Table 1.

Outcomes of the described reconstructive methods of the facial nerve, the number of patients included in the given study, the underlying cause of facial paralysis, the chosen reconstructive method, and the type of facial paralysis and its duration, as well as the follow-up period.

Study (Date of Publication)	No. of Patients (Total No. in Study)	Reconstructive Method	Facial Nerve Function/Type of Paralysis	Duration of Facial Palsy	Outcome	Follow-Up Period	Underlying Conditions
Malik et al. (2005) [27]	66	13 patients, end-to-end anastomosis 25 patients, non-vascularized interpositional nerve graft 28 patients, faciohypoglossal transposition	HB grade VI	Ranging from none to several years)	86% of EA ≤ III HB 56% of NING ≤ III HB 25% of FHT ≤ III HB	36 months	GJ, VS, PC, PM, FN, M, CHG, CSOM, SS, HS, SBF
Rashid et al. (2019) [36]	22	Non-vascularized interpositional nerve graft with sural nerve or greater auricular nerve	HB grade VI	Immediate nerve rehabilitation	4 patients, HB V 7 patients, HB IV 8 patients, HB III 3 patients, HB II	8 months	PTE
Mohamed et al. (2016) [37]	22	3 patients, end-to-end VII–XII anastomosis 4 patients, direct end-to-side VII–XII anastomosis 2 patients, end-to-side VII–XII interpositional graft; 2 patients, side-to-side VII–XII anastomosis 11 patients, facial nerve interpositional graft (great auricular nerve or cervical cutaneous nerves)	HB grade VI	15-immediate nerve rehabilitation, 7 patients-from 2 weeks to 4 months	Eight (73%) of the facial nerve interpositional graft cases improved their facial function up to HB grade III, and three cases (27%) up to HB-grade IV	2 years	PM, VS, FC, TP, BPT
Volk et al. (2020) [50]	41	Hypoglossal–facial jump nerve suture	Mean: Resting symmetry, 12.63 Symmetry of voluntary movement, 49.68 Synkinesis, 1.05 Composite score, 35.92 eFace total score, 63.97	Mean 14 months	Mean: Resting symmetry, 11.38 Symmetry of voluntary movement, 63.20 Synkinesis, 2.38 Composite score, 49.46 eFace total score, 57.30	Mean, 42 months	TP, TR
Terzis et al. (2009) [54]	20	Coaptation of 40% of the ipsilateralhypoglossal nerve to facial nerve on the affected side, performed concomitantly with cross-facial nerve grafting and secondary microcoaptations 8 to 15 months later	14 patients, complete facial palsy; 6 patients demonstrated fibrillations on needle electromyography	Mean 14 months	All patients obtained a degree of emotional and coordinated movement Symmetry: 1, excellent 14, good 3, moderate 2, inadequate Lower lip depression: 2, full denture smile 15. nearly full denture smile 3, inadequate excursion and symmetry but observable movement	From 2 to 20 years	TR,TP ICVMR, BP
Bianchi et al. (2014) [55]	8	One-stage cross-facial nerve graft and masseteric nerve cooptation	Complete unilateral facial paralysis	Mean 10.2 months	All patients developed spontaneous and emotional contraction with complete release from biting action. The esthetic results were: 1 moderate 5 good 2 excellent	From 9 to 45 months	AN, CPA
Morley et al. (2021) [56]	27	Cross-facial nerve graft(s) with an ipsilateral end-to-side nerve-to-masseter transfer	Incomplete facial paralysis	From 10 to 144 months	Average improvement in the Sunnybrook score: 33 Average improvement in commissure excursion on weak side: 4.7 mm Number of patients describing smile as spontaneous: 22	Minimum 9 months from surgery	BP, AN, TP, CN, RHS, I
Balaji et al. (2002) [59]	5	Modified temporalis muscle flap		2 patients, congenital 1 patient, 3 years 1 patient, 2 years 1 patient, 7 years	3 patients, symmetry at rest and symmetrical smile 1 patient, symmetrical smile and partial eye closure 1 patient, over-corrected smile	5 years	CN, AN, BP, PTE
Croisé et al. (2019) [61]	13	Lengthening temporalis myoplasty	Permanent facial paralysis with a Freyss test measuring severity less than 15	From 11 to 144 months	Improvements: Lip force (manometric test): from 58.23 ± 23.35 mmHg to 91.15 ± 18.36 mmHg; Drooling (self-administered questionnaire) from 4.31 ± 1.8 to 3 ± 1.41; A decrease in bolus residue (visual assessment); the score decreased from 1.39 ± 0.77 to 0.46 ± 0.66; reduction in perceived physical disability (self-administered questionnaire); the score decreased from 6.15 ± 3.74 to 3.46 ± 5.70	6 months	FN, M, CN, BP, RP, CB
Tzafetta et al. (2021) [63]	27	Cross-facial nerve graft with a transposition of the anterior belly of digastric muscle, innervated by the cross-facial nerve graft	Complete paralysis of the lower lip, isolated lower lip paralysis, partial paralysis, complete facial palsy	NS	No change in resting symmetry, improved lower lip height, improved dental show, improved lower lip symmetry, improved smile angle, Terzis scores improved from 2.1 to 3.2	From 18 to 72 months	CN, TR, BP, I, NF
Faris et al. (2018) [66]	12	Free gracilis transfer by cross-face nerve graft, free gracilis transfer by dual innervation	FaCE instrument score, 33.9 ±11.6	From 12 months to 204 months	Improvement in ipsilateral commissure excursion with smile (preoperatively: 2.2 mm (SD 2.3 mm) vs. postoperatively: 7.9 mm (SD 2.5 mm); P = 0.002), meaningful smile achieved in 11 of 12 patients	Mean follow-up, 54.7 months in gracilis patients with cross-face nerve graft; mean follow-up, 36 months in gracilis patients with dual innervation	RP
Morley et al. (2019) [69]	15	8 patients, free gracilis muscle flap 7 patients, latissimus dorsi free flap	NS	NS	An average increase in miodolar movement of 6.1 cm, resting asymmetry of the modiolus reduced by 8.5 mm, improvement in Sunnybrook Grading System averaged 39	Mean follow-up, 55 months	PM, I, MS, CN, AN, TBM, BC, EFT, CVM, MM
Lindsay et al. (2014) [70]	66	Free gracilis muscle flap	Flaccid or non-flaccid facial palsy	NS	Mean (SD) FaCE score, 42.30 (15.9) vs. 58.5 (17.60); paired two-tailed t test, p < 0.001. Mean (SD) FACE scores, 37.8 (19.9) vs. 52.9 (19.3); p = 0.02	18 months	BT, VS, CN, PM, BP, BFN, I, TBF
Bedarida et al. (2020) [41]	8	Vascularized thoracodorsal nerve free flap	HB grade VI	Immediate nerve rehabilitation	100% recovered eye closure HB of mouth: 7 patients, III HB 1 patient, IV HB HB of forehead: 1 patient, II HB 3 patients, III HB 4 patients, IV HB	From 14 to 58 months	RP
Watanabe et al. (2020) [71]	7	Double innervated (by paralyzed masseter nerve and healthy buccal branch) latissimus dorsi–serratus anterior muscle flap	Complete, established unilateral facial paralysis	Longer than 18 months	Harii’s mean evaluation criteria was 4.8 at 12 months or later from surgery; all patients had symmetric balance and good facial tone at rest and a spontaneous natural smile	24 months	BT
Biglioli et al. (2012) [64]	4	A gracilis muscle flap innervated by the masseteric nerve, a cross-face sural nerve graft anastomosed to the contralateral facial nerve branch	Longstanding unilateral facial paralysis (House–Brackmann stage VI)	NS	According to Terzis and Noah’s 5-stage classification of reanimation outcomes, 2 patients had excellent outcomes and 2 had good outcomes	18 months	NS
Sakuma et al. (2019) [72]	12	Multivector muscle transfer using two or three superficial subslips of the serratus anterior muscle on a single neurovascular pedicle	Incomplete or complete facial paralysis	Longstanding, irreversible	According to the Terzis’ functional and aesthetic grading system for smile: 7 patients, excellent outcomes 5 patients, good outcomes	Mean 46.7 months	TP, MS, AN, CN, RHS

HB—House–Brackmann Grade, GJ—glomus jugulare, VS—vestibular schwannoma, PC—petrosal cholesteatoma, PM—parotid malignancy, FN—facial neuroma, M—meningioma, CHG—cholesterol granuloma, CSOM—Chronic suppurative otitis media, SS—synovial sarcoma, HS—hypoglossal schwannoma, SBF—skull base fracture, RP—radical parotidectomy, CN—congenital, AN—acoustic neuroma, BP—Bell’s palsy, PTE—parotid tumor excision, I—iatrogenic, MS—Moebius syndrome, TBM—temporal bone malignancy, BC—buccal malignancy, EFT—excision facial tumor, CVM—cranial vascular malformation, MM—mandibular malignancy, FC—facial schwannoma, TP—traumatic palsy, BPT—benign parotid tumor, BT—brain tumor, TR—tumor resection, EA—end-to-end anastomosis, ICVMR—intracranial vascular malformation resection, CPA—cerebellopontine angle astrocytoma, SH—shingles, CB—cavernoma bleeding, NS—not specified, RHS—Ramsay Hunt syndrome, BFN—benign facial nerve neoplasm, TBF—temporal bone fracture, NF—neurofibromatosis.