Amelogenesis imperfecta. This is a radiographic view of amelogenesis imperfecta showing the altered thickness and shape of the enamel crown that is characteristic of this disease. In this patient the condition was inherited as an autosomal dominant - PowerPoint PPT Presentation

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Amelogenesis imperfecta. This is a radiographic view of amelogenesis imperfecta showing the altered thickness and shape of the enamel crown that is characteristic of this disease. In this patient the condition was inherited as an autosomal dominant

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Title: Amelogenesis imperfecta. This is a radiographic view of amelogenesis imperfecta showing the altered thickness and shape of the enamel crown that is characteristic of this disease. In this patient the condition was inherited as an autosomal dominant


1
  • Amelogenesis imperfecta. This is a radiographic
    view of amelogenesis imperfecta showing the
    altered thickness and shape of the enamel crown
    that is characteristic of this disease. In this
    patient the condition was inherited as an
    autosomal dominant trait..

2
  • Hypodontia. This radiograph shows a retained
    deciduous, mandibular second molar. Note that the
    first premolar is in place, fully erupted, and
    apparently functional. There may be carious
    involvement of the distal aspect of the crown of
    the deciduous second molar.

3
  • This photograph presents a clinical view of a
    nine-year-old boy who has ectodermal dysplasia, a
    condition which affects all ectodermally-derived
    structures. It is inherited as both an X-linked
    and an autosomal recessive trait. Note that the
    hair is sparse and there is an absence of both
    the eyebrows and eyelashes. Fingernails and
    toenails are affected as well. What oral findings
    might you expect?

4
  • Hypodontia associated with ectodermal dysplasia.
    This photograph shows an intraoral view that is
    characteristic of patients with ectodermal
    dysplasia. In this case only the two maxillary
    canine teeth have developed. The secondary
    dentition was also affected in this patient, and
    there were no succedaneous replacements, even for
    these two primary teeth. Because of the absence
    of teeth, alveolar bone also fails to form.
    Patients with ectodermal dysplasia are best
    treated through provision of full upper and full
    lower dentures, which must be replaced at regular
    intervals as growth takes place.

5
  • False anodontia. This frame shows an interesting
    clinical phenomenon. This nine-year-old girl
    presented clinically with an "absence of teeth".
    Radiographs, however, revealed the presence of
    teeth beneath the existing gingiva. This
    condition was caused by the overgrowth of gingiva
    as a result of a phenomenon called gingival
    hyperplasia (increased cellular proliferation).
    In this case, the condition was triggered by the
    gradual and continual eruption of the teeth. As
    the teeth emerge from the alveolar process, the
    gingiva overgrows and keeps pace with the rate of
    eruption. Patients with this condition are best
    treated by regular gingivoplasty and gingivectomy
    to allow normal function and aesthetics. Gingival
    overgrowth can also be initiated in patients
    taking Dilantin (antiseizure medication),
    Cylcosporine (immunosuppressive drug) or calcium
    channel blocker, particularly Nifedipine
    (treatment of angina and hypertension). Good oral
    hygiene has been shown to reduce the severity of
    drug-induced gingival hyperplasia.

6
  • Supernumerary teeth. This clinical view shows a
    supernumerary tooth which has erupted in the
    mid-line between the left and right maxillary
    central incisors. The mesiodens, as it is called,
    is one of the more common forms of supernumerary
    teeth. In this case the supernumerary tooth was
    acceptable aesthetically, and therefore, no
    treatment was provided to the patient. A less
    esthetically acceptable example of a mesodens is
    shown here. Not all supernumerary teeth resemble
    a normal tooth in either size or shape. Such
    teeth are often called accessory teeth.

7
  • Supernumerary teeth. This is an example of an
    impacted supernumerary tooth (found in the
    maxilla between the lateral incisor and canine)
    that was found during a routine radiographic
    examination. Multiple supernumerary teeth, many
    of them impacted, are characteristically found in
    cleidocranial dysostosis. Gardner's Syndrome is
    another condition characterized by the occurence
    of multiple, impacted supernumerary teeth. This
    disease is of interest to the dental profession,
    because the presence of the supernumerary teeth,
    and multiple osteomas in the mandible and
    maxilla, may lead to its diagnosis.

8
  • Dens-in-dente (Dens invaginatus). This radiograph
    show an example of what happens when there is a
    distortion of the enamel organ. As a consequence,
    an aberrant crown forms in which there is
    commonly a communication between the surface of
    the crown and the pulp chamber. Carious
    involvement of this usually deep pit in the crown
    leads to bacterial invasion of the dental pulp.
    This radiograph demonstrates bony tissue
    breakdown as a consequence of a severe
    inflammatory response in the pulp of this tooth.
    There is a large radiolucency at the apex of this
    tooth. Also note that this tooth has a widened
    pulp canal inconsistent with the patient's age
    (compare this canal with that of the adjacent
    canine tooth). Secondary dentin formation that
    would have resulted in normal narrowing of this
    canal did not take place because of the death of
    the pulp.
  • Dens-in-dente. This is another example of a
    "tooth within a tooth", but there is no evidence
    of a connection between the surface of the crown
    and the dental pulp.

9
  • Gemination. This clinical view reveals the
    presence of a rather large lateral incisor. Count
    the teeth. How many incisors are there? This
    oversized tooth is a result of gemination or
    twinning of the enamel organ during development.
    This partial splitting results in a larger
    template for the crown, and the clinical crown
    becomes much larger than normal. Such large
    teeth, often with clefts in their surfaces,
    should be considered twinned teeth if the proper
    number of teeth are present
  • Gemination. This is a radiograph of another
    patient showing that in a "twinned" tooth, the
    pulp chamber is often divided into two chambers
    within the single partially divided crown of the
    tooth. Notice that there is a single pulp canal.

10
  • Fusion. In this case, how many teeth are present?
    This is a clinical example of fusion. Fusion
    occurs when neighboring toothbuds fuse, which as
    in gemination also results in a single
    larger-than-normal tooth. Counting the teeth in
    this mandibular arch should have revealed the
    absence of a right lateral incisor. The lateral
    incisor and the central incisor have fused to
    make a single "macrodont" tooth. Fused teeth
    commonly have a clinical crown that is fissured,
    as you see here. They also usually have two pulp
    chambers and two pulp canals, but these
    characteristics depend on the time at which
    fusion took place. A second example of fusion is
    shown here.

11
  • Dilaceration. This photograph, and frame 17 show
    examples of dilaceration, or curving of the
    roots. This results from a distortion of
    Hertwig's root sheath during development. Such
    teeth may present severe problems for either
    endodontic treatment or extraction. They are
    usually vital and functional. Surprisingly,
    eruption does not seem to be affected by the
    altered shape of the roots.

12
  • Accessory roots. This is an example of accessory
    root formation that can occur as a result of an
    alteration in root sheath development.

13
  • Rootless tooth. A 31-year-old male patient
    complained of a molar that was "loose".
    Radiographs revealed an absence of roots. Because
    of the high mobility of the tooth, it was
    extracted. For whatever reason, proliferation of
    Hertwig's root sheath abruptly ceased before much
    of the roots were formed. The cervical line of
    the tooth is clearly evident.
  • Rootless teeth. This is another example of a
    patient who complained of "loose" teeth.
    Radiographs revealed only short stubby roots. The
    cervical line of the tooth is clearly evident,
    and the staining is due to tetracycline. For
    whatever reason, proliferation of Hertwig's root
    sheath abruptly ceased, but is not known whether
    tetracycline was a factor

14
  • namel pearl. An enamel "pearl" is demonstrated in
    this photograph of an extracted tooth. The
    "pearl" lies in the furca (groove) between the
    mesial and distal roots of this maxillary molar.
    The differentiation of ameloblasts, and the
    formation of small amounts of enamel below the
    level of the cervical occurs with some
    regularity. The production of an actual "enamel
    pearl" is not as commonly seen. Radiographically,
    this would have been recognized as a very bright
    radiopacity overlying the furcal area of this
    tooth. The presence of these ectopic enamel
    deposits can have significant consequences for
    the periodontal health of these teeth. Notice
    that the palatal root of this tooth is affected
    by dilaceration.

15
  • Hutchinson's or "Screwdriver-shaped" incisors.
    This clinical photograph presents an example of
    peg-shaped and misshapen incisors in both the
    maxilla and the mandible that occur in patients
    with congenital syphilis. Another anomaly,
    "mulberry molars," is shown in frame 22. There
    is narrowing of the incisal third of the
    maxillary and mandibular incisors, a form which
    has been described as screwdriver-shaped. The
    Treponemes (T. pallidum) that cause syphilis
    cross the placenta, and the fate of the infected
    fetus depends on the duration and the stage of
    the mother's disease.

16
  • Mulberry molars. This clinical photograph
    presents a second example of the effects of
    congenital syphilis on the developing dentition.
    The first anomaly, "screw-driver shaped" incisors
    is shown in the previous frame. The blebbed
    surface of the mulberry molar wears away rather
    quickly, and carious involvement of the multiple
    pits is not an uncommon feature of these teeth.

17
  • Enamel Hypoplasia. Hypoplasia commonly leads to
    an altered tooth form as a result of a reduction
    in the quantity of the organic matrix produced.
    Not uncommonly there is also a defect in the
    mineralization process. Hypoplastic and
    hypomineralization defects usually occur as a
    consequence of disease states. Because of the
    pitting, and other structural defects,
    hypoplastic enamel is often more susceptible to
    dental caries. This clinical photograph shows
    severe hypoplasia in the incisal third of the
    crowns with loss of some of the enamel.

18
  • Enamel Hypoplasia. In this patient, hypoplasia
    resulted in enamel pitting that predisposed these
    teeth to carious attack.

19
  • Enamel Hypomineralization. This clinical view
    presents an example of "snow-capped" teeth. This
    phenomenon is a form of hypomineralization.
    Notice that all four incisor teeth are affected
    with the central incisors showing the greatest
    defect. Only the maxillary teeth were involved in
    this patient. This condition may be due to a
    dietary deficiency, a systemic disease, or to an
    inherited defect in mineralization.

20
  • Enamel hypoplasia associated with rickets. This
    is a case of avitaminosis D that results in the
    clinical condition of Vitamin D-dependent
    rickets. Severe hypoplastic defects are present
    in all eight maxillary and mandibular permanent
    incisors. This gives some idea of the time in
    which the nutritional deficiency took place. In
    some cases, vitamin C and vitamin A deficiencies
    can lead to similar hypoplastic defects in
    enamel.

21
  • Enamel fluorosis (mottled enamel). Low-grade
    pitting, followed by pigmentation of the pitted
    areas can be seen in teeth when exposure levels
    of fluoride exceed 1-2 parts per million in the
    drinking water, or if inappropriate fluoride
    supplementation is carried out during early
    infancy and childhood. The degree of fluorosis
    seen in this patient suggests that fluoride
    levels in the drinking water exceeded 5 parts per
    million. The high levels of fluoride incorporated
    into the hydroxyapatite crystals of the enamel
    renders these teeth extremely resistant to
    carious attack. In fact, the beneficial effects
    of fluoride were recognized after epidemiological
    studies of communities in which fluorosis was
    endemic revealed a significant reduction in the
    prevalence of dental caries. A second example of
    fluorosis is shown here.

22
  • Amelogenesis imperfecta. This patient
    demonstrates an inherited form of enamel
    hypomineralization in which tooth form is
    reasonably good. Any genetically inherited form
    of hypomineralization or hypoplasia is called
    amelogenesis imperfecta, and there are at least
    13 distinct inheritance patterns that have been
    characterized, including both autosomal and
    sex-linked recessive and dominant forms.. The
    thinness of the enamel and its poor attachment to
    the underlying dentin lead to the rapid loss of
    the enamel from the surface of the crown. The
    brown areas seen in this photograph represent
    discolored areas of exposed dentin. A second
    patient is shown here.

23
  • Amelogenesis imperfecta. This is different
    patient presenting a more severe type of
    amelogenesis imperfecta. In this case there is
    both a hypoplasia and a hypomineralization of the
    enamel.

24
  • Amelogenesis imperfecta. This is a radiographic
    view of amelogenesis imperfecta showing the
    altered thickness and shape of the enamel crown
    that is characteristic of this disease. In this
    patient the condition was inherited as an
    autosomal dominant trait..

25
  • Dentinogenesis imperfecta. Dentinogenesis
    imperfecta is often associated with a systemic
    condition known as osteogenesis imperfecta in
    which bone is affected, as well as teeth. In the
    latter condition, a peculiar blue coloration of
    the sclera of the eye may sometimes be seen.
    Dentinogenesis imperfecta is characterized by the
    presence of a pearl-gray coloration of the teeth
    and an early loss of the enamel, particularly
    from incisal and occlusal surfaces. The loss of
    the enamel is the result of an abnormal
    dentinoenamel junction. In addition, the dentin
    is excessively "soft" due to the high amount of
    interglobular dentin, which is hypomineralized,
    and thus support for the enamel is poor. The
    peculiar coloration of the tooth is a result of
    the obliteration the pulp chamber, which normally
    gives a pinkish coloration to the dentin. A
    second view is shown in Frame 34 presents a
    radiograph of these teeth showing several
    distinctive features.

26
  • Dentinogenesis imperfecta. Dentinogenesis
    imperfecta is characterized by the presence of a
    pearl-gray coloration of the teeth and an early
    loss of the enamel, particularly from incisal and
    occlusal surfaces. The loss of the enamel is the
    result of an abnormal dentinoenamel junction. In
    addition, the dentin is excessively "soft" due to
    the high amount of interglobular dentin, which is
    hypomineralized, and thus support for the enamel
    is poor. The premature loss of enamel exposes the
    dentin to occlusal forces that can lead to severe
    attrition. As in this patient, full crown
    coverage is often used to preserve occlusal
    height. A another view is shown in frame 33.
    Frame 35 presents a radiograph of these teeth
    showing several distinctive features.

27
  • Dentinogenesis imperfecta. This is a radiograph
    of the previous patient showing several
    distinctive features of dentinogenesis
    imperfecta. Clinical photographs are shown in
    frame 33 and frame 34. The teeth have a
    "lollipop" look, i.e. a bulbous crown that
    appears to be attached to a narrow root. There is
    a marked reduction in the size of the pulp
    chambers and pulp canals, with an absence of the
    canals in at least one of these teeth. It is not
    uncommon for these teeth to be painful, but the
    cause of the pain is not fully understood. In
    contrast, it is uncommon for patients who have
    amelogenesis imperfecta to experience pain, even
    in teeth that have been denuded of their enamel.
    A closer look is shown in this radiograph.

28
  • Dentinal dysplasia. This is a rare phenomenon in
    which there is abnormal dentin development and
    aberrant root formation. The dentin is poorly
    formed with large amounts of interglobular dentin
    present, and pulp chambers and pulp canals are
    virtually nonexistent. These teeth quickly become
    mobile, and are commonly extracted because they
    cannot withstand the forces of occlusion.

29
  • Hypercementosis. This radiograph reveals an
    excessive radiopacity surrounding the root.
    However, careful inspection will reveal the
    presence of a radiolucency (the periodontal
    ligament space) and a radiodense line (the lamina
    dura).

30
  • Concrescence. This frames shows the clinical
    features of the condition known as concrescence
    wherein hypercementosis has resulted in the union
    of two or more teeth. The histological appearance
    is shown in frame 38. The cause of this
    condition is not understood, but it presents
    significant problems for extraction of these
    teeth. Normal function, however, seems to be
    unaffected.

31
  • Concrescence. This frames shows the histological
    features of the condition known as concrescence
    wherein hypercementosis has resulted in the union
    of two or more teeth. The clinical appearance is
    shown in frame 37. Note that there is an absence
    of the intervening alveolar bone.
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