Developmental disorders or anomalies

1
Developmental disorders or anomalies

• A failure or disturbance that occurs during the
  developmental processes causing a lack, excess or
  deformity of a body part.

2
Inherited or Congenital Disorders

• Inherited different from developmental in that
  they are caused by an abnormality in the genetic
  makeup - transmitted from parent to offspring
• Congenital present at birth
• Can be inherited or developmental.congenital
  abnormalities usually have an unknown cause.

3
Developmental Soft Tissue Abnormalities

• Ankyloglossia tongue-tied complete or
  partial fusion of the lingual frenum to the floor
  of the mouth or lingual attached gingiva
• May have problems with speech
• May need frenectomy

4
Commissural Lip Pits

• Epithelium-lined blind tracts located at the
  corners of the mouth
• Congenital lip pit midline of the vermilion
  border of the lip

5
Lingual Thyroid

• Ectopic lingual thyroid nodule a mass of
  thyroid tissue located on the tongue away from
  the normal anatomic location of the thyroid
  gland.
• Appears as a smooth nodular mass at the base of
  the tongue posterior to the circumvallate
  papillae on or near the midline.

6
Developmental Cysts

• A cyst is an abnormal, pathologic sac or cavity
  lined by epithelium and enclosed in a connective
  tissue capsule
• The most common cyst observed in the oral cavity
  is caused by pulpal inflammation and is called
  the radicular cyst
• The residual cyst is a radicular cyst that
  remains after extraction of the offending tooth

7
Developmental Cysts

• Odontogenic related to tooth development
• Nonodontogenic not related to tooth development
• Intraosseous occur within bone
• Extraosseous occur in soft tissue (out of bone)

8
Odontogenic Cysts

• Dentigerous cyst forms around the crown of an
  unerupted or developing tooth.
• This radiograph features the typical example of a
  dentigerous cyst. The well-defined radiolucency
  surrounding the crown of the unerupted molar.
  Cysts of this size are generally asymptomatic and
  are discovered on routine radiographic examination

9
Primordial Cyst

• The difference between primordial and dentigerous
  cysts is illustrated well in this case. A
  dentigerous cyst is associated with the unerupted
  lower molar while the large well-defined
  radiolucency extending from the midline to the
  opposite lower first molar proved to be a
  primordial cyst on biopsy examination.
• Primordial cysts do not involve crowns of
  unerupted teeth.

10
Primordial Cyst
11
Primordial Cyst

• This is a typical example of the primordial cyst
  occurring in the third molar area. No tooth had
  developed so we can assume the cyst originated
  from either the enamel organ prior to
  calcification or from rests of the dental lamina.

12
Odontogenic Keratocyst

• Pre-Operative
• This large odontogenic keratocyst involving the
  angle and ramus (37) was curetted only to
  "recur" two years later as a lesion high in the
  ramus (38)
• Post-Operative
• Because of the tendency to recur, all patients
  should be kept on long-term radiographic and
  clinical observation

13
Calcifying Odontogenic Cyst

• The calcifying odontogenic cyst is less common
  than other odontogenic cysts but displays
  interesting radiographic and histopathologic
  features. It may or may not be associated with an
  unerupted tooth and possesses considerable growth
  potential so that many examples are large and
  somewhat destructive. Any area of the jaw may be
  involved.

14
Calcifying Odontogenic Cyst

• "Ghost Cells"
• These illustrations show the typical morphologic
  pattern of the calcifying odontogenic cyst. An
  odontogenic epithelial membrane lines it with
  columnar basal cells and areas of stellate
  reticulum. There are numerous keratin masses that
  are described as ghost cells . Dystrophic
  calcification is prominent and even melanin
  granules can be seen

15
Lateral Periodontal Cyst

• The lateral periodontal cyst is generally
  small and well demarcated. It occurs most
  frequently in the premolar region and is adjacent
  to vital teeth.
• Radiolucencies are generally ovoid.
• Here are typical examples

16
Gingival Cyst

• This is a good illustration of a small slightly
  bluish gingival cyst on the mandibular gingiva
  between the lateral incisor and cuspid. Gingival
  cysts differ from lateral periodontal cysts only
  by the fact that no significant radiographic
  findings are present in association with the
  gingival cyst.

17
Nasopalatine Canal Cyst

• Arise from remnants of the nasopalatine duct are
  divided into two varieties incisive canal type
  and those originating in the papilla palatina.
  Almost all nasopalatine duct cysts occur within
  the incisive canal and are intraosseous. They may
  occur at any level between the nasal and the oral
  cavity and are always radiolucent. Cysts of the
  papilla palatina show no radiographic changes
  because they are entirely within soft tissue.
• This incisive canal cyst is relatively small but
  of typical location and shape. It has a somewhat
  teardrop shape and shows a well-demarcated
  border.

18
Median Palatal Cyst

• Median palatal cysts occur at the midline of the
  palate posterior to the incisive canal and are
  thought to originate from remnants of epithelium
  remaining after fusion of the palatine processes
  of the maxilla.
• This radiograph is from a 43 year-old female who
  presented with swelling of the midline of the
  palate for two weeks. The radiograph displays an
  ovoid radiolucency at the midline that extends
  quite a distance posteriorly. Note the nasal
  septum that is clearly visible. This lesion must
  be differentiated from the incisive canal cyst
  and from cysts of inflammatory origin associated
  with adjacent teeth. At surgery it was found that
  this lesion did not involve the incisive canal
  and that teeth were vital.

19
Globulomaxillary Cyst

• Often misdiagnosed as a globulomaxillary cyst
  when in reality it is a periapical cyst.

20
Lymphoepithelial Cyst

• Branchial Cleft Cyst
• There is some controversy as to the exact origin
  of this cyst that occurs at various levels in the
  lateral neck. Some believe the lesion arises from
  remnants of pharyngeal pouches or branchial
  arches while others think the lesion originates
  from cystic alteration of salivary gland type
  epithelium often found within lymph nodes of the
  neck.
• This large branchial cleft cyst was moveable,
  asymptomatic and slightly fluctuant.

21
Thyroglossal Duct Cyst

• This asymptomatic swelling near the midline is a
  good example of the thyroglossal duct cyst which
  is an epithelial lined structure originating from
  remnants of the thyroglossal duct.
• The thyroid gland originates from the area of
  the foramen cecum at the base of the tongue. The
  thyroid tissues then migrate to programmed
  location. Remnants of epithelium remain along
  this tract and these may become cystic or even
  tumorous.

22
Static Bone Cavity

• Static Bone Cavity
• Developmental mandibular lingual salivary gland
  depression (static bone cavity, lingual salivary
  gland depression, and Stafne bone cavity)
  represent cortical depressions or defects on the
  lingual aspect of the posterior body of the
  mandible.
• These are often bilateral, are asymptomatic and
  are discovered on routine radiographic
  examination.
• In most cases the radiolucency is in continuity
  with the inferior border of the mandible and is
  below the mandibular canal.

23
Developmental Dental Abnormalities

• Anodontia - congenital lack of teeth
• Hypodontia - lack of one or more teeth
• Microdontia smaller (peg lateral)
• Macrodontia larger
• Supernumerary- extra tooth usually smaller
  (mesiodens, distomolar)
• familial tendency

24
Developmental Dental Abnormalities

• Gemination
• Fusion
• Ectopic Cusp
• Concresence
• Dilaceration
• Enamel Pearl
• Taurodont
• Dens in Dente
• Dens Evaginatus

25
Abnormalities in the shape of teeth

• Gemination-a single tooth bud divides and
  results in the incomplete formation of two teeth

26
Fusion

• Union of two normally separated adjacent tooth
  germs.

27
More abnormalities in the shape of teeth

• Concrescence - two adjacent teeth are united by
  cementum only
• Dilaceration - abnormal root morphology
• Enamel Pearl - small enamel projection located on
  a root surfacethought to occur as a result of
  the abnormal displacement of ameloblasts during
  tooth formation.

28
Concrescence
29
Ectopic Cusp

• Talon Cusp - a supernumerary cusp which arises
  from the cingulum portion of an incisor and
  extends to the incisal edge as a prominent
  projection of enamel.

30
Taurodont

• A malformed multirooted tooth characterized by an
  altered crown-to-root ratio the crown being of
  normal length, the roots being abnormally short
  and the pulp chamber being abnormally large.

31
Dilaceration
32
Enamel Pearl
33
Dens in Dente

• "A tooth within a tootha malformation caused by
  an invagination of the crown before it is
  calcified.

34
Dens Evaginatus

• A developmental anomaly in which a focal area of
  the crown projects outward and produces what
  appears as an extra cusp or an abnormal shape to
  existing cuspal arrangements (e.g.,talon cusp)

Primarily premolar usually bilateral conical,
tuberculated projection from the central fissure
of the occlusal surface can interfere with
tooth eruption causing malalignment often in
individuals of Mongolian origin
35
Abnormalities of tooth structure

• Enamel hypoplasia-incomplete or defective
  formation of enamel, resulting in the alteration
  of tooth form or color
• Results from a disturbance of or damage to
  ameloblasts during enamel matrix formation

36
Enamel HypoplasiaA defect in tooth enamel that
results in less quantity of enamel than normally
formed
pits, grooves, lines or larger areas of missing
enamel surface  - reduction in enamel thickness
 - possible occlusal distortion, aesthetic
problems, sensitivity --  yellowish or brownish
discolorationmay be localized or present on
numerous teeth and all or part of the surfaces of
each affected tooth may be involved
37
Regional Odontodysplasia

• A developmental disturbance of several adjacent
  teeth in which the enamel and dentin are thin and
  irregular and fail to adequately mineralize
  surrounding soft tissue may be hyperplastic and
  contain focal accumulations of spherical
  calcifications and odontogenic rests.

Ghost Teeth
38
Abnormalities of tooth eruption

• Impacted teeth

39
Ankylosed Teeth

• Roots are fused to the alveolar bone
• Especially common with retained deciduous molars