They are those alterations that affect the upper jaw and the lower jaw or mandible. Cysts, trauma, alterations due to metabolic disorders, congenital alterations in the development of the jaws and tumors are some of the pathologies that affect the jaws and which we will comment on below.
They are cavities lined with epithelium that contain a liquid or semi-solid material inside. The cysts are benign , although in a very small percentage, they can become malignant. The most common locations for cysts are the mandible and upper jaw, specifically, on the central incisors or blades. It is a small ball in the jaw bone that can be of two types in 90% of cases:
- The periapical or radicular cysts are the most common entities. The epithelium comes from the epithelial remains of Malassez (remains of the odontogenesis process). The transformation of these epithelial cells into cysts can occur due to caries (with the consequent necrosis of the pulp tissue inside the tooth). Faced with a persistent and not intense inflammatory stimulus, the result of our body’s defensive reaction is the formation of a granuloma. The proliferation of epithelial cells is irregular and progressive. The cells inside become necrotic, forming a fluid-filled cavity.
- The dentigerous or eruption cyst is generated in the process of eruption and formation of the tooth. There is an accumulation of liquid between the crown and the epithelium of the enamel organ that makes up the follicle (or bag where the tooth is formed) and progresses towards the gum. The cyst is associated with the delay in the eruption of the teeth or retained teeth. It most often affects the lower wisdom teeth and the upper canines.
The accidents , sports and labor concentrated much of fractures maxilla and mandible. Together with cysts, they are the most frequent alterations of the jaws. Generally, fractures of the upper jaw are usually associated with the involvement of other facial and cranial bones. The Lefort classification is the most used to group these types of injuries.
This classification takes into account the fracture marks of the upper jaw and the existence of fracture in other bones, specifically the bones of the nose, frontal bone and other minor bones. The trauma to the chin are responsible for most of mandibular fractures. Mandibular condyle fractures, which is one of the elements that makes up the temporomandibular joint , are very common.
Bone inflammatory processes
Bone inflammatory processes are the result of infections from cavities, gums and deep wounds on the jaws. Uncontrolled evolution can lead to bone infections, osteitis, and eventually osteomyelitis. Special mention would have the dry socket, which is an osteitis that occurs after the extraction of a tooth. The cause is not known. The typical symptomatology is intense pain in the area of the extraction that begins during the first 48 hours and usually lasts for five days, subsiding later.
The jaws, like any part of our body, are subject to constant changes. The metabolism of the bones is centered in the exchange of calcium-phosphorus and in the balance between the resorption (osteolysis) and the formation (osteoblastosis) of the bone. This metabolism is very important to maintain healthy and vital bone.
Pathologies such as hyperparathyroidism, Paget’s disease and osteoporosis could be included within the group of diseases that alter bone metabolism. Medications such as bisphosphonates (indicated in the treatment of osteoporosis) can have an unwanted effect on maxillary bone metabolism, affecting its vitality. Other diseases such as osteopetrosis and osteogenesis imperfecta, both hereditary, act on bone formation, generating brittle bone.
Congenital alterations in the development of the jaws
Mild manifestations of jaw growth disorders are common, but severe ones are not. They can be congenital or acquired.
- Those acquired are usually secondary to infectious or traumatic processes . These growth alterations generate bone and dental malocclusions due to dental incongruity between both arches.
- We call retrognathia the aesthetic result of an undersized jaw , or what is equivalent, a retracted chin. Prognathism refers to an exaggerated size of the jaw giving the image of a very pronounced chin.
- Laterognathia is an asymmetry with mandibular deviation and can be secondary to craniofacial malformations, trauma, tumors, etc.
- Maxillary hypoplasia is the case of an underdeveloped maxilla in the anteroposterior direction (maxillary retrusion) or vertically. The most frequent cause is usually cleft lip-palate , the sequela of which is a defect in maxillary bone growth.
- Maxillary hypertrophy is an exaggerated development of the upper jaw . Vertically causes the gummy smile.
- Fortunately, Pierre Robin Syndrome is very rare, and is characterized by severe congenital micrognathia and retrognathia, sporadic in nature (not hereditary) associated with cleft palate and a large tongue (macroglossia). It is associated with respiratory problems due to upper airway obstruction.
Masses in the jaws are not frequent. Tumors can come from dental, bone, vascular and connective tissues (present in the gum). The jaws, too, are receptors for tumors originating in other organs, that is, the so-called metastases.