Hypocalcification
Date: 2015-10-07; view: 666.
In this type of AI both primary and permanent teeth erupt with enamel which has a dull, lustreless, opaque white, honey coloured, or light brown surface. The degree to which teeth are affected is not usually evenly distributed around the arch, although there is frequent bilateral symmetry. In severely affected ted the soft enamel wears away rapidly leaving rough, discoloured, highly sensitive exposed to the oral environment. In the same teeth portions of the enamel, especially towards the cervical region of the crown, may be more highly mineralized and may resist wear. A few reported cases have shown delayed or failed eruption of teeth, the latter exhibiting evidence of coronal resorption. Radiographic contrast between enamel and dentine is absent and the crowns may appear uneven from irregular loss of enamel. Supragingival calculus is often abundant in affected individuals with associated gingivitis or periodontitis. The organic matrix of the enamel appears relatively normal on histological examination.
Hypomaturation
The descriptive term snow-capped teeth has been given to this type of hypomaturation defect. The hypomineralized defects are limited to the incisal portions of crowns in anterior teeth and to the occlusal portions in posterior teeth. The affected areas of the crown are mottled with either flecks of opaque white enamel or larger demarcated lesions resembling opaque white ground glass. Maxillary teeth are always involved to a greater extent than mandibular teeth. In the maxilla incisors and canines are commonly affected but the lesions may extend backwards to involve premolars and even molars. The defect appears to be conveyed by an autosomal dominant gene of variable expressivity and occasional lack of penetration.
Treatment
The treatment of children with enamel defects requires more consideration than simply mechanical treatment of the teeth. Children with amelogenesis imperfecta, in particular, may be subjected to teasing. This is a serious issue and requires the most sensitive handling by professionals. Affected adult family members will often describe their own childhood in lurid and painful terms. Many children will not admit to this from the outset and need to be given 'permission' (with their parent's knowledge) to contact the practitioner at a later date to revisit these issues. Typically, as well as the aesthetics, there may be thermal, contact or osmotic sensitivity of the teeth. Oral hygiene may be poor and irremediable as a result. The occlusion may be compromised by lack of vertical dimension as a result of thinner enamel than normal, or there may be loss of enamel because of poorly mineralized enamel matrix. Some practitioners advocate the early preventive use of full coverage restorations in the primary dentition for these children.
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