Subjective Sensory Symptoms Associated With Axonal and Demyelinating Nerve Injuries After Mandibular Sagittal Split Osteotomy

Comprehensive evaluation of advanced platelet-rich fibrin in common complications following sagittal split ramus osteotomy: a double-blind, split-mouth, randomized clinical trial

The sagittal split ramus osteotomy (SSRO) carries potential risks and complications. A double-blind, split-mouth, randomized clinical trial was performed, involving 30 patients undergoing mandibular setback. Advanced platelet-rich fibrin (A-PRF) was applied to one side, and the other side served as a control. The volume of postoperative drainage over 24 h was recorded. At 1, 2, and 5 days, and 3 months postsurgery, nerve recovery was assessed using the two-point discrimination test (TPD), while pain was evaluated using a visual analogue scale (VAS pain). Facial swelling was evaluated by taking linear measurements from facial reference points at the same time intervals. In the treatment group, the 24-hour drainage volume was lower (P = 0.011), pain was better on day 5 (P = 0.011), and TPD was better on day 2 (P = 0.011), day 5 (P = 0.007), and 3 months postoperatively (P = 0.020) than in the control group. There was also less facial swelling in the treatment group when compared to the baseline of 3 months postoperative (day 1, P = 0.012; day 2, P = 0.001; day 5, P = 0.011). The difference in bone mineral density (HU) at 3 months between the treatment group (469.7 ± 134.2) and the control group (348.3 ± 127.2) was statistically significant (P = 0.011), in favour of the treatment group. A-PRF may reduce postoperative complications such as neurosensory disturbance of the inferior alveolar nerve, pain, swelling, and drainage while enhancing bone healing in the osteotomy gap following SSRO. TRIAL REGISTRATION: The study was registered with the Chinese Clinical Trial Register (ChiCTR2200064534).

Longitudinal recovery pattern of neurosensory deficit after Le Fort I osteotomy

The purpose of this study was to investigate the incidence and recovery pattern of neurosensory deficit (NSD) following Le Fort I osteotomy, and to identify the possible risk factors that might contribute to the complication. A prospective longitudinal observational study on the incidence of NSD was conducted on patients who received Le Fort I osteotomy. Subjective and objective standardized neurosensory assessments were performed preoperatively as the baseline, and postoperatively at 2 weeks, 6 weeks, 3 months, 6 months, 12 months, and 24 months. Possible risk factors for NSD including patient age and sex, surgeon experience, and Le Fort I osteotomy with or without multi-segmentation were analysed. Sixty-six patients (43 female, 23 male) with 132 sides of Le Fort I osteotomy were recruited. The incidence of NSD at 2 weeks, 6 weeks, 3 months, 6 months, 12 months, and 24 months was 81.8%, 59.8%, 39.4%, 19.7%, 7.6%, and 3.2%, respectively. Subjective severity of NSD improved with time. Older age was found to be a risk factor for NSD in the early postoperative period, but there was no difference in the long-term. Patient sex, surgeon experience, and the need for multi-segmentation were not found to be related to the incidence of NSD after Le Fort I osteotomy.

Long-term neurosensory disturbances after modified sagittal split osteotomy

We have investigated the long-term incidence of neurosensory disturbances after modified bilateral sagittal split osteotomy, and identified associated risk factors. We prospectively studied 376 patients, and their self-reported neurosensory disturbances were evaluated six months, and one, two, and three years postoperatively. The correlations between the following risk factors and neurosensory disturbances were investigated using univariate analysis and stepwise multivariate analysis: age at operation, sex, type of movement (advancement, setback, or rotation), concurrent genioplasty, type of detachment, iliac crest bone graft, and use of dicalcium phosphate synthetic bone graft. Probabilities of less than 0.05 were accepted as significant. Three years postoperatively, 57 patients (15%) reported altered sensation of the lower lip or chin. Older age correlated significantly with neurosensory disturbances (p<0.0001). Greater mandibular advancement correlated with postoperative "positive" neurosensory phenomena (right side p=0.08; left side p=0.03). Intraoperative surgical manipulation of the left inferior alveolar nerve was significantly associated with postoperative hypoaesthesia (p=0.014). Older age at surgery, extensive mandibular advancement, and surgical manipulation of the left inferior alveolar nerve, were associated with long-term neurosensory disturbances after modified bilateral sagittal split osteotomy. The modified operation seems to safeguard the inferior alveolar nerve from transection, without causing damage to other nerves.

Differential Diagnosis of Chronic Neuropathic Orofacial Pain: Role of Clinical Neurophysiology

Orofacial pain syndromes encompass several clinically defined and classified entities. The focus here is on the role of clinical neurophysiologic and psychophysical tests in the diagnosis, differential diagnosis, and pathophysiological mechanisms of definite trigeminal neuropathic pain and other chronic orofacial pain conditions (excluding headache and temporomandibular disorders). The International Classification of Headache Disorders 2018 classifies these facial pain disorders under the heading Painful cranial neuropathies and other facial pains. In addition to unambiguous painful posttraumatic or postherpetic trigeminal neuropathies, burning mouth syndrome, persistent idiopathic facial and dental pain, and trigeminal neuralgia have also been identified with neurophysiologic and quantitative sensory testing to involve the nervous system. Despite normal clinical examination, these all include clusters of patients with evidence for either peripheral or central nervous system pathology compatible with the subclinical end of a continuum of trigeminal neuropathic pain conditions. Useful tests in the diagnostic process include electroneuromyography with specific needle, neurography techniques for the inferior alveolar and infraorbital nerves, brain stem reflex recordings (blink reflex with stimulation of the supraorbital, infraorbital, mental, and lingual nerves; jaw jerk; masseter silent period), evoked potential recordings, and quantitative sensory testing. Habituation of the blink reflex and evoked potential responses to repeated stimuli evaluate top-down inhibition, and navigated transcranial magnetic stimulation allows the mapping of reorganization within the motor cortex in chronic neuropathic pain. With systematic use of neurophysiologic and quantitative sensory testing, many of the current ambiguities in the diagnosis, classification, and understanding of chronic orofacial syndromes can be clarified for clinical practice and future research.

AAPT Diagnostic Criteria for Peripheral Neuropathic Pain: Focal and Segmental Disorders

Peripheral neuropathic pain is among the most prevalent types of neuropathic pain. No comprehensive peripheral neuropathic pain classification system that incorporates contemporary clinical, diagnostic, biological, and psychological information exists. To address this need, this article covers the taxonomy for 4 focal or segmental peripheral neuropathic pain disorders, as part of the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership and the American Pain Society (APS) collaborative to develop a standardized, evidence-based taxonomy initiative: the ACTTION-APS Pain Taxonomy (AAPT). The disorders-postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia-were selected because of their clinical and clinical research relevance. The multidimensional features of the taxonomy are suitable for clinical trials and can also facilitate hypothesis-driven case-control and cohort epidemiologic studies. PERSPECTIVE: The AAPT peripheral neuropathic pain taxonomy subdivides the peripheral neuropathic pain disorders into those that are generalized and symmetric and those that are focal or segmental and asymmetric. In this article, we cover the focal and segmental disorders: postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia. The taxonomy is evidence-based and multidimensional, with the following dimensions: 1) core diagnostic criteria; 2) common features; 3) common medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors.

Hypoesthesia associated with mandibular movement after sagittal split ramus osteotomy

PURPOSE

This retrospective study investigated the relationship between the degree of neurosensory disturbance (NSD) and mandibular movement distance after sagittal split ramus osteotomy (SSRO) and assessed sensory recovery.

METHODS

Lower lip hypoesthesia was evaluated at 1 week, 1 month, and 2 months after SSRO in 38 patients categorized according to the distance of mandibular movement: S group (0-7 mm; n = 17, 4 males and 13 females) and L group (7-14 mm; n = 21, 7 males, 14 females). Symptoms were evaluated by visual analog scale (VAS), tactile-threshold (SW) test, static 2-point discrimination (s-2PD) test, and current perception threshold (CPT) test.

RESULTS

The two groups did not differ significantly in gender and age. The Aβ fiber results of the CPT test differed significantly between the groups at 1 week and 1 month postsurgery (P < 0.05). There were no significant differences between the groups throughout the period in terms of VAS, SW, s-2PD, Aδ fiber, and C fiber of CPT.

CONCLUSIONS

Post-SSRO, the incidence of NSD in terms of tactile sensation may be greater in the L group early postoperatively. This may assist surgeons in explaining postoperative hypoesthesia to patients preoperatively.

Complications associated with orthognathic surgery

While most patients undergo orthognathic surgery for aesthetic purposes, aesthetic improvements are most often followed by postoperative functional complications. Therefore, patients must carefully decide whether their purpose of undergoing orthognathic surgery lies on the aesthetic side or the functional side. There is a wide variety of complications associated with orthognathic surgery. There should be a clear distinction between malpractice and complications. Complications can be resolved without any serious problems if the cause is detected early and adequate treatment provided. Oral and maxillofacial surgeons must have a full understanding of the types, causes, and treatment of complications, and should deliver this information to patients who develop these complications.

Short-term effects of orthognathic surgery on somatosensory function and recovery pattern in the early postoperative period

We examined the short-term surgical effects of orthognathic surgery on somatosensory function. Observations were made over a short period: 3 months postoperatively. In total, 14 patients and 32 healthy controls participated. Among the 14 patients, one underwent bilateral sagittal split osteotomy alone and 13 underwent bilateral sagittal split osteotomy in combination with a Le Fort I osteotomy. A modified quantitative sensory testing (QST) protocol (the German Research Network on Neuropathic Pain, DFNS) was used to evaluate clinically the skin of the chin for sensory disturbances before surgery and at 1 week, 1 month, and 3 months postoperatively. A visual analog scale and the Japanese Version of the McGill Pain Questionnaire were completed by all participants. Both sides of the mandible showed postoperative functional loss in cold detection threshold, warmth detection threshold, thermal sensory limen, and mechanical detection threshold. All function gradually recovered to baseline conditions at 3 months postoperatively. Cold detection threshold, warmth detection threshold, thermal sensory limen, and mechanical detection threshold appeared to be useful QST parameters for evaluating neurosensory disturbances during the early postoperative period. (J Oral Sci 58, 177-184, 2016).

Analgesic effects of nefopam in patients undergoing bimaxillary osteotomy: A double-blind, randomized, placebo-controlled study

PURPOSE

Many studies have examined the postoperative analgesic effects of nefopam in various settings. However, although nefopam is expected to be useful in bimaxillary osteotomy, no published data are available.

MATERIAL AND METHODS

We divided 42 patients into nefopam [n = 21, nefopam 20 mg intravenous (i.v.) 30 min before surgery, followed by an i.v. infusion (5 mg/h) beginning immediately postoperatively for 24 h] and control [n = 21, normal saline] groups. Then we compared the analgesic efficacy, side effects, and degree of patient satisfaction with postoperative analgesia.

RESULTS

Pain was lower in the nefopam group than in the controls in the recovery room [4.6 (3.0-6.0) vs. 6.0 (5.5-7.0), median (interquartile range), P = 0.002] and on the ward. Fewer patients in the nefopam group required rescue analgesics, and the degree of patient satisfaction was significantly higher in the nefopam group (P < 0.001). There were no significant differences in other side effects between the groups. However, the control group showed more sedation 1 h postoperatively (P = 0.009).

CONCLUSION

Nefopam is an effective analgesic in bimaxillary osteotomy in that it can reduce the use of opioids and nonsteroidal anti-inflammatory drugs, thereby reducing the side effects of conventional analgesics. (

TRIAL REGISTRATION

ClinicalTrials.gov (NCT 01461031)).

Altered pain modulation in patients with persistent postendodontic pain

Persistent pain may follow nerve injuries associated with invasive therapeutic interventions. About 3% to 7% of the patients remain with chronic pain after endodontic treatment, and these are described as suffering from painful posttraumatic trigeminal neuropathy (PTTN). Unfortunately, we are unable to identify which patients undergoing such procedures are at increased risk of developing PTTN. Recent findings suggest that impaired endogenous analgesia may be associated with the development of postsurgical chronic pain. We hypothesized that patients with PTTN display pronociceptive pain modulation, in line with other chronic pain disorders. Dynamic (conditioned pain modulation, temporal summation) and static (response to mechanical and cold stimulation) psychophysical tests were performed intraorally and in the forearm of 27 patients with PTTN and 27 sex- and age-matched controls. The dynamic sensory testing demonstrated less efficient conditioned pain modulation, suggesting reduced function of the inhibitory endogenous pain-modulatory system, in patients with PTTN, mainly in those suffering from the condition for more than a year. The static sensory testing of patients with PTTN demonstrated forearm hyperalgesia to mechanical stimulation mainly in patients suffering from the condition for less than a year and prolonged painful sensation after intraoral cold stimulus mainly in patients suffering from the condition for more than a year. These findings suggest that PTTN is associated more with the inhibitory rather than the facilitatory arm of pain modulation and that the central nervous system has a role in PTTN pathophysiology, possibly in a time-dependent fashion.

Preoperative, intraoperative, and postoperative complications in orthognathic surgery: a systematic review

Objectives

The aim of this study was to determine whether orthognathic surgery is associated with any complications, and what type of complications may occur.

Materials and methods

Data were obtained using PubMed (MEDLINE), ISI Web of Knowledge, Ovid, Cochrane Library, Embase Library, and an additional manual search. The titles and abstracts of the electronic search results were screened and evaluated by two observers for eligibility according to the inclusion and exclusion criteria.

Results

A total of 1924 articles were identified, and we retained 44 articles for the final analysis. The Prisma diagram flowchart demonstrates our selection scheme. For the purpose of this study, the Cochrane data extraction form was modified. One review author extracted data from the included studies, and the second author checked all of the forms. The hierarchy of evidence classification from the UK NHS Centre for Reviews and Dissemination was used to assess the level of evidence for the retrieved studies.

Conclusions

An evaluation of the obtained studies revealed the existence of a large number of varied complications associated with orthognathic surgery procedures.

Clinical relevance

Oral and maxillofacial surgeons, orthodontists, and the surgical team need to prevent such complications during preoperative, intraoperative, and postoperative periods to increase the safety of orthognathic surgery procedures. This review was registered on http://www.crd.york.ac.uk/PROSPERO as CRD42013004711.

Electronic supplementary material

The online version of this article (doi:10.1007/s00784-015-1452-1) contains supplementary material, which is available to authorized users.

Three-dimensional computed tomographic evaluation of bilateral sagittal split osteotomy lingual fracture line and le fort I pterygomaxillary separation in orthognathic surgery using cadaver heads: ultrasonic osteotome versus conventional saw

PURPOSE

The purpose of this study was to observe the quality of the fracture line on the lingual side of the mandible after sagittal split osteotomy and the quality of pterygomaxillary separation after Le Fort I osteotomy using the BoneScalpel ultrasonic osteotome.

MATERIALS AND METHODS

Bimaxillary procedures, according to the standard protocol, were performed using 10 fresh cadaver heads. The ultrasonic osteotome was used in the study group, and a reciprocating saw was used in the control group. Three-dimensional reconstructions of postoperative computed tomographic scans were obtained. The lingual ramus fracture pattern and the pterygomaxillary separation pattern were observed, classified, and compared. Postoperative dissections of the skulls were performed to assess the integrity of the infra-alveolar nerve and the descending palatine artery.

RESULTS

No significant differences were found in the cutting time of bone between the BoneScalpel and the sagittal saw. Of the sagittal split osteotomies in the study group, 90% showed a good pattern (vertical pattern of fracture line extending to the inferior border of the mandible running behind the mandibular canal) compared with 50% of the sagittal split osteotomies in the control group. Ideal separation of the pterygoid plates without fractures was observed in 80% of the Le Fort I osteotomies in the study group compared with 50% of the osteotomies in the control group. High-level fractures occurred in 30% of cases in the control group compared with none in the study group. The integrities of the infra-alveolar nerve and the descending palatine artery were preserved in all cases.

CONCLUSION

Use of the ultrasonic BoneScalpel did not require more time than the conventional method. An improved pattern of lingual fracture lines in mandibular sagittal split osteotomy procedures and the pattern of pterygomaxillary separation in Le Fort I osteotomy procedures were observed.

Gliding mentoplasty: a new technique

BACKGROUND

The goal of mentoplasty is to improve chin projection. Traditionally, this is accomplished by either mandibular osteotomy or alloplastic implants. However, these procedures are not free of complications. This report describes gliding mentoplasty, a novel, simple technique for chin projection.

METHODS

The 12 patients in this study underwent gliding mentoplasty. By means of a 2-cm intraoral incision, a subcutaneous dissection was made in the caudal direction. The dissection then proceeded in the subperiosteal plane, leaving a 1-cm cuff of muscle attached to the bone, and advanced toward the lower border of the chin. Subsequently, the dissection was extended laterally, and the whole mental area was dissected from the surrounding tissue. Three 2-0 monofilament nylon sutures were placed in the submandibular periosteum and connected through the remaining muscle cuff to the periosteum. These key sutures allowed the submandibular region to slide forward, project the subcutaneous tissue and mentalis muscle, define the labiomental fold, and improve the pogonion projection.

RESULTS

Gliding mentoplasty resulted in a symmetric projection of the chin in all cases. In two patients, a submandibular dimple developed, which spontaneously resolved in 1 month. No revision surgery was performed, and no tissue relapse was noted. The mean follow-up period was 24.7 ± 5.17 months (range 19-33 months). All the patients were satisfied with the result.

CONCLUSION

Gliding mentoplasty is a simple, easy-to-perform, rapid surgical technique of chin projection that produces low pain, rapid recovery, and excellent cosmetic results.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Neuropathic pain after orthognathic surgery

OBJECTIVE

This study assesses the incidence of neuropathic pain after orthognathic surgery at our center and briefly reports the cases found.

STUDY DESIGN

All records of orthognathic surgical patients between 2001 and 2011 were exported from the hospital information system into a Portable Document Format platform (Adobe Acrobat) to simplify keyword searching. Records of patients that developed debilitating chronic pain were isolated and examined.

RESULTS

Records included 982 bilateral sagittal split osteotomies, 536 LeFort I procedures, and 335 surgically assisted rapid palatal expansion procedures. Six records were identified that described cases in which patients developed debilitating chronic neuropathic pain after orthognathic surgery (mean age at surgery, 43 years).

CONCLUSIONS

The exposure of the inferior alveolar nerve or partial axonal injury together with a disruption of the bony environment of the inferior alveolar nerve is a risk factor after bilateral sagittal split osteotomy.