Please enable JavaScript.
Coggle requires JavaScript to display documents.
Malocclusion (Etiology of Malocclusion (Defect in embryonic/dental…
Malocclusion
Etiology of Malocclusion
-
-
Inherited pattern
- Hereditary factors are responsible for only 40%
- Hapsburg Family Lineage – pedigree analysis 95.5% penetration
- Hereditability of skeletal characteristic was stronger than the heritability of dental characteristics
- Mand shape is more genetically controlled than the size
- Vertical parameters > genetically influ than the A-P ones
-
Environment
Trauma
- Condyle trauma
- postoperative scarring
- traumatic displacement
Habits
- Alters resting forces on teeth
- digit sucking or nail biting
Types of Malocclusion
Space Discrepancy
Crowding
- Disharmony between tooth-size and jaw-size
(anterior Mx = 60%)
Prevalence:
- Supernumeraries = 2-3%
- Ectopic Canines = 2-3%
- Transposed teeth = <1%
Spacing
- disharmony between tooth-size and jaw-size
- abnormal tongue thrusting activity
- congenitally missing teeth
Prevalence:
- Hypodontia = 2-3%
ex. Missing laterals
- Diastema = 7%
Sagittal Problems
Reverse OJ
-
Management:
- Mx retrusion = reverse E/O headgear
- Alternative = Functional +Fixed appliances
Increased OJ
Class II
Prognathic Maxilla/Retrognathic mandible
- maxilla forward relative to mandible
- proclined anterior teeth
Management:
- Max protrusion = E/O Head gear (300-500g/side)
- Mdb retrusion = Twinblocks or Activator
- Alternative: Functional + fixed appliances
Vertical Problems
Open Bite
- no vertical overlap of the incisors
- Short Ramus – increased FMPA +/- Anterior Open Bite
- Growth Pattern = Backward rotation
Eitology
- Habits
- Prolonged thumb/finger sucking
- Tx around habit cessation
- Tongue Thrust
- Tongue thrust during swallowing produce significant forces
- Loss of condylar Ramus Height
- Tumor, osteoarthritis, idiopathic resorption
- Tx w/ fixed/removable bite planes
-
Management:
- Primary:
- Permanent:
- Cessation support of habits /and or orthodontic appliance ie tongue crib
- Fixed ortho appliances w/ age timing, maybe orthognathic surgery
Deep Bite - excessive overlap of the incisors (Class II, div 2)
- Decreased FMPA +/- Deep Bite
- Growth Pattern = Forward Rotation
-
Aeitology:
- Strong genetic predisposition
Management
- Removable or fixed bite planes
- Other ortho fixed applainces
- Cervical headgear (extrude upper posterior teeth)
- Orthognathic surgery
Transverse Problems
-
Facial Asymmetry
- Dissimilarities on either side of facial midline
Etiology:
Genetic (craniofacial microsomia, unilateral CLP)
Environmental (pathology, excessive asymmetric condylar growth)
Functional deviations (premature contacts, constricted mx)
Local (restrained/missing teeth)
Management:
Minimize mx cant during growth (esp. CF microsomia)
Orthognathic surgery
Soft tissue augmentation
Functional adjustments
Exodontia
Scissor Bite
- Posterior teeth positioned completely buccally or lingually exhibiting a vertical overlap
- Prevalence = 2%
Etiology of Classes
Class II, Div 1 malocclusion
-
-
Class II, Div 2 malocclusion
-
Class III malocclusion
-
Environemntal Influence
Enlarged tonsils, nasal blockage
Posture
Trauma, disease
Ideal Occlsuion
- Hypothetical concept
- Benchmark to judge irregularities
Normal Occlusion
- Usual, common occlusion
- minor deviation from ideal without functional or aesthetic problems
Malrelationship between the arches or in which there anomalies in tooth position
- deviation from norm
- developmental conditions w/ complex etiologies
-