Craniofacial Growth and Development
Growth principles
Candidates must understand the mechanisms of craniofacial growth: sutural growth, apposition and resorption, endochondral versus intramembranous ossification, and the concept of displacement and remodeling. Know the cephalocaudal gradient and the adolescent growth spurt, and know how to assess maturity - chronological age, dental age, skeletal age via hand-wrist or cervical vertebral maturation, and the pubertal peak.
Key concepts
Understand the roles of the nasal septum, the synchondroses of the cranial base, and condylar cartilage in mandibular growth. Know that the mandible grows primarily by apposition at the posterior border and condyle, with remodeling at the anterior border, and that the maxilla grows by sutural apposition and surface remodeling. Understand the functional matrix concept: soft tissue growth influences skeletal growth.
Traps
A common trap is assuming that growth continues equally in all dimensions - the mandible and maxilla grow at different rates and times, and transverse growth finishes earlier than sagittal growth. Another trap is treating a patient at the wrong time: functional appliances need remaining growth, whereas rapid palatal expansion is most effective before sutural fusion. Questions may also test whether you can distinguish genetic from environmental influences on growth.
Worked example
A 10-year-old girl with a Class II division 1 malocclusion and a skeletal age of 11 years. Rule of thumb: peak mandibular growth typically occurs about one year after peak height velocity, and cervical vertebral maturation stage 3 indicates the growth spurt is imminent. Plan treatment to coincide with this window rather than relying on chronological age alone.