Orthodontics and Pediatric Dentistry
Two disciplines, one domain
Pediatric questions test development, behavior guidance, prevention, and trauma; orthodontic questions test growth, diagnosis, and biomechanics.
Development milestones
- Primary eruption begins with the mandibular central incisor at 6–10 months; the first primary molar erupts around 12–16 months, and the primary dentition is complete near 2.5–3 years.
- Mixed dentition: leeway space is larger in the mandible (about 2.5 mm per side) than the maxilla (about 1.5 mm per side). Primate spaces lie between the maxillary lateral incisor and canine and between the mandibular canine and first molar.
- Ankylosed primary molars can block eruption of successors and cause impaction.
Behavior and prevention
Frankl scale, tell-show-do, voice control, positive reinforcement, and nitrous oxide. Fluoride varnish, sealants, and dietary counseling; early childhood caries is behavior-driven and infectious, and a parent's oral health is a risk factor for the child.
Orthodontics
Angle classification, cephalometric landmarks (SNA, SNB, ANB), anchorage control, light continuous force (roughly 50–150 g for tipping), and retention. Headgear and functional appliances influence growth; aligner success depends on compliance.
Traps
Do not confuse leeway space with primate space, and remember mandibular leeway exceeds maxillary. In trauma, an intruded primary tooth is often allowed to re-erupt unless it threatens the permanent bud, whereas an avulsed permanent tooth is replanted promptly, stored in milk or saline, and splinted flexibly for about two weeks.
Rule of thumb
Approximate the number of erupted primary teeth by subtracting 6 from the child's age in months.