Acute periapical abscess and spread of inflammationDr. Fahed S.Habash.2nd Semester, 2004

Acute Periapical Abscess and Spread of InflammationAetiology and microbiology: -An acute periapical abscess may develop directly from acute periapical periodontitis or more usually from a chronic periapical periodontitis (granuloma).Mixed bacterial infection.Synergistic interaction between organisms will increase the severity of the infection.

Routes of SpreadIf the cause of the abscess is not removed, suppuration will continue and the abscess continues to enlarge.In some cases, a balance may eventually be established between the irritant and the host defenses and the abscess becomes chronic and remain localized.More frequently, the increase in hydrostatic pressure within the abscess associated with progressive suppuration causes the pus to track in one of a number of directions.

Possible Routes of SpreadIt may drain through the root canal into the mouth.It may track through the periodontal ligament to discharge into the gingival sulcus.It may track through the cancellous bone and perforates the cortex.Once the cortical plate is perforated the pus strips up the periostium and may result in the formation of subperiosteal abscess.

It may penetrates the periosteum & may track in various direction (affected by anatomical factors).The relationship of the cortical perforation (which related to the apex of the abscessed root) to the origins of muscles, for example buccinator and Mylohyoid, and the strength of the overlying periosteum are important factors.

Possible outcomes of infection spreadThe pus may discharge directly into the oral cavity through a sinus following local penetration of the overlying periosteum & mucosa.On other occasions the pus may accumulate beneath the mucosa and the patient may complain of a gumboil before a sinus develops.A nodule of granulation tissue often forms in response to the irritation by pus and marks the opening of the sinus.

2. The dense palatel mucoperiosteum is resistance to penetration by pus. Pus tracking palatally may spread under the mucoperiostium and present as a palatal abscess.

3. Abscess in the molar region of either Jaw may penetrate the buccal cortical plate above (in the maxilla) or below (in the mandible) the attachments of the buccinator muscle spreading of the infection in the soft tissue of the face or neck (cellulitis). Or less frequently as a localized soft tissue abscess.4. Abscess developing of the root apices of maxillary molars and premolars are very close to the floor of the maxillary sinus and consequently may discharge into the sinus.5. Abscess related to ant. maxillary teeth may pass into the upper lip.

6. An abscess related to mandibular premolar or molar tooth may perforate the lingual plate of the mandible below the attachment of mylohyoid muscle to involve the submandibular space. This cause a marked swelling at the lower border of the mandible spreading toward the neck (submandibular space has communications with the sublingual and lateral pharyngeal spaces).7. Pus from an abscess associated with a mandibular incisor or canine may track labially and perforate the bone below the insertion of the mentalis muscle and pass downwards to present as a subcutaneous abscess. (most often at the mid line).

CellulitisPotentially life-threatening infections due to spread of bacteria into perioral fascial spaces.Associated with steptococcal infections and the rapid spread due to the release of large amounts of steptokinase and hyaluronidase. Its not localized and affected tissues swollen.Infection usually arises from lower second or third molars. Cellulitis may associated with maxillary teeth involves the upper half of the face. Severe systematic upset associated.Ludwigs angina comprises bilateral involvement of sublingual and submandibular spaces usually as a result of initial involvement of submandibular space. This diffuse infection may tracks backwards to involve the pharynx and larynx with risk of death by suffocation..