Frey's Syndrome Consequent to an Unusual Pattern of Temporomandibular Joint Dislocation: Case Report with Review of Its Incidence and Etiology

Abstract

Frey's syndrome was first described in the 18(th) century. Recognizing it as a nonspecific condition, the symptom of gustatory sweating in patients with parotid gland inflammation was described by Duphenix and Baillarger. However, as a specific diagnostic entity, gustatory sweating, following trauma to parotid glands, was first described by Polish neurologist Lucie Frey, in 1923, and hence he proposed the term auriculotemporal syndrome. The condition is characterized by sweating, flushing, a sense of warmth, and occasional pain in the preauricular and temporal areas, following the production of a strong salivary stimulus. Several etiologies of Frey's syndrome have been mentioned in the literature; however, none attribute dislocation of the "intact" mandibular condyle as a cause of the syndrome. Reviewing its pathophysiology, etiology, and incidence in detail, we describe a case of Frey's syndrome subsequent to superolateral dislocation of the intact mandibular condyle following fracture of the anterior mandible. Its management and prevention are also discussed in brief.

Keywords: Frey's syndrome; Minor's test; mandibular condyle; superolateral dislocation.

Figure 1

Schematic diagram depicting the normal innervation to the parotid gland and sweat glands of the parotid region. (1) Sweat gland; (2) parotid gland; (3) sympathetic supply to sweat gland; (4) parasympathetic supply to the parotid; (5) ATN. Abbreviation: ATN, auriculotemporal nerve.

Figure 2

Schematic diagram indicating the disrupted parotid gland innervation (following parotidectomy) leading to Frey's syndrome. (1) Sweat gland; (2) parotid gland; (3) aberrant re-innervation of parasympathetic nerve fibers to a regional sweat gland; (4) injured ATN. Abbreviation: ATN, auriculotemporal nerve.

Figure 3

Preoperative photograph showing a diffuse swelling over the left temporomandibular joint.

Figure 4

Preoperative computed tomography scan showing superolateral dislocation of the left condyle with an associated midsymphyseal fracture.

Figure 5

Postoperative orthopantomogram (OPT) showing the reduced and fixed midsymphysis fracture with both the condyles seated in the glenoid fossa.

Figure 6

(A) Gustatory sweating observed over the left preauricular region. (B) A positive Minor's test over the left preauricular region.

Figure 7

(A) Relations of the medial aspect of the mandible: (1) medial pterygoid muscle; (2) maxillary artery; (3) lingual nerve; (4) inferior alveolar nerve; (5) middle meningeal artery; (6) motor root of mandibular nerve; (7) sensory root of mandibular nerve; (8) auriculotemporal nerve; (9) lateral pterygoid muscle; (10) temporomandibular joint capsule; (11) external carotid artery; (12) inferior alveolar artery. (B) Frontal view depicting the vertical distance from superior border of the condyle to the auriculotemporal nerve (0 to 13 mm) and horizontal distance averaging 0 to 1 mm.

Figure 8

Schematic diagram depicting the possible etiopathogenetic mechanism (of superolateral temporomandibular joint dislocation) leading to Frey's syndrome. (1) Parotid gland; (2) injury to ATN; (3) ATN; (4) superolaterally dislocated mandibular condyle. Abbreviations: ATN, auriculotemporal nerve.

Figure 9

Schematic diagram depicting the possible etiopathogenetic mechanism of superolateral dislocation of the mandibular condyle entailing Frey's syndrome. Also seen is the facial nerve coursing through the substance of the ipsilateral parotid gland: (1) facial nerve; (2) parotid gland; (3) injured auriculotemporal nerve; (4) sweat gland; (5) misdirected parasympathetic fibers to a regional sweat gland; (6) superolaterally dislocated mandibular condyle entailing Frey's syndrome.