Case• 27. Discoloured anterior teeth
A 22-year-old woman presents at your general dental practice surgery complaining of the poor appearance of her teeth. What is the cause and what treatment is appropriate?
She is unhappy with the colour of the teeth which she feels are becoming darker. She is very conscious of them and realizes that she is reluctant to smile because of their appearance.
History of complaint
The teeth looked slightly grey on eruption but they have slowly darkened.
The patient has had very little dental treatment but received regular preventive care from your practice until the age of 16. Your notes record that she was given oral fluoride supplementation as a child. This was provided as fluoride drops at a dose of 0.25mg daily from birth to 2 years and 0.5 mg daily as tablets from 2 to 4 years, rising to 1 mg daily from 4 to 12 years of age.
The patient is fit and healthy with no relevant medical conditions noted on her medical history questionnaire.
▪ What are the possible causes of discolouration of teeth? What features of each cause aid differential diagnosis?
The possible causes and relevant features are presented in Table 27.1.
Dietary stains such as tea, coffee, cigarette smoke, betel quid
Pigments produced by the normal oral flora, usually the subgingival flora
|Usually worse around gingival margin and in less well cleaned areas because these agents stain pellicle and plaque rather than enamel.|
|Turner tooth||Infection of the deciduous predecessor causes enamel hypoplasia in a permanent tooth and the porous enamel absorbs extrinsic stains. Tooth shape abnormal.|
|Dental caries||Associated with softening. Characteristic distribution of lesions. Slowly progressing and dentine caries are the types most frequently stained.|
|Blood pigments||Seen most frequently in nonvital teeth (as a result of pulp necrosis). Rarely may affect all teeth in conditions including rhesus incompatibility (in the deciduous teeth only), porphyria and hyperbilirubinaemia. Colour ranges from dull red through brown to grey or black.|
|Tetracycline staining||Caused by administration of tetracyclines during tooth formation. When severe, this is a generalized green, brown or yellow colour, darkening with time. The teeth may fluoresce under ultraviolet light in the early stages but this reduces as the colour darkens. When mild there may be a chronological banding pattern with horizontal lines of discoloured enamel corresponding to individual courses of tetracycline. Tooth shape is normal.|
|Fluorosis||Varies from mild flecks of opaque white enamel to severely hypoplastic patches which take up extrinsic stain. The latter is only seen in areas where fluorosis is endemic. The mildest effects are impossible to tell from the opaque flecks seen when water fluoride concentration is very low. Affects all teeth. Moderately affected cases of endemic fluorosis may have an apparent chronological pattern of fine white lines associated with periods of exposure to higher doses. Tooth shape normal unless condition is severe.|
|Amelogenesis imperfecta||Numerous types. Affects all teeth, though some forms are much milder in the deciduous dentition. Colour change varies and is secondary to either hypoplasia (thin hard translucent enamel through which dentine is visible), hypocalcification (chalky white opaque soft enamel) and hypomaturation (patchy distribution of white opacities). Affected areas may also take up extrinsic stain. Tooth shape may be normal and some types have a vertical banding, pitting or ridging pattern. Family history will be positive in many cases. Mild types are difficult to distinguish from fluorosis.|
|Dentinogenesis imperfecta||All teeth are an even grey-brown colour with altered translucency. The shape of the tooth crowns is normal but the roots are thin and taper sharply. There is gradual pulpal obliteration by dentine. There may be a family history and, in some cases, osteogenesis imperfecta is associated. Enamel fractures from the dentine and severe wear follow shortly after eruption.|
|Regional odontodysplasia||Affects a group of adjacent deciduous and permanent teeth on one side of midline. Enamel hypoplasia leads to uptake of extrinsic stain and yellow cementum may be present over the crown. Characteristic defects on radiography include thin enamel and dentine, large pulps. Affected teeth often fail to erupt.|
|Chronological hypoplasia||Horizontal band(s) of enamel hypoplasia, each associated with a specific insult, usually a severe illness or metabolic upset including severe attacks of the common viral diseases of childhood. Affected bands are abnormal enamel which may be pitted, hypoplastic, rough, opaque or completely absent, and also take up extrinsic stain.|
|Age change||Teeth become yellower and slightly darker with age. This is an even colour change and it is usually mild.|
▪ What specific questions would you ask this patient? Explain why.
Did she suffer any illness between birth and 6 years? This might account directly for the discolouration or could have been the reason for antibiotic treatment with tetracyclines. Further information on chronological hypoplasia will be found in Case 56.
What toothpaste was used during fluoride supplementation? The fluoride supplementation regimen provided for this patient was recommended during her childhood, but the doses would now be considered too high. On these doses, a small proportion of patients would be expected to show mild fluorosis. More severe fluorosis would be associated with a second source of fluoride. The most probable additional source would be ingestion of adult-formula fluoride toothpaste, though living in an area with fluoridated water should also be excluded.