Assessment of facial nerve injury with "House and Brackmann facial nerve grading system" in patients of temporomandibular joint ankylosis operated using deep subfascial approach

"Does the Exploration of the Temporomandibular Joint Using a Deep Subfascial Technique Result in a Superior Operative Outcome?"

PURPOSE

The literature is replete with various approaches for the temporomandibular joint (TMJ), each with its own distinct advantages and disadvantages. None of these approaches, however, have been associated with superior operative outcomes. The purpose of this study was to measure the efficacy of three operative approaches to TMJ, namely superficial, subfascial, and deep subfascial approaches. The aim was to contrast selected intraoperative and postoperative outcomes among these surgical approaches.

METHODS

This was a prospective randomized clinical trial of subjects presenting to outpatient department. The primary predictor variables were three dissection planes of TMJ: Group-I (superficial), Group-II (subfascial), and Group-III (deep subfascial). The primary outcome variables were quality of surgical field employing fromme scale, dissection time in minutes, amount of blood loss in milliliters, and facial nerve function (FNF) using House-Brackmann scale. The secondary outcome variables were postoperative pain using visual-analog scale and swelling in millimeters measured on 1st, 3rd, and 7th postoperative days and quality of life using facial clinimetric evaluation questionnaire at 6-month follow-up. Age, gender, side, diagnosis, and type of surgery were the covariates. The data were analyzed using descriptive, comparative, and regression analysis. A P value of less than .05 was considered statistically significant.

RESULT

The study included thirty subjects (8 males and 22 females) with various TMJ disorders ranging in age from 8 years to 65 years (mean 27.83 ± 10.52). On evaluation of intraoperative parameters, subfascial approach had statistically significant superior quality of surgical field (Group-I: 1.90 ± 0.57; Group-II: 1.10 ± 0.32; Group-III: 1.40 ± 0.52; P value = .006), statistically significant shortest dissection time (Group-I: 18.30 ± 3.74 min; Group-II: 13.240 ± 1.96 min; Group-III: 16.20 ± 1.99 min; with P value = .03), and statistically significant lower amount of blood loss compared with other groups (Group-I: 92.40 ± 4.74 ml: Group-II: 82.30 ± 3.77 ml; Group-III: 84.60 ± 3.06 ml; P value<.001). On assessment of postoperative parameters, only FNF of temporal branch showed statistically significant difference from 24 hours till 3 months with better outcome in deep subfascial approach. Mean scores of FNF at 24 hours and 1-week (Group-I: 4.20 ± 2.39; Group-II: 2.40 ± 2.27; Group-III: 1.50 ± 1.58 P = .02) and 1-month and 3-month (Group-I: 2.70 ± 1.82; Group-II: 1.20 ± 0.63; Group-III: 1.00 ± 0.00 P = .04).

CONCLUSIONS

The subfascial approach significantly improved intraoperative outcomes and deep subfascial approach was comparatively safe with fewer incidence of facial nerve injury.

The Facial Nerve Injury After Temporomandibular Joint Surgery after Endaural Approach with Sharp Dissection

Several authors have extensively modified approaches to temporomandibular joint surgery throughout history to improve access, improve aesthetics, and decrease the risk of nerve damage. However, This is why this retrospective cross-sectional is carried out to show the rate of facial nerve injury after the endaural approach with sharp dissection for the temporomandibular joint with a low rate of facial nerve paresis our case series.

Does Evoked Electromyography Detect the Injured Facial Nerve Recovery Earlier Than Clinical Assessments?

PURPOSE

The key element in managing postoperative facial nerve (FN) injuries is timely diagnosis and intervention as indicated. The purpose of this study was to measure and compare evoked electromyography (EEMG) and clinical assessment in terms of the recovery of the injured FN in operated temporomandibular joint ankylosis (TMJA) cases.

METHODS

The investigators designed a prospective cohort study in the primary operated TMJA patients. The primary predictor variable was the technique used to assess FN function, House-Brackmann Facial Nerve Grading System (HBFNGS) or EEMG. The primary outcome variable was time to FN recovery. The FN recovery was assessed in different time points (1 week, 1 month, 3 months, and 6 months). Age, gender, side (unilateral/bilateral), type of ankylosis (Sawhney's classification), and operating time were kept as covariates. Categorical variables were analyzed using Fisher's exact test. Multilevel survival analysis was performed considering the subject as cluster to perform Kaplan-Meier analysis and compute the hazards ratio using the Cox-regression method with adjustment for covariates. P <0.05 was set as statistically significant.

RESULTS

The study sample composed of 43 (69 sides) TMJA cases who underwent surgery developed iatrogenic FN injury in 10 cases (14 sides [9 right; 5 left]). The incidence of FN injury was 20.3% (14/69). Sawhey's type III/type IV ankylosis and the operating time for more than 2 hours showed a statistically significant (p<0.05) increase in FN injury. The mean duration to detect FN recovery by EEMG was 9 days (95% confidence interval, 5 to 12 days), but the HBFNGS took 161 days (95% confidence interval, 141 to 181 days). The chance of early detection by EEMG was 18.6 times more than the chance by the HBFNGS (Cox-hazard ratio, 18.6).

CONCLUSIONS

To conclude, EEMG is a noninvasive and reliable tool that detects FN recovery much earlier than the HBFNGS in the postoperative TMJA cases.

Abdominal Dermis-Fat Graft Versus Conventional Temporalis Myofascial Flap Interposition in Temporomandibular Joint Ankylosis: A Prospective Clinical Comparative Study

INTRODUCTION

Temporomandibular joint (TMJ) ankylosis is an extremely disabling condition with almost complete inability to open the jaws causing difficulty in chewing, speech, poor oral hygiene and cosmetic disfigurement. Temporalis myofascial flap still remains the most common interpositional material used; however, patients usually complain of pain during movement, unesthetic bulging in the temporal region and trismus due to scar contracture. The main aim of the study was to evaluate the efficacy of abdominal dermis-fat graft and compare it with temporalis myofascial flap as to see which of the two grafts offers more advantages and provides better postoperative results following TMJ ankylosis surgery.

MATERIALS AND METHODS

A total of 30 diagnosed cases of TMJ ankylosis were randomly divided into two groups of 15 patients each. All the patients underwent TMJ ankylosis release under general anesthesia followed by abdominal dermis-fat interposition in Group A and temporalis muscle in Group B. The patients were assessed for pre-operative and postoperative mouth opening (immediate and 6 month postoperative), pain during physiotherapy, donor and surgical site complications and recurrence of ankylosis.

RESULTS

The mean maximum inter-incisal opening in dermis-fat group was significantly higher than temporalis group both at immediate and 6 month postoperative periods (p = 0.041, 0.001). Physiotherapy was less painful in dermis-fat group than in temporalis group, and the differences in VAS scores among the 2 groups showed high statistical significance (p < 0.001). Hypertrophic scar developed at the donor site in 2 patients in dermis-fat group; however, it was located below the beltline and hardly noticeable. A total of 9 patients (4 in Group A and 5 in Group B) developed temporary facial nerve weakness, and no case of re-ankylosis was noted in either group.

CONCLUSION

Dermis-fat graft in temporomandibular joint ankylosis showed better results than conventional temporalis myofascial flap in terms of postoperative mouth opening, physiotherapy and jaw function with esthetically acceptable results.