Table 2: Phases of the proposed life cycle (The 10-phase Life Cycle), with the striking and frequent characteristics of each phase.
| Phase (chronological age) | Dentition | Dental features | Skeletal and developmental features | Growth stages (carpal radiograph) |
General features | |
|---|---|---|---|---|---|---|
| Pre peak of pubertal growth spurt (PGS) | Newborn (From birth to 29 days) |
Period of gingival rollers | Absence of teeth | Physiological dystocclusion | Not applicable | Complete dependence on parents; Exclusive breastfeeding |
| Baby (From 30 days to 23 months) |
Deciduous | Beginning of eruption of deciduous teeth | Reduction of physiological distoclusion | Not applicable | Great dependence on parents; introduction of solid foods; speech evolution |
|
| Preschool Childhood (2 -5 years) |
Deciduous/early mixed | Complete deciduous dentition. Determination of the occlusion key of deciduous second molars Transition to mixed dentition, with eruption of first molars and permanent incisors. |
Intersphenoidal synchondrosis fusion | Generally does not apply | Many cognitive skills develop | |
| Beginning of PGS, or Ascending curve of PGS, or Pubertal growth spurt speed peak (PGSSP) | Childhood (6 - 12 years) |
Mixed | Ugly duckling phase Eruption of permanent canines and premolars |
Spheno-ethmoidal synchondrosis fusion | Ascending curve of pubertal growth spurt Proximity to the peak of the pubertal growth spurt |
Development of logical thinking, improvement of language and memory; Appearance of secondary sexual characters; Period of menarche (girls) |
| Ascending curve of PGS, or Pubertal growth spurt speed peak (PGSSP), or Descending curve of PGS | Adolescence (13 - 18 years) |
Mixed late | Eruption of permanent canines | Presence of growth (stages CS3 to CS5 of cervical vertebrae maturation) | Peak of the pubertal growth spurt | Appearance of secondary sexual characters Period of menarche/post-menarche (girls); |
| Permanent | Presence of permanent second molars; Possible eruption of third molars |
Descending curve of pubertal growth | Search for the identity and maturity of the reproductive system | |||
| Descending curve of PGS After the end of PGS, or End of the growth | Young adult (19 - 24 years) |
Permanent | Presence of third molars | Final or absence of growth (stages CS5 to CS6 of cervical vertebrae maturation) | Descending curve | Stability of personality traits; Physical and cognitive peak |
| Beginning of synostosis of the coronal and sagittal sutures, and fusion of the spheno-occipital synchondrosis | Or the end of the pubertal growth spurt | Maximum performance of adult life | ||||
| End of the growth | Adult (25 - 44 years) |
Permanent | Complete permanent dentition | Synostosis of the lambdoid suture | No longer shows growth |
Increase in the number of marital relationships; paternity/maternity |
| Middle age (45- 64 years) |
Permanent | Possible tooth loss due to fractures, trauma; Dental wear; Reduction in the length and perimeter of the arch; increased overbite; and lower anterior crowding. | Fused sutures and synchondroses | No longer shows growth |
First signs of physical degeneration; Decreased sperm quality Menopause / Andropause |
|
| Older adults (65 - 79 years) |
Permanent | Eventual partial or total dental absences and use of dental prostheses; Teeth in more yellowish, brown, or gray tones; Erosion, abrasion. |
Fused sutures and synchondroses; Greater resorption in the maxilla and mandible. | No longer shows growth |
Increased physical and cognitive fragility; higher risk of bone fractures. Reduced muscle tone |
|
| Older adults + (80 years or older) |
Permanent | Eventual partial or total dental absences and use of dental prostheses; Partial or complete obliteration of the volume of the canals and pulp chamber; reduced salivary volume; difficulty eating. | Fused sutures and synchondroses | No longer shows growth |
Frequent chronic pain Reduced muscle tone |
|