Key points

In the dental office, there are a number of conditions that can be classified as unscheduled dental emergencies ranging from tooth pain, to a fractured or avulsed tooth, to odontogenic infections. For the general dentist management of odontogenic infections can be the most concerning of these office based emergencies owing to the complex microbiology of odontogenic infections and potential for advancement to life-threatening medical emergencies. Odontogenic infections encompass a variety of conditions ranging from localized abscesses to deep space head and neck infections. Deep space infections can carry a high incidence of morbidity and mortality. Because these patients often present to the dental office unexpectedly, it is imperative for the dental professional to have an understanding of treatment and management of such infections. Management of patient with an odontogenic infection is a multifaceted approach involving an examination and assessment of the patient, identifying the source of the infection, anatomic considerations, surgical intervention, administration of the appropriate antimicrobial therapy, and referral to an appropriately trained provider if indicated. This article provides a basic understanding of the diagnosis and pharmacologic management of patients with infections that are odontogenic in origin. This article is limited to management in the outpatient setting. It is recommended that providers with desires to manage infections in the inpatient setting to review the literature on therapeutic management of these patients before treatment.

Examination and assessment

A thorough patient examination is a critical component of treatment of odontogenic infections. Patient evaluation begins with a comprehensive history and physical examination followed by an assessment of the pertinent findings. This is then followed by a diagnosis and development of a treatment plan for patient care. Failure to complete a comprehensive history and examination of the patient can lead to improper treatment and/or delayed treatment of infections, potentially leading to serious complications, including but not limited to airway compromise, mediastinitis, sepsis, and death.

A patient history includes attaining information regarding the symptoms, onset, and duration of the present illness. This information helps to form an understanding of the severity of the patient’s infection. Common signs and symptoms that should alert a provider of a developing or established infection include trismus, fever, difficulty swallowing, pain, difficulty breathing, and pain on swallowing. The patient’s medical history and current medications are key in assessing the patient’s ability to fight infection as well as providing insight to potential drug interactions.

The physical examination oftentimes begins before the provider enters the room with the recording of vital signs or on introduction with visual inspection swelling or general appearance and posturing. Airway assessment is a critical component of this examination. It allows for assessment of the necessity for emergent referral. Palpation, percussion, and thorough visual examination of the extraoral and intraoral cavities provide necessary information for identifying the source and location of the infection. Providers should pay close attention size of swelling, tongue position, floor of the mouth swelling or elevation, visual disturbances, voice changes, vestibules, and uvula position. This should be followed by radiographic examination.

After subjective and objective information has been gathered and interpreted an appropriate diagnosis is made, which guides the plan of treatment. This treatment could vary based on the findings present but can involve antibiotic therapy, surgical management, or a combination of both with or without an urgent referral to an oral and maxillofacial surgeon or hospital.

Examination and assessment

A thorough patient examination is a critical component of treatment of odontogenic infections. Patient evaluation begins with a comprehensive history and physical examination followed by an assessment of the pertinent findings. This is then followed by a diagnosis and development of a treatment plan for patient care. Failure to complete a comprehensive history and examination of the patient can lead to improper treatment and/or delayed treatment of infections, potentially leading to serious complications, including but not limited to airway compromise, mediastinitis, sepsis, and death.

A patient history includes attaining information regarding the symptoms, onset, and duration of the present illness. This information helps to form an understanding of the severity of the patient’s infection. Common signs and symptoms that should alert a provider of a developing or established infection include trismus, fever, difficulty swallowing, pain, difficulty breathing, and pain on swallowing. The patient’s medical history and current medications are key in assessing the patient’s ability to fight infection as well as providing insight to potential drug interactions.

The physical examination oftentimes begins before the provider enters the room with the recording of vital signs or on introduction with visual inspection swelling or general appearance and posturing. Airway assessment is a critical component of this examination. It allows for assessment of the necessity for emergent referral. Palpation, percussion, and thorough visual examination of the extraoral and intraoral cavities provide necessary information for identifying the source and location of the infection. Providers should pay close attention size of swelling, tongue position, floor of the mouth swelling or elevation, visual disturbances, voice changes, vestibules, and uvula position. This should be followed by radiographic examination.

After subjective and objective information has been gathered and interpreted an appropriate diagnosis is made, which guides the plan of treatment. This treatment could vary based on the findings present but can involve antibiotic therapy, surgical management, or a combination of both with or without an urgent referral to an oral and maxillofacial surgeon or hospital.

Stages of abscess development

The source of odontogenic infections is commonly bacteria native to the oral cavity. This bacteria acts on a tooth or the periodontium. In periodontal infections, attachment loss of the gingival fibers and destruction of supportive structures expose the teeth and tissues to bacterial introduction. Periapical infections begin with a carious lesion causing pupal necrosis, which introduces the pulp to microorganisms. This process then proceeds until the bacteria invades the periapical tissues. Upon accessing the periapical tissues, the process can remain localized to the bony structures as a cyst, granuloma, or focal osteomyelitis. A second alternate a progressive process may ensue as periapical infection spreads through cortical bone involving cellulitis, and localized and deep space abscess formation.

After inoculation of bacteria into deeper tissues abscess, development progresses through cellulitis to abscess formation without early intervention. Cellulitis is an acute disorder associated with warm, diffuse, painful, indurated swelling of soft tissues that also may present with erythema. Next, the indurated swelling begins to soften as an abscess develops represented by localized area fluctuance. An abscess is collection of purulent material containing necrotic tissue, bacteria, and dead white blood cells. Patients may present at varying stages of the process. Bacteria from a dental infections also has the ability spread hematogenously owing to the high vascularity of head and neck structures, allowing infections to present in distant sites including the orbit, brain, and spine.

Anatomic considerations

Odontogenic infections spread from the bony structures through the cortical bone along the path of least resistance, with the affected fascial spaces determined by the structures in proximity to the tooth roots. This necessitates an understanding of fascial spaces and anatomy to effectively diagnose and develop a surgical plan for management of infections. The spaces that are primarily affected by odontogenic infections are located adjacent to the origin. Those spaces are categorized as primary fascial spaces. They include buccal, canine, sublingual, submandibular, submental, and vestibular spaces.

After infection spreads to primary spaces, they can progress to include secondary spaces ( Table 1 ). Secondary spaces include pterygomandibular, infratemporal, masseteric, lateral pharyngeal, superficial and deep temporal, masticator, and retropharyngeal.

A basic understanding of the spread of infections into the primary spaces is established by understanding the origin and insertions of the buccinator and mylohyoid muscles in relation to the maxilla and the mandible. The buccinator inserts superiorly into the alveolus of the maxilla and inferiorly in the alveolus of the mandible. An infection that spreads within the constraints of those insertions results in a vestibular abscess and spread of infection above or below these insertions forms a buccal space infection. The mylohyoid muscle’s origin is from the mylohyoid line of the mandible. Teeth with root apices below this origin are the mandibular second and third molars. Infectious spread of these teeth through the lingual plate forms submandibular space infections. The roots of the mandibular premolars and first molars lie above the mylohyoid and, therefore, infectious spread lingually associated with these teeth create sublingual space infections. Relations of teeth to primary fascial spaces are provided in Table 2 . The teeth most frequently identified as the source of an infection are the mandibular molars, followed by the mandibular premolars.

A special note should be made of an indurated cellulitis involving bilateral submandibular, sublingual, and submental spaces with drooling, tongue displacement, dysphagia, and patient head positioned in the “sniffing” position. This is the classic description of Ludwig’s angina. This is a medical emergency in need of definitive airway management and timely surgical management, and should be referred immediately to the nearest hospital for treatment. Patients with infections associated with maxillary molars may also present with maxillary sinusitis owing to the close proximity of roots apices with the floor of the maxillary sinus. Conversely, patients with maxillary sinusitis may also present with symptoms of an infection, so it is prudent to perform an examination to develop the appropriate diagnosis.

Surgical intervention

Resolution of an odontogenic infection occurs after pharmacotherapy, but it is often studied in combination with surgical treatment. Surgical invention is believed by many to be the most important aspect of management of odontogenic infection. The goal of surgical intervention is to remove the source of the infection. Eradication of the infection source is performed by tooth extraction, root canal therapy, or incision and drainage with intervention as early in the infectious process as possible. The extent of the general dentists’ involvement in treating an odontogenic infection lies in the training and comfort level of the provider. Root canal therapy and tooth extractions are routinely performed by dental professionals; however, these procedures with associated fascial space spread of infection could lead to a decision to refer the patient to a specialist for management of the infection. Many general dentists are trained to manage some primary space infections, but should use their judgment based on subjective and objective findings on examination of the patient to guide the decision to treat or refer immediately. Patients presenting with infections of the secondary fascial spaces should be referred immediately to owing to the sequelae of potential complications of improper treatment, advancement of infection to other fascial spaces, the necessity for extraoral approaches, and potential for surgical or nonsurgical airway management.