Facial nerve paralysis and frey syndrome in an infant following removal of an internal mandibular distraction device

Facial Nerve Dysfunction After Mandibular Distraction Osteogenesis in Patients with Robin Sequence: A Systematic Review and Meta-Analysis

OBJECTIVE

Robin Sequence (RS), characterized by micrognathia, glossoptosis, and upper airway obstruction, is an increasingly recognized diagnosis. An effective surgical intervention is mandibular distraction osteogenesis (MDO). This study analyzes published evidence regarding facial nerve dysfunction (FND) associated with MDO.

DESIGN AND SETTING

According to PRISMA guidelines, a systematic review was carried out with databases queried in June 2019 using MESH terms, or equivalent terms, as follows: "distraction osteogenesis" and "Robin Sequence". A review of original Spanish and English articles, were included. Outcome measures included the prevalence of FND; the affected branches; the rate of permanent vs. transient FND; the use of an internal vs. external device; the daily distraction rate; and finally, the overall distraction length. Subsequently, a meta-analysis was conducted to collate results regarding the prevalence of FND and the factors associated with it.

RESULTS

Of 239 unique studies identified, 19 studies with 729 patients met inclusion criteria; 52 patients developed FND after MDO. A random-effects meta-analysis yielded a pooled prevalence of FND of 6.40%, with moderately heterogeneous studies (I2 = 41%, τ2 = 0.006). Marginal mandibular nerve involvement was most commonly noted. Nine studies reported transient FND, six permanent, one both, and two unspecified. Internal distractors were used in 8 studies and external in 3 and both in 2. Distraction rate was 1.00 to 2.00 mm/day and total distraction length ranged from 13.00 to 22.3 mm. Sample size was the only parameter inversely associated with rate of FND (p = 0.04).

CONCLUSION

This analysis of FND associated with MDO for patients with RS demonstrates a lack of consistent documentation. MDO-associated FND does not appear to be uncommon, and permanent dysfunction can occur. This review underscores the importance of thorough documentation to elucidate the mechanism of FND.

Timing and Duration of Facial Nerve Dysfunction After Mandibular Distraction Osteogenesis for Robin Sequence

Objective

Collect data from craniofacial surgeons to analyze mandibular distraction osteogenesis (MDO) protocols, and facial nerve dysfunction (FND) to characterize this common, but poorly documented complication after MDO in infants with Robin Sequence (RS).

Design, Setting, and Participants

A 16-question anonymous survey designed through REDCap was digitally distributed to members of the American Cleft Palate-Craniofacial Association and International Society of Craniofacial Surgery (ISCFS).

Main Outcome Measure(s)

Demographic information, MDO perioperative variables, surgeon experience with FND after MDO for patients with RS, and the timing and duration of FND were analyzed.

Results

Eighty-four responses were collected, with 80 included for analysis. Almost two-thirds of respondent surgeons reported FND as a complication of MDO in patients with RS (51, 63.8%); 58.8% (n   =   47) transient FND and 5% (n   =   4) with permanent facial nerve palsy only. Both transient and permanent FND was documented by 13 (16.3%) respondents. Among respondents, FND was observed immediately following initial device placement/osteotomies in 45.1%, during distraction in 45.1%, during consolidation in 19.6%, and following device removal in 43.1%. Twenty-five of these respondent surgeons reported resolution of FND between 1 and 3 months (53.2%, n   =   25).

Conclusions

FND after MDO in patients with RS was noted by most respondents in this survey study. While most surgeons noted temporary FND, one-fifth reported long-term dysfunction. FND was documented most commonly following device placement/osteotomies or during active distraction. Further research should seek to establish risk factors associated with FND and identify surgical and perioperative prevention strategies

Total facial nerve injury during mandibular distraction osteogenesis

INTRODUCTION

Over the last 10-15 years, usage of internal mandibular distraction systems has increased in the pediatric population, particularly for craniofacial syndromes. Mandibular distraction osteogenesis (MDO) has been shown to be effective in avoiding tracheostomy or achieving early decannulation in patients with micro-retrognathic mandibles in hemifacial microsomia or Pierre Robin sequence. As the frequency of the application of MDO has increased, so has the awareness and management of subsequent complications from the procedure. In this study, we discuss a complication involving paresis and eventual recovery of cranial nerve (CN) VII after the application of an MDO internal device at our institution in two cases. We also review the literature and propose multiple anatomic considerations that can impact more than just the marginal branch of CN VII.

METHOD

This study is a retrospective case study from our institution and a review of the literature. Pubmed was queried for terms singularly and in combination including "mandibular distraction osteogenesis", "facial nerve", "cranial nerve", "complications", "micrognathia", "retrognathia". After reviewing the results, studies discussing complications of MDO that involved CN VII were reviewed and included.

RESULTS

In the literature review and our retrospective review, CN VII injuries from MDO vary in their length and timing of onset. Management of this complication depended on the timing of onset and ranged from conservative management to removal of the distraction device. Majority (7/9) of the cases resolved to an eventual House-Brackmann of 0/6 with conservative measures.

CONCLUSION

Total facial nerve injury in association with MDO, has been scarcely reported, though the facial nerve is at great risk given its intimate location near the mandible particularly in neonates. It is encouraging that though it could be a devastating complication, out of all the cases reported, the large majority resolve with a combination of time and steroids.