Cephalometrics, classifications, biomechanics
Class I = normal molar, crowding. Class II Div 1 = proclined upper incisors. Class II Div 2 = retroclined. Class III = mesial molar. Key = UPPER FIRST MOLAR to LOWER FIRST MOLAR.
SNA = 82° (maxilla to skull). SNB = 80° (mandible to skull). ANB = 2° (skeletal relationship). ANB>4 = Class II, ANB<0 = Class III. Wits appraisal when ANB unreliable.
Neural growth = first to complete. Lymphoid = exceeds adult size then decreases. Genital = late spurt. Scammon's growth curves. CVM (cervical vertebral maturation) = CS3-CS4 = peak.
Twin Block = most popular. Activator = most studied. Frankel = vestibular shield. Bionator = modified activator. All work by = mandibular advancement.
NiTi = most flexible, lowest stiffness (alignment). Stainless steel = highest stiffness (finishing). TMA = intermediate. MBT vs Roth prescription. Ideal arch wire sequence: NiTi → TMA → SS.
Carey's analysis = mixed dentition. Moyers = probability table. Bolton analysis = tooth size discrepancy. Extraction patterns: 4 first premolars (most common), serial extraction for severe crowding.
Nance holding arch = maxillary. Lingual arch = mandibular. TADs (mini screws) = absolute anchorage. Headgear = extraoral anchorage. Critical anchorage = ALL space for crowding.
Lip repair = 10 weeks (Rule of 10). Palate repair = 18 months. Alveolar bone graft = 9-11 years (mixed dentition). NAM = Nasoalveolar molding (presurgical).
Most common relapse = lower anterior crowding. Bonded retainer = permanent. Hawley = removable. Circumferential supracrestal fiberotomy = prevents rotational relapse.