Color Atlas of Oral Diseases in Children and Adolescents. George Laskaris
• No treatment is required, since the affected teeth are asymptomatic.
Odontomas
Definition
• Refers to odontogenic hamartomatous "tumors" containing dental calcified tissues.
Etiology
• Unknown. These structures are malformations rather than tumors, originating from the dental tissues or their formative elements.
Occurrence in children
• Rare (0.15 per thousand).
• These are the most frequent odontogenic "tumors" (67%).
Localization
• Compound and mixed odontomas more frequently in the anterior maxilla.
• Complex odontomas more frequently in the premolar/molar region of both jaws.
• Primary dentition is rarely involved (2% of the cases).
Clinical features
• Odontomas are asymptomatic and frequently diagnosed radiographically (Fig. 1.14).
• They are classified in two major types. Compound odontomas are masses composed of multiple, discrete, small, tooth-like formations with well-recognized dental hard tissues, whereas complex odontomas are a more homogeneous mass of disorganized different anomalous dental tissues. Sometimes both types exist simultaneously, and the defect is termed mixed odontoma.
Complications
• Frequently (30–50%), they cause disturbance or total failure of eruption of the adjacent permanent teeth.
Treatment
• Surgical removal of the odontoma and, in case of eruption disturbances of the adjacent permanent teeth, orthodontic treatment.
Fig. 1.12 Enamel pearl in the cervical furcation of an upper first molar
Fig. 1.13 Radiological features of enamel pearl in the root of an upper first molar
Fig. 1.14 Radiological features of odontomas in the upper anterior region resulting in eruption failure of the adjacent tooth
Defects in Location
These defects result from etiological factors acting during the initiation and proliferation stages of dental development.
Ectopic Localization, Eruption
Definition
• Refers to a defect characterized by the eruption of a normal tooth into another location in the dental arch.
Etiology
• The defect results from ectopic placement of the tooth bud, or an irregular eruption path (Fig. 1.15). This is either caused by congenital migration of the tooth bud at the start of embryogenesis, related to genetic and environmental factors, or by displacement of the tooth during eruption, related to local factors.
• Local factors implicated are tooth-dental arch size discrepancy, prolonged primary tooth retention, presence of clefts, ankylosis, cystic or neo-plastic formations, trauma. Generalized factors implicated are endocrine deficiency, febrile disease and irradiation.
Occurrence in children
• Ectopic location, rare.
• Ectopic eruption, 0.9–2.0%.
• Females more frequently affected than males (2:1).
Localization
• Canines and incisors.
• First permanent molars.
• Maxillary teeth more frequently affected than mandibular (3:1).
Clinical features
• A radiographically normal tooth located or erupting at an abnormal site.
Complications
• Frequently, ectopic localization/eruption is followed by impaction of the tooth concerned. Resorption of the adjacent teeth can also be found in some cases, particularly in the case of permanent molars.
Treatment
• Orthodontic treatment. Combined surgical-orthodontic approach in case of impaction.
Defects in Number
These defects result from the action of various etiological factors during the initiation and proliferation stages of the dental development.
Anodontia, Hypodontia
Definition
• Refers to a defect characterized by congenital absence from the dental arch of some teeth (hypodontia) or all of them (anodontia) (Figs. 1.16, 1.17). Severe hypodontia is also termed oligodontia.
• Anodontia and hypodontia may affect both the primary and permanent dentition. Pseudohypodontia is characterized by the absence of teeth from the dental arch due to impaction, delay of eruption, or early exfoliation.
Etiology
• The defect results from dental lamina obstruction or disruption during the early stages of embryogenesis, caused by abnormal activity of local, systemic, and genetic factors. Genetic factors, usually multigenic, have been strongly implicated.
• Hypodontia and anodontia are frequently associated with more than 70 genetic disorders and syndromes, primarily with those characterized by ectodermal involvement, such as the ectodermal dysplasias and the following syndromes: Rieger’s, incontinentia pigmenti, Robinson’s, Seckel’s, orofaciodigital, focal dermal hypoplasia, Hallermann-Streiff, oculoden-todigital, Russell-Silver, chondroectodermal dysplasia, frontometaphyseal dysplasia, craniofacial dysplasia, and others. It is also a frequent finding in patients with cleft lip and cleft palate.
Occurrence in children
• Anodontia: rare.
• Hypodontia of primary teeth: 0.1–0.7%.
• Hypodontia of permanent teeth, excluding third molars: 3.0–7.5%.
• In hypodontia, two or more teeth are involved in 50% of the cases.
• Considerable ethnic variation.
Localization
• Third molars, upper lateral incisors, second premolars.
Clinical features
• Missing teeth, spacing, and occasionally abnormal location in the remaining teeth.
Complications
• Aesthetic and mastication problems.