Space Analysis And Extraction Need Flashcards
How can you work space out?
- Visualisation
- Brass wire technique
- Relfex microscope
- Scanning program
Visualisation
- Count up overlap of each tooth (minus any area of spacing e.g. between lower 1s.
- Very unreliable and most common method used.
- It’s overestimate crowding
Brass wire technique
- Cut piece of brass wire to best fit arch form from distal of 6’s.
- Add up mediocre- distal widths of each tooth from 6-6 with caliper.
- Take the sum widths away from length of a brass wire to give you how many mm crowding there is.
- Best to carried out on study model
- Time consuming
- Underestimate crowding
Relfex microscop
- A computer program linked to microscope accurately estimates crowding
- Very accurate
- Expensive equipment
- Time consuming
- Not practical in real world
Scanning programmes
- Rapidly growing area of dentistry
- Improving in accuracy speed and cost.
- Linked with computer programmes which can estimate amount of crowding
Which one is best technique to measure crowding?
- Brass wire
Scale of crowding
- Mild - 0-4
- Mod 4-8
- Sever more than 8
Royal London space planning ?
Space requirements implication
- Crowding / spacing
- Levelling curve of spee
- Arch expansion
- Incisor A-P position
- Angulation of teeth
- Inclination of teeth
Once you add up space requirement and space creation the total should be zero
Royal London space analysis conclusion
- Very rigid and formal way
- time consuming
- most orthodontist learn to this in their head with experiences
When do we extract 4s not 5s ?
- More crowding 4s
- Less crowding 5s
When do we extract 5s ?
- Lower in Proclined after tb phase because they don’t want to Retroclined incisor again
- less crowding case
Methods of orthodontic space creation
- Tooth extraction
- Expansion
- Distal movement e.g using HD or TAD’s
- IPR (interproximal enamel reduction)
Angles 1910,
- Believed 32 teeth would provide functional and best aesthetic that’s why believed in expansion
- Strongly criticised angles’s non xtn because Aesthetic effect - excess facial protrusion following extreme expansion
1940’s Tweed and begg
Tweed - Disappointed with relapse - Hence retreated 100 pt with Xtn upper 4s
- Observed occlusion was more settle
Begg- also abandoned a non Xtn policy due to of relapse
Why we need extraction teeth?
- Relief crowding
- OJ and OB Reduction
- Anchorage considerations
- buccal segment relationship correction
- To correct incisor relationship in CLASS III - lower incisor retroclination to correct CL III relationship
Proposed disadvantages of Extraction
- Less attractive facial appearance
- Potential longer treatments
- Pain , anxiety, other possible adverse effects of actual Xtn procedure
Factors in Xtn decision
- Before planing Xtn of any permanent teeth it is essential to ensure that all remaining teeth are present , healthy, and developed in satisfactory position
- Medical history
- Tooth quality
- Pathology
- Amount of crowding
- Impacted teeth
- Occlusal feature
- Skeletal feature
- Ease of Xtn
- Profile and soft tissue
Factor in Xtn decision - Occlusal feature
- OJ, OB - flattening of curve of spee require space
- buccal segment relationship
- Central line discrepancies
Factor in Xtn decision
Skeletal condition
- Saggital jaw relationship - More severe crowding less space is available for camouflage
- Vertical relationship- Low angle less likely Xtn space closure more difficult
- Transverse relationship- Elimination of crossbite
Assessing space requirements in orthodontic planing -
- Assesment of crowding / spacing
- Anchorage planning
- Xtn planning
- Levelling curve of spee
- Tooth angulation
- Tooth size
