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Jaw and Facial Growth – Changes Over Time

Jaw growth continues longer than previously assumed, potentially up to age 40. This impacts treatment planning in orthognathic surgery and implant procedures. Studies reveal individual growth pattern variations, making wrist X-rays unreliable for predictions.

Author: Krister Bjerklin • Orthodontist • Associate Professor • Malmö University
Reviewed by: Mikael Sonesson • Orthodontist • Senior Lecturer • Faculty of Odontology • Malmö University
5 min read
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    This article is based on an original article in Swedish which can be found here

    BACKGROUND

    Dentoalveolar development is a complex biological process(1). This development occurs continuously over a long period. The question is how long it lasts and whether it is similar throughout the facial and jaw complex?

    There are, for obvious reasons, no prospective randomized studies that can provide answers to this. However, there are a few retrospective studies with varying follow-up times (2-7).

    Previously, it was believed that when body hight growth is completed, growth in the jaws is also finished. Using wrist radiographs, attempts have been made to determine when growth in the jaws is completed. It has been considered that when the epiphysis and diaphysis for the radius (the radial bone) and ulna (the ulnar bone) are fused, facial and jaw growth should be complete. This has been of interest to know, for example, prior to orthognathic surgical interventions.

    Later studies show that jaw growth continues significantly later into adulthood. This should be taken into account when planning therapy for orthognathic surgery and implant-supported prosthetics, as well as regarding retention treatment and the risk of relapse in orthodontic patients.

    These studies only include individuals with a neutral occlusion (Angle Class I) and those treated early for a postnormal occlusion (Angle Class II:1). It would have been of great value if there had been studies with long-term follow-up of individuals with a prenormal occlusion (Angle Class III), but such studies do not exist. However, it is often considered that individuals with a prenormal occlusion, especially boys, continue to growth in the mandible well into adulthood, significantly after the age of 20.

    STUDIES

    Behrents (1985) (2) found that 50% showed skeletal growth after the age of 25, 24% after 30, 9% after 35, and 4% after 40.

    Lewis and Roche published an article in 1988 (3) showing that facial and jaw growth occurs beyond the age of 20. However, they also stated that after the age of 30, growth was completed for most.

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