Prevention of Pericoronitis
When a tooth is partially impacted with a large’ amount of soft tissue over the axial and occlusal surfaces, the patient frequently has one Or more episodes of pericoronitis.” Pericoronitis is an infection of the soft tissuearound the crown of a partially impacted tooth and is caused by the normal oral flora. For ‘most patients the bacteria and host defenses maintain a delicate balance, but host defenses cannot eliminate the bacteria.
If the host defenses-are compromised (e.g., during minor illnesses, such as influenza or an upper respiratory infection, or from severe fatigue), infection can occur. Thus although the impacted tooth has been present for some time without infectlon, if the patient experiences a mild, transient decrease in host defenses, pericoronitis may result.Pericoronitis can also arise secondary to minor trauma from a maxillary third molar. The soft tissue that covers the occlusal surface of the partially erupted mandibular third molar (known as the operculums can be traumatized and become swollen. Often the maxillary third molar further traumatizes the already swollen operculum, which causes increased swelling that again cap be traumatized more easily. This spiraling cycle of trauma and swelling is often
interrupted only by removal of the maxillary third molar. Another common cause of pericoronitis is entrapment of food under the operculum. During eating, a small amount of food may be packed into the pocket between the operculum and the impacted tooth. Because this pocket cannot be cleaned, bacteria invade it and pericoronitis begins.
Streptococci and a large variety of anaerobic; bacteria (the usual bacteria that inhabit the gingival sulcus) cause pericoronitis. It can be treated initially by mechanically debriding the large periodontal pocket that exists under the operculum by using hydrogen peroxide as an irrigating
solution. Hydrogen peroxide not only ‘mechanically removes bacteria with its foaming action, it also reduces the number of anaerobic bacteria by releasing oxygen into the usually anaerobic environment of the oral cavity.
Other irrigates, such as chlorhexidine ‘or iodophors, can reduce the bacterial population of the pocket. Pcricoronitls can present as a very mild infection or as a severe infection that requires hospitalization (\1’ the
patient. Just as the severity of the infection varies. the FIG. 9-4 Radiograph of caries in mandibular impacted molar btreatment and management of..this problem vary from very mild to aggressive. In its mildest form, pericoronitis is a localized tissue swelling and soreness. For patients with a mild infection, irrigation and curettage by the dentist and home irriga-.
tions by the patient usually suffice. If the infection is slightly more severe with a large amount of local soft tissue swelling that is traumatized by a
maxillary third molar, the dentist should consider extracting the maxillary third molar in addition to local irrigation.
For patients who have (in addition to local swelling and pain) mild facial swelling, mild trismus secondary to inflammation extending into the muscles of mastication, and a low-grade fever, the dentist should consider administering an antibiotic along with irrigation and extraction. The antibiotic of choice is penicillin. Pericoronitis can lead to serious fascial space infections. Because the infection begins in the posterior mouth, it can
spread rapidly into the fascial spaces of the mandibular ramus and the lateral neck. If a patient develops trismus (with an inability to open the mouth more than 20 mrn), a temperature of greater than 1010 F, facial swelling, pain, . and malaise, the patient should be referred to an oral and
maxillofacial surgeon, who may admit the patient to the hospital, .
Patients who have had one episode of pericoronitis, .although managed successfully by these methods, will continue to have episodes of pericoronitis, unless the offending mandibular ·third molar is removed. The
patient should be informed that the tooth should be removed at the earliest possible-time to prevent recurrent infections. The mandibular third molar should not be removed until the signs and symptoms of pericoronitis
have been completely resolved. The incidence of stoperative complications; specifically dry socket an~ postop erative infection, increases if the tooth is removed during the time of active infection.Prevention of pericoronitis can be achieved by removing the impacted third molars before they penetrate the oral mucosa and are visible. Although excision of the surrounding soft tissue, or operculectomy, has, been advocated as a method for preventing pericoronltts without removal of the impacted tooth, it is very-painful and usually does not work. The soft tissue excess tends to recur, because it drapes over the impacted tooth and causes regrowth of the operculum. The overwhelming majority of cases of pence ronitis can be prevented only by extraction of the tooth.