Josip Hat

Mandibular neuralgia due to anatomical variations

Abstract In our large collection of macerated human adult skulls and disarticulated skulls of young individuals we found cases with an extremely large lateral lamina of the pterygoid process. The medial wall of the infratemporal fossa was defined as its formation by the lateral lamina of the pterygoid process and the medial pterygoid muscle. The muscular part formed two-thirds and the lateral lamina one-third of this wall. In cases of a very large lateral lamina in our specimens nearly the whole medial wall was osseous. The third portion of the trigeminal nerve gives off the lingual nerve and alveolar mandibular nerve in the region of the infratemporal fossa. These two nerves generally passed between the lateral and medial pterygoid muscles to their terminal sites. In cases of extremely large lateral laminae the nerves had to make a curve in their course, following the shape of the enlarged lamina. During contraction of the pterygoid muscles both nerves can be compressed. Since the lingual nerve runs between muscular elements, tension and compression is probably avoided. In contrast, the mandibular nerve fixed between the oval and mandibular foramina cannot avoid tension and compression. The result is possible pain, especially during chewing, and may finally create a trigeminal neuralgia. Similar symptoms could be provoked by a foramen pterygospinale or ovalis canal replacing the foramen ovale.

Tonsillolithiasis and orofacial pain.

Tonsilloliths are rare calcified structures that usually result from chronic inflammation of the tonsils. Concretions show differences in size, shape and colour. They are usually asymptomatic but can be associated with halitosis, foreign body sensation, dysphagia and odynophagia, otalgia, and neck pain. A patient was referred because panoramic radiography performed by a general dentist revealed radiopaque shadows over the ascending rami of the mandible, located bilaterally: a solitary structure on the higher portion of the right side and two small structures on the left side. Paroxysmal attacks of orofacial pain and symptoms such as dysphagia and swallowing pain on the left side distributed within the tonsillar fossa and pharynx and the angle of the lower jaw were present. The computed tomography images revealed bilateral tonsilloliths. Clinically, there was no sign of inflammation, and the patients past history revealed an approximately 2-year history of dysphagia, swallowing pain and left-sided neck pain. At the request of the patient, no surgical intervention was carried out. Glossopharyngeal neuralgia is a rare entity, and the aim of this report was to indicate the importance of tonsilloliths as a cause of orofacial pain.

Variations of the ethmoid labyrinth and sphenoid sinus and CT imaging

SummaryThree hundred macerated and partly isolated postmortem mid-facial bones were studied for the development, variations and dimensions of the structures of the nasal cavity. On 184 axial CT scans of bones (102 male, 82 female) from patients ranging in age from 1 to 90 years old, the dimensions of the ethmoid labyrinth and sphenoid sinus were studied in detail in order to determine which anatomic situation might be unsafe during clinical endoscopic interventions. Six anatomic variations were identified. Most unsafe for surgery seemed to be the following types: type 111, in which the anterior diameter of the ethmoid labyrinth was large and the posterior ethmoid and sphenoid diameters were relatively narrow; type V, in which both ethmoid dimensions were large and the sphenoid diameter was narrow: type VI, in which the ethmoid labyrinth had an “hour-glass” shape. Present findings indicate that CT orientation before any endoscopic intervention might help to avoid serious complications.

Relation of the ethmoidal cells to the floor of the anterior cranial fossa.

The shape of the anterior part of the anterior cranial fossa undergoes important changes in the postnatal life depending on the degree of pneumatisation of the ethmoid labyrinth and/or the frontal sinus. There exist three possibilities in these relations: 1) From the newborn period up to 9 years of age, in the majority of the cases the cribrous plate is situated at the level of the roof of the ethmoid labyrinth with the width of the ethmoid incisure corresponding to the width of the cribrous plate. 2) In the period from 9-35 years of age, in the majority of cases, the ethmoidal cells are partly or completely incorporated into the floor of the anterior cranial fossa with the width of the ethmoid incisure corresponding to the number of cells forming the floor of the anterior cranial fossa. 3) In the period from 35-80 years of age, the cribrous lamina is in the majority of cases lowered due to the intensive development of the frontal sinus. The medial wall of the ethmoid labyrinth consists of a thin bony strip, the width of which depends upon the degree of lowering of the cribrous plate. Adequate CT imaging may clarify the situation.

The frontal sinus and the ethmoidal labyrinth

In the “standard” anatomic description, the frontal bone and cribriform plate of the ethmoid bone form the base of the anterior cranial fossa. We studied the development of the ethmoidal bone as well as its relations to the frontal bone in macerated disarticulated skull bones and macerated skull bases of 35 individuals between 9 and 35 years of age. In 19 cases the ethmoidal cells were completely or partly uncovered by the frontal bone. In 6 of 19 cases the frontal bone did not cover any of the ethmoidal cells; in 10 further cases the frontal bone covered only the anterior and in 3 cases the anterior and middle ethmoidal cells. In a 60-year-old subject the ethmoidal cells were incorporated in the base of the anterior cranial fossa, a rare finding. Thus, a depressed lamina cribrosa is not the only danger in ethmoidectomy. Based on the present data ethmoidal cells uncovered by the frontal bone may involve a serious risk during ethmoidectomy even if the surgeon remains lateral to the insertion of the middle concha. The discrepancy between common descriptions of this region and our own findings may be related to imprecise data concerning the life stage of the cases described in the literature.