Diagnosis & Considerations
Tooth-jaw size discrepancy (primary spacing)
True small tooth size to jaw size discrepancy of such as microdontia or hypodontia can arise from genetics like the MSX 1 and PAX9 genes (Cobourne 2007) and it can be associated with syndromes such as Down’s syndrome, ectodermal dysplasia and cleft lip and palates.
Secondary spacing
Spacing can occur due to environmental factors such as early loss of teeth, obstruction of teeth (like a freenum or mesioden) or lower lip trap causing excessive proclination of teeth.
Clinical Considerations
Soft tissue equilibrium and relapse
In primary spaced dentitions, the teeth are held in a soft tissue equilibrium. Closing spaces will push those teeth outside their equilibrium and it has a high risk of relapse.
Transient spacing
Spacing can be transient such as the normal interdental spacing in the primary or developing dentition.
