Experiencing your own orthognathic surgery: A personal case report

There has been much research on minimizing the side effects of orthognathic surgery. However, there are very few doctors and researchers who themselves have undergone this surgery. This case report describes the findings of a maxillofacial surgeon who underwent combined orthodontic and orthognathic treatment for correction of Class II malocclusion. In March 2012, the surgeon was referred to an orthodontist, and an orthodontic examination revealed a Class II, division 2, malocclusion with a traumatic palatal bite and attrition of the lower front teeth. The patient underwent alignment of the upper and lower arches, followed by a bilateral sagittal split osteotomy. During this treatment, he made many interesting observations and learned much as a patient, which can have implications in improving the outcomes and quality of care for patients receiving such treatment. Thus, this case report aims to provide a critical perspective of the surgical procedure and treatment from the viewpoint of a maxillofacial surgeon who himself experienced the surgery as a patient.     

Effect of bilateral sagittal split ramus osteotomy on temporomandibular joint symptom and condylar position in patients with skeletal class Ⅲ malocclusion by cone beam computed tomography

目的 探讨双侧下颌骨升支矢状劈开截骨后退术（BSSRO）对行正畸—正颌联合治疗的骨性Ⅲ类错牙合患者颞下颌关节（TMJ）症状及髁突位置的影响。方法 选取24例行正畸-正颌联合治疗的骨性Ⅲ类错牙合患者,分别在BSSRO术前、术后1个月、术后12个月按Helkimo指数整理记录关节症状,并行锥形束CT（CBCT）扫描,在三维方向上测量髁突水平位及冠状截面最大径、髁突短轴径、髁突颈部宽度、髁突高度、不同角度（45°、90°、135°）下关节间隙宽度、双侧髁突间距及髁突角度（水平角、垂直角、受力角）,分析不同时期TMJ症状及骨性结构的变化情况。结果 BSSRO术前与术后的Helkimo指数均为Ai、Di 0级或1级,二者之间无差异。与术前相比,术后1个月时髁突水平角、45°及90°下关节间隙宽度增大,135°下关节间隙宽度减小（P<0.05）;术后12个月时,除髁突水平角增大（P<0.05）外,其余测量项目间差异均无统计学意义（P>0.05）。结论 在正畸—正颌联合治疗中,BSSRO不会对Helkimo指数为Ai、Di 0级或1级的骨性Ⅲ类错牙合患者的TMJ症状及髁突位置产生明显的影响。     

CT三维重建下探讨BSSRO术舌侧水平截骨线与骨劈开效果的关系

目的:应用CT三维重建来探讨双侧下颌骨矢状劈开截骨术舌侧水平截骨线与骨劈开效果的关系,为下颌骨矢状劈开截骨术舌侧水平截骨位置的选择提供指导。方法:选择17例双侧下颌骨前突患者(34例),经过下颌骨矢状劈开截骨术,术后应用三维重建观测水平截骨线及劈开效果。结果:只有10.87%的劈开结果理想(符合Hunsuck描述),54.35%的劈开效果较理想,32.61%的穿过了下颌管,4.35%穿过了其它部位。劈开的效果直接受水平截骨位置的影响(P<0.01)。结论:三维CT在评价下颌骨矢状劈开截骨术效果方面是有效的工具,为下颌骨矢状劈开截骨术选择舌侧水平截骨线位置提供重要数据,并能降低不良劈开的发生率。     

Evaluation of the lingual fracture patterns after bilateral sagittal split osteotomy according to Hunsuck/Epker modified by an additional inferior border osteotomy using a burr or ultrasonic device

This study was conducted to compare fracture patterns and operation times after sagittal split osteotomy (SSO) by Hunsuck/Epker approach, performed using a burr or ultrasonic device, with and without osteotomy modification. A total of 80 SSOs were performed in fresh human cadavers using a burr or ultrasonic device to investigate the influence of surgical instruments as well as an additional bone cut on the inferior border of the mandible in terms of lingual fracture patterns. The times required for osteotomy and sagittal split were measured, and postoperative cone beam computed tomography images of all splits were analyzed. Without an additional inferior osteotomy, preferred splits according to Hunsuck/Epker were achieved in 35% of cases (7/20) with the burr and 45% (9/20) with the ultrasonic instrument. The inferior modification resulted in a greater number of unwanted fracture patterns in both groups. There was no relationship between the split technique and the fracture pattern (P = 0.7854). Statistically significant differences in osteotomy time were observed between burr osteotomy and modified burr osteotomy (P = 0.006), as well as modified ultrasonic osteotomy (P < 0.001), but not between burr and ultrasonic surgery both without the inferior cut (P = 0.36). The bone cut on the inferior border did not improve split control, but rather increased the risk of unwanted fractures and extended the operation time.     

Trauma of treatment failure: a case report

Abstract A large overjet is a well-recognised predisposing factor to traumatic injuries of upper incisor teeth. In order to reduce this risk factor, early reduction of an increased overjet has been recommended. This was attempted, but unfortunately was unsuccessful and further trauma resulted in loss of the upper central incisor teeth.     

In vitro study of a modified sagittal split osteotomy fixation technique of the mandible: a mechanical test

This study was performed to evaluate the compressive mechanical strength of rigid internal fixation (RIF) using 1.5-mm L-shaped plates fixed with monocortical screws in sagittal split osteotomy (SSO). Thirty synthetic hemimandibles, which had all undergone a 5-mm advancement, were divided into three groups: three 12-mm bicortical titanium screws were placed in an inverted L pattern in group A; one straight 2.0-mm system spaced titanium plate fixed with four 5-mm monocortical screws was used in group B; two 1.5-mm system L-shaped titanium plates, each fixed with four 5-mm monocortical screws, were used in group C. The models were subjected to compressive and progressive mechanical tests with forces applied in the area between the second premolar and first molar to verify resistance in Newtons (N). A displacement speed of 1 mm/min was applied, with a maximum 10 mm displacement of the distal segment or until disruption of the fixation. The deformity and/or eventual rupture of the plates were evaluated, and consequently their technical stability was determined. The results showed that the modified fixation technique tested in this study on synthetic mandibles resulted in adequate stability and superior mechanical behaviour compared to simulated osteosynthesis with the use of a straight 2.0-mm titanium plate.     

Position of the mandibular canal before and after bilateral sagittal split ramus osteotomy: a cone beam computed tomographic study

The aim of this study was to evaluate the position of the mandibular canal (MC) before and after bilateral sagittal split ramus osteotomy (BSSRO) using cone-beam computed tomography (CT), and to compare the position of the MC in Class II and Class III patients in the preoperative period. Patients were divided into two groups: Class II (n = 38) and Class III (n = 41). Measurements of the superior, inferior, buccal, and lingual distances of the MC in relation to the cortical bone were taken at three levels in the proximal segment of the mandible. Results were analysed using the Kruskal–Wallis test (p < 0.05). In the Class II group the superior distance of the MC at levels 2 and 3, and the inferior distance at level 3 significantly decreased after BSSRO. In the Class III group, no significant differences were found at any level, and the inferior distances at all levels were smaller preoperatively than those in the Class II group. In the Class II group the position of the MC altered in relation to superior and inferior cortical bone after BSSRO. However, the position of the MC remained stable in the Class III group. Our results also suggest a deeper cut in inferior cortical bone in Class III patients.     

The spatial location of the mandibular canal in Chinese: a CT study

The inferior alveolar nerve (IAN) is vulnerable to injury from mandible fractures and surgical procedures so anatomical variations of IAN are important. Postoperative sensory alteration of the lip and chin region is high after mandibular orthognathic surgery. The incidence of IAN paresthesia following sagittal split ramus osteotomy (SSRO) ranges from 54% to 86% at 4–8 days, 41 to 75% at 1 month, 33 to 66% at 3 months, 17 to 58% at 6 months and 15 to 33% at 1 year postoperatively. This study determined the anatomical position of the mandibular canal in relation to cortical bone and molar teeth in Chinese using archived CT records. The mandibular canal was the farthest from the buccal cortex at the second molar region (mean 6.79 mm; minimum distance 4.80 mm). The anatomical location of the mandibular canal in local Chinese compares with studies on Asian cadavers. The mandible body was thickest in the region of the second molar (11.9 mm). The vertical buccal cut for SSRO should be in the region of the mandibular second molar where the bone is thickest and the mandibular canal is furthest from the buccal cortex. The safe depth for the vertical buccal cut is 4.8 mm (minimum horizontal distance).     

A study of unfavorable splits in the sagittal ramus osteotomy with a short lingual cut

In the bilateral sagittal split osteotomy, a short lingual cut is made on the medial side of the ramus; however, in some cases, a true fracture occurs on the buccal side of the ramus. The purpose of this study was to evaluate the relationship between the splitting pattern of the mandible and the form of the mandible, the surgical technique used, and the postoperative occurrence of relapse after ‘unfavorable’ splits. The investigation examined 143 patients in whom a short lingual cut was attempted. The rate of unfavorable split was 14.7% (42/286). A strong correlation was observed between the reach of the lateral bone cut to the inferior border of the mandible and an unfavorable split. According to multivariate regression, the factors leading to an insufficient lateral bone cut were the degree of inward curvature of the ramus (P = 0.001) and the position of the lateral bone cut (P = 0.002). There was no significant difference in relapse between cases of unfavorable and normal splits. An unfavorable split does not affect the prognosis of the occlusion, but it is important to confirm the inward curvature of the ramus and set the position of the lateral bone cut adequately to avoid unfavorable splits.     

Effect of the lateral bone cut end on pattern of lingual split during bilateral sagittal split osteotomy in patients with skeletal class III malocclusion

This study examines the effect of the lateral bone cut end (LBCE) on the pattern of lingual split during bilateral sagittal split osteotomy (BSSO) in patients with skeletal class III malocclusion. A case-control study according to the pattern of the sagittal split osteotomy (SSO) lingual split line was conducted in patients who underwent BSSO. The primary predictor variable was the ratio of the LBCE. The primary outcome variable was the type of lingual fracture line classified according to the lingual split scale (LSS). Other variables included patients’ weight, sex, age, left and right sides of the mandible, and experience of the surgeon. Logistic regression analysis or the chi-squared test was performed to determine the effect of these variables on various types of lingual fracture line. The significance level was 95% (p < 0.05). There were 271 patients enrolled in this study. The SSO lingual split lines were divided into LSS1 (329/542), LSS2 (82/542), LSS3 (93/542), and LSS4 (38/542) splits. Logistic regression analysis showed that the LSS3 split was more likely to appear when the LBCE was closer to the lingual side (p = 0.0017). The age of patients significantly affected the possibilities of LSS2 (p = 0.0008) and LSS3 (p = 0.0023) splits. A LBCE close to the lingual side was an inducer for the formation of a LSS3 split in patients with skeletal class III malocclusion during BSSO. The age of the patient also affected the possibility of LSS2 and LSS3 splits.     

Fixation methods in sagittal split ramus osteotomy: a systematic review on in vitro biomechanical assessments

The aim of this systematic review was to assess the stability of rigid internal fixation (RIF) techniques in sagittal split ramus osteotomy (SSRO) based on in vitro biomechanical assessments, with particular interest in large mandibular advancements. In general, RIF methods can be divided into three groups: bicortical screws, miniplates, and a combination of the two. An electronic search of the PubMed, CINAHL, and Embase databases was performed, and studies published between January 2003 and March 2018 were screened for inclusion. Comparative studies with an in vitro experimental design, using biomechanical assessments to measure the stability of RIF methods in SSRO, were included. Of 104 unique studies identified in the initial search, 24 were included. Twenty-two of these 24 studies analyzed an advancement of the mandible of 7 mm or less. The use of a single four-hole or six-hole miniplate was less stable than the use of bicortical screws, hybrid techniques, double miniplates, or grid plates. Two studies analyzed advancements of 10 mm, for which two miniplates placed in parallel and a grid plate showed most stability. Although there was agreement between studies with regard to results, more biomechanical studies are required to quantify the stability of fixation methods in larger mandibular advancements.     

Multidisciplinary approach for the treatment of an oblique root fracture: a case report

Abstract –  This clinical case study describes a multidisciplinary modified technique for the treatment of an oblique root fracture. A-38-year old woman with a history of trauma and a broken tooth was referred to our clinic. There was an oblique crown fracture extending the coronal third of the root just underneath the cingulum of the crown. The patient was willing to keep her tooth in function by any means. Two weeks after root canal therapy the flap was raised. The coronal two third of the root canal was enlarged. An impression of the enlarged root canal and tooth surface with surrounding bone was taken. The flap was sutured and the impression was sent to the laboratory for the post-casting preparation. After 7 days, the flap was opened again and casting was cemented. The flap was sutured. Ten days after the second surgery, three anterior teeth were prepared and a final impression was taken for the preparation of porcelain crowns. Restoration was finished 15 days after the second operation. The patient is still under maintenance therapy and the 12 month results are presented in this report. Extraction may not be the only alternative for the root fractures. Even for fractures under the alveolar margin, alternative multidisciplinary approaches can be used to restore and allow the tooth to survive.     

Irrigational therapy of a dentigerous cyst in a geriatric patient: a case report

Dentigerous cysts are recognized as one of the most common lesions of the jaws. Although surgical enucleation is usually the preferred treatment method, it is not always the best choice for elderly patients who have other medical complications. With cyst irrigational therapy, repeated irrigation allows bone regeneration around the cyst to progress more rapidly than that around a cyst treated operatively with marsupialization. We used irrigational therapy to treat a dentigerous cyst in a 72-year-old man who did not agree to surgery because he had no symptoms associated with the cyst, and he had other medical complications. After one year, remarkable bone regeneration was observed. We conclude that irrigational therapy appears to be an effective, less-invasive alternative to surgery for geriatric patients.     

Treatment of traumatized permanent incisors with crown and root fractures: a case report

Abstract – A case report of the treatment of permanent incisors with crown and root fractures is presented. A radiolucent lesion at the fracture lines was treated with calcium hydroxide in the coronal fragments for 18 months. Clinically, the teeth became firm and the radiographic results after 2 years showed healing of the lesion and hard tissue filling in the space at the fracture lines.     

Antibiotic prophylaxis for sagittal split ramus osteotomy using resorbable plate and screw fixation: a randomised trial to compare extended dual-agent and inpatient single-agent regimens

Resorbable materials are used to fix bony fragments after sagittal split ramus osteotomy (SSRO), but to our knowledge, there is no clear regimen for antibiotic prophylaxis when such materials are used. The purpose of this study therefore was to compare inpatient single-agent and extended dual-agent antibiotic prophylaxis for the prevention of surgical site infections (SSI) in patients after SSRO. This prospective study included 100 patients who underwent SSRO for deformities of the jaw. Cephalometric analysis was performed preoperatively, and at one month and one year postoperatively. Patients were divided into two groups of 50 each. Group A was given cefazolin sodium 1g preoperatively and every eight hours for 48 hours postoperatively. Group B was given cefazolin sodium 1g preoperatively and every eight hours for 48 hours postoperatively, after which they were provided with oral amoxicillin for three days. Both groups were assessed for SSIs for one year postoperatively using the Clavien-Dindo classification. SSIs were documented in seven patients in Group A and six in Group B, with no significant difference between the groups. The two regimens had no significant association with SSI. In conclusion, our results suggest that the inpatient, single-agent, postoperative antibiotic regimen is sufficient to prevent SSI in patients who have SSRO with resorbable plate and screw fixation.     

Surgical morbidities of sagittal split ramus osteotomy versus intraoral vertical ramus osteotomy for the correction of mandibular prognathism: a randomized clinical trial

The sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) are two common orthognathic procedures for the treatment of mandibular prognathism. This randomized clinical trial compared the surgical morbidities between SSRO and IVRO for patients with mandibular prognathism over the first 2 years postoperative. Ninety-eight patients (40 male, 58 female) with a mean age of 24.4 ± 3.5 years underwent bilateral SSRO (98 sides) or IVRO (98 sides) as part or all of their orthognathic surgery. IVRO presented less short-term and long-term surgical morbidity in general. The SSRO group had a greater incidence of inferior alveolar nerve deficit at all follow-up time points (P <  0.01). There was more TMJ pain at 6 weeks (P =  0.047) and 3 months (P =  0.001) postoperative in the SSRO group. The SSRO group also presented more minor complications, which were related to titanium plate exposure and infection. There were no major complications for either technique in this study. Despite the need for intermaxillary fixation, IVRO appears to be associated with less surgical morbidity than SSRO when performed as a mandibular setback procedure to treat mandibular prognathism.     

Tooth eruption in a patient with craniometaphyseal dysplasia: case report

Craniometaphyseal dysplasia (CMD) is a very rare genetic disorder of bone remodeling caused by osteoclast dysfunction. The clinical and radiographical features of oral findings are presented in a sporadic case of CMD in a child (age 10 years, 7 months). An intraoral examination showed severe malocclusions, including anterior crossbite and deep bite. Furthermore, a radiographic examination showed increased radiopacity of the maxilla and mandibular bones due to hyperostosis and sclerosis of the jaw. There was no root resorption of the canines or molars in the primary dentition, although root formation of the permanent teeth was proceeding. Dental age was calculated to be approximately 1 year, 4 months younger than his chronological age. The eruption speed of the permanent lateral incisors after the gingival emergence was shown to be within normal values, and we discuss whether the canines and premolars in the permanent dentition could erupt or not.     

Repair of untreated root fracture: a case report

Abstract A case is presented in which an untreated root fracture in a maxillary central incisor of an adult male was found radiographically 10 years after injury. The tooth was removed and the area of the root corresponding to the fracture line was examined by SEM while the remaining tooth was processed for decalcified sections. Calcification of the coronal pulp associated with extensive tissue atrophy and normal pulp tissue apically was observed. Two barriers composed of dent in al and cemental hard tissue were present apically in the coronal fragment and in the fracture line.     

Endoscopically assisted tunnel approach for minimally invasive corticotomies: a preliminary report

Background: The dental community has expressed low acceptance of traditional corticotomy techniques for corticotomy‐facilitated orthodontics. These procedures are time consuming, entail substantial postoperative morbidity and periodontal risks, and are often perceived as highly invasive. Methods: A total of 114 interdental sites were treated in nine consecutive patients. Under local anesthesia, a tunnel approach requiring one to three vertical incisions per arch (depending on the targeted teeth) was used. Piezosurgical corticotomies and elective bone augmentation procedures were performed under endoscopic assistance. Postoperative cone‐beam computerized tomography evaluation was used to confirm adequate corticotomy depth. Results: Procedures were completed in a mean time of 26 minutes. Follow‐up evaluations revealed no loss of tooth vitality, no changes in periodontal probing depth, good preservation of the papillae, and no gingival recession. No evidence of crestal bone height reduction or apical root resorption was detected. Conclusions: The tunnel approach minimizes soft‐tissue debridement and permits effective cortical cuts. The combination of piezosurgery technique with endoscopic assistance provides a quick, reliable means to design and perform these corticotomies while maximizing root integrity preservation. Moreover, the sites needing bone augmentation are selected under direct vision. Compared to traditional corticotomies, this procedure has manifest advantages in surgical time, technical complexity, patient morbidity, and periodontium preservation.