Etiology of Malocclusion (Graber's Classification)
Your Ad Here

Etiology of Malocclusion (Graber's Classification)

Etiology Of Maloccusion

Orthodontics

Etiology of Malocclusion

Etiology:

  • Cause or causes of malocclusion is the study
  • Recognition and elimination of the etiological factors is important so that one can prevent and correct the malocclusion and obtain a permanent result.
  • Etiological factors contribute to the variations more often than simple cause.

The Orthodontic Equation:

 

Cause
         ↓ act at
time
     ↓ on
tissue
                ↓ producing
result

 

Graber's Classification:

Graber classified the etiologic factors as local and general factors.

 

General Factors:

Hereditary

Following human traits are influenced by genes:

 

  • Frenum
  • Interarch variation
  • Tooth Size
  • Arch dimensions
  • Crowding
  • Spacing
  • Overjet
  • Tooth number
  • Tooth shape

Congenital Defects

Following are congenital defect causing malocclusion:

 

  • Cleft palate
  • Torticollis
  • Syphillis
  • Cerebral palsy
  • Cleidocranial Dysostosis

Environmental

Prenatal:

  1. Trauma
  2. German Measles
  3. Maternal diet
  4. Maternal metabolism

Postnatal:

 

  1. Birth injury
  2. Cerebral palsy
  3. TMJ injury

Predisposing metabolic Climate and Disease

 

  • Endocrine imbalance
  • Metabolic Disturbances
  • Infectious diseases (Poliomyelitis)

 

Dietary problems

Abnormal pressure habits and functional aberrations

 

  • Abnormal sucking
  • Psychogenic aberrations- clenching/bruxism
  • Speech defects
  • Lip/nail biting
  • Tongue thrusting and sucking
  • Thumb and Finger sucking
  • Abnormal Swallowing
  • Tonsils/ adenoids
  • Respiratory abnormalities

Posture

Trauma

 

Local Factors:

1. Anomalies of number:

 

  • Missing- congenital absence or loss due to accidents, caries
  • Supernumerary- teeth that are extra to the normal complement are called as supernumerary teeth.

Classification:

 

  • Peg shaped conical
  • Barrel shaped/tuberculate
  • Supplemental
  • Odontomes

2. Abnormalities in tooth size:

  i. Macrodontia: 

  • Any teeth or tooth larger than normal for that particular tooth type
  • Result in crowding

  ii. Microdontia:

  • Teeth that appear smaller in size
  • Result in spacing

  iii. Most of these conditions show a positive family history

3. Abnormalities in tooth shape:

  • Presence of peg shaped maxillary lateral incisors-spacing and migration
  • Presence of large cingulum-prevent normal overjet and overbite

4. Abnormal labial frenum, mucosal barriers

5. Premature loss

6. Prolonged retention-lead to malocclusion

     Causes of prolong retention of deciduous teeth:

 

  • Absence of underlying permanent teeth
  • Endocrine disturbances (hypothyroidism)
  • Ankylosed deciduous teeth that fail for resorb
  • Nonvital deciduous teeth that do not resorb

7. Delayed eruption of permanent teeth:

    Causes:

  • Congenital absence
  • Presence of supernumerary teeth or pathology
  • Heavy mucosal barriers
  • Presence of deciduous root fragments.

8. Abnormal eruptive path

9. Ankylosis

10. Dental caries

11. Improper dental restorations

 

 

Your Ad Here