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Anomalies of Tooth Structure

Course Number: 651

Alterations in the Size of Teeth

Tooth size is variable among racial groups and between genders. Generally speaking, males have larger teeth than females.7,9 Both genetic and environmental factors can impact the size of the developing teeth.7,97 Microdontia is the term used for teeth that are smaller than normal while macrodontia is the presence of teeth that are larger than usual.7,9,10 Typically, these conditions do not affect the entire dentition.9


In microdontia, the teeth are visibly smaller and may have an altered shape.7 Supernumerary teeth may present as microdonts as well.9 The maxillary lateral incisor tooth (Figure 26) is the most frequently involved and typically demonstrates a peg-shaped crown.7,9,10 Microdontia is associated with hypodontia and occurs more frequently in females.7 Third molar teeth are often affected by microdontia as seen in Figure 27.9 Of note, these same teeth are often congenitally missing.

Figure 26.

Periapical radiograph of a peg lateral incisors, #7 and #10.

Figure 27.

Cropped panoramic image of microdont third molar, #1.


Macrodontia is sometimes called megalodontia or megadontia.7,9,10 Macrodont teeth appear larger and may be associated with crowding, malocclusion, or impaction.9 Often a single tooth or several teeth are involved rather than affecting the entire dentition.7 Macrodontia is associated with hyperdontia and occurs more frequently in males.7 Macrodontia tends to occur in incisor or canine teeth but may also occur in second premolars and third molars.7 Macrodontia terminology should not be applied to teeth that have been altered by gemination or fusion processes which will be discussed next7