Intraoral Vertico-sagittal Ramus Osteotomy Research Articles

Improvement of the temporomandibular joint symptoms due to the condylar position change following modified L-shaped intraoral vertico-sagittal ramus osteotomy: a single-center, retrospective study.

Intraoral vertico-sagittal ramus osteotomy (IVSRO) was first reported by Choung in 1992 as a surgical procedure to decrease postoperative condylar dislocation. In 2017, Iwanaga et al. developed modified L-shaped IVSRO (mIVSRO) to reduce postoperative nerve dysfunction and achieved favorable outcomes. This study aimed to clarify the effect of mIVSRO on changes in temporomandibular joint (TMJ) symptoms and three-dimensional condylar position. We conducted a retrospective study of thirty sides in fifteen Japanese adults diagnosed with jaw deformities who underwent mIVSRO and sagittal split ramus osteotomy (SSRO). TMJ symptoms were assessed chronologically, and the condylar long axis and the condylar position were analyzed two- and three-dimensionally using axial cephalograms and cone-beam computed tomography. Postoperative TMJ symptoms improved by 90% (9/10 sides) in the mIVSRO group and by 50% (7/14 sides) in the SSRO group. The mIVSRO group exhibited outward rotation of the condylar long axis, while the SSRO group exhibited inward rotation. Moreover, mIVSRO induced residual anteromedial-inferior deviation of the condyle. The inclination angle of the condylar process was not significantly different between the two procedures pre- and postoperatively. These results clearly demonstrated the effect of mIVSRO on symptomatic TMJ. Residual changes in the position of the condyle following mIVSRO may not affect jaw function.

Treatment of Acquired Retrognathia Secondary to Infantile Temporomandibular Joint Luxation with Intraoral Vertico-Sagittal Ramus Osteotomy

Temporomandibular joint (TMJ) disorders are under-diagnosed in pediatric patients, and infantile TMJ luxation is a very rare condition. Luxation early in life can cause skletofacial problems, such as retrognathia, if it is left untreated for a long time. It is well known that severe retrognathia is one of the most common causes of sleep-disordered breathing (SDB).

Evaluation of neurosensory disturbances of the inferior alveolar nerve after intraoral verticosagittal ramus osteotomy

PurposeTo assess the incidence of neurosensory disturbances (NSD) of the inferior alveolar nerve (IAN) after Intraoral verticosagittal ramus osteotomy (IVSRO). Materials and methodsThe sensibility of the chin and lower lip of ten consecutive patients undergoing IVSRO was assessed. Evaluations were performed at 7 days preoperatively, 7 days, one month and six months postoperatively. The chin was divided into four quadrants, which were tested separately. The tests used were: two-point discrimination (2-P), brush stroke direction discrimination (BSD) and thermal stimuli (TH). Postoperatively, patients also answered a questionnaire. ResultsThe values for 2-P showed statistically significant difference when compared to preoperative measurements (P>0.05) in all quadrants, with exception to quadrant D. There was no statistically significant difference among preoperative values and 7 days, 1 month and 6 months postoperative values. For BSD and TH tests, no differences were found among time points. None of the 10 patients reported complete numbness after 1 week. After 6 months, complete recovery of the chin sensibility was reported in all 10 cases. ConclusionThis study showed, objectively and subjectively, a low incidence of NSD after IVSRO. Further studies with larger samples are necessary to confirm these results.

Changes of Transverse Mandibular Width in Set-Back Mandibular Surgery: Sagittal Split versus Intraoral Verticosagittal Osteotomy

Aim: This study was performed to evaluate the movement of the proximal segment following different methods of ramus osteotomy that is one of the side effects of orthognathic surgery. Theoretically, with intraoral verticosagittal ramus osteotomy, it can minimize the movement of the proximal segment. The changes in the intergonal distance of mandible and the angle of the ramus flaring in two methods of osteotomy have been compared in this study. Materials and Methods: In this randomized clinical trial, included 60 patients (32 males) with mandibular prognathism and without any asymmetry were selected and divided into two groups (n = 30). One group underwent bilateral sagittal split ramus osteotomy technique to achieve mandibular setback and the other by the intraoral verticosagittal ramus osteotomy technique. Intergonial width and inner-ramal angle in the transverse plane were measured on radiographs preoperatively and 1 and 12 weeks postoperatively. Data were analyzed using covariance test with the significance level set at P 0.1). Conclusion: Considering our findings, there was no significant difference between two ramus osteotomy techniques regarding changes in mandibular width and inter-ramal flaring angle.

Morphological variations of lingula and prevalence of accessory mandibular foramina in mandibles: A study.

Introduction:The lingula is used for identifying the site for injection of local anesthetics and for excision of nerve in facial neuralgia. The relationship between lingula and lingual nerves may aid in risk associated with an impacted third molar. Due to its connection to nerve and vascular structures, the study of the lingula provides important information related to oral and maxillofacial surgical procedures, such as the sagittal split ramus osteotomy and the intraoral vertico-sagittal ramus osteotomy carried out to correct dento facial deformities. Intra-operative complications such as hemorrhage, fracture, and nerve injury may occur if lingula is not correctly identified.Materials and Methods:This study was conducted in the Department of Oral Medicine and Radiology, Career Post Graduate Institute of Dental Sciences and Hospital, Lucknow, U. P (India) on fifty (100 sides) dry adult human mandibles to determine the different shapes of lingula. The shapes of the lingula were classified as triangular, truncated, nodular, and assimilated types.Results:The most common shape found in the study was the triangular (61.6%) while the least common shape was the assimilated (11.6%). All types of lingule were more prevalent unilaterally. The prevalence of accessory mandibular foramina (AMF) was 12% on the right side and 4% on the left side of the mandible.Conclusion:The present study provides information regarding different shapes of lingule and incidence of AMF in the populations of Lucknow and its surrounding areas (Uttar Pradesh) North India. The findings of the present study are very helpful to oro-dental surgeons, anthropologists, and forensic practice experts.

A Comparative Review of Mandibular Orthognathic Surgeries with a Focus on Intraoral Vertico-sagittal Ramus Osteotomy.

Severe dentofacial deformities require both orthodontics and surgical management to repair. Modern mandibular orthognathic surgery commonly uses sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) methods to treat patients. However, complications like neurosensory disturbances and temporomandibular joint disorders are common following both procedures. In 1992, Choung introduced the intraoral vertico-sagittal ramus osteotomy (IVSRO) which led to a decrease in postoperative complications. The 'straight' IVSRO or Choung’s type II osteotomy has a 'condylotomy' effect that reduces iatrogenic temporomandibular joint symptoms and treats preoperative temporomandibular joint symptoms. This osteotomy type is especially applicable for prognathism with excessive flaring of the ramus and with temporomandibular joint dysfunction. The 'L-shaped' IVSRO or Choung’s type I osteotomy is indicated for patients with condylar hyperplasia and high condylar process fractures.

Intraoral vertico-sagittal ramus osteotomy: modification of the L-shaped osteotomy

The sagittal split ramus osteotomy and intraoral vertical ramus osteotomy carry the potential risk of postoperative nerve paralysis, bleeding, and fracture and dislocation of the condyle. In 1992, Choung first described the intraoral vertico-sagittal ramus osteotomy for the purpose of avoiding postoperative dislocation of the condyle. However, there is still potential for damaging the inferior alveolar nerve and maxillary artery with this technique. The authors have developed a modified technique to minimize these risks. An evaluation of surgical experience and patient outcomes with the use of this technique is presented herein. One hundred twenty-two sides in 97 Japanese patients diagnosed with a jaw deformity were analyzed. This technique includes a horizontal osteotomy that is performed at a higher position than in the original Choung procedure. Intraoperatively, there was no unexpected bleeding from the operative site. Proximal segment dislocation from the glenoid fossa was observed on one side (0.82%). Non-union of the osteotomy was not observed in any patient. Intraoperative fracture of the coronoid process occurred in 2.46%, but none necessitated treatment of the fracture. Nerve dysfunction was found in 2.46% at the 12-month postoperative follow-up. The modified technique presented herein was developed to reduce postoperative nerve dysfunction and intraoperative hemorrhage.

Managing complications in intraoral vertico-sagittal ramus osteotomy

Intraoral vertico-sagittal ramus osteotomy is a suitable osteotomy for correction of mandibular prognathism and small retrognathism, associated with predictable results. Although few complications have been described when this technique is used, the Oral and Maxillofacial Surgeon must be prepared to manage them when they occur. The purpose of this presentation is to point the most common problems and the decisions we have been taking in our 15 years experience doing this osteotomy.

Evaluation of Neurosensory Disturbances of the Inferior Alveolar Nerve after Intraoral Verticosagittal Ramus Osteotomy

Purpose: The aim of the present paper is to assess the incidence of Neurosensory Disturbances (NSD) of the Inferior Alveolar Nerve (IAN) after the Intraoral Verticosagittal Ramus Osteotomy (IVSRO), through subjective and objective methods.

Stability of intraoral verticosagittal ramus osteotomy in mandibular setbacks: retrospective analyses of 40 cases

Stability of intraoral verticosagittal ramus osteotomy in mandibular setbacks: retrospective analyses of 40 cases

Transverse Displacement and Angulation of the Proximal Segment After Mandibular Setback by Means of Bilateral Intraoral Vertico-Sagittal Ramus Osteotomy

The purpose of this study was to assess the transverse displacement and angulation of the proximal segment after a bilateral intraoral vertico-sagittal ramus osteotomy (IVSRO) and its relation with mandibular setback. Sixty patients were recruited into this study and underwent a mandibular setback with bilateral IVSRO with wire fixation. Posteroanterior and lateral cephalometric radiographs were obtained 1 month before and 1 month after surgery. The transverse displacement and angulation of the proximal segments after surgery were measured on posteroanterior radiographs, via the best-fit method. The correlation of the amount of mandibular setback with the amount of transverse displacement and angulation of proximal segment was also assessed. A statistically significant increase was seen in intergonial width (P < .001), and inter-ramus width (P < .001) with a mean of 2.25 mm (SD, 0.82) and 4.45 mm (SD, 1.18), respectively. Both the right and left ramus angles showed an increased angle on average: mean, 1.70° (SD, 0.91) and 1.43° (SD, 0.66), respectively. There was a statistically significant increase in both angles 1 month after surgery (P < .001). There was a statistically significant relation between the amount of mandibular body setback measured at B point and increase in intergonial width (P = .012, r = 0.45), inter-ramus width (P = .018, r = 0.42), left ramus angle (P = .007, r = 0.48), and right ramus angle (P = .008, r = 0.47). This study suggested that IVSRO leads to an increase in intergonial width and inter-ramus width, as well as the outward angulation of the condylar fragment. In addition, there was a significant correlation between the amount of setback and intergonial width, inter-ramus width, and medial ramus angles.

Analysis of 40 Cases of Intraoral Verticosagittal Ramus Osteotomies to Treat Dentofacial Deformities

The aim of the present study was to report the experience of 40 patients who had undergone intraoral verticosagittal ramus osteotomy (IVSRO) to treat dentofacial deformities. The charts of 40 consecutive patients who had undergone IVSRO were analyzed regarding the diagnosis, amount of mandibular movement, and complications. Eighty IVSROs were performed in 40 patients. The mean follow-up was 18 months. Mandibular protrusion in both genders was the main preoperative diagnosis (25 patients), and the treatment was 2-jaw surgery in 36 patients. The mean amount of movement was 2 mm for the mandible setback and advancement, 3 mm for mandible counterclockwise rotations, and 2 mm for mandible clockwise rotations. The mean period of maxillomandibular fixation was 15 days, followed by a period of heavy elastics. The rate of complications was 2%, including 2 bad splits, and 2 cases of intraoperative bleeding. No nerve injury was observed in the 40 patients studied. The IVSRO is efficient and versatile, with low morbidity, and is an option for the oral and maxillofacial surgeon to treat patients with mandibular dentoskeletal discrepancies.

Severe Class II malocclusion with facial asymmetry treated with intraoral vertico-sagittal ramus osteotomy and LeFort I osteotomy

In this article, we report the successful treatment of a patient, aged 19 years 11 months, who had a severe Class II malocclusion and facial asymmetry. A combination of intraoral vertical-sagittal ramus osteotomy (IVSRO), intraoral vertical ramus osteotomy (IVRO), and LeFort I osteotomy was used for mandibular advancement and maxillary impaction. The patient had a convex profile because of a retrognathic mandible. She also had severe mandibular deviation and vertical maxillary excess with a canted occlusal plane. A deep overbite of 8.0 mm and an excessive overjet of 10.0 mm were observed. After 16 months of presurgical orthodontic treatment, IVRO in the left ramus and IVSRO in the right ramus were performed with maxillary impaction by LeFort I osteotomy. The mandible was advanced 6.0 mm on the right side, and the maxilla was impacted 4.0 mm at ANS, 2.0 mm at the right first molar, and 5.0 mm at the left first molar. The total active treatment time was 35 months. Both occlusion and facial appearance were significantly improved by the surgical-orthodontic treatment. Occlusion was stable after a year of retention. There were no functional problems during or after treatment. Our results suggest that IVSRO and IVRO combined with LeFort I osteotomy in a patient with severe mandibular retrusion with facial asymmetry might be useful to improve occlusion and facial esthetics.

Evaluation of Intraoral Verticosagittal Ramus Osteotomy for Correction of Mandibular Prognathism: A 10-Year Study

To identify intraoperative complications, neurosensory disturbance (NSD), and horizontal relapse after surgical correction of mandibular prognathism using bilateral intraoral verticosagittal ramus osteotomy (IVSRO). Between 1995 and 2005, 237 Iranian patients underwent IVSRO to achieve mandibular setback. Their operation reports, cephalometric radiographs (2 weeks preoperatively and 12 months postoperatively), and neurosensory questionnaires were assessed to identify intraoperative complications, NSD of the inferior alveolar nerve (IAN), and horizontal relapse. Intraoperative complications occurred in 26 cases (11%). A total of 17 patients (7.2%) reported NSD of the IAN. The mean surgical setback was 7.99 mm at the B point, and the mean horizontal relapse was 2.16 mm at the B point (after 1 year). Considering our findings, the benefits of the IVSRO technique (eg, good contact between the 2 parts of the osteotomy, capacity for rigid fixation, low incidence of IAN injury) demonstrate that this technique can easily replace the intraoral vertical ramus osteotomy technique to treat mandibular prognathism and is a viable alternative to the sagittal split osteotomy technique to provide mandibular setback.

Anatomical Study of the Complications of Intraoral Vertico-Sagittal Ramus Osteotomy

The present study was performed to determine the variations in anatomical features of the ramus and the course of the maxillary artery to reduce the risk of injury during intraoral vertico-sagittal ramus osteotomy (IVSRO). The locations and sizes of anatomical features of the medial aspect of mandibular rami were measured in 94 bilateral sides of 47 dry mandibles as a control group, and the results were compared with 3-dimensional computed tomography images of 44 sides of 22 patients with prognathism. We also dissected 12 sides of 6 mandibles from cadavers in a simulated IVSRO procedure to determine the course of the maxillary artery near the medial aspect of the ramus. In the dry mandibles and patients with prognathism, the mandibular foramen was located slightly posterior to the center of the width of the mandibular ramus, and the lingula tip was located about one third the distance from the sigmoid notch to the inferior border of the ramus. The distance from the lateral margin of the mandibular foramen to the lateral surface of the mandibular ramus ranged from 3.1 to 4.4 mm. However, these distances showed various ranges. In the mandibles from Asian cadavers, the maxillary artery approached close to the ramus and passed lateral to the lower head of the lateral pterygoid muscle. The position of the mandibular foramen in rami varies among individuals and, therefore, should be confirmed preoperatively on axial CT images. In addition, the maxillary artery approaches close to the medial aspect of the sigmoid notch in many cases. Therefore, the medial aspect from the sigmoid notch should be exposed carefully in the IVSRO procedure to avoid damaging the maxillary artery.

Comparison of the clinical outcomes of patients having sounds in the temporomandibular joint with skeletal mandibular deformities treated by vertico-sagittal ramus osteotomy or vertical ramus osteotomy

Objective This article describes the effects of the intraoral vertico-sagittal ramus osteotomy (IVSRO) procedure on the jaw of patients with temporomandibular joint (TMJ) disorders. Study design IVSRO was performed on 15 patients (30 sides) who had mandibular protrusion or asymmetry with TMJ dysfunction. IVRO was performed on another 15 patients (30 sides). All of the 30 patients had sounds in the TMJ uni- or bilaterally. The relative positions of the condyle and disc and the range of motion of the condyles were determined by magnetic resonance imaging (MRI) before and 12 months after the operations. Results Sounds such as clicking improved in 92% (24/26) of the joints in the IVSRO group, and in 83% (20/24) of the joints in the IVRO group 12 months after the operation. The positional relationship between the condyle and disc on the MR images improved in 82% (9/11) of the joints with reduction of the anterior disc displacement; in 60% (3/5) of the joints without reduction of the anterior disc displacement in the IVSRO group; in 75% (9/12) of the joints with reduction of the anterior disc displacement; and in 40% (2/5) of the joints without reduction of the anterior disc displacement in the IVRO group. Immediately after the operation, the condyle was displaced anterio-inferiorly in all joints in both groups, but gradually returned to close to the preoperative position. There were no significant differences between the 2 groups regarding the extent of shift of the condylar head at 2 weeks and 12 months after the operation. Conclusion The clinical outcomes of the IVSRO procedure are similar to those of the IVRO procedure. Therefore, IVSRO may be a suitable procedure for patients having TMJ dysfunction with skeletal mandibular deformities, particularly when an IVRO is unsuitable.

Advantages of intraoral verticosagittal ramus osteotomy in skeletofacial deformity patients with temporomandibular joint disorders

This preliminary study was performed to clarify the usefulness of intraoral verticosagittal ramus osteotomy (IVSRO) in patients with temporomandibular joint (TMJ) disorders. We examined 34 sides in 19 consecutive patients with dentofacial deformities with TMJ dysfunction undergoing IVSRO. Preoperatively, 15 patients had TMJ sounds bilaterally and 4 had sounds unilaterally. Five sides in 3 patients had pain in the TMJ, and 4 sides in 3 patients had masticatory muscle pain. The TMJ symptoms, including TMJ sounds, pain in the TMJ, and masticatory muscle pain in each patient, were assessed clinically before and approximately 12 months after IVSRO. Magnetic resonance imaging was also performed to determine joint status, including determination of the positions of the condyle and disc. The symptoms of the TMJ after 12 months of orthodontic treatment showed marked improvements, with the disappearance of the TMJ sounds in 94% of the sides examined. Pain in the TMJ improved in 4 of 5 sides, and pain of the masticatory muscle improved in 3 of 4 sides. With regard to the relative positions of the condyle and disc on magnetic resonance imaging, 6 of 8 joints and 5 of 7 joints showed improvement in anterior disc displacement with and without reduction, respectively. The direction and mean amount of movement in the distal segment were 8 mm in setback, 4 mm in advance, and 5 mm counterclockwise. IVSRO is potentially as useful for the treatment of TMJ disorders in orthognathic surgery patients as is intraoral vertical ramus osteotomy, and IVSRO can be used selectively in cases in which intraoral vertical ramus osteotomy is contraindicated.

An intraoral approach to treatment of condylar hyperplasia or high condylar process fractures using the intraoral vertico-sagittal ramus osteotomy

Purpose: The intraoral vertico-sagittal ramus osteotomy (J Craniomaxillofac Surg 20:153, 1992) can be used to reduce high condylar process fractures and recontour hyperplastic condyles while simultaneously correcting the malocclusion. This article presents the technique and reports the clinical results. Patients and Methods: A technique for removal and replantation of the condyloid process using the vertico-sagittal ramus osteotomy and rigid fixation was used to treat 23 patients with markedly displaced, high condylar process fractures and condylar hyperplasia associated with malocclusion. Results: The replanted condyles did not show ischemic necrosis or any functional disturbance when followed for more than 3 years. All patients showed nearly normal mouth opening, with slight mandibular deviation, usually in sixth postoperative month. Conclusions: In selected patients, this technique allows intraoral accessibility to the condyle and its repositioning. The method is particularly useful to treat vertical discrepancies associated with the hyperplastic or hypoplastic condyle.

Intraoral approach of condylar neck-fractures

Purpose: The intraoral vertico-sagittal ramus osteotomy (J Craniomaxillofac Surg 20:153, 1992) can be used to reduce high condylar process fractures and recontour hyperplastic condyles while simultaneously correcting the malocclusion. This article presents the technique and reports the clinical results.Patients and Methods: A technique for removal and replantation of the condyloid process using the vertico-sagittal ramus osteotomy and rigid fixation was used to treat 23 patients with markedly displaced, high condylar process fractures and condylar hyperplasia associated with malocclusion.Results: The replanted condyles did not show ischemic necrosis or any functional disturbance when followed for more than 3 years. All patients showed nearly normal mouth opening, with slight mandibular deviation, usually in sixth postoperative month.Conclusions: In selected patients, this technique allows intraoral accessibility to the condyle and its repositioning. The method is particularly useful to treat vertical discrepancies associated with the hyperplastic or hypoplastic condyle.

A new osteotomy for the correction of mandibular prognathism: techniques and rationale of the intraoral vertico-sagittal ramus osteotomy

The sagittal split ramus osteotomy (SSRO) and the intraoral vertical ramus osteotomy (IVRO) are long established methods for correcting mandibular prognathism, each having its own advantages. However, both procedures have the same disadvantage: the potential for postoperative condylar displacement. The displacement of the condyle is mainly due to the fact that the osteotomy plane is not parallel to the original sagittal plane in which the mandible is repositioned. The author has developed a new ramus osteotomy since 1985 in which the osteotomy plane is theoretically parallel to the original sagittal plane and thereby attempting to decrease the incidence of condylar displacement. This osteotomy was designed additionally to decrease neurosensory disturbances and has the advantages of both methods, and therefore has been named 'intraoral vertico-sagittal ramus osteotomy (IVSRO)'. Initial experience with the 24 prognathic patients operated on by means of the IVSRO indicated excellent clinical results. It has been noted clinically that the IVSRO is very effective in reducing postoperative iatrogenic TMJ symptoms and in treating preoperative TMJ symptoms. It has the additional effect of reducing neurosensory disturbances. This osteotomy seems to be more applicable in mandibular prognathism with excessive flaring of the ramus, particularly that associated with TMJ dysfunction, because the IVSRO has a 'condylotomy effect' and its splitting plane diverges less from the original sagittal plane than that of the SSRO and the IVRO.