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 optic atrophy (GAPO) syndrome
• Mucopolysaccharidosis I, II, VI
• Mucolipidosis II
• Faciogenital dysplasia (Aarskog’s syndrome)
• Cornelia de Lange syndrome
• Schinzel–Giedion syndrome
• Prader–Willi syndrome
• Otodental syndrome
• Robinson’s syndrome
• Amelo–onychohypohidrotic dysplasia
Complications
• Usually, severe dental crowding in the affected area.
Treatment
• In case of delayed tooth eruption caused by local etiological factors, removal of the factor and orthodontic evaluation followed by surgical or orthodontic treatment, or both, when needed.
Ankylosis
Definition
• Ankylosis appears clinically as an eruption defect, frequently followed by irregular occlusion. It is characterized by occlusal surface retention of the affected teeth, at a level at least 1 mm or more cervical to the adjacent teeth (Fig. 1.23).
Etiology
• The defect is caused by local traumatic and metabolic factors, whereas genetic factors have also been implicated. It is the result of continuing eruption of the adjacent teeth in contrast to the immobilization of the affected teeth.
Occurrence in children
• Primary teeth 1.3–9.9%.
• Coexistence of missing successors 11–20%.
• Permanent teeth, rare compared to primary (1:10).
Localization
• Primary and permanent molars.
• More frequently in the mandible.
• Frequently a bilateral finding.
Clinical features
• Occlusal surface at least 1 mm cervically compared to adjacent teeth.
• Sharp, clear sound on percussion.
• Absence of regular mobility.
• Three clinical forms: mild, moderate, severe.
Radiological features
• Break of periodontal membrane continuity.
• Absence of findings in ankylosed buccal and lingual surfaces.
• Findings in 30% of the cases with ankylosed proximal surfaces (Figs. 1.24, 1.25).
