Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Istanbul University, Istanbul, Turkey.
Istanbul Medical Faculty, Department of Neurology, Istanbul University, Istanbul, Turkey.
J Orofac Orthop. 2023 Mar;84(2):100-109. doi: 10.1007/s00056-021-00350-x. Epub 2021 Sep 27.
This prospective study was designed to assess whether patients with skeletal deformities show characteristic masseter inhibitory reflex (MIR) and blink reflex (BR) patterns. A secondary aim was to investigate whether these reflexes change following bilateral sagittal split osteotomy (BSSO).
Fourteen consecutive patients who underwent single-jaw BSSO and 14 class I subjects who constituted the control group were enrolled into the study. MIR and BR, obtained by the stimulation of supraorbital (SBR) and mental nerves (MBR), were electrophysiologically recorded. Sensory impairment in the mental nerve distribution was clinically tested. Three evaluation periods were specified as immediately before (T0), 1 month (T1) and 6 months (T2) after surgery.
MIR early silent period duration was significantly shorter in the patients at T0 (p < 0.001). Sensory deficits developed on 23 sides after BSSO, of which, 17 recovered after 6 months. At T1, MBR was inelicitable bilaterally in 3 patients and unilaterally in 2 patients. These responses were still unrecordable bilaterally in 1 patient, and unilaterally in 4 patients at T2. MIR were unrecordable on 18 sides at T1 and recovered on 11 sides at T2. There were no parallels between the clinical sensory deficits and the abnormal results of the reflexes.
Shorter MIR in patients with dentofacial abnormalities may be a reflection of an adapted trigeminal reflex mechanism. Although MBR and MIR abnormalities do not develop parallel to the clinical sensory deficits, their course might provide insights into the disturbed trigeminal reflex pathways.
本前瞻性研究旨在评估骨骼畸形患者是否表现出特征性的咬肌抑制反射（MIR）和眨眼反射（BR）模式。次要目的是研究双侧矢状劈开截骨术（BSSO）后这些反射是否会发生变化。
本研究纳入了 14 例接受单颌 BSSO 的连续患者和 14 例构成对照组的 I 类患者。通过眶上神经（SBR）和颏神经（MBR）刺激获得 MIR 和 BR，并进行电生理记录。临床测试颏神经分布感觉障碍。指定了三个评估期，分别为手术前即刻（T0）、术后 1 个月（T1）和 6 个月（T2）。
患者在 T0 时 MIR 早期静默期持续时间明显缩短（p<0.001）。BSSO 后 23 侧出现感觉缺失，其中 17 例在 6 个月后恢复。在 T1，3 例双侧 MBR 无法引出，2 例单侧无法引出。1 例双侧仍无法引出，4 例单侧无法引出。18 侧在 T1 时 MIR 无法记录，11 侧在 T2 时恢复。临床感觉缺失与反射异常之间没有平行关系。
牙颌面畸形患者的 MIR 缩短可能反映了三叉神经反射机制的适应性。尽管 MBR 和 MIR 异常的发展与临床感觉缺失不一致，但它们的过程可能提供对受损三叉神经反射通路的深入了解。
