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
