BDS3 ortho assessment Flashcards
what is Ideal occlusion?
Rare
1. Molar relationship
* Distal surface of disto-buccal cusp of upper first molar occludes with mesial surface of mesio-buccal cups of lower 2nd molar
2. Crown angulation
3. Crown inclination
4. No rotations
5. No spaces
6. Flat occlusal planes
(Andrews 6 keys)
what is malocclusion?
Are more sig deviations from the ideal that may be considered unsatisfactory (aesthetically or functionally)
May require tx but pt factor may influence decision
what must you ask about in relation to PDH for ortho exam?
Ask about trauma to permanent dentition
* History of trauma
* Root resorption?
* RCT?
what habits are important to know of when doing ortho exam?
- Thumb sucking
- Lower lip sucking
- Tongue thrust
- Chewing finger nails
what are competent lips?
- Competent – lips meet at rest
o Relaxed mentalis M
what are incompetent lips?
o Lips that do not meet at rest
o Relaxed mentalis M
what is a lip trap? and what could a relapse lead to?
- May procline upper incisors
- May lead to relapse of overjet if persists at end of tx
what would hyper active lower lip do?
retrocline lower incisorS
What should you know about tongue when doing ortho exam?
Position
Habitual
Swallowing
in terms of tongue position and swallowing pattern when doing ortho exam what should you know?
- Tongue position and swallowing pattern
o Tongue thrust on swallowing can be associated with an anterior (AOB)
o Can be either endogenous or adaptive tongue thrust (cause or effect?)
o May cause relapse of AOB at end of tx if endogenous
what are occlusal effects of a thumb habit?
o Proclination of upper anteriors
o Retroclination of lower anteriros
o Localise AOB or incomplete OB
o Narrow upper arch +/- unilateral posterior cross bite
o Remember that effects will be superimposed on existing skeletal pattern and incisor relationship
what should you know about TMJ when doing ortho exam?
- Patho of closure
- Range of movement
- Pain, click from joint
- Deviation on opening
- Muscle tenderness
- Mandibular displacement
o Discrepancy in retruded contact position and inter cuspal position
o RCP does not equal ICP
o Displacement of mandible up and to the right from RCP to ICP -note center line position
what are the 3 planes facial skeleton is considered in?
- Antero-posterior
- Vertical
- Transverse
what is a class I skeletal?
maxilla 2-3mm in front of mandible
what is a class II skeletal?
maxilla more than 3mm in front
what is a class III skeletal?
mandible in front of maxilla
how do you check skeletal bases?
- Direct palpation of skeletal bases
how is vertical skeletal assessment done?
Frankfort – mandibular planes angle (FMPA)
how is lateral skeletal assessment done?
Mid sagittal ref line
what must you assess during IO for ortho exam?
- Crowding
- Space
- Rotations
- Palpate for canines if not erupted
- Note teeth of abnormal shape/size e.g peg lateral
- Lower arch – angulation of incisors to mandibular plane – upright, proclined, retroclined
- Upper arch – angulation of incisors to Frankfort plane – upright, proclined, retroclined
- Teeth in occlusion
what do you check when teeth in occlusion during ortho exam?
Max interdigitation or RCP
what involves with checking max interdigitation or rcp?
Incisor relationship
Overjet
Overbite/ open bite
Molar relationship (angle’s classification)
Canine relationship
Cross bites
Centre lines
what is incisor relationship classes?
o Class I
Lower incisor edges occlude with or lie immediately below cingulum plateau of upper central incisors
o Class II
Lower incisor edges lie posterior to cingulum plateau of upper incsiors
Division 1
- Upper incisors are proclined or of average inclination there is an increase in overjet
Division 2
- Upper central incisors are retroclined. The overjet is usually minimal or may be increased
o Class II
Lower incisor edges lie anterior to the cingulum plateau of the upper incisors. The overjet is reduced or reversed
what does molar relationship (angle’s classification) also mean?
buccal segment relationship
what is involved with buccal segment relationship?
- Angles classification
o Class I
o Class II
o Class III - Crossbites
what do you compare patient to parent for?
Malocclusion
* Especially class 3 malocclusions
Growth potential
what radiographs can you do for ortho exam?
OPT
Maxillary anterior occlusal
Lateral cephalogram
what is this and what are subtypes
what is this example of?
crossbites
