Osteogenesis imperfecta

Sometimes, individuals with osteogenesis imperfecta (OI) may experience altered development of the facial bones, leading to malocclusion. Under normal conditions, there should be a proper alignment between the upper and lower teeth, allowing them to make symmetrical contact when biting. Malocclusion refers to a deviation from this ideal relationship, which can cause difficulties in biting and chewing.

Dental or skeletal anomalies can cause malocclusion. In particular, one standard and distinctive anomaly is when the upper maxillary bone fails to grow as much as the lower maxillary bone (mandible), resulting in the protrusion of the mandible and lower teeth compared to the upper maxilla. This condition, known as class III malocclusion, is characterised by the lower teeth being positioned more forward than the upper teeth when the mouth is closed, giving the appearance of a prominent jaw (as shown in Figure 4).

Similarly, another condition known as an open bite can be observed, where there is a noticeable gap between the upper and lower teeth when biting down, and they fail to make proper contact.

As one would expect, these abnormalities can disrupt the normal chewing process and affect the proper functioning of the temporomandibular joint or TMJ (the joint that enables jaw movements). Occasionally, discomfort may arise at this level.