Join me for Mohammed Al Muzian’s rules in orthodontic practice

Part 1 we will cover half of the 32 tips the following topics: Knowledge Vs confidence, space requirements and creation, IPR, expansion, inclination changes and treatment planning

Knowledge Vs confidence

· We tend to be overconfident at the beginning of our careers, and under-confident in the middle. Kruger’s curve

Space assessment

Calculate space requirements in the lower arch Use T-SCOTAR

o Torque

o Spee curve

o Crowding

o Overjet

o Teeth size discrepancy

o Angulation of teeth

o Rotation

Space creation

Use SPEEDAR for space provision

o Stripping

o Proclination of incisors

o Extraction

o Expansion

o Distalisation

o Angulation

o Rotation

IPR

· A maximum of 0.75mmof IPR per tooth can be tolerated depending on the shape and size

· Up to 4-6mm can be achieved sometime, but you need to balance that with the opposing to avoid TSD

Inclination change and effects

o 2 mm of crowding= 50 of proclination =1 mm change in the overjet and overbite (draw bridge effect)

o 2 mmof spacing= 50 of retroclination=1 mm change in the overjet and overbite Eberhart et al (1990), Sangcharearn and Hob (2007), Kapoor 2014, Aziz et. al 2011

o All cases can be retroclined or proclined by 5 degrees without affecting the PDL..

o Some may accept 10 degrees if I have good gingival biotype, thick symphasis, no recession, no PDL problem and Avoid Jiggling forces.

o Do not procline the uppers more than 1200

o Do not retrocline the lowers to less than 800

· Lower arch: Cannot expand (unless Class II/2 and canines trapped )

· Upper arch: Can expand

o Maximum 0.5mm of space per 1mm expansion

o Why do you lose half of the expanded space? Due to the backward movement of the anterior teeth.

· Expansion retainer:– wire reinforcement of essix retainer

· Bonded RME

o Design with big hole in housing: to easily remove the RME

o Expansion amount guided by lower arch ideal alignment (Andrews plane)

o Use Monoject or Water jet (flosser) with CORSYDOL to clean under the RME

o Plan around the lower arch

o Rationale:

§ Limited labio-lingual alveolar bone

§ Upper arch labio-palatal bone can be remodelled

o MOOH – planning around the lower arch

o Midline

o Overjet

o Overbite

o Health of PDL

§ If ALL above cannot be achieved non-extraction = extractions required