Developmental disturbances of the teeth (loạn dưỡng hệ răng)

DEVELOPMENTA
L
DISTURBANCES
OF THE TEETH

Prepared by:
Dr. Rea Corpuz


Developmental
Disturbances
 (1) Size
 (2) Number and Eruption
 (3) Shape/Form
 (4) Defects of Enamel and Dentin


Size
 Microdontia
 Macrodontia


Siz
e
 Microdontia
 (1) True Generalized
Microdontia
 (2) Relative Generalized
Microdontia
 (3) Focal or Localized
Microdontia

(1) True
Generalized
Microdontia
 all teeth are smaller than
normal
 occur in some cases of
pituitary dawrfism
 exceedingly rare
 teeth are well formed


(2) Relative
Generalized
Microdontia
 normal or slightly smaller
than
normal teeth
 are present in jaws that are
somewhat larger than
normal


(3) Focal/Localized
Microdontia
 common condition
 affects most often maxillary
lateral incisior + 3rd molar
 these 2 teeth are most often

congenitally missing


(3) Focal/Localized
Microdontia
 common forms of localized
microdontia is that which
affects maxillary lateral
incisior
 peg lateral
 instead of parallel or
diverging mesial + distal
surfaces


(3) Focal/Localized
Microdontia
 sides converge or taper
together incisally
 forms cone-shaped crown
 root is frequently shorter
than usual


Size
 Microdontia
 Macrodontia


Siz

e
 Macrodontia
 (1) True Generalized
Macrodontia
 (2) Relative Generalized
Macrodontia
 (3) Focal or Localized
Macrodontia


(1) True
Generalized
Macrodontia
 all teeth are larger than
normal
 associated with
pituitary gigantism
 exceedingly rare


(2) Relative
Generalized
Macrodontia
 normal or slightly larger than
normal teeth in small jaws
 results in crowding of
teeth
 insufficient arch space

(3) Focal/Localized
Macrodontia
 uncommon condition
 unknown etiology
 usually seen with
mandibular 3rd molars


Developmental
Disturbances
 (1) Size
 (2) Number and Eruption
 (3) Shape/Form
 (4) Defects of Enamel and Dentin


Number and Eruption
 Supernumerary
 Anodontia
 Impaction


Number and Eruption
 Supernumerary
 results from continued
proliferation of
permanent
or primary dental lamina
to form third tooth germ
 teeth may have:

• normal morphology
• rudimentary


Number and Eruption
 Supernumerary
 more often in permanent
dentition than primary
dentition
 more in the maxilla than
in
mandible


Number and Eruption
 Supernumerary
 may be impacted erupted
or impacted
 because of additional
tooth
bulk, it causes:
• malposition of adjacent
teeth


Number and Eruption
 Supernumerary
 many are impacted
• characteristically found
in cleidocranial

dysostosis


Number and Eruption
 Supernumerary
 Mesiodens
 Fourth molar
•Maxillary Paramolar
• Distomolar or Distodens
 Mandibular Premolar
 Maxillary lateral incisors


Number and Eruption
 Supernumerary
 Mandibular central
incisors
 Maxillary Premolars


Mesiodens
 most common
supernumerary tooth
 tooth situated between
maxillary central incisors
 singly
 paired
 erupted or impacted

Mesiodens
 small tooth
 cone-shaped crown
 short root


Fourth Molar
 2nd most common
 situated distal to 3rd molar
 small rudimentary tooth,
but may be of normal size
 mandibular 4th molar also is
seen occasionally, but less
common than maxillary
molar