Static Light Touch Research Articles

The Effect of Delayed Photobiomodulation Therapy on Inferior Alveolar Nerve Recovery After Third Molar Removal: A Triple-Blinded Randomized Clinical Trial.

Background: Third molar removal is the primary reason for inferior alveolar nerve (IAN) damage, with 2% causing persistent neurosensory deficits. This study aimed to investigate how delayed photobiomodulation therapy affects long-lasting neurosensory disturbances. Methods: This study was conducted on patients with neurosensory disturbances lasting longer than 6 months. Patients were randomly allocated to the study and control groups, with the study group receiving a low-power diode laser (continuous wavelength of 810 nm, power of 200 mW) on 16 points (30 sec at each) for 12 sessions (2 sessions/week), while the control group received a placebo treatment by switched-off laser probe. Visual analog scale (VAS; ranging from 1 to 5), static light touch, two-point discrimination, direction discrimination, pinprick, and thermal discrimination tests were performed on each visit up to 9 months post-therapy to evaluate the recovery status. Results: Each group comprised 18 participants. The mean time since injury was 8.26 ± 2.05 and 8.38 ± 1.98 months for the control and intervention groups, respectively (p = 0.81). There was a significant improvement in the intervention group on the static light touch (p = 0.041), two-point discrimination (p = 0.028), VAS (p = 0.031), and pinprick (p = 0.014) tests on the 11th session and subsequent visits and also on direction discrimination test on the 12th session (p = 0.044) and after that. There was no significant difference in the thermal discrimination tests between the two groups (p > 0.05). Conclusion: Photobiomodulation demonstrated potential benefits in resolving persistent neurosensory deficits of the IAN, with noticeable improvements typically observed after around 35 days of treatment initiation (10 sessions).

Evaluation of Intraoperative Inferior Alveolar Nerve Exposure During and Postoperative Neurosensory Disturbances after Bilateral Sagittal Split Osteotomy: A Prospective Cross-sectional Study in Iran

Introduction: Inferior Alveolar Nerve (IAN) exposure and neurosensory disturbances (NSDs) following bilateral sagittal split osteotomy (BSSO) of the mandible are paramount. We aimed to assess intraoperative IAN exposure during and NSDs after BSOO surgery using different clinical assessment methods in a prospective study in a local setting.
 Materials and methods: The present study was a prospective cross-sectional study. We monitored the nerve exposure status during the BSSO. Our time points were: before surgery, one day after, one month later, three months after and six months after the BSSO surgery. We performed two-point discrimination test, static light touch test and pinprick test on both mental regions of the cases.
 Results: We included seven women and eight men. The average age of the participants was 25.13 ± 3.27 years. The results of the two-point discrimination test showed the following: the day after the BSSO compared to before the surgery, the sensation is significantly impaired in both mental regions. In addition, it is noted that during our study, the two-point discrimination test results showed a gradient healing, though not reaching the point before the surgery (P>0.05). The results of the Pinprick test also showed a gradual resolution of the NSDs; however, a significant sensation difference remained between six months after the BSSO and before the surgery.
 Conclusion: The BSSO surgery significantly impairs the IAN sensation, causing intraoperative IAN exposure and postoperative NSDs for the patients. A gradient resolution of the NSDs was observed in all the cases, though; the sensation of the mental region did not reach the pre-surgical levels.

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

This study aimed to investigate the incidence and recovery of neurosensory deficit (NSD) after LeFort I osteotomy over 12months 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. A prospective cohort study consisting of 31 patients. Subjects were assessed at baseline, 1week (T1), 1month, 3months, 6months, and 12months (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. Twenty-eight patients (16 females and 12 males) with a mean age of 24.5years (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 12months (P=0.031). NSD is high after LeFort I surgery, particularly intraorally in the palate. At 12months, the incidence of NSD is 17.9%. Recovery of NSD to a nonsignificant value from baseline takes up to 3months for extraoral sites and between 3 and 6months for intraoral soft tissues. The maxillary dentition continues to recover from NSD up to 12months postsurgery. Age, gender, and extent of the surgical movement do not influence the extent of NSD at 12months. 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.

Piezosurgery for Sagittal Split Osteotomy: Procedure Duration and Postoperative Sensory Perturbation

To evaluate piezosurgery for bilateral sagittal split osteotomy (BSSO) for its duration and inferior alveolar nerve (IAN) perturbation. In this prospective randomized study, the authors evaluated 100 BSSO procedures in 50 patients. Piezoelectric (group I) and conventional (group II) osteotomies were carried out on each side of the mandible of a patient by 2 specialists. The surgeons had at least 1year of experience using piezosurgery. The period from incision to complete splitting of the mandibular bone was recorded (ie, procedure duration). The intraoperative status (visibility and relocation) of the IAN also was recorded. The neurosensory function of the IAN was measured by the 2-point discrimination threshold and static light touch methods before surgery and postoperatively (1, 3, and 6weeks and 6 and 12months). Parameters were compared between the test groups by the paired t, nonparametric Wilcoxon, or χ2 test. Intergroup comparison showed the mean duration of osteotomy was significantly shorter for group I (17±6 vs 25±9minutes; P<.001). The rate of intraoperative exposures of the IAN was slightly lower for group I (68%) compared with group II (81%). However, the difference was not relevant. Neurosensory disturbance and recovery of the IAN did not differ between groups. Piezoelectric osteotomy requires considerably less time than conventional mechanical approaches, but shows no advantage in preventing neurosensory perturbation.

The effect of a platelet-rich fibrin conduit on neurosensory recovery following inferior alveolar nerve lateralization: a preliminary clinical study

This retrospective study aimed to assess the recovery of neurosensory dysfunction following modified inferior alveolar nerve (IAN) lateralization surgery compared to the conventional approach. Data from two groups of patients who underwent IAN lateralization in 2014 were included in this study. In one group, platelet-rich fibrin was placed over the IAN and this was protected with a collagen membrane conduit; the other group underwent the conventional IAN lateralization procedure. Implants were placed immediately. Neurosensory dysfunction was evaluated at 3, 6, and 12 months post-surgery. Demographic, neurosensory disturbance (NSD), subjective two-point discrimination test (TPD), and static light touch test (SLT) data were obtained. Twenty-three IAN lateralization procedures with the placement of 51 implants were performed in 14 patients. At the 6-month follow-up, the number of patients experiencing normal sensation was greater in the modified surgery group, but the 12-month follow-up results were the same in the two groups. More precise sensation was observed with the TPD in the modified group at 6 months, and the modified group demonstrated better SLT scores at 6 months. Although the two groups had comparable results at the 12-month follow-up, it was observed that the modified technique accelerated neural healing within 6 months and reduced the length of the discomfort period.

Vitality of intact teeth anterior to the mental foramen after inferior alveolar nerve repositioning: nerve transpositioning versus nerve lateralization

The aim of the present study was to compare two methods used in inferior alveolar nerve (IAN) repositioning to evaluate their effect on the vitality of intact teeth anterior to the mental foramen. Nerve lateralization (NL) is defined as the lateral reflection of the IAN without incisive nerve transection; nerve transposition (NT) involves sacrifice of the incisive nerve. Twenty-one patients were included in this study. Vitality tests for the teeth anterior to the mental foramen, including pulse oximetry and electric pulp testing, were evaluated at 1 week prior to surgery and at 1 week, 1, 3, 6, and 12 months after surgery. Lower lip and chin neurosensory changes were also recorded at the same time intervals by static light touch test with a cotton-tipped applicator and two-point discrimination test with sharp callipers. Vitality tests were negative after the operation in the NT group, while all had normal values at 1 week prior to the operation. In the NL group, only two patients (20%) had negative test results at 1 week after surgery. Lip and chin neurosensory changes in the total transpositions (28 operations) were seen in 7.1% at 1 year after the operation. It appears that NL is a more physiological procedure than NT.

Evaluation of Patients’ Perceptions of Alterations After Chin Bone Graft Harvesting

To evaluate patients' perceptions of alterations occurring after chin bone harvesting. Thirty patients were evaluated subjectively by visual analog scale-related sensitivity, facial aesthetics, eating, speaking, and lower lip movement, during 12 months. Objective analysis used the static light touch neurosensorial test. The statistical analysis was executed with Friedman test with P < 0.05 for both samples. Subjective analysis revealed no alterations (1) to facial aesthetics, eating, speaking or lower lip movement but sensitivity of the mental region went from a lot of alteration initially (5) to little at the end of the study (3). Objective analysis results showed normal sensitivity (1) in the region after 12 months. The discrepancy between subjective and objective analyses may be indicative of the limited precision of clinical testing for subjective impressions assessment.

Prospective Clinical Assessment of Morbidity After Chin Bone Harvest

The aim of this prospective research was to assess soft tissue morbidity in the symphyseal region after bone graft harvesting. Thirty patients, with average age 45 years, underwent symphyseal bone graft harvesting followed up for a period of 12 months. Follow-up involved neurosensory testing of 2-point discrimination, static light touch, brush directional stroke, pinprick, and thermal discrimination to cold and hot; the statistical analysis was performed using McNemar test and Friedman test with P < 0.05. The results showed that 50% of patients had postoperative morbidity in the first month after surgery showing statistical positive relation with surgery (P < 0.05); at 6 months, this situation diminished to 23%, and at the end of the monitoring period (1 year); the neurosensory tests revealed no persistent morbidity. In conclusion, all neurosensory tests revealed high morbidity in the first month with total resolutions at 1-year follow-up; however, this complication associated to surgery is indispensable to discharge the patient properly.

Extension of normal values on sensory function for facial areas using clinical tests on touch and two-point discrimination

The threshold value of a sensory test provides a numerical measure of the sensory function. In order to decide whether a threshold value from an affected site indicates 'abnormal' sensory function, it can be compared with normal values from a healthy control population. The aim of this study was to extend current information on normal values for static light touch and static two-point discrimination for facial sites. Using simple hand-held devices, 95% upper limits of confidence intervals of threshold values were determined for facial sites other than those studied previously and for a large sample of 100 healthy subjects. The MacKinnon-Dellon Disk-Criminator and the Aesthesiometer were used to measure novel normal values of two-point discrimination. As threshold values for two-point discrimination from the Aesthesiometer were similar to those obtained using the Disk-Criminator, the use of the Aesthesiometer might not be indicated. Apart from the Pressure Specified Sensory Device (a device with pressure control), Semmes-Weinstein nylon monofilaments and the Disk-Criminator are useful devices for studying sensory function, in particular under clinical test conditions in which easy and fast application are advantageous.

Facial skin sensibility in a young healthy chinese population

To quantify normal neurosensory facial sensibility in a young healthy Chinese population for use as a reference when evaluating postoperative nerve damage. One hundred consecutive eligible normal young Chinese individuals were included. Each subject underwent objective neurosensory testing (static light touch, 2-point static, and pain detection thresholds) at 8 facial sites within the distribution of the trigeminal nerve. Data were calculated into means and standard deviations, and paired t tests were used to compare values between the left and right sides and quadrants; unpaired t test was used to compare the values between genders. A P value of <or=.05 was considered to be significant. The chin region was least sensitive to light touch detection, and the normal thresholds ranged from 1.72 to 1.80. The infraorbital areas were least sensitive for 2-point discrimination, and the normal values for this modality ranged from 7.04 mm to 11.87 mm. Infraorbital areas were also most resistant to pain, and normal values ranged from 13.17 g to 20.30 g. There was no statistically significant difference between facial sides or quadrants. Male subjects were found to have a higher pain detection threshold, especially in the chin and the right infraorbital areas. Reference values for normal facial sensibility in the form of objective neurosensory testing scores have been documented for a healthy Chinese population. These results provide baseline data for future surgical studies in this and similar populations.

Evaluation of the neurosensory deficiencies of oral and maxillofacial region following surgery

Maxillofacial neurosensory deficiencies may be caused by various surgical procedures such as tooth extraction, osteotomies, preprosthetic procedures, excision of tumors or cysts, surgery of the TMJ and surgical treatment of fractures and cleft lip/palate. These deficiencies may be intolerable for the patient, mainly because of the elective nature of the procedures such as osteotomies. In this study, a retrospective evaluation of incidence of neurosensory deficiencies (NSD) in 227 patients who underwent different kinds of surgeries in the maxillofacial region is presented. Clinical neurosensory testing such as two-point discrimination, static light touch, brush directional stroke, pin-prick, thermal discrimination and dental vitality tests were used for evaluation. All the patients were grouped according to the surgical procedures and all of them were evaluated at least one year post operation. It was concluded that osteotomies, especially sagittal split ramus osteotomies, have the highest incidence of postoperative NSD.

Evaluation of the neurosensory deficiencies of oral and maxillofacial region following surgery

Maxillofacial neurosensory deficiencies may be caused by various surgical procedures such as tooth extraction, osteotomies, preprosthetic procedures, excision of tumors or cysts, surgery of the TMJ and surgical treatment of fractures and cleft lip/palate. These deficiencies may be intolerable for the patient, mainly because of the elective nature of the procedures such as osteotomies. In this study, a retrospective evaluation of incidence of neurosensory deficiencies (NSD) in 227 patients who underwent different kinds of surgeries in the maxillofacial region is presented. Clinical neurosensory testing such as two-point discrimination, static light touch, brush directional stroke, pin-prick, thermal discrimination and dental vitality tests were used for evaluation. All the patients were grouped according to the surgical procedures and all of them were evaluated at least one year post operation. It was concluded that osteotomies, especially sagittal split ramus osteotomies, have the highest incidence of postoperative NSD.

Neurosensory recovery following the mandibular bilateral sagittal split osteotomy

Purpose: This prospective study evaluated the neurosensory recovery pattern of the inferior alveolar nerve following the bilateral sagittal split osteotomy (BSSO). Patients and Methods: Forty-two consecutive patients undergoing BSSO were studied using five neurosensory tests: 1) static light touch, 2) moving touch discrimination, 3) two-point discrimination, 4) nociception, and 5) thermoreception. Intraoperative assessment of inferior alveolar nerve damage was made; other variables recorded included type of fixation, age, concomitant procedures, advancement vs setback, and magnitude of the movement. A subjective questionnaire was completed by the patient. Results: The variables that affected neurosensory function following BSSO were degree of nerve damage and the amount of time elapsed following surgery. Larger myelinated fibers (A-α) recovered slower and to a lesser degree at all time intervals up to 2 years when compared with small myelinated and unmyelinated nerve fibers. The magnitude of nerve damage directly correlated with early neurosensory deficit, but equalized over time. Conclusion: The long term (6 months and greater) chance for neurosensory recovery is good despite intraoperative nerve manipulation. Patients seem to adapt and report normal neurosensory function even though objective testing indicates continued neurosensory deficit.

Recovery of neurosensory function following orthognathic surgery

The purpose of this study was to prospectively define the recovery of touch discrimination following four commonly performed surgical procedures in 22 consecutive patients with no previous maxillofacial surgery. The surgical groups studied were Le Fort I osteotomy (LEFORT; n = 13), sagittal split ramus osteotomy (SSRO; n = 6), intraoral vertical ramus osteotomy (IVRO; n = 9), and isolated genioplasty (GENIO; n = 5). Neurosensory function was assessed by three different testing modalities which included static light touch (SLT), moving touch discrimination (MTD), and two-point discrimination (TPD). Cutaneous sensation of the lower lip and chin were examined for the mandibular procedures, whereas the infraorbital and upper lip regions were evaluated following maxillary surgery. Immediately following surgery, each group varied in both the incidence and magnitude of neurosensory deficits (NSD). The SSRO group had the highest percentage of sites with immediate postsurgical NSD to both SLT (72%) and MTD (67%), followed by the LEFORT (SLT = 50%, MDT = 58%), GENIO (SLT = 27%, MTD = 6%), and IVRO groups (SLT = 11%, MTD = 18%), respectively. Each group also varied in the severity of the initial postoperative deficit as measured by SLT, with the SSRO group showing the greatest deficit followed by the LEFORT, GENIO, and IVRO groups. During the 6-month recovery period each group approached preoperative levels of sensation at a different rate. The LEFORT group recovered most rapidly, with few anatomic sites showing NSD (SLT = 20%, MTD = 5%) at the 1-month postoperative examination, and the majority of the group (96%) returned to preoperative sensation by 3 months following surgery. The SSRO group recovered more slowly, with approximately half of the group demonstrating a deficit (SLT = 50%, MTD = 59%) at 1 month, which diminished to about one fourth of the sites (SLT = 25%, MTD = 5%) by 3 months. Most of the SSRO group (90%) exhibited no residual deficit 6 months following surgery. The IVRO group had few sites with immediate NSD (SLT = 11%, MTD = 15%). In none of the surgical groups was a statistically significant correlation found between the severity of the initial NSD and length of time to complete recovery.

Quantitative static light touch and nociceptive examination: A prerequisite to microneurosurgery

Quantitative static light touch and nociceptive examination: A prerequisite to microneurosurgery