The growing face of a child

The face consists of three sections when looked from the front, and roughly divided into - the upper third --- the skull with the forehead - the middle third (upper jaw) --- predominantly the maxillary bones with a smaller zygomatic bone on each side determining the cheek bone - the lower third (lower jaw) --- the mandible. The skull/forehead is fixed and we don't normally try changing it. The maxilla in the middle third and the mandible in the lower third are, however, joined to the skull via sutures or ball joints, so they could end up sitting in a good, intended position, or too far forward from the skull base, or too far backward from the skull base. Sometimes that happens with only one of them, sometimes both. It's kind of like stacking a jigsaw puzzle together. The maxilla tends to finish ~90% of its development by ~ age 9-10 (on average) while the mandible starts developing more significantly in the teenage years. As the mandible is held in space, connecting to the skull base only loosely by muscles, tendons and ball joints, it is strongly guided and restricted by the maxilla and the maxillary teeth. In a way, it's like the maxilla is the "lid" and the mandible is the "box", and the body tends to get the "box" to fit the "lid". While the child is still young enough and actively growing, it is possible to guide and modify the development of the maxillary bones, to encourage the maxilla to grow towards its genetic potential. On each of the maxillary and mandibular bones sit the teeth. The tooth positions can sometimes be off-centred or less than ideal. It may be due to genetic factors, but more often than not, as a result of muscle imbalance (be it directly or indirectly). These muscles are the tongue, the lips and the various surrounding muscles that form the mouth and face of this region. You can have a mismatch of teeth alignment, with or without any underlying bony discrepancies. So now you have 2 more pieces of jigsaw to consider in the puzzle.