Recovery of sensation after orthognathic treatment: Patients' perspective

Does mandibular osteotomy affect the infraorbital nerve? a prospective study

OBJECTIVES

The aim of this study was to evaluate the sensory function of the infraorbital nerve after orthognathic surgery (OS).

MATERIALS AND METHODS

Patients who underwent Le Fort I osteotomy with or without BSSO for dentofacial deformity treatment were studied. Two groups were created according to whether BSSO was performed. Class A tests were performed to determine the degree of peripheral nerve damage. The Class B test was performed if decreased sensation was detected in at least one of these tests. A Class C test was performed if abnormal sensation was detected.

RESULTS

Twenty-eight patients (n=56) who underwent OS were included in this prospective study. Of the patients, 57.1% were female, 42.9% were male, and the mean age was 24.6 (±3.8). Seven patients were in group 1 (n=14), and 21 patients were in group 2 (n=42). In both groups, there were statistically significant differences between T1 and T2 (p<0.001), and the mean NSD score at T2 was higher than that at T1. The mean NSD score in the single jaw group was higher than that in the double jaw group at all time points.

CONCLUSIONS

Bimaxillary surgeries had a negative effect on the somatosensory changes that developed in the early period. The upper lip's somatosensorial recovery was faster than IOR and single jaw recovery was faster than double jaw.

CLINICAL RELEVANCE

Maxillofacial surgeons performing orthognathic surgery should be aware that in double jaw operations, changes in the somatosensory function of the ION are more severe.

A prospective cohort study evaluating subjective and objective neurosensory changes following LeFort I osteotomy

INTRODUCTION

This study aimed to investigate the incidence and recovery of neurosensory deficit (NSD) after LeFort I osteotomy over 12 months and identify any association between age, gender, and extent of surgical movement on recovery. Furthermore, the study explored the relationship between objective and subjective outcome measures.

METHODS

A prospective cohort study consisting of 31 patients. Subjects were assessed at baseline, 1 week (T1), 1 month, 3 months, 6 months, and 12 months (T5) after LeFort I osteotomy. Objective assessment measures included pinprick (PP), static light touch (SLT), static 2-point discrimination (STPD), and electric pulp testing (EPT). Subjective reporting was undertaken using a visual analog scale. Patients rated the impact of NSD on intraoral and extraoral sites at the same time points as for objective measures.

RESULTS

Twenty-eight patients (16 females and 12 males) with a mean age of 24.5 years (standard deviation, 7.4) completed the study. There was a notable reduction in NSD from T1 (85.7%) to T5 (17.9%). No significant differences were found with respect to the influence of gender; PP (P = 0.06), SLT (P = 0.10), STPD (P = 0.65) and EPT (P = 0.19) or extent of surgical movement; PP (P = 0.50), SLT (P = 0.72), STPD (P = 0.06) and EPT (P = 0.74) on NSD. Age is a significant factor for intraoral NSD in the immediate postoperative period; PP (P < 0.0001) and SLT (P < 0.0001). Subjectively, patients reported a high degree of concern associated with NSD immediately after surgery with a gradual reduction from T1 to T5. There is a significant difference in subjective reporting between those with intraoral NSD than those with no intraoral NSD at 12 months (P = 0.031).

CONCLUSIONS

NSD is high after LeFort I surgery, particularly intraorally in the palate. At 12 months, the incidence of NSD is 17.9%. Recovery of NSD to a nonsignificant value from baseline takes up to 3 months for extraoral sites and between 3 and 6 months for intraoral soft tissues. The maxillary dentition continues to recover from NSD up to 12 months postsurgery. Age, gender, and extent of the surgical movement do not influence the extent of NSD at 12 months. Increasing age is associated with increased NSD at intraoral sites immediately after surgery. Intraoral NSD is more of a concern to patients than extraoral NSD. Patients' concerns associated with NSD reduced over time, demonstrating a degree of adaptation in the longer term.

Does Sensory Retraining Improve Subjective Rating of Sensory Impairment after Bilateral Sagittal Split Osteotomy?

Background:

Sensory retraining could ameliorate neurosensory disturbance (NSD) resulting from the injury of the inferior alveolar nerve after a bilateral sagittal split osteotomy (BSSO). The aim of this study was to measure the effects of sensory retraining on NSD.

Methods:

A randomized, prospective, single-blinded clinical trial was conducted on consecutive patients with NSD resulting from a BSSO to correct skeletal class III malocclusion. The outcome measurement of sensory recovery was performed using a patient-centered survey assessed by the total score of questionnaire (TSQ) and visual analogue scale (VAS) at preoperation (T0), 1 week after surgery (T1), each month from 1 to 6 months after surgery (T2–T7), and 1 year after surgery (T8).

Results:

In total, 115 consecutive patients were randomized into a control group (56 patients without sensory retraining) or study group (59 patients with sensory retraining). TSQ and VAS values continually decreased from T1 to T8 in both groups. The study group tended to have lower, but not significantly lower, TSQ and VAS values than the control group at each postoperative time point. Women and men responded similarly to sensory retraining at each time point. The oldest patients did not respond well to sensory retraining, compared with the youngest patients, from T1 to T8, and this age effect evaluated by the VAS reached a significant difference at T7 and T8.

Conclusion:

NSD, assessed by the TSQ and VAS, continually decreased over time after the BSSO. Sensory retraining could improve NSD, but not significantly.

Nerve injury associated with orthognathic surgery. Part 2: inferior alveolar nerve

The inferior alveolar nerve (IAN) is the most commonly injured structure during mandibular osteotomies. The prevalence of temporary injury has been reported as 70/100 patients (95% CI 67 to 73/100) or 56/100 nerves (95% CI 46 to 65/100), and the prevalence of permanent alteration in sensation was 33/100 patients (95% CI 30 to 35/100) or 20/100 nerves (95% CI 18 to 21/100) when assessed subjectively. The prevalence varied significantly between different operations (p<0.0001). It was significantly higher for sagittal split osteotomy (SSO) combined with genioplasty than for SSO alone (p<0.0001) or vertical ramus osteotomy (VRO) (p<0.0001). Injury may result from traction during stripping or manipulation of the distal fragment, incorrect placement of the cuts, or misjudged placement of fixation in ramus ostotomy. During SSO, they can occur during retraction to make cuts in the medial ramus, when the bone is cut or split, and on fixation. The impact of injury is generally said to be low as it does not seem to affect patients' opinions about the operation.