aetiology

Question 1

how long does a force require to move tooth

Answer 1

6 hours

therefore mastication and swallowing not really move teeth

Question 2

what tissues can exert forces on teeth?

Answer 2

tongue, cheeks, lips, gingival and PDL

Question 3

how do tissues push teeth

Answer 3

poor lip tonicity/incompetent lips
prolonged thumb sucking
forward resting tongue posture 
macroglossia
can lead to vertical and transverse effects

Question 4

how do muscle habits affect growth

Answer 4

point of muscle attachment results in more bone deposit, sharper gonial angle in patients who brux or clench

Question 5

can masticatory effort influence size of dental arch?

Answer 5

unclear, if yes must happen early in life

Question 6

does bite force affect?

Answer 6

short face do have greater bite force and long face smalled bite force
but thats an effect as it occurs later in life while facial pattern is established earlier
exception: muscular dystrophy or weakness syndromes

Question 7

what happens in thumb sucking

Answer 7

thumb displaces upper incisors labially, lower incisors lingually–> increase over jet
interfereing