Maxillofacial Fractures: Midface and Internal Orbit-Part I: Classification and Assessment.

Fractures of the midface and internal orbit occur isolated or in combination with other injuries. Frequently, the patients are first seen in emergency rooms responsible for the coordination of initial diagnostic procedures, followed by the transfer to specialties for further treatment. It is, therefore, important for all physicians treating facial trauma patients to understand the basic principles of injuries to the midface. Thus, this article aims to describe the anatomy and the current classification systems in use, the related clinical symptoms, and the essential diagnostic measures to obtain precise information about the injury pattern.

Traumatic superior orbital fissure syndrome: assessment of cranial nerve recovery in 33 cases.

BACKGROUND: Superior orbital fissure syndrome is a rare complication that occurs in association with craniofacial trauma. The characteristics of superior orbital fissure syndrome are attributable to a constellation of cranial nerve III, IV, and VI palsies. This is the largest series describing traumatic superior orbital fissure syndrome that assesses the recovery of individual cranial nerve function after treatment. METHODS: In a review from 1988 to 2002, 33 patients with superior orbital fissure syndrome were identified from 11,284 patients (0.3 percent) with skull and facial fractures. Severity of cranial nerve injury and functional recovery were evaluated by extraocular muscle movement. Patients were evaluated on average 6 days after initial injury, and average follow-up was 11.8 months. RESULTS: There were 23 male patients. The average age was 31 years. The major mechanism of injury was motorcycle accident (67 percent). Twenty-two received conservative treatment, five were treated with steroids, and six patients underwent surgical decompression of the superior orbital fissure. After initial injury, cranial nerve VI suffered the most damage, whereas cranial nerve IV sustained the least. In the first 3 months, recovery was greatest in cranial nerve VI. At 9 months, function was lowest in cranial nerve VI and highest in cranial nerve IV. Eight patients (24 percent) had complete recovery of all cranial nerves. Functional recovery of all cranial nerves reached a plateau at 6 months after trauma. CONCLUSIONS: Cranial nerve IV suffered the least injury, whereas cranial nerve VI experienced the most neurologic deficits. Cranial nerve palsies improved to their final recovery endpoints by 6 months. Surgical decompression is considered when there is evidence of bony compression of the superior orbital fissure.

Assessment of trigeminal nerve functions by quantitative sensory testing in patients and healthy volunteers.

PURPOSE: Orofacial sensory dysfunction plays an important role in oral and maxillofacial surgery. Quantitative sensory testing (QST) is a psychophysical approach to evaluate thermal and mechanical somatosensation. PATIENTS AND METHODS: The present human study 1) collected normative QST data in extraoral and intraoral regions, 2) analyzed effects of age, gender, and anatomical sites on QST, and 3) applied QST in 11 patients with iatrogenic inferior alveolar nerve lesions. Sixty (30 male and 30 female) healthy volunteers were tested bilaterally in the innervation areas of infraorbital, mental, and lingual nerves. Ten patients with sensory disturbances in innervation areas of the mental nerve were investigated at 1, 4, and 8 weeks after surgery. Another patient with a complete sensory loss after surgery was repetitively tested within 453 days after primary surgery (dental implant) and subsequent surgical reconstruction of the inferior alveolar nerve by autologous graft. RESULTS: Older subjects were significantly less sensitive than younger subjects for thermal parameters. Thermal detection thresholds in infraorbital and mental regions showed higher sensitivity in women. Sensitivity to thermal stimulation was higher in the infraorbital region than in the mental and lingual regions. QST monitored somatosensory deficits and recovery of inferior alveolar nerve functions in all patients. CONCLUSIONS: Age, gender, and anatomic region affect various QST parameters. QST might be useful in the diagnosis of inferior alveolar nerve disorders in patients. In dentistry, the monitoring of afferent nerve fiber functions by QST might support decisions on further interventions.

Physical neurosensory testing versus current perception threshold assessment in trigeminal nerve injuries related to dental treatment: a retrospective study.

OBJECTIVE: To provide a preliminary comparison of traditional clinical neurosensory examination (CNE) and current perception threshold (CPT). METHOD AND MATERIALS: This is a retrospective chart audit of patients with trigeminal nerve injuries related to dental treatment who were evaluated with both CNE and CPT assessments (electrical stimulus tests) after presenting with altered sensation involving either the inferior alveolar nerve (IAN) or lingual nerve (LN) distributions. The tests were performed on the anterior two-thirds of the tongue for LN injuries and the lower lip and chin for IAN injuries. Results were defined as hyper-, hypo-, or normal sensory response. RESULTS: Twelve charts were reviewed; 10 of the 12 nerve injuries occurred secondary to mandibular third molar extraction affecting 7 LN and 5 IAN branches. Following LN injuries, the C, and A-delta fibers assessment demonstrated hyposensitivity in the affected nerve territory in CPT and the CNE tests with the exception of 1 normal nerve response in 5-Hz CPT. Within the LN injury group, good correlation was observed between the CNE and CPT tests with the exception of brush stroke and 250-Hz CPT stimuli. Following IAN injuries, sensory testing results were more varied. A-beta fiber evaluation demonstrated hyposensitivity to VF in all patients and in 4 of 5 for brush test. One patient was hypersensitive for the brush test. The response to 2,000-Hz electrical stimulus demonstrated hyposensitivity in 3 patients, hypersensitivity in 1 (the same patient that was hypersensitive for brush), and normal sensitivity in 1 patient. Good correlations were found only between the CPT 5-Hz and heat and cold tests. Only 1 patient (IAN injury) reported pain that was hypersensitive for heat, cold, pinprick, brush, and 250-Hz and 2,000-Hz stimuli. CONCLUSION: Following LN injuries, CNE and CPT tests provided similar findings. More disparity was observed between the CNE and CPT methods in the IAN injury evaluation. For LN injury assessments, CNE alone appears to be adequate for assessing nerve injuries.

Trigeminal nerve injury following accidental airbag deployment and assessment with quantitative sensory testing.

High velocity motor vehicle accidents are associated with an increase in mortality rates and a significant number of facial injuries. Accidental deployment of airbags and the associated release of hot gases can result in both thermal and mechanical injuries. The more commonly reported maxillofacial injuries include temporomandibular joint fractures and dislocations, dental trauma, facial nerve paralysis, and other orofacial pain complaints. The following case report describes a patient with facial trauma from the accidental deployment of an airbag resulting in complaints consistent with a neurological injury for which quantitative sensory testing was used in confirming the diagnosis.

Simplifying the assessment of the recovery from surgical injury to the lingual nerve.

OBJECTIVE: To determine the sensitivity of conventional sensory assessment in monitoring lingual nerve recovery subsequent to third molar surgery and to evaluate if the assessment methods can be predictive of injury outcome. METHOD: A prospective case series of 94 patients presenting with lingual nerve injuries evaluated using objective mechanosensory and subjective methods during the recovery period of up to 12 months. RESULTS: The conventional tests were often unable to diagnose the presence of injury due to variability and they were not predictive of outcome. As a result of this study, we are able to identify patients more likely to have permanent rather than temporary lingual nerve injury at four to eight weeks post injury, using patient reported subjective function. The subjective function test also minimises the requirements for specialist training or equipment providing an ideal method for general dental practice. CONCLUSIONS: The development of these simple subjective tests may enable us to identify which patients are at risk of permanent lingual nerve injuries in the early post injury phase, thus allowing expeditious therapy when indicated.

Quantitative sensory testing in trigeminal nerve damage assessment.

Evaluating sensory nerve damage is a challenging and often frustrating process. Diagnosis and follow-up is usually based on the patient's history and gross physical evaluation in addition to simple sensory tests such as brushing or pin prick. Based on evidence accumulated from clinical and animal experiments, quantitative sensory testing (QST) has emerged as a useful tool in the assessment of sensory nerve damage. QST has demonstrated diagnostic capabilities in temporomandibular disorders, burning mouth syndrome, oral malignancies, numb chin syndrome, posttraumatic pain, and whiplash injuries, and in elucidating mechanisms of central sensitization. In this article specific clinical uses of QST are described and its clinical applicability is demonstrated. Future studies should be directed at exploring the use of QST in the diagnosis and classification of further nerve pathologies.

A prospective electromyographic and computer-aided thermal sensitivity assessment of nerve lesions after sagittal split osteotomy and Le Fort I osteotomy.

PURPOSE: The purpose of this study was to determine the incidence of temporary and permanent sensory disturbance of the inferior alveolar nerve (IAN) after bilateral sagittal split osteotomy (BSSO) of the mandible and of the infraorbital nerve (ION) after Le Fort I osteotomy, as well as the rate of recovery of sensory function using subjective and objective measures. PATIENTS AND METHODS: Preoperatively and after 1 week, and 1, 3, 6, and 12 months postoperatively, sensibility in the distribution of 36 IONs after Le Fort I osteotomy and 24 IANs after BSSO in 19 patients were investigated by using sharp-blunt testing, 2-point discrimination, electromyographic recording, and thermal sensitivity (Pain and Thermal Sensitivity Test Device [PATH]) tests of the Adelta and C nerve fibers. RESULTS: With conventional clinical sharp-blunt and 2-point discrimination tests, the incidence of temporary impairment was 81% for the ION (29 of 36) and 83% for the IAN (20 of 24). The rate of permanent sensibility disturbance with conventional clinical testing was 6% for the ION and 15% for the IAN. Obvious recovery was found after 1 to 3 months for the ION, but it took 6 to 12 months for the IAN. In contrast, electromyography (EMG) testing showed lower rates of temporary sensory disturbance, namely, 54% (13 of 24) for the ION and 68% (15 of 22) for the IAN. Permanent sensory losses were not found. The results of the EMG test was confirmed by the PATH test. CONCLUSIONS: Objective tests for sensory disturbances show lower rates than the conventional tests. For quality control, preoperative and postoperative measurement and documentation of postoperative recovery of sensation is recommended.

Role of thermography in the assessment of infraorbital nerve injury after malar fractures.

We studied 45 patients with malar fractures who had some degree of infraorbital nerve deficit. Thermographic facial images failed to show any substantial changes in the temperature profiles of the affected and the normal control sides in relation to reco very of their facial sensation. Although some patients who had thermography on the day of injury showed significant temperature differences between the affected and the normal sides, these differences were probably the result of the acute inflammatory ch anges caused by the injury. We suggest that infrared thermography has little place in the assessment of infraorbital nerve deficits.

[Simple assessment of trigeminal nerve injury]. / Eenvoudig onderzoek naar letsel van de nervus trigeminus.

This paper describes a simple method to assess trigeminal nerve injury. An easy and feasible technique, in particular for the dental surgeon, is scanning the area with altered sensation as indicated by the patient. It is important to refer the eligible patient in time for microsurgical repair of the damaged nerve.