Maxillary hyperplasia is a condition characterized by the excessive growth of the maxilla, the upper jawbone. This overgrowth leads to an increased size of the upper jaw, often disproportionate to the lower jaw. This can alter facial structure and lead to functional and aesthetic concerns.
Understanding Maxillary Hyperplasia
The maxilla is a paired, pyramidal-shaped bone located in the midface, forming the upper jaw and contributing to the floor of the orbits (eye sockets), the nasal cavity, and the hard palate (roof of the mouth). It houses the upper teeth and plays a role in chewing, speaking, and breathing. Hyperplasia refers to an increase in the number of cells in a tissue or organ, leading to its enlargement. In maxillary hyperplasia, this means an excessive proliferation of bone tissue cells in the upper jaw.
Maxillary hyperplasia can affect one side (unilateral) or both sides (bilateral) of the jaw. The abnormal growth can lead to increased vertical development, sometimes called vertical maxillary excess (VME). This can result in a large midface and significantly impact facial proportions and overall appearance.
Identifying the Causes
The exact causes of maxillary hyperplasia are not always clear, but various factors can contribute to its development. These include genetic predispositions, developmental factors affecting facial bone growth during adolescence, and a family history of facial imbalances.
Certain medical conditions and syndromes are associated with maxillary hyperplasia. Fibrous dysplasia, a benign bone disorder where normal bone is replaced by abnormal fibrous tissue, commonly affects craniofacial bones, including the maxilla. Paget’s disease of bone, a chronic condition characterized by disordered bone remodeling, can also lead to enlargement of the maxilla, though this is less common.
Hormonal imbalances, specifically an overproduction of growth hormone as seen in conditions like acromegaly, can cause overgrowth of facial bones, including the maxilla. Genetic syndromes such as Gardner’s syndrome (characterized by intestinal polyps and multiple benign bone growths) can manifest with osteomas in the maxilla and mandible. Cherubism, a rare genetic disorder, leads to bilateral enlargement of the mandible and/or maxilla due to abnormal bone tissue. Trauma or chronic irritation, such as from ill-fitting dentures, can also contribute to localized bone overgrowth in the maxilla.
Recognizing the Symptoms
Symptoms of maxillary hyperplasia often arise from the physical overgrowth of the upper jaw, leading to both aesthetic and functional issues. One noticeable sign is an altered facial appearance, which can include a “gummy smile” (excess gum tissue visible when smiling due to maxillary overgrowth). The midface may also appear elongated, contributing to facial asymmetry.
Individuals may experience difficulty with chewing and biting due to dental malocclusion, a misalignment where the upper and lower teeth do not fit together properly. This can result in an open bite or other bite problems. Speech difficulties can also occur as a result of the altered jaw structure.
In some instances, the overgrowth can lead to breathing problems, particularly during sleep. While bone overgrowth in the maxilla is often painless, severe cases may lead to discomfort or pain. Overcrowding of teeth due to the enlarged maxilla can also increase the risk of gingivitis and periodontal disease.
Diagnosis and Treatment Options
Diagnosing maxillary hyperplasia involves a comprehensive approach, beginning with a clinical examination to assess facial symmetry and palpate for abnormal bone growths. Imaging techniques like X-rays, computed tomography (CT) scans, and magnetic resonance imaging (MRI) provide precise information about the extent and nature of the overgrowth. In certain cases, a biopsy of the bone tissue may be performed to confirm the diagnosis and rule out other conditions, such as tumors or other bone disorders. Genetic testing may also be considered to identify any underlying genetic causes, especially when a syndrome is suspected.
Treatment for maxillary hyperplasia is individualized, depending on the severity of the condition, its underlying cause, and the specific symptoms experienced by the patient. Non-surgical options include orthodontic management to address bite issues and align teeth, often with braces. Pain management strategies are also employed if discomfort is a symptom.
For significant cases, surgical intervention is often necessary. Orthognathic surgery, also known as corrective jaw surgery, is a common approach to address skeletal discrepancies. A specific procedure called a Le Fort I osteotomy involves making a horizontal cut across the maxilla to allow for its repositioning. This surgical technique enables the maxilla to be moved upward or shortened to correct a gummy smile, reduce facial elongation, and improve facial symmetry. The repositioned jaw is then secured with small metal plates and screws.
In some instances, orthognathic surgery may involve repositioning both the upper and lower jaws (bimaxillary surgery) to achieve optimal alignment and facial harmony. A multidisciplinary team, including oral and maxillofacial surgeons and orthodontists, collaborates to develop a comprehensive treatment plan.