Hereditary and environmental factors in facial development

• 1.

  1. Developmental growth expresses itself as local increase of dimensions in an orderly pattern which may be interrupted by disease, intermittent starvation and adverse socio-economic conditions.

• 2.

  2. Developmental growth implies modification of proportions and constant readjustment of parts as well as local dimensional increase.

• 3.

  3. The foregoing principles can readily be demonstrated by experimental interference.

• 4.

  4. Facial growth is subject to the same general influences and interferences as general bodily growth.

• 5.

  5. In early childhood antero-posterior (and transverse) growth is largely controlled by cranial (brain) development. Vertical facial growth is largely determined by bodily respiratory needs.

• 6.

  6. In suitably oriented roentgenograms the developing upper central milk incisor is a useful indicator of comparative facial growth.

• 7.

  7. The incisor travels forward with antero-posterior facial growth and downward with vertical facial growth.

• 8.

  8. Interruption in bodily development in infancy retards anterior progress of face (and incisor) more than vertical progress which is more closely related to bodily size than to bodily maturation.

• 9.

  9. As a rule the increased velocity of growth during convalescence or restoration repairs the defective facial growth but severe disturbance may remain as a permanent defect requiring readjustment of parts and in later chilhood orthodontic treatment.