Text Book Reading ODONTOGENIC INFECTIONS

Text Book Reading

ODONTOGENIC INFECTIONSBailey 5th edition Chapter 53Odontogenic infections are common infections are usually associated with dental caries or periodontal disease and are seen more often in underserved populations where regular dental care is lacking.Those individuals with poor dental hygiene and those who are immunosuppressed are most susceptible.

In most cases, odontogenic infections are successfully treated in the early stages by the dental professional with a minor dental procedure and oral antibiotics.In some cases, the infection will spread from the dental alveolar structures into the adjacent soft tissue spaces. This can lead to serious infections of the fascial spaces of the face and neck.When these infections are not promptly managed, serious, even life-threatening complications can arise.DemographicsAlthough any tooth can produce an odontogenic infection, most infections involve the mandibular first, second, and third molarsIn the pediatric population, odontogenic infections are less common overall, but are more likely to occur in maxillary teethMicrobiologyNormal flora in the oral cavity contains over 1,000,000 organisms per cubic centimeter of which 10% are aerobic cocci and 90% anaerobic bacteria:Streptococci are the most common aerobic bacteria found in the oral cavityStaph are more prevalent in the setting of a mixed flora infection. Anaerobes increase in number in the setting of chronic infections like periodontitis all casesSpread Of Localized InfectionsMost odontogenic infections begin with necrosis in the dental pulp from deep caries then followed by the spread of bacteria through the pulp chamber into the adjacent bone and soft tissuesIt may take several months and even years for an infection from dental decay to reach the dental pulp and produce pulp necrosis and periapical abscess.If the infection involves the adjacent soft tissue, it can cause a diffuse inflammatory response with cellulitis or form an abscess.Spread Of Localized InfectionsAn odontogenic infection produces pain when the necrotic pupal contents are under pressure and when the soft tissues and periosteum over the cortical bone are distended. The pain can decrease significantly as the tissue pressure drops when infection spreads through the bone and periosteum into the soft tissues.The treatment of a dental infection at this stage drainage of the infected soft tissues combined with extraction of the offending tooth and administration of systemic antibiotics

Spread Of Localized InfectionsDental infections of the anterior maxilla will spread superiorly into potential space bounded by the mimetic muscles. Maxillary tooth infections occasionally can also spread via the dental roots into the maxillary sinus.

Canine Space InfectionsInfection from a maxillary cuspid tooth perforates the lateral cortex, superior to the attachment of those upper lip elevator produces a firm swelling of the medial cheek and lateral surface of the nose that blunts the nasal labial crease rarely involve the orbit.Treated by drainage with an intraoral incision placed high in the maxillary vestibuleBuccal Space InfectionsInfection perforating the bone above the attachment of the buccinator muscle on the maxilla or below the attachments of the buccinator muscle on the mandible leads to a buccal space infection or abscessUsually a buccal infection will be superficial to the orbital septum and not involve the orbital contents.The buccal space has an ability to expand to a surprisingly large volume with purulent secretions. Despite the impressive swelling, a patient may not have much trismus.

Masticator Space InfectionsThe masticator spaces include the masseteric space, the pterygoid space, and the temporal spaces.The source is usually the mandibular molar but can also be a maxillary molar.Infections of the temporal space can usually be drained either intraorally or externally but are probably best drained with an external incision

Mandibular Space InfectionsThe mylohyoid is the critical structure in understanding sublingual and submandibular space infections. The mylohyoid forms the floor of the oral cavity and separates the sublingual space above from the submandibular space below.Sublingual SpaceInfections of the sublingual space typically start out as tender brawny swellings of the lateral floor of the mouth near the mandible. As the infection progresses, it spreads towards midline and often to the opposite sublingual space.

Submandibular spaceThe submandibular space is separated from the overlying sublingual space by the mylohyoid muscle.The lateral extent of the submandibular space is the skin, superficial fascial and platysma muscle.

Submandibular spaceThe medial limits of the space are the mylohyoid. hypoglossus, and styloglossus muscles, while the inferior border is the anterior and posterior digastric muscles.The anterior portion of the submandibular space communicates freely with the submental space, while the posterior portion communicates with the sublingual space and deeper neck spaces

Submental SpaceThe submental space represents a midline space beneath the anterior aspect of the lower jaw.Its boundaries both anterior digastric muscles, while the roof consists of the mylohyoid muscle and the floor of the mouth mucosa.The anterior and lateral borders are formed by the anterior mandible arch, while the hyoid is the posterior border.Angina LudwigLudwig angina is a distinct pattern of infection that usually originates in the submandibular or sublingual space and then disseminates to all the floor of the mouth spaces by way of the posterior border of the mylohyoid to involve the submandibular and sublingual spaces bilaterally as well as the submental space.Angina LudwigThe infection begins as a cellulitis, advances to a fasciitis, and then becomes a true suppurative infection.Over 90% of cases of Ludwig angina are odontogenic, usually arising from infected second and third mandibular molarsAngina LudwigLudwig infections tend to spread quickly from one space to another, resulting in progressive brawny edema of the anterior and lateral neck skin with the floor of the mouth swelling and elevation of the tongue odynophagia, dysphagia, drooling.Effective treatment of Ludwig angina involves three critical elements. These are (a) securing a safe airway, (b) administering appropriate antibiotics, and (c) surgical drainage of the infected spaces.Angina LudwigWhen the diagnosis of Ludwig angina is made and the disease puts the airway at risk, all authors agree that establishing a secure airway is critical tracheostomy prior to surgical drainage of the infection if necessarySurgical drainage is clearly indicated for patients with an abscess, patients with impending complications, and those showing no improvement after 24 to 48 hours of appropriate parenteral antibiotics.Angina LudwigTraditional surgical management of Ludwig angina called for a horizontal incision placed superior to the hyoid and extending laterally to a few centimeters below each angle of the mandible. Recent studies reported early surgical drainage using multiple small incisions as equally effective in treating the infection.General Treatment GuidanceThe appropriate management of an odontogenic infection can involve medical, surgical, or dental treatment or some combination of all of these.The use of drains in treating infections has not been studied specifically. Some surgeons prefer suction drains, while others favor passive dependent drainage.ImagingThe use of diagnostic imaging has become routine in the management of an odontogenic infection. Dental films often will reveal a radiolucency, and orthopantograms may show some thinning of the cortical bone.Computerized tomography (CT) with contrast is the most commonly ordered study. The CT scan can show the presence or absence of a fluid collection as well as involvement of the various anatomic spaces.Treatment With Antibiotics

Complications Of OdontogenicInfectionsDeep Neck Space InfectionsThe deep neck space infections associated with odontogenic sources include infections involving the retropharyngeal space and the parapharyngeal space require treatment with incision and drainage and administration of systemic antibiotics.Complications Of OdontogenicInfectionsCervical Necrotizing FasciitisNecrotizing fasciitis is a rare but severe bacterial infection of the soft tissues of the neck and its fasciaWhen the diagnosis is missed or when treatment is delayed, the infection can spread rapidly to involve the subcutaneous fat, deep fascia, and musclesComplications Of OdontogenicInfectionsMediastinitisInfections that reach the deep neck spaces as well as those that extend in the soft tissues of the lower neck can extend to involve the mediastinum.These infections are potentially lethal and must be treated aggressively.Surgical drainage of both the neck and mediastinum, eradication of the odontogenic source and broad-spectrum intravenous antibiotic therapy are all required.Thank You