This leads to an increase in the thickness and the length of the stylohyoid process and the ligament. Pain is felt due to the pressure applied to the internal jugular vein. Eagle syndrome occurs due to elongation of the styloid process or calcification of the stylohyoid ligament. However, the cause of the elongation has not been known clearly. It could occur spontaneously or could arise since birth. Usually normal stylohyoid process is 2.5–3 cm in length, if the length is longer than 3 cm, it is classified as an elongated stylohyoid process. Acquired
Vascular
Infective
Bacterial

(Plaque-induced) gingivitis—A common periodontal (gum) disease is Gingivitis. Periodontal refers to the area the infection affects, which include the teeth, gums, and tissues surrounding the teeth. Bacteria cause inflammation of the gums which become red, swollen and can bleed easily. The bacteria along with mucus form a sticky colorless substance called plaque which harbours the bacteria. Plaque that is not removed by brushing and flossing hardens to form tartar that brushing doesnt clean. Smoking is a major risk factor. Treatment of gingivitis is dependent on how severe and how far the disease has progressed. If the disease is not too severe it is possible to treat it with chlorhexidine rinse and brushing with fluoride toothpaste to kill the bacteria and remove the plaque, but once the infection has progressed antibiotics may be needed to kill the bacteria. Periodontitis—When gingivitis is not treated it can advance to periodontitis, when the gums pull away from the teeth and form pockets that harbor the bacteria.
Differential diagnosis allows for decisions on what further investigations are needed in each case.There are many types of investigations in diagnosis of oral and maxillofacial diseases, including screening tests, imaging (radiographs, CBCT, CT, MRI, ultrasound) and histopathology (biopsy). Biopsy
A biopsy is indicated when the patients clinical presentation, past history or imaging studies do not allow a definitive diagnosis. A biopsy is a surgical procedure that involves the removal of a piece of tissue sample from the living organism for the purpose of microscopic examination. In most cases, biopsies are carried out under local anaesthesia. Some biopsies are carried out endoscopically, others under image guidance, for instance ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) in the radiology suite. Examples of the most common tissues examined by means of a biopsy include oral and sinus mucosa, bone, soft tissue, skin and lymph nodes.Types of biopsies typically used for diagnosing oral and maxillofacial pathology are:
Excisional biopsy:  A small lesion is totally excised. This method is preferred, if the lesions are approximately 1 cm or less in diameter, clinically and seemingly benign and surgically accessible. Large lesions which are more diffused and dispersed in nature or those which are seemed to be more clinically malignant are not conducive to total removal.Incisional biopsy: A small portion of the tissue is removed from an abnormal-looking area for examination. This method is useful in dealing with large lesions. If the abnormal region is easily accessed, the sample may be taken at your doctors office.