Neurosensory Alteration in the Lower Lip and Chin Area After Orthognathic Surgery: Bilateral Sagittal Split Osteotomy Versus Inverted L Ramus Osteotomy

Retrospective study of changes in the sensitivity of the oral mucosa: sagittal split ramus osteotomy (SSRO) versus intraoral vertical ramus osteotomy (IVRO)

“…20 Meanwhile, Kobayashi et al reported that the threshold improved in 79.5-87.0% of their patients among two groups of subjects undergoing SSRO. 21 Our results are similar to these findings. 9 A positive correlation between age and the incidence of neurosensory disturbances has been reported.…”

“…Some investigators have reported that symptoms of NSD occur more in the older patients than in the younger patients. 16,20,21 In the G1 gingival and B1 buccal mucosa (based on the buccal nerve), the incidence of reduced NSF and NSD at 8, 12, and 24 weeks after surgery was significantly low. The number of points showing reduced NSF and NSD in the G1 gingival mucosa was not significantly different at 8 and 24 weeks after surgery.…”

“…This means that the operative time may be shorter than for other methods, and the technique may be useful for treating temporomandibular disorders. 21 However, when performing the IVRO method, longterm IMF is occasionally necessary, and performing fixation of bone fragments, if needed, is more difficult than with other methods. 22 There are various sensory examinations that may be used after orthognathic procedures such as IVRO and SSRO, including measurements of the touch detection threshold using a Semmes-Weinstein pressure aesthesiometer, 20-22 light touch sensation tests using a sharpened pin or cotton, 4,5,23,24 electrical stimulation tests, 8,25 two-point discrimination tests, 20,23-25 somatosensory evoked potential tests, 25 thermal stimulation tests, 23,24,26 brush-stroke directional discrimination tests, 20,23,24,26 and questionnaires designed to investigate subjective NSD.…”

Behavioural and histological observations of sensory impairment caused by tight ligation of the trigeminal nerve in mice

“…Furthermore, sensory impairment was reported to improve more quickly after maxillary operations than after mandibular operations (Karas et al, 1990). On the other hand, different sensory impairments seem to exist within the area innervated by the mandibular nerve, among which earlier improvement of sensory impairment is observed in the lower lip compared with the chin area after jaw surgery (Kobayashi et al, 2006). These lines of evidence suggest the possibility of region-dependent sensory abnormalities, even if they are innervated by the same nerve.…”

Evaluation of lip sensory disturbance using somatosensory evoked magnetic fields

“…Iatrogenic inferior alveolar nerve (IAN) injury causes complication of the patients due to its resultant sensory impairment of the lower lip, chin, and lower teeth (Kobayashi et al, 2006;Lee et al, 2011). For example, previous reports have documented that the incident rate of IAN injury by third molar extraction varied from 2 to 17% (Renton et al, 2005;Hatano et al, 2009;Leung and Cheung, 2009;Cilasun et al, 2011;Long et al, 2012).…”