FASCIAL SPACE INFECTIONS

FASCIAL SPACE INFECTIONS

When dental infection spreads deeply into the soft tissue rather than existing superficially through oral or subcutaneous route. Fascial space may become involved.  Follows the path of least resistance through connective tissue and along Fascial planes.Its called space infections .

Fascial layers may be divided anatomically into Superficial and Deep layers. The superficial fascia in the face is quite similar to subcutaneous tissue.

DEEP CERVICAL FASCIA

The deep cervical fascia is generally described to possess three layers from outside inwards—investing fascia, pretracheal fascia and prevertebral fascia.

INVESTING FASCIA

It lies under cover of the platysma and is remarkable for the frequency with which it splits into two.

Attachments: behind-ligamentum nuchae and the seventh cervical spine;

 in front-continuous with the similar fascia of opposite side across the middle line and is attached to the hyoid bone;

Above {from behind forwards}

i.            External occipital protuberance and superior nuchal line of occipital bone;

ii.            Mastoid part and its process of the temporal bone;

iii.            Cartilaginous part of external acoustic meatus;

iv.            Lower margin of the zygomatic arch;

       v.            Lower border of the body of the mandible extending from the angle of mandible to the symphysis menti.

Below {from behind forward}

i.            Spine and acromion process of scapula;

ii.            Upper surface of the clavicle;

iii.            Suprasternal notch of manubrium sterni.

Tracings: Horizontal extentàtraced forward from ligamentum nuchae, the fascia splits to enclose the trapezius, reunites at the anterior border of the muscle and extends forward as the roof of the posterior triangle.

Vertical extentàtraced above: the fascia splits to enclose the submandibular and parotid glands. At the lower border of submandibular gland the fascia splits into superficial and deep layers. At the lower pole of parotid gland it splits into superficial and deep layers. The superficial layer is attached to the lower margin of zygomatic arch and blends with the epimysium of the masseter to form a strong Parotido-masseteric  fascia. Collection of inflammatory exudate beneath this fascia produces severe radiating pain. The deep layer is attached to the lower border of the tympanic plate and the styloid process of the temporal bone. Here the deep layer is thickened to form the stylomandibular ligament, which extends from tip of styloid process to angle of mandible. This ligament separates the parotid from the submandibular glands.

Traced below:  the deep cervical fascia splits to enclose two spacesàsuprasternal and supraclavicular.

Suprasternal space{space of burn’s}- it is a triangular space above the  manubrium sterni where the investing fascia splits into superficial and deep layers, and are attached  respectively to the anterior and posterior borders of the suprasternal notch. The space contains:

[  Sternal head of sternocleidomastoid

[  Jugular venous arch connecting the anterior jugular veins;

[  Interclavicular ligament;

[  A lymph node sometimes.

Supraclavicular space-Above the middle third of the clavicle the investing fascia splits into two layers which are attached respectively to the anterior and posterior borders of the upper surface of clavicle, enclosing the supraclavicular space. The supraclavicular space contains:

S  Terminal part of  external jugular vein, and

S  Supraclavicular nerves before it becomes cutaneous.

PRETRACHEAL FASCIA

Horizontal extent—it passes medially forming the anterior wall of carotid sheath, splits into two layers to enclose the thyroid gland, and then passes in front of trachea to be continuous with similar layers of the opposite fascia across the middle line. A fibrous band known as  the ligament of berry is derived from this fascia and connects the lobe of thyroid gland with the cricoid cartilage.

Vertical extent—   traced above, the pretracheal fascia is attached to the hyoid bone in the middle line and to the oblique line of thyroid cartilage o each side. Traced below, the fascia enters the thorax in front of the trachea and inferior thyroid veins, and blends with the apex of fibrous pericardium. At the thoracic inlet it is also continuous with the suprapleural membrane (Sibson’s fascia)

PREVERTEBRAL FASCIA

Horizontal extent—it passes medially forming the posterior wall of the carotid sheath, covers the cervical vertebrae and pre vertebral muscles, and is continuous with the similar fascia of the opposite side.

Vertical extent—it is attached above to the bones of the base of skull. Traced below, the fascia splits in anterior and posterior layers. Anterior layer is known as the alar fascia.

Suprahyoid muscles: The suprahyoid muscles suspend the hyoid bone from the skull and comprise four pair of musclesà Digastric, Stylohyoid, Mylohyoid and Geniohyoid. The hyoglossus and genioglossus although suprahyoid in position belongs to the extrinsic muscles of tongue.

Infrahyoid muscles:  The infrahyoid muscles are strap muscles and consists of:-Sternohyoid, Omohyoid, Sternothyroid and thyrohyoid. They are arranged in superficial and deep layers.

CLASSIFICATION OF FASCIAL SPACES

Based on mode of involvement

J  Direct involvement: Primary spaceàa)Maxillary  space b)Mandibular space

J  Indirect involvement: Secondary space

Based on space involved in odontogenic infection

¥  Primary maxillary spaceàCanine space, Buccal space and infratemporal  space

¥  Primary mandibular spaceàSubmental,Buccal,Submandibular and Sublingual spaces

¥  Secondary fascial spaceàMasseteric,Pterygomandibular,Superficial and deep temporal,Lateral pharyngeal,Retropharyngeal and Prevertebral spaces

Based on clinical significance

­  FaceàBuccal, Canine, Masticatory and Parotid spaces.

­  Suprahyoidà Sublingual,Submandibular,Submental,Pterygomaxillary and  Peritonsillar

­  Infrahyoidà Anterovisceral{pretracheal}  space

­  Space of total neckàretropharyngeal space of carotid sheath.

CANINE SPACE

Involvement: a) Odontogenic infection b) Nasal infection—less frequent

Periapical abscess which discharge buccally from an upper canine or 1st premolar may lead to accumulation of pus in canine fossa deep to muscle of facial expression moving upper lip.

Surgical anatomy:

 Superiorly-levator labi superior alaque nasi, levator labi and zygomaticus minor muscle.

Inferiorly-Caninus muscle

Anteriorly-Orbicularis oris

Posteriorly-Buccinator muscles

Medially-Anterolateral surface of maxilla

Clinical features:

ü  Swelling of cheek and upper lip{vestibular abscess}

ü  Obliteration of nasolabial fold{pus accumulates in canine fossa}

ü  Drooling of angle of mouth

ü  Oedema of lower eyelid

ü  Redness and marked tenderness of facial tissue

ü  The offending tooth is mobile and is tender to percussion

Incision and drainage

The approach to this area is through the mucosa of buccal vestibule in the region of lateral incisor and canine. A curve mosquito forceps is inserted superior to the attachment of Caninus muscle and the infraorbital space is entered. Pus is evacuated and a drain is inserted and is secured in place with suture.

BUCCAL SPACE

It is the potential space between buccinator muscle and masseter muscle

Boundary:

Medially—buccinator and buccopharyngeal fascia.

Laterally—Skin of the cheek.

Anteriorly—Labial muscles {zygomaticus and depressor anguli oris}

Superiorly—Zygomatic arch.

Inferiorly—Lower border of mandible

Posteriorly—Pterygomandibular raphe

Contents

²  Buccal pad of fat

²  Parotid duct

²  Facial artery

²  Branches of facial nerves

Etiology

         Odontogenic origin: when the root apex of molar and premolar teeth situated above maxillary/mandibular below. The origin of buccinator with the jaw bone, then infection from these teeth perforating the buccal cortical plate spread into the buccal space.

Non-odontogenic: cellulitis caused by H.influenzae.

Clinical features

_  Pus accumulates on oral side of the muscle.’ Gum boil’ is seen in the vestibule

_  Marked swelling of the cheek

_  Presence of diseased teeth

_  Fever, sign of inflammation

_  Lymphadenopathy, fluctuation.

Management

Surgical drainage:- cutaneous  incisionàhorizontally low down the cheek, inferior to most fluctuant point. Care should be taken not to damage into the depth of extreme boundaries of space

Antibiotic therapy

Removal of the offending tooth infection

SUBMENTAL SPACE

A potential space exist in the chin and occasionally infection originating from the six anterior mandibular teeth, perforates the cortical plate below the origin of mentalis muscle labially and Mylohyoid lingually.

Boundary:

Lateral—lower border of mandible and anterior bellies of digastric muscle.

Superior—Mylohyoid muscle.

Inferior—suprahyoid portion of the investing layer of deep cervical fascia.

Contents

  • Submental lymph node
  • Anterior jugular vein
  • Lymph nodes

Clinical features

  1. Distinct firm swelling in the midline. Swelling is board like and taut. Fluctuation may be present.
  2. The anterior teeth are non-vital, fractured or carious. Tenderness on percussion

Incision and drainage

Making a transverse incision in the skin below the symphysis of the mandible. Blunt dissection is carried out by a Kelly’s forceps or Sinus forceps through this incision upward and backward.

SUBLINGUAL SPACE

This space is V-shaped trough lying lateral to muscles of tongue including hyoglossus, genioglossus and geniohyoid.

Involvement: the teeth which frequently give rise to involvement of sublingual space are mandibular incisor, canine, premolar and sometime 1st molar teeth. It is a paired space but the two sides communicate anteriorly. This space communicates with submandibular space around the posterior border of Mylohyoid muscle.

Boundary:

Inferiorly—Mylohyoid muscle.

Laterally—medial side of mandible

Medially— hyoglossus, genioglossus and geniohyoid muscles

Posteriorly—hyoid bone

Contents

  • Geniohyoid and genioglossus muscles
  • Deeper part of the submandibular salivary gland
  • Sublingual salivary gland

Clinical features

i.            Little or no swelling.

ii.            The lymph node may be enlarged and tender.

iii.            Pain and discomfort on deglutition.

iv.            Speech may be affected.

Surgical drainage

The sublingual space drainage should be performed intraorally by an incision through the mucosa parallel to the Wharton’s duct. Bilaterally if the submandibular space is also to be drained both space can be reached through a submandibular approach.

SUBMANDIBULAR SPACE

The space between the anterior and posterior bellies of digastric muscles is the submandibular space. The upper part lies beneath the inferior border of mandible and the lower part lies deep to the investing layer of the deep cervical fascia.

Involvement: most frequently involved by infection originating from the mandibular molar. The pus perforates the lingual cortical plate of mandible.

Boundary

Laterally—Posterior partà of lower border of mandible.

Anterior partàskin, superficial facsia, platysma, deep cervical fascia.

Medially—Mylohyoid muscle, hyoglossus.

 Anteriorly—Mylohyoid muscle blends with lingual surface of mandible

Inferiorly—Digastric muscles

Posteriorly—lower part extends to the hyoid bone; upper part attached Mylohyoid to mandible.

Contents

­  Submandibular salivary gland

­  Proximal part of Wharton’s duct

­  Facial artery

­  Submandibular lymph node

­  Lingual and hyoglossal nerves

Communications

n  Sublingual space

n  Submental space

n  Masticatory space

n  Contralateral submandibular space

n  Pharyngeal space

n  Through the space in the neck to the mandible.

Etiology

It is caused by odontogenic infection

-infection of mandible by 2nd and 3rd molar. Sometimes 1st molar.

-infection from sublingual and submental space.

Clinical features

  1. Patient present with soft browny swelling close to the lower border of mandible.
  2. Little elevation of tongue
  3. Fever, lymphadenopathy, anorexia

Treatment

        Surgical drainage: incision is given parallel with the lower border of mandible 2cm below. Then blunt dissection is carried out to the depth of the space to its anterior and posterior margin with care to vital structure.

MASTICATORY SPACE

The masticatory space comprise of:

  1. a.      Submasseteric space
  2. b.      Pterygomandibular space
  3. Temporal space—i}deep   ii}superficial

These spaces are well differentiated but communicate with each other as well as with the buccal, submandibular and Para pharyngeal space.

Involvement: infection may be confined to any one of these compartment or may spread to any or all of the other compartment. Thus the masticatory space as a unit is bounded by fascia

Contents

v  Muscle of mastication

v  Internal maxillary artery

v  Mandibular nerve

If subdivided masseteric compartment bounded laterally by masseter muscle and the mandibular ascending ramus medially; whereas pterygoid compartment medially by pterygoid muscle and laterally by mandible. Both these compartments communicate freely with the superficial and deep temporal pouch superiorly, buccal space anteriorly and lateral pharyngeal space posteriorly.

Etiology

Infection most frequently from molar teeth mainly 3rd molar.

-pericoronitis of gingival flap of 3rd molar

-caries induced dental abscess

-contaminated mandibular block anaesthesia

-direct trauma of muscles of mastication

Clinical features

I.            Hallmark of masticatory space infection is trismus.

II.            Swelling, cardinal sign of infection.

Treatment

Surgical drainage: drainage of Pterygomandibular space infection

     Intra-oral: When trismus is less, sicher’s incision along the pterygomandibualr raphe

Extra-oral: LAàsharp dissection at the external angle of mandible to cut skin soft fasciaà blunt dissection to reach Pterygomandibular spaceàdependent drainage.

PHARYNGEAL SPACE

The lateral pharyngeal space is a lateral neck space whose space is that of an inverted cone , with its base at the skull and its apex at the hyoid bone. Its medial wall is contiguous with the carotid sheath and lies deep to the pharyngeal constrictor muscles. It is divided for surgical and anatomical purpose into anterior and posterior compartments

Involvement: infection of lateral pharyngeal space may result from pharyngitis, tonsillitis, parotitis, otitis, mastoiditis and dental infection. Specially if the masticator spaces are primarily infected.

Etiology

-herpetic gingivostomatitis involving pericoronal tissue has also been reported as a cause of lateral pharyngeal abscess

Clinical features

Anterior compartment: pain, fever, chills, medial bulging of the lateral wall, dysphagia, swelling below the angle of mandible, trismus.

Posterior compartment: absence of trismus, visible swelling, respiratory obstruction, septic thrombosis of internal jugular vein.

Surgical treatment

Oral incision of lateral pharyngeal wall or external by exposure of carotid sheath near the lateral tip of hyoid bone after retraction of sternocleidomastoidàfurther dissection along the posterior border of the digastric muscles leads to lateral pharyngeal wall.

-antibiotic therapy

-tracheostomy

HILTON’S METHOD OF INCISION AND DRAINAGE

The method of opening an abscess ensures that the blood vessels or nerve in the vicinity is damaged and is called Hilton’s method.

Steps:-

Topical anaesthesia: topical anaesthesia is achieved with the help of ethyl chloride spray.

Stab incision: made over a point of maximum fluctuation in the most dependent area along the skin creases through skin and subcutaneous tissue

If the pus is not encountered, further depending of surgical site is achieved with Sinus forceps.

Closed forceps are pushed through the tough deep fascia and advanced towards the pus collection.

Abscess cavity is entered and forceps opened in a direction parallel to vital structure.

Pus flows along sides of the beaks

Explore the entire cavity for additional loculi.

Placement of drain: a soft corrugated rubber drain is inserted into the depth of the cavity and external part is secured to the wound margin with the help of suture

Drain left for at least 24hrs

Dressing is applied over the site of incision taken extra orally without pressure.

Incision and drainage helps:

I.            To get rid of toxic purulent materials

II.            To decompress the oedematous tissue

III.            To allow better perfusion of blood containing antibiotic and defensive element.

IV.            To increase oxygenation of infected area.

LUDWIG’S ANGINA

This is a severe, life threatening cellulitis that tends to spread through tissue spaces and fascial planes.

Etiology

1} odontogenic infection—usually from mandibular 2nd, 3rd molar

[  Acute dento-alveolar abscess

[  Periodontal abscess

[  Periapical abscess

[  Infected mandibular cyst

2} Trauma—i) mandibular fracture ii) deep laceration or penetrating wound into the floor of the mouth.

3) Infection from submandibular or sublingual salivary gland

4) Secondarily infected malignant tumors

5} Infection of tonsils, pharynx.

6} Osteomyelitis of mandible

Clinical features:

  1. Patient looks toxic, ill, dehydrated. Pyrexia, chills, malaise, anorexia, impaired speech and difficulties I deglutition are also present.
  2. Firm, browny board like swelling of the bilateral submandibular and sublingual regime which tends to spread backward along the anterior part of neck.
  3. Mouth remains slightly open due to elevation of tongue and floor of the mouth.
  4. Respiratory difficulties, cyanosis, increased respiratory rate, stridor may appear subsequently.
  5. Increased salivation, stiffness of tongue, and difficulties in swallowing.

Risk

S  Spread of infection posteriorly leads to oedema of glosstis and inlet of larynxàsuffocationàdeath.

S  Spread of infection to mediastinum

S  Septicaemia and septic shock

S  Venous and cavernous sinus thrombosis, carotid sheath erosion

S  Brain abscess and meningitis.

S  Aspiration pneumonia

S  Pericarditis.

S  Death

Management

  1. Early diagnosis and hospitalization
  2. Maintenance of airway—i} cricothyrotomy/laryngotomy s done. Tracheostomy is avoided.

ii} Nasoendotracheal intubation using fibre optic laryngoscope.

Blind endotracheal intubation is avoided.

  1. Anaesthesia—with LA into superficial tissue of neck or if intubation is already done then G.A.
  2. I.V. analgesics—to relieve pain. Narcotics and sedative are avoided.
  3. Removal of cause– extraction of offending tooth which facilitates evacuation of pus present in close vicinity to tooth. In early lesions, simple extraction and antibiotic therapy may be sufficient to control Ludwig’s angina.
  4. Surgical decompression: asepsisàanaesthesiaà bilateral incision of 1-2cm below the lower border of mandible and separate midline incision for submental spaceàblunt dissection to reach deep to the spaceàinitially no pus comes, but later on profuse pus drains outàincision must be secured by suturing.
  5. Antibiotic therapy
  • Aqs. Penicillin– 2-4MU i.v. 4hourly, then penicillin V- 500mg orally slowly.
  • Amoxicillin- 500mg TDS orally
  • Cloxacillin-500mg TDS orally
  • Erythromycin-600mg 6-8hourly
  • Clindamycin-600mg i.v. à300-400mg orally TDS
  • Cephalosporin

E.   Treatment of dehydration—excess oral fluid intake or i.v. fluid infusion.

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