At the maximum mouth opening, the distance between incisal edges of the middle incisor teeth should be about 3.5 to 4 cm. This distance varies individually, although if a patient cannot open his/her mouth to the distance of at least 3 cm, it can be felt as an unpleasant functional restriction. A restricted ability of the lower jaw to move is designated as contracture which has several forms:
Inflammatory contracture has its origin at an inflammation around the mandibular elevators (mainly the m. pterygoideus medialis).
Muscular contracture appears by damage of the above mentioned muscle during mandibular anesthesia.
Arthrogenous contracture is caused by inflammations of the mandibular joint or by a chronic traumatization of the joint at occlusion defects.
Fibrous contracture is determined by fibrous changes at the mandibular joint area after traumas or burns.
Neurogenic contracture (trismus) appears at tetanus.
Therapy of restricted mouth opening should focus on elimination of underlying causes. In cases of an inflammation at the mandibular joint area, a temporary loose immobilization of jaws by a wire bonding has its place, besides the anti-inflammatory therapy. At other kinds of contractures, physical therapy (red Solux lamp), active and passive exercises and laser therapy are often used. Fibrous contractures need to be released surgically in some cases.
A total immobility of the mandibular joint is called ankylosis. It is a coalescence of the lower jaw articular process with the temporal bone. Its cause is usually the mandibular joint purulent inflammation associated with otitis or osteomyelitis during childhood, or an intra-articular fracture or contusion with the joint hematoma. It results at a significant restriction of mobility of the mandible. A diagnosis is confirmed by an X-ray examination at Schüller’s projection, or a computer tomography examination. Ankylosis is treated surgically - arthro-plastic surgery - that includes cutting out the bone bridge followed by insertion of other material (fascia, cartilage) into the neo-formed glenoid.
8.6 Inflammations Around the Jaws
Inflammatory illnesses of the oro-facial area are very common. They can be divided into two groups:
Non-specific inflammations that are caused by a bacterial flora inhabiting and growing saprophytically inside the oral cavity under aerobic or anaerobic conditions.
Specific inflammations, caused by a particular infectious agent, such as actinomycosis, tuberculosis and lues.
Non-specific inflammations are mostly of an odontogenous origin. They arise from an acutely exacerbating chronic periodontitis that appears during dentitio difficilis of the lower third molar as a result of an infected alveolar socket after an extraction. Other causes include infected dental cysts, penetrating injuries, skin inflammation (furuncles), periodontal cysts, inflammation of salivary glands or lymphatic nodes. An inflammation has usually a course of an interstitial process; either a delineated abscess or diffusely spreading phlegmona originates depending on a causative bacterial agent’s virulence and an organism’s immunity. An inflammation spreads per continuitatem at different rates through the bone tissues at the root’s tip underneath the periosteum (sub-periosteal abscess) and further into submucous tissues (parulis). At better cases, the abscess fluid gets emptied through the alveolar ridge mucosa to the mouth vestibule or by the oral way, thus creating an inner draining fistula. At more serious cases, the infection spreads by pre-formed paths, along muscles, their attachments and fasciae in such manner that it affects areas around the jaws. Inflammations around the jaws occur, affecting usually more than one area. Inflammatory processes diagnostics should focus on both overall and local signs that indicate harms of a particular area around the jaws. General signs include the rate of onset of problems, fever, the shivers and previous treatment. Of local signs, one should register swelling, palpation sensitivity of an affected region, skin color, fluctuation, chewing muscles contracture. During inflammations that originate at the upper jaw, a large swelling of eye lids and cheeks occurs, however the extent of swelling does not have to be related to an inflammation severity. Inflammations that take place around the lower jaw, a progressing contracture of chewing muscles and difficulties during swallowing occur, as well as submandibular infiltrate and swelling which move towards the neck area.
Therapy of these inflammatory processes is surgical only. It is based on draining a puss from the abscess cavity by a wide enough intra-oral or extra-oral incision. A purulent exudate is collected into a sterile sample tube for microbiological examinations and determination of a bacterial flora’s sensitivity to antibiotics. A wound is then drained by a sufficiently long rubber or plastic drain, flat or tubular. The aim of drainage is enabling the purulent exudate to flow out freely and prevention of reconnection of wound edges. After an acute inflammation phase diminishes, extraction of the causative tooth is performed. Extraction can be also done during an abscess incision, under an antibiotic screen.
According to anatomical localization, inflammations around the jaws can be divided into the following groups:
Retro-maxillar abscess. An infection penetrates the retro-maxillar space from gangrenous upper molars, infected cysts, sometimes by infection of a hematoma after an injection anesthesia at tuber maxillae (puncture of plexus venosus pterygoideus).
Abscess of the pterygo-palatal, infratemporal or temporal regions. Originates by broadening of a retro-maxillar abscess into its surroundings. Besides a high fever of septic character and changes of a patient’s general condition, infiltration of the temporal area, swelling both above and below the zygomatic arch, orbital signs (edema of eye lids, protrusion of eyeballs), and contracture occur. There is a para-pharyngeal swelling and redness inside the oral cavity.
Submental and submandibular abscess. These inflammations are mainly caused by gangrenous teeth of the lower arch: the frontal teeth in case of a submental abscess, molars in case of a submandibular abscess. Clinical picture shows primarily an increasing swelling of submental or submandibular areas, reddish and warm skin. Fevers and difficulties during swallowing occur, even contracture of chewing muscles. The submandibular area has a fundamental importance for surgical therapy of inflammations around the jaws, since from there it is possible to drain all regions around the mandible, including the para-pharyngeal space, after an external incision.
Pterygomandibular and para-pharyngeal abscess. These inflammations are often caused by difficult eruption of the third lower molar. A contracture, high fevers, overall condition changes, difficulties to swallow are common signs. Expansion of a para-pharyngeal abscess into the mediastinum and formation of purulent mediastinitis is a very serious condition and despite combined surgical and antibiotic therapy, it may be lethal.
Abscesses of the tongue and sub-lingual region. These abscesses originate mainly after injuring the tongue by biting or by a foreign object. They can be found on the surface under the mucosa, or interstitially at the tongue’s base. A sub-lingual abscess can be a result of gangrenous molars or premolars whose roots are positioned at the level of the attachment m. mylohyoideus. Infection may as well be transferred from the submandibular areas. The tongue’s movements are restricted, speech is altered, swallowing and mouth opening are painful and restrained.
Specific inflammations. These are chronic inflammations caused by a specific etiologic agent, accompanied by formation of granulous tissue (actinomycoma, tubercle, gumma). They should be considered if an acute inflammation process does not recede after a treatment and changes into a chronic state. This is true especially in case of actinomycosis whose cervico-facial form is far more frequent than abdominal and pulmonary forms. The cause of the disease is the anaerobic Actinomyces israeli or Nocardia asteroides that inhabit the oral cavity of healthy people. The clinical picture is dominated by a tough, inflammatory infiltrate at an affected area, abscesses and external fistulas are formed, from which leaks a thin purulent exudate with yellowish druses of actinomycetes. In addition to surgeries, therapy also includes high doses of penicillin (mega-doses). Tuberculosis of the oral mucosa may appear at patients suffering from the open form of lung tuberculosis. Upon a microscopic examination, the subepithelial connective tissue contains epithelial nodes with multi-nuclear cells of Langhans type. Manifestations of syphilis at the oral cavity can be found during all three phases of the disease. A specific granulomatous inflammation (gumma) is a sign of the third stage of the disease which affects mainly the nose septum, palate and tongue. Therapy is conducted by specialists - a phthisiologist or a venereologist.