Quantitative analysis of facial motion components: anatomic and nonanatomic motion in normal persons and in patients with complete facial paralysis.

The maximal static response assay of facial motion, described in 1994, enables the simultaneous measurement of multiple facial motions by tracking the positions of specific facial points. While the maximal static response assay provides accurate measurement of facial motion, the analysis of these data lacks the simplicity of a single-number scale such as the House-Brackmann system, a subjective scale traditionally used to classify facial function. The purpose of this study was to develop a simplified numerical index capable of summarizing the data generated by the maximal static response assay in a clinically meaningful way. We also wanted to develop a method whereby only anatomic motion or nonanatomic motion in the paralyzed face could be quantitated. Anatomic motion is the motion of the specific facial points studied by the maximal static response assay that can be attributed solely to the pull of the regional facial muscles that govern the movement of those points. Nonanatomic motion is motion that is secondary to the pull of the unaffected contralateral muscles that is transmitted to the paralyzed hemiface. Thirty-four patients with complete facial paralysis were studied. The maximal static response assay was performed on all patients on presentation to the Facial Nerve Center at the University of Pittsburgh Medical Center or after development of complete facial palsy postoperatively. The data from these patients were compared with maximal static response assay data from 26 unaffected controls. The anatomic index of facial motion and the nonanatomic index of facial motion were calculated for all study participants. The anatomic index of facial motion measures anatomic facial motion, and the nonanatomic index of facial motion measures nonanatomic facial motion. To calculate the anatomic index of facial motion, the vector magnitudes of the supraorbital, infraorbital, and modiolar motions during brow lift, eye closure, and smile are summed. The anatomic index of facial motion represents a ratio of this sum on the affected side to the corresponding sum on the unaffected side using only anatomic motions. The nonanatomic index of facial motion is a similar ratio using nonanatomic motion only (i.e., motions in directions that cannot be produced by the ipsilateral muscles). The anatomic index of facial motion represents a single number that can be used to assess facial motion. The value of the anatomic index of facial motion for patients with complete facial paralysis is 0.07 +/- 0.08. The anatomic index of facial motion for normal individuals is 1.05 +/- 0.13 (p < 0.0001, Mann-Whitney rank-sum test). The nonanatomic index of facial motion in normal individuals is 0.05 +/- 0.08; in patients with complete facial paralysis, it is 0.34 +/- 0.32 (p < 0.0001, Mann-Whitney rank-sum test). During recovery from complete facial paralysis, the anatomic index of facial motion and the nonanatomic index of facial motion each revert steadily toward normal values. The anatomic index of facial motion and the nonanatomic index of facial motion are single numbers based on the maximal static response assay, which quantitatively describes anatomic motion and nonanatomic motion in patients with complete facial paralysis. Although patients with complete facial paralysis have motion on the paralyzed hemiface, the motion is primarily nonanatomic. Both indices can be used to track recovery from complete facial paralysis.

Quantitation of patterns of facial movement in patients with ocular to oral synkinesis.

As patients with facial paralysis regain facial nerve function, they must endure and adapt to complications associated with recovery, such as synkinesis. Synkinesis is the presence of unintentional movement in one area of the face when intentionally performing movement in another area of the face. We used the Maximal Static Response Assay of facial motion to better define the differences between eye closure-associated perioral motion in normal individuals, motion of the affected side in patients with synkinesis, and motion of the unaffected side in patients with synkinesis, thereby characterizing the syndrome of ocular to oral synkinesis. The study population consisted of 78 patients with clinically defined ocular to oral synkinesis of the left or right hemiface and 27 individuals without facial impairment (control subjects). We used the Maximal Static Response Assay to quantify facial motion on the affected and unaffected sides during the motions of eye closure and smile in both groups. Patients with ocular to oral synkinesis had decreased supraorbital and infraorbital motion of the orbicularis oculi during eye closure on both the affected and unaffected sides relative to control subjects. They also had increased modiolar motion during eye closure on both sides relative to control subjects. On the affected side, the modiolus tended to move laterally; on the unaffected side, the modiolus tended to move medially (i.e., toward the side affected by the synkinesis). Modiolar motion present during eye closure in patients with ocular to oral synkinesis was not statistically different from modiolar motion present during smile on the affected side (eye closure, 0.39 cm +/- 0.25; smile, 0.47 cm +/- 0.30, p > 0.05). Using the Maximal Static Response Assay, we have quantitatively defined synkinesis of the affected hemiface and have shown that movement of the unaffected hemiface is influenced by the synkinetic movements of the affected hemiface. These data may provide the basis for a rational system of facial neuromuscular rehabilitation in this patient group.

Quantitative facial motion analysis after functional free muscle reanimation procedures.

The purpose of this study was to evaluate the success of functional free muscle transfer in patients with chronic facial paralysis using a recently developed quantitative method known as the maximum static response assay of facial motion. A retrospective review of a single surgeon series of six patients with longstanding facial paralysis was performed. The maximum static response assay was performed on all patients preoperatively and serially during the postoperative period. Twenty-seven patients (54 sides) with normal facial function were also evaluated and served as controls. The contralateral normal side in those patients with unilateral facial paralysis (n = 4) also served as a control. Movement of the modiolus during smile was recorded in the x axis and y axis. To determine net smile movement, the vector of movement was calculated by means of the Pythagorean theorem. Vectors were then defined mathematically by calculating direction and magnitude. The average direction of the vector during smile for the normal control population was 58.3 degrees (range 32.5 to 83.1 degrees) from the horizontal through the modioli, and the average magnitude was 10.6 mm (range 4.2 to 20.1 mm). The average preoperative direction for the reanimated sides was 176.8 degrees with a range of 83.3 to 225 degrees. Patients with bilateral paralysis (n = 2) were excluded for calculation of the vectors on the normal contralateral side. The average preoperative direction for the normal contralateral side in patients with facial paralysis was 58.3 degrees with a range of 48.2 to 68.4 degrees. Postoperatively, the average direction of the vector during smile for the reanimated sides improved to a value of 77.6 degrees with a range of 45.7 to 113.8 degrees. The average change in direction of the preoperative reanimated side compared with the postoperative reanimated side was significant (p = 0.01). Postoperatively, the average direction of the vector for the contralateral normal sides was 43 degrees with a range of 11 to 57.2 degrees. The change in direction for the contralateral normal side was not significant (p = 0.18). The average magnitude of the reanimated side improved from a non-anatomic 2.8 mm preoperatively (range 0.8 to 6.8 mm) to an anatomic 4.9 mm postoperatively (p = 0.02). The contralateral normal side magnitude decreased from 9.4 mm (range 7.3 to 11.6 mm) preoperatively to 5.7 mm (range 3.8 to 7.7 mm) postoperatively (p = 0.006). More specifically, the absolute change in movement on the reanimated side during smile for the x axis and y axis was 2.3 mm (p = 0.05) and 4.0 mm (p = 0.002), respectively. This corresponded to an absolute change in the magnitude of the vector of 4.6 mm in an anatomic direction. On the contralateral side the absolute change in magnitude during smile from preoperative to postoperative for the x axis and y axis decreased by 1.5 mm (p = 0.13) and 5.3 mm (p = 0.05), respectively. This reflected an absolute change in the magnitude of the vector of 5.5 mm. Functional free muscle transfer in patients with chronic facial paralysis resulted in anatomic recovery of motion in the majority of patients in this series. The maximum static response assay can be used to objectively assess the results of facial reanimation.

Specific impairment of smiling increases the severity of depressive symptoms in patients with facial neuromuscular disorders.

Depressive symptoms and related emotional distress are prevalent among patients with facial neuromuscular disorders, and the psychological distress impacts the functional disabilities associated with the facial impairment. A specific impairment in the ability to smile may elevate the risk for depression, with patients experiencing a reduced physiological feedback associated with smiling as well as the social consequences of the inability to communicate positive emotion. We tested the hypothesis that specific impairments in the ability to smile increase the severity of depressive symptoms in patients with facial neuromuscular disorders. Twenty-nine consecutive patients (mean age, 50.2 years; SD, 17.0 years; range, 18-81 years) with a facial neuromuscular disorder, who volunteered and completed all of the assessment measures participated. Facial neuromuscular impairments were assessed using multiple measures of facial motility and dysfunction, and emotional functioning was assessed using self-report measures of depression, anxiety, and positive and negative affect. Severity of global facial impairment was statistically controlled in evaluating the association between specific impairment in smiling and the degree of depressive symptoms. Separate hierarchical linear regression analyses indicated the specific impairment of smiling contributed to the prediction of depression (R(2) =.41, df = 3,25, p =.00) and anxiety (R(2) =.35, df = 3,25, p =.00), controlling first for the contribution of global impairment and facial physical disability. The specific impairment of smiling did not contribute to the prediction of positive emotional experience. Specific impairment of smiling and physical disability, but not global impairment of facial motion, were key predictors of depression in patients with facial neuromuscular disorders. The results emphasize the need to assess and treat depression and anxiety in patients with a facial neuromuscular disorder.