A retrospective study of unfavorable fractures during sagittal split osteotomy:A single surgeon’s experience

Background:Unfavorable fractures are among the most common complications of bilateral sagittal split ramus osteotomy(BSSRO).This study aimed to evaluate unfavorable fracture patterns during BSSRO and assess the related risk factors and treatment measures.Methods:The clinical records and radiographs of 679 patients(1358 sides)who underwent BSSRO at Shanghai Ninth People’s Hospital between September 2013 and December 2021 were examined.Results:Patients with unfavorable fractures who underwent surgical restoration were studied.The incidence of unfavorable fractures was 0.8%(n¼11),with the highest rate in the third year.The unfavorable fractures were divided into three types by location and clinical treatment:(1)SSRO could still be completed after buccal/lingual plate unfavorable fracture(0.6%,n=8);(2)condylar/coronoid process fractures/intermaxillary fixation needed(0.1%,n=2);(3)additional osteotomy required(0.07%,n=1).Conclusion:These results suggest that as a surgeon’s experience increases,the rate of unfavorable fractures may decrease.The novel classification of unfavorable fractures for SSRO might be useful for surgeons to make appropriate treatment choices during orthognathic surgery.

Combined Therapy for Mandibular Prognathism:Sagittal Split Osteotomy with Excision of Tongue

In the evaluation of the beauty and functional integrity of the lower face, the oral cavity, teeth, mandible, maxilla, and the size and position of the tongue are important. The tongue locates forward and is larger than normal in prognathism, in which the jaw protrudes from the skull. It is not clear whether an enlarged tongue causes the open bite, protrusion or dental arch misalignment, or is a result of them. Here, we report two patients with mandibular prognathism and relative macroglossia, which were treated by mandibular setback surgery using a bilateral sagittal split osteotomy (BSSO) and excision of the tongue. This procedure achieved aesthetic improvement of the face and dentition.

CHANGES IN AIRWAY SPACE FOLLOWING MANDIBULAR SETBACK USING SAGITTAL SPLIT OSTEOTOMY AND RIGID INTERNAL FIXATION

The changes in airway space following mandibular setback using sagittal split osteotomy and rigid internal fixation were studied in 28 Japanese patients with mandibular prognathism. The correlation between the amount of mandibular setback and airway space changes,as well as the correlation between the amount of airway space changes and relapse of pognion point during the following-up period were also studied. Lateral cephalometric radiographs were taken immediately before and shortly after surgery as well as 5 to 12 months postoperation. The cephalometric evaluations of airway space width and area were based on stable craniofacial landmarks. The mean setback of mandible was 8.3 mm in the right side,and 8. 2 mm in the left side. The mean amount of relapse of pogonion point during the following-up period was 0. 52 mm horizontally,and 0. 92 mm vertically. A significant decrease in airway space width and area,especially in the lower part of airway space was found following mandibular setback shortly after surgery. Although there was some increase both in airway space width and area during the following-up period,they did not increase to their original values. This suggests that the narrowing of airway space following mandibular setback using sagittal split osteotomy can be permanent. No significant correlation was found between the amount of mandibular setback and airway space changes. Since the relapse of pogonion point during the following-up period was too small,there is no significant correlation between it and the amount of airway space changes.

The Effect of Sagittal Split Ramos Osteotomy Advancement and Setback Mandible on Occlusal Force and Masticatory Efficiency.

The occlusal force and masticatory efficiency in twenty-one patients (mandibular prognathism =11, mandibular retrognathism = 10) undergone sagittal split

Neuropathic pain after bilateral sagittal split osteotomy:management and prevention

Neuropathic pain is characterized by spontaneous and provoked pain and other signs reflecting neural damage.Aberrant regeneration following peripheral nerve lesions leaves neurons unusually sensitive and prone to spontaneous pathological activity,abnormal excitability and heightened sensitivity to stimuli.This review covers the current understanding of neuropathic pain after bilateral sagittal split osteotomy(BSSO)of the lower jaw.The reported incidence of neuropathic pain after mandibular osteotomies is less than 1%,while the incidence in patients with iatrogenic inferior alveolar nerve(IAN)injuries during BSSO can be as high as 45%.The factors which modulate the healing process toward neuropathic pain during or after nerve damage have not yet been elucidated.Patients at highest risk for developing post-BSSO neuropathic pain are older than 45 years and have undergone procedures involving IAN compression,partial severance,or complete discontinuity of the lingual nerve with a proximal stump neuroma,patients with nerve injury repair delayed longer than 12 months and patients with chronic illnesses that compromise healing or increase risk for peripheral neuropathy.Although neuropathic pain tends to be long-lasting,some patients can recover completely.Preventive measures include risk assessment prior to surgery,prevention of nerve damage during surgery,and early repair of nerve injury.

A guiding oblique osteotomy cut to prevent bad split in sagittal split ramus osteotomy:a technical note

Aim:To present a simple technical modification of a medial osteotomy cut which prevents its misdirection and overcomes various anatomical variations as well as technical problems.Methods:The medial osteotomy cut is modified in the posterior half at an angle of 15°-20°following novel landmarks.Results:The proposed cut exclusively directs the splitting forces downwards to create a favorable lingual fracture,preventing the possibility of an upwards split which would cause a coronoid or condylar fracture.Conclusion:This modification has proven to be successful to date without encountering the complications of a bad split or nerve damage.