presentations. In addition, the literature related to the etiology, clinical presentation, diagnosis, and management of mesiodentes is reviewed.

Concepts: Greek loanwords, Hyperdontia, Supernumerary body parts


Numerical anomalies, either addition or deletion, are quite a common findings in human dentition. However, it is extremely rare to find both hypodontia and hyperdontia simultaneously in the same individual. This condition is referred as concomitant hypohyperdontia (CHH). Aetiology of this condition is still obscure. The prevalence of CHH has been reported to be between 0.002% and 3.1%. This case report highlights a rare occurrence of bimaxillary CHH represented by the absence of both mandibular central incisors and presence of two supernumerary teeth in the maxillary anterior segment. The rarity of such condition of mixed hypodontia as well as hyperdontia in single human dentition prompted the author to report the case.

Concepts: Teeth, Tooth, Maxillary central incisor, Hyperdontia, Mandibular central incisor, Hypodontia, Oral pathology, Supernumerary body parts


Most mesiodens remain impacted and can affect the growth and development of adjacent permanent teeth. Impacted mesiodens are usually located in an intraosseous position associated with complicated anatomical structures, necessitating minimally invasive surgical approaches. This article demonstrates a simple customized surgical stent for extraction of impacted mesiodens. Its use and advantages are described.

Concepts: Medicine, Surgery, Physician, Minimally invasive, Anatomy, Hyperdontia, Supernumerary body parts


Teeth in excess number than the normal count are called supernumerary teeth. They can be either unilateral or bilateral and single or multiple, found at any place in the dental arch, but most commonly found in the anterior maxillary region. Supernumerary teeth are commonly associated with syndromes when present in more numbers, but can be idiopathic. The present study shows a case report of a 16-year-old female patient who reported with overretained deciduous teeth. A panoramic radiograph showed multiple impacted supernumerary teeth. Based on clinical features and radiographic examination, a diagnosis of idiopathic hyperdontia was given. In such types of patients, management must be planned by a multidisciplinary approach.

Concepts: Medical terms, Medical imaging, Number, Teeth, Tooth development, Hyperdontia


A common disorder of human dentition is the existence of supernumerary teeth. Impacted supernumerary teeth occur most frequently in the maxillary incisor area and are termed mesiodens. We conducted whole-exome sequencing of non-syndromic Japanese individuals possessing supernumerary teeth to identify genes and/or loci involved in the pathogenesis of the condition.

Concepts: Life, Mammal, Primate, Teeth, Tooth, Hyperdontia, Heterodont, Supernumerary body parts


Crouzon syndrome (CS) is an autosomal dominant disorder characterized by craniofacial deformities caused by the early closure of cranial sutures. It is diagnosed by the presence of a flat sphenoid bone, protrusion of eyeballs (exophthalmos), and midfacial hypoplasia. Although hypodontia is usually present in cases with CS, supernumerary teeth are rarely seen. A 16-year-old male patient with CS was referred to our clinic. He had a high forehead, beaked nose, hypertelorism, palpebral ptosis, and asymmetrical orbits. Bilateral multiple supernumerary teeth were observed in his upper and lower jaws. Early diagnosis of CS is helpful in dental and craniofacial treatment. Because of multiple facial and oral problems, this patient required a multidisciplinary treatment approach.

Concepts: Medical terms, Diagnosis, Syndromes, Skull, Oral and maxillofacial surgery, Hyperdontia, Forehead, Crouzon syndrome


Bilaterally mandibular and maxillary fourth molars, concomitant to hypodontia, are uncommon. These dental anomalies, called hypohyperdontia, are rare and etiology is not well defined. Several complications may occur as a consequence of supernumerary teeth, such as teeth impaction, resorption of adjacent teeth, and development of cysts and tumors. The authors present an uncommon occurrence of three-fourth molars concomitant to hypodontia and dentigerous cyst associated with impacted mandibular second and third molars in a nonsyndromic patient. The authors attempt to discuss the occurrence of bilaterally fourth molars and reinforce the importance of clinical approach, considering risks and benefits for the patient.

Concepts: Teeth, Cyst, Fecal impaction, Hyperdontia, Oral pathology, Dentigerous cyst


A Thai mother and her two daughters were affected with tricho-rhino-phalangeal syndrome type I. The daughters had 15 and 18 supernumerary teeth, respectively. The mother had normal dentition. Mutation analysis of TRPS1 showed a novel heterozygous c.3809_3811delACTinsCATGTTGTG mutation in all. This mutation is predicted to cause amino acid changes in the Ikaros-like zinc finger domain near the C-terminal end of TRPS1, which is important for repressive protein function. The results of our study and the comprehensive review of the literature show that pathways of forming supernumerary teeth appear to involve APC and RUNX2, the genes responsible for familial adenomatous polyposis syndrome and cleidocranial dysplasia, respectively. The final pathway resulting in supernumerary teeth seems to involve Wnt, a morphogen active during many stages of development. © 2016 Wiley Periodicals, Inc.

Concepts: Family, Protein, Protein structure, Amino acid, Acid, Familial adenomatous polyposis, Hyperdontia, Cleidocranial dysostosis