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mise à jour du
6 mai 2004
Arch Otolaryngol
1981; 107; 460
Fracture of an ossified stylohyoïd bone
John M. McGinnis
Montpelier, Vt
Fractures of the styloid process and stylohyoid ligament: an uncommon injury McCorkell
Bâillements et stomatologie


I enjoyed reading Dr Goodman's clinical memorandum on fractures of an ossified stylohyoid ligament in the february Archives Otolaryngol 1981; 107; 129-130
I recently had a case that illustrates some of his points:
Report of a Case : A 52-year-old man with diabetes, previously disabled by a low-back injury, consulted me about a lump and soreness in the right submaxillary area of three weeks' duration. Physical examination disclosed a bony, hard mass in the submaxillary triangle separate from the mandible and fixed. Roentgenographic examination showed an unusually large and well-developed stylohyoid bone. This measured about 7 cm in length, with the maximum width of the shaft about 9 mm. There was a well-defined medullary cavity and bony cortex, an articulation proximally at the styloid process, and a somewhat less well-defined apparent articulation distally at the anterolateral aspect of the hyoid bone.
Two days later, while the patient was yawning vigorously, he heard a loud crack. Acute pain developed in the area. The following day, a roentgenogram showed a fracture with slight angulation in the middle portion of the shaft of this stylohyoid bone.
Comment : We elected to treat this surgically by removing the distal portion through an external approach. The patient had an uneventful postoperative course and has since then been asymptomatic.

Fracture of an ossified stylohyoid ligament
Archives Otolaryngol 1981;107; 129-130
The styloid process of the temporal bone varies in length frorn a long bone, reaching almost to the hyoid and palpable in the tonsillar fossa, to a tiny structure barely visible in the dried skull, and difficult to identify roentgenographically. It is connected to the hyoid bone by the stylohyoid ligament, which may be ossified to a variable degree. Anatomic variations of the styloid bone and stylohyoid ligament may present confusing clinical and roentgenographic pictures.
Report of a Case : A 51-year-old woman was in good health until she lost control of her automobile at low speed and drove it into a tree. She was thrown forward by the impact and struck the steering wheel with her neck. When brought to the emergency room, she was in no respiratory distress but complained of neck pain and hoarseness. Lateral neck films were obtained and initially seemed to show a fracture of the hyoid bone with soft-tissue swelling and airway compromise. I was called to see the patient immediately.
On examination, the patient was uncomfortable but in no acute distress. There was no stridor. Her neck was diffusely tender, but all landmarks were palpable and intact. Indirect laryngoscopy showed the airway to be widely patent. The vocal cords wee mobile, and there were no lacerations or hematomas of the laryngeal mucosa.
The patient was hospitalized for observation and given 100 mg of methylprednisolone sodium succinate (Solumedrol) intravenously to prevent tissue swelling. A tracheotomy set was placed at her bedside, and she was informed that an emergency tracheotomy might be necessary in the event of tissue swelling and airway compromise. During the next 48 hours, she had no respiratory difficulty, and repeated examination results were normal. The neck pain and general tenderness gradually subsided; the tenderness could then be localized to the left side. At the time of her discharge from the hospital, there were still pain and a grating sensation in the left side of the neck on swallowing. An anteroposterior view of the neck demonstrated that an ossified stylohyoid ligament was present in the left side of her neck.
Comment : The styloid process and the lesser cornu of the hyoid bone develop from the cartilage of the second branchial arch. Connecting them is the stylohyoid ligament. In some mammals it is normal to find an ossified chain in place of this ligament; in humans this is an uncommon (but not rare) anatomic variant. In one series, ossification of the stylohyoid ligament was found in 23 of 516 unselected neck films, in patients as young as 19 years. It has been noted in patients as young as 2 years. This strongly suggests that the cause is not degeneration with calcification, but true ossification.
In the human embryo, the epihyal cartilage is resorbed, and its fibrous sheath persists as the stylohyoid ligament. Failure of this step leaves cartilage that may ossify. Instead of a single structure, there may be a chain of three or four bony parts, reflecting the multiple cartilages of the embryo. The width of the structures, length, and the degree of ossification are highly variable. Ossification, when it occurs, is usually (but not always) bilateral.
Because it is uncommon, an ossified stylohyoid ligament may prove confusing. Roentgenographically it bas been mistaken for a foreign body, with some patients undergoing endoscopies because of it. On palpation it may mimic a tumor. In this case the roentgenograms were misread as showing a fracture of the hyoid bone. Porrath, states that hyoid fractures are unusual even in cases of direct trauma. This is because of the mobility of the bone and its protection by a covering of soft tissue. However, he believes that hyoid fractures may accompany mandibular fractures more commonly than is appreciated. Papavasiliou and Speas on the other hand, argue that hyoid fractures may only seem to be unusual because such an injury often causes asphyxiation before the victim can be examined. They observed two patients with hyoid fractures, both of whom required tracheotomies. In one of these patients the neek appeared normal after the injury. However, Porrath states that fracture of the hyoid bone does not necessarily indicate laryngeal damage and that, in the absence of other findings, conservative treatment may be appropriate unless there is laceration of the mucosa.
It is impossible to generalize about fractures of an ossified stylohyoid ligament, as this has apparently been reported only once in the past. In that case, the patient complained of a persistent foreign-body sensation. The patient may have sustained the fracture through muscular action while retching on a piece of meat, as violent muscular contractions have been reported to cause hyoid fractures.
An elongated styloid process can cause vague discomfort in the throat or even pain (Eagle's syndrome). The problem in these cases is often elusive but can be determined by palpating the bone in the tonsillar fossa or by roentgenography. The syndrome has been treated by transoral excision of the tip of the bone, but also by deliberate fracture. No ill effects have been reported in these fractures, and it is likely that a fracture of an ossified stylohyoid ligament would be similarly benign. It does, however, serve as an indicator of neek trauma and require further investigation.
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