holmes2016

Antimicrobial Therapy in
Management of
Odontogenic Infections in
General Dentistry
Curtis J. Holmes, DDS
a,
*, Robert Pellecchia, DDS
b
In the dental office, there are a number of conditions that can be classified as un-
scheduled 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 infec-
tions.
1
Deep space infections can carry a high incidence of morbidity and mortality.
2
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 multifac-
eted approach involving an examination and assessment of the patient, identifying
the source of the infection, anatomic considerations, surgical intervention, administra-
tion of the appropriate antimicrobial therapy, and referral to an appropriately trained
a
Department of Dentistry and Oral and Maxillofacial Surgery, The Brooklyn Hospital Center,
Brooklyn, NY, USA;
b
Department of Dentistry and Oral and Maxillofacial Surgery, Geisinger
Medical Center, Danville, PA, USA
* Corresponding author. 100 North Academy Avenue, Danville, PA 17821.
E-mail address: dr[email protected]
KEYWORDS
Odontogenic infections Antimicrobial therapy Antibiotic therapy Dental abscess
Antibiotics Allergy Diagnosis and treatment plan
KEY POINTS
This article focuses on the diagnosis and management of odontogenic infections.
Current antibiotic regimens are reviewed and discussed including use of alternative anti-
biotics with patients known to have a penicillin allergy.
Emphasis is made on proper examination of the patient with use of diagnostic aids to pro-
vide the correct treatment of choice.
Dent Clin N Am 60 (2016) 497–507
http://dx.doi.org/10.1016/j.cden.2015.11.013 dental.theclinics.com
0011-8532/16/$ – see front matter Ó2016 Elsevier Inc. All rights reserved.

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 liter-
ature 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 exam-
ination 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.
2
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 swal-
lowing, pain, difficulty breathing, and pain on swallowing.
1–3
The patient’s medical his-
tory 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.
1,4
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
Holmes & Pellecchia
498

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 infec-
tions 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.
1,4
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.
5
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 estab-
lished 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 infec-
tion that spreads within the constraints of those insertions results in a vestibular ab-
scess 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.
2,3,5
A special note should be made of an indurated cellulitis involving bilateral subman-
dibular, 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
Table 1
Fascial spaces of odontogenic infections
Primary Vestibular
Buccal
Canine
Sublingual
Submandibular
Submental
Secondary Masseteric
Masticator
Pterygomandibular
Lateral pharyngeal
Infratemporal
Superficial temporal
Deep temporal
Retropharyngeal
Management of Odontogenic Infections 499

airway management and timely surgical management, and should be referred imme-
diately 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.
2,3,6
Surgical invention is believed by
many to be the most important aspect of management of odontogenic infection.
1
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 extrac-
tions are routinely performed by dental professionals; however, these procedures with
associated fascial space spread of infection could lead to a decision to refer the pa-
tient 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 nonsur-
gical airway management.
Microbiology of an Odontogenic Infection
It has been stated that odontogenic infections arise from bacterial introduction in the
deeper tissues of the head and neck. There is vast array of bacterial species all
Table 2
Relationship of teeth and primary fascial spaces
Vestibular Maxillary incisors
Maxillary canines
Maxillary premolars
Maxillary molars
Mandibular incisors
Mandibular canines
Mandibular premolars
Mandibular molars
Buccal Maxillary premolars
Maxillary premolars
Maxillary molars
Mandibular premolars
Canine Maxillary incisors
Maxillary canines
Maxillary premolars
Sublingual Mandibular premolars
Mandibular first molars
Submandibular Mandibular second
Mandibular third molars
Submental Mandibular incisors
Mandibular canines
Holmes & Pellecchia
500

residing contemporaneously in the oral cavity and contribute the normal oral flora.
Odontogenic infections are characterized as a combination of aerobic and anaerobic
bacteria. This is why they are considered mixed infections. Streptomyces species are
often responsible for orofacial cellulitis and abscess. Aerobic bacteria including
Streptococcus viridans,Streptococcus milleri group species, beta-hemolytic strepto-
coccus, and coagulase-negative staphylococci have been cultured from odontogenic
infections. Within the S milleri group, the members S anginosus,S intermedius, and
S constellatus are most often associated with cellulitis. Anaerobic bacteria is often
isolated from sites with chronic abscess formation. These pathogens include
Peptostreptococcus,Prevotella,Prophyromonas,Fusobacterium,Bacteroides, and
EIkenella.
1,3,7–10
The most common microorganisms isolated from odontogenic infec-
tions has been consistent over the years.
3,8
However, what has changed is the prev-
alence, the ability to isolate and the ability to classify them owing to changes in
nomenclature.
1,5,11
Over the years, studies have shown that there has been a change in the antibiotic
susceptibility of isolated organisms. Although many strepotococci are still sensitive
to penicillin,
1,12
especially those that are prevalent during the first 3 days of clinical
symptoms, the gram-negative obligate anaerobes, present abundantly after 3 days,
are producing penicillin-resistant strains.
7,13
It has also been found that there is an in-
crease in aerobes and anaerobes that are resistant to clindamycin regimens.
1,14
This
complicates recommendations for therapeutics for orofacial infections; however,
traditionally used empirical antibiotics are excellent options if culture and sensitivity
testing are not performed at or before the time of surgery. Nonetheless, providers
must not forget about the potential resistant organisms to empirical antibiotics.
ANTIBIOTICS OF CHOICE
Antibiotics are antimicrobials used for the treatment and prevention of infections. They
are classified as either bactericidal or bacteriostatic. Bactericidal antibiotics kill bac-
teria by inhibiting cell wall synthesis and bacteriostatic antibiotics inhibit bacterial
growth and reproductions. Table 3 lists common antibiotics and their classification.
The choice of antimicrobial therapy for patients with an odontogenic infections can
be complex owing to numerous variables that must be considered. Factors involved
in antibiotic selection include host-specific factors and pharmacologic factors.
Table 3
Bactericidal and bacteriostatic antibiotics
Bactericidal Bacteriostatic
Beta-lactams
Penicillins
Cephalosporins
Carbapenems
Monobactams
Macrolides
Erythromycin
Clarithromycin
Azithromycin
Aminoglycosides Clindamycin
Vancomycin Tetracyclines
Metronidazole Sulfa antibiotics
Fluoroquinolones —
From Flynn TR, Halpern LR. Antibiotic selection in head and neck infections. Oral Maxillofac Surg
Clin North Am 2003;15(1):21; with permission.
Management of Odontogenic Infections 501