Submandibular Space Infection

Anatomy-Space below the mandible and mylohyoid muscle, bordered medially by the anterior belly of the digastric muscle, posteriorly by the posterior border of the submandibular gland, and reaching inferiorly to the level of the hyoid bone. The submandibular space consists mainly of fat, the submandibular gland and lymph nodes.

   Spread of infection: (according to)

(I)      

1- The position of the myelohyoid ridge

The myelohyoid ridge runs obliquely, higher posteriorly than anteriorly

In the lower posterior aspect, the apices of teeth related to the area below the myelohyoid ridge will spread infection into the submandibular space.

2- Level of the apices of the lower arch (Direct penetration of the lingual plate).

(II)              Secondary to involvement of submandibular lymph nodes.

Sublingual space, superior to mylohyoid muscle. The submandibular space is inferior to the mylohyoid muscle

Spread of process superiorly and posteriorly elevates floor of mouth and tongue. In anterior spread, the hyoid bone limits spread inferiorly, causing a "bull neck" appearance.

    Signs & symptoms

-         Usual systemic signs & symptoms.

-         Massive browny swelling along the lower border of the mandible extending posteriorly to the angle.

-         Moderate mandibular limitation.

-         The swelling is board-like, tender, indurated, inflammatory red & hot.

¥    The moderate limitation of the mandible arise from the involvement of the medial pterygoid muscle which extend posteriorly in the space not within the infection.

¥    The difficulty with swallowing arise from the large surface area of myelohyoid muscle that is involved.

Treatment: Extra-oral Incision & Drainage

The incision should be done at the deepest area of infection to help the drainage rapidly & completely with the aid of gravity.

Incision in the stage of pitted on edema or localized swelling...

This incision should be:

1-     Anatomically should be away from any important anatomical structures (mandibular branch of facial nerve).

2-     At minimally scanning or disfiguring area "Cosmotic consideration" e.g along  skin creases

The incision should pass through the (skin, superficial fascia, platysma, deep fascia) layer by layer with blunt dissection.

Further more, a blunt instrument should be inserted within the infected space to completely damage any septi & partition to ensure complete drainage of pus.

The ideal blunt instrument is an index finger.

Finally, the space should be filled with gauze by a mosquito forceps & left there for 24 hours. This drain will allow pus evacuation from un-reached areas & the newly formed pus.

This drainage should be left in place to keep the incision line patent until the entire induration is relieved.

Finally, dressing is placed externally to allow healing.

 

Ludwig's AnginaLudwig's Angina is a severe form of cervico-fascial infection / cellulitis which
usually arises from the lower second or third molars (wisdom teeth).Deep fascial space infections cause gross inflammatory exudates (a fluid with a
high content of protein and cellular debris which has escaped from blood vessels
and has been deposited in tissues or on tissue surfaces, usually as a result of
inflammation. It may be septic or non-septic) and tissue œdema (swelling),
associated with fever and toxæmia (blood poisoning).  Before the advent of
antibiotics, the mortality was high and the disease is still life-threatening if
treatment is delayed.

The main fascial spaces involved in Ludwig’s Angina are the sublingual, submandibular and para-pharyngeal.  Normally, the spaces both side of the
midline (ie bilateral) are effected.

The characteristic features are:

•        diffuse swelling, pain, fever and malaise.
•        The swelling is tense and tender, with a characteristic ‘board-like’ firmness.
•        The overlying skin is taut and shiny.
•        Pain and œdema (swelling) that limit opening the mouth and often cause dysphagia (difficulties in swallowing)
•        Systemic upset is severe, with worsening fever, toxæmia (blood poisoning)
and leucocytosis.
•        The regional lymph nodes are swollen and tender.
•        In Ludwig's Angina particularly, airway obstruction can quickly result in asphyxia.
Pathology Anærobic bacteria are primarily responsible and infection mainly spreads from mandibular third molars (lower jaw wisdom teeth) whose apices (root tips) are closely related to several fascial spaces.  Fasciæ, covering muscles and other
structures are normally adherent but can be spread apart by inflammatory exudate.

Spaces created in this way are almost avascular (do not have a blood supply) and
inflammatory exudate carries bacteria widely through them. It involves the sub-lingual and sub-mandibular spaces bilaterally (on both sides) almost
simultaneously; it readily spreads into the lateral pharyngeal and pterygoid spaces  
and can extend into the mediastinum. The main features are rapidly spreading sub-
lingual and sub-maxillary cellulitis with painful, brawny swelling of the upper part
of the neck and the floor of the mouth on both sides.  With involvement of the para-
pharyngeal space, the swelling tracks down the neck and œdema can quickly
spread to the glottis.

Swallowing and opening the mouth become difficult and the tongue may be pushed
up against the soft palate.  The latter or œdema of the glottis causes worsening respiratory obstruction. The patient soon becomes desperately ill, with fever, respiratory distress, headache and malaise.
Management The main requirements are:

•        immediate admission to hospital
•        procurement of a sample for culture and sensitivity testing
•        aggressive antibiotic treatment
•        securement of the airway by tracheostomy if necessary, and
•        drainage of the swelling to reduce pressure.