symmetrically, hence the presence of a supernumerary in one part of the jaws should
lead to consideration of further supernumeraries elsewhere. Supernumerary teeth may
fail to erupt and may delay eruption of a permanent tooth which is developing deeper
within the jaw. This commonly occurs in the case of a mesiodens. (789HFig. 13.6 (a) and
(b)).
There is a significant association between supernumerary teeth and invaginated teeth
(see 790HSection 13.5.3). There is also an association with palatal clefts, with approx-
imately 40 % of patients with a cleft of the anterior palate having supernumerary
teeth.
Multiple supernumerary teeth are seen in cleidocranial dysplasia as well as in other
syndromes such as oral-facial-digital syndrome type 1 and Gardner syndrome. The
management of supernumerary teeth is discussed in 791HChapter 14.
Key Points
Supernumerary teeth
- 0.2-0.8% of the primary dentition;
- 1.5-3.5% of the permanent dentition;
- 2 : 1 male to female ratio;
- 5 : 1 maxilla to mandible ratio.
792H
Fig. 13.5 Supplemental tooth 12.793H
Fig. 13.6 Supernumerary tooth
delaying the exfoliation of teeth 61, 62,
and the eruption of tooth 21.13.4 ABNORMALITY OF TOOTH SIZE
13.4.1 Crown size
There is a degree of subjectivity regarding what constitutes normal ('ordinary') tooth