Color Atlas of Oral Diseases in Children and Adolescents. George Laskaris
Orthodontic and prosthetic treatment, implants.
Fig. 1.15 Ectopic location and eruption of a lower lateral incisor
Fig. 1.16 Anodontia in a patient with hypohidrotic ectodermal dysplasia
Fig. 1.17 Hypodontia in a patient with hypohidrotic ectodermal dysplasia
Supernumerary Teeth
Definition
• Refers to a condition characterized by the presence of supernumerary teeth in the dental arch. These teeth may be either of normal morphology (supplemental) or, more frequently, are anomalous, with irregular size and shape (accessory).
Etiology
• The defect results from continuing abnormal activity of the dental lamina, which leads to the formation of supernumerary tooth buds. The etiology of the defect is multifactorial, although there is a strong genetic background under the control of several different loci.
• Frequent finding in patients with Gardner’s syndrome, cleidocranial dysplasia, Hallermann-Streiff syndrome, and orofaciodigital syndrome type I.
Occurrence in children
• Primary dentition 0.3–0.6%, permanent dentition 1.0–3.5%.
• More frequently observed in the maxilla, by a ratio of 9:1.
• Supernumeraries in the primary dentition may be followed by supernumeraries in the permanent dentition in 30–50% of cases.
• Males more frequently affected than females (2:1).
• Ethnic variation.
Localization
• Near the middle line in the incisal region of the maxilla (mesiodens).
• Beyond the third molar (distomolars) or in the molar area (paramolars).
Clinical features
• Supplemental or conical, tuberculate, and odontoma-like shape (Figs. 1.18, 1.19).
• 75% of these teeth remain impacted in the bone, and are diagnosed only radiographically.
Complications
• In the case of impacted supernumerary teeth, there is an increased possibility of inhibited or delayed eruption of adjacent teeth. If the supernumeraries erupt in the dental arch, they usually cause functional and aesthetic problems.
Treatment
• Removal of the supernumerary teeth and orthodontic treatment of the affected area.
Defects of Eruption and Exfoliation
These defects result from the action of various etiological factors during the eruption stage of the dental development.
Eruption Defects
Early eruption
Definition
• This refers to accelerated eruption of either the primary or permanent teeth. In addition, the term "natal teeth" refers to primary teeth that have already erupted at birth (Fig. 1.20), whereas neonatal teeth are teeth erupting within one month after birth. These two defects usually represent regular primary teeth with imperfect roots, although sometimes they are supernumerary.
Etiology
• Multifactorial, implicating local, systemic, and strong genetic factors. Early eruption of primary and permanent teeth can be found in the following syndromes: pycnodysostosis, hemihypertrophy, holoprosencephaly, Sotos, Klippel–Trenaunay–Weber, Sturge–Weber.
• Excluding cases of isolated random occurrence of natal teeth, this defect may be associated with certain genetic disorders, such as the following syndromes: Ellis–van Creveld, Hallermann–Streiff, Saldino–Noonan, odonto-onychodysplasia, pachonychia congenita, X-linked ectodermal dysplasia.
Complications
• Frequently, natal teeth cause great difficulties in breast feeding, since they are usually lower central incisors.
Treatment
• In case of early eruption, no treatment is required. In case of natal teeth, extraction because of feeding problems is indicated.
Fig. 1.18 Erupted supernumerary teeth (mesiodens) in the upper anterior area
Fig. 1.19 Radiological features of upper anterior supernumerary teeth, resulting in eruption delay of the adjacent central incisors
Fig. 1.20 Natal teeth in a newborn baby
Delayed eruption
Definition
• This refers to delay of eruption by more than six months for primary teeth, or more than 6–10 months for permanent teeth (Figs. 1.21, 1.22).
Etiology
• Delayed eruption can be caused by either local or systemic factors and genetic disorders.
Local factors
• Space loss and dental crowding
• Trauma, radiation
• Supernumerary teeth, odontomas
• Delay of primary teeth exfoliation
• Early primary teeth exfoliation
• Dentigerous cyst, eruption cyst
• Dilaceration
• Pathological local defects of bone or soft tissues
Genetic/systemic disorders
• Vitamin D–resistant rickets
• Hypothyroidism
• Fibrous dysplasia
• Pycnodysostosis
• Cleidocranial dysplasia
• Down’s syndrome
• Incontinentia pigmenti
• Gardner’s syndrome
• Focal dermal hypoplasia (Goltz syndrome)
• Osteopetrosis
• Pseudohypoparathyroidism (Albright hereditary osteodystrophy)
• Apert syndrome
• Growth retardation, alopecia, pseudo-anodontia, and