Jaw malformations. Introduction.
"Jaw malformations” represent all the malformations of the lower jaw (mandible) and the upper jaw (maxillary). They can focus on either the mandible or the maxillary or the mandible and the maxillary.
In the presence of a jaw malformation, several rules are observed:
1) No treatment can be offered without a complete assessment in which many specialties participate: Maxillofacial Surgery, Orthodontics and orofacial physiotherapy. Other specialties are sometimes involved: ENT (for the study of breathing and the assessment of the airways), Ophthalmology (in case of oculomotor muscle disorders), Genetics (in case of a potentially transmissible family anomaly), Psychology ... The treatment is almost always multidisciplinary involving Maxillofacial Surgery, Orthodontics and Orofacial Physiotherapy (to rehabilitate swallowing and phonation). Otorhinolaryngology is frequently associated to suppress a respiratory obstruction. Multidisciplinary collaboration is essential and is one of the conditions to obtain a successful treatment and therefore a stable result.
2) There is no emergency to treat jaw malformation. This is a non-vital therapeutic indication; thorough information has to be given to the patient about the origin of the malformation and its mechanism of installation, the various possible treatments (and for each of them the advantages and disadvantages), the overall medical care duration , the operative follow-up and the risks of relapse according to the therapeutic strategy chosen. As with any treatment, a complete quote is given to the patient before the beginning of any treatment.
Two types of bone coexist in the jaws.
• Alveolar bone
The alveolar bone is the bone that surrounds the teeth and holds them on the dental arch. Throughout life, the alveolar bone undergoes remodelling according to the forces or the stresses that it undergoes (action of facial muscles and the tongue, orthodontic forces). During the course of life, its dimensions can thus tend to increase (in case of dental eruption or dental extrusion) or decrease (dental decoupling).
"The alveolar bone is born and dies with the tooth". It forms and develops around dental germs during foetal life and childhood. In case of congenital absence of teeth (dental agenesis) the alveolar bone is not formed; there is a primitive atrophy of the alveolar ridge. During aging and in case of loss of teeth, the alveolar bone will gradually be absorbed; it is a secondary bone atrophy (acquired atrophy).