Handbook of Oral Pathology and Oral Medicine. S. R. Prabhu

variations exist. The global prevalence of fluorosis is reported to be about 32%

      1.13.3 Aetiology/Risk Factors

       A higher than normal amount of fluoride ingestion while teeth are forming

       When the level of fluoride is above 1.5 mg/l (1.5 ppm) in drinking water, dental fluorosis occurs

       The severity of fluorosis is dependent on the dose and time of exposure to fluoride levels

       Other sources of fluoride: toothpastes, mouth rinses, fluoride supplements, beverages (brick tea, tea and butter tea) and food (infant formula, fish, beans, potatoes and wheat)

      1.13.4 Clinical Features

       Severity of fluorosis is dose dependent

       Mild fluorosis: opaque lines following the perikymata

       Moderate fluorosis: the opaque lines merge and more irregular cloudy areas become visible

       Severe fluorosis: enamel is grossly defective with opaque chalky appearance and punched out pits. Extrinsic brown staining in the pits is frequent (Figure 1.11)

       Moderate to severe enamel fluorosis is called mottled enamel

       Teeth with fluorosis are weak but resistant to caries

      1.13.5 Differential Diagnosis

       Turner's hypoplasia

       Hypoplastic teeth in systemic disorders

       Amelogenesis imperfecta

       Early carious lesions

       Tetracycline staining of teeth

      1.13.6 Diagnosis

       History (residence/ migration, water fluoridation, other sources of fluorides in the diet)

       Clinical examination

      1.13.7 Management

       Aesthetic procedures as requiredFigure 1.11 Yellow‐brown discoloration of maxillary incisors due to fluorosis(source: From Mary A. Aubertin. 2014. Common Benign Dental and Periodontal Lesions. In: Diagnosis and Management of Oral Lesions and Conditions: A Resource Handbook for the Clinician. ed. Cesar A. Migliorati and Fotinos S. Panagakos. IntechOpen. doi: 10.5772/57597).

       Close monitoring of sources of fluoride during the first three years of age

       Water fluoridation: 0.7–1 ppm recommended

       Use of fluoride tooth paste after 12 months of age

       Infant formula with fluoridated water to be avoided

       Fluoride supplements only in non‐fluoridated areas

1.14 Tetracycline‐Induced Discoloration of Teeth: Key Features

       Tetracycline is a broad‐spectrum antibiotic commonly used for infections

       Tetracycline has several different analogues such as doxycycline, oxytetracycline, minocycline, chlortetracycline, demeclocycline

       Tetracycline can stain teeth if ingested by the mother in the third trimester or by the child during the years of tooth formation of deciduous and permanent dentition

       The discoloration, which is permanent, varies from yellow or grey to brown (Figure 1.12)

       Administration of tetracycline to pregnant women must be avoided during the second or third trimester of gestation and to children up to eight years of age.

       Tetracycline‐stained teeth must be differentiated from dentinogenesis imperfectaFigure 1.12 Tetracycline‐induced grey/brown discolouration of deciduous teeth in a child(source: by kind permission of Professor Charles Dunlap, Kansas City, Kansas, USA).

1.15 Enamel Pearl: Key Features

       The enamel pearl is a globule of enamel formation located on the root surface (Figure 1.13)

       It is characterized by a core of dentin covered by enamel and may contain a pulp chamber

       Enamel pearl may cause periodontal pockets and periodontitisFigure 1.13 Enamel pearl on the cementum(source: by kind permission of Professor Charles Dunlap, Kansas City, Kansas, USA).

1.16 Talon Cusp: Key Features

       Talon cusp is a rare developmental anomaly presenting as a wisp‐like structure arising from the cervical region of anterior teeth

       Resembles an eagle's talonFigure 1.14 Periapical radiograph of talon cusp on a partially erupted upper left permanent maxillary incisor in an eight‐year‐old boy. Note V‐shaped radiopaque structure overlapping the affected crown with its apex directed incisally(source: Matthew Fergusson, https://en.wikipedia.org/wiki/File:Talon_cusp.png. Licensed under CC BY‐SA 4.0).

       In canines and incisors, it originates usually in the palatal cingulum as a tubercle projecting from the palatal surface

       Its prevalence varies from less than 1% to approximately 8%

       Radiographically, talon cusp appears as appears as a V‐shaped radiopaque structure overlapping the affected crown with its apex directed incisally (Figure 1.14)

       Symptoms include interference with occlusion, irritation of soft tissues, accidental cusp fracture and susceptible to dental caries

1.17 Hutchinson's Incisors and Mulberry Molars: Key Features

       ‘Hutchinson's incisors’ and ‘Mulberry molars’ are dental developmental defects seen in children with congenital syphilis; they are rare conditions

       In Hutchinson's incisors, the incisal edge is either notched or screwdriver shaped. The bulbous crown is short and narrow (‘barrel shaped’). In the centre of the incisal edge a deep vertical central notch may be present (Figure 1.15a)

       Mulberry molars are characterized by multiple rounded rudimentary enamel cusps on the permanent first molars (Figure 1.15b)

       Hutchinson's incisors and mulberry molars are caused by direct invasion of tooth germs by Treponema organisms during tooth developmentFigure 1.15 (a) Hutchinson's incisors of congenital syphilis. Note screwdriver shape and central notch on the crowns of upper and lower permanent incisors. (b) Mulberry molars of