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

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J Oral Maxillofac Surg 67:1840-1843, 2009

Analysis of 40 Cases of Intraoral Verticosagittal Ramus Osteotomies to Treat Dentofacial Deformities Sergio Monteiro Lima Júnior, DDS,* Rodrigo Granato, DDS, MS,† Charles Marin, DDS, MS,‡ Maximiana Cristina de Souza Maliska, DDS,§ and José Nazareno Gil, DDS, MS, PhD¶ Purpose: 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. Patients and Methods: The charts of 40 consecutive patients who had undergone IVSRO were analyzed regarding the diagnosis, amount of mandibular movement, and complications. Results: 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. Conclusions: 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. © 2009 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 67:1840-1843, 2009 The intraoral verticosagittal ramus osteotomy (IVSRO) was reported by Choung1 to correct mandibular prognathism. This osteotomy was indicated to treat patients with condylar hyperplasia, high condylar process fractures,2 and dentofacial deformities associated with temporomandibular disorders.3,4 It produces the condylotomy effect, which changes the relationship between the condyle and the articular disc, improving temporomandibular joint symptoms.3,4 Furthermore, this osteotomy produces a larger contact area between the proximal and distal segments compared with the intraoral vertical ramus osteotomy (IVRO), allowing a versatility of movements of the dentate segment, such as mandibular advancement and rotation.3 Additionally, the IVSRO might decrease the risk Received from the Department of Oral and Maxillofacial Surgery, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil. *Oral and Maxillofacial Surgeon. †Oral and Maxillofacial Surgeon. ‡Oral and Maxillofacial Surgeon. §Clinician. ¶Professor and Residence Program Director.

of nerve injury and reduces the costs of the surgery, because no internal rigid fixation is necessary. Because of the advantages of IVSRO, our surgical team has routinely included this osteotomy in the procedures indicated for the treatment of dentofacial deformities. The purpose of the present study was to report the data from 40 patients who had undergone IVSRO, including the amount of movement, complications, and postoperative results.

Patients and Methods The present retrospective study evaluated the characteristics of 80 IVSROs performed during single-jaw or 2-jaw surgery from October 1, 2004 to December Address correspondence and reprint requests to Dr Nazareno Gil: Department of Oral and Maxillofacial Surgery, Federal University of Santa Catarina, Rua Tenente Silveira, 293, sala 1001, ed. Reflex, Centro., Florianópolis, SC, Brazil; e-mail: [email protected] © 2009 American Association of Oral and Maxillofacial Surgeons

0278-2391/09/6709-0009$36.00/0 doi:10.1016/j.joms.2009.04.028

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31, 2007, in the Department of Oral and Maxillofacial Surgery at the University of Santa Catarina, Brazil. The inclusion criteria were complete preoperative and postoperative cephalometric documentation, predictive tracings, mock surgery casts, hospital records showing the planned movement of mandibular surgery, and postoperative follow-up. The diagnosis, amount of mandibular movement, and complications were recorded. The movements were measured using an Erickson Platform. The complications studied were divided into transoperative and postoperative. Transoperative complications included excessive bleeding, defined as bleeding that required stopping the surgical procedure and attention and was treated with at least compression; and a bad split, defined as an incorrect or unpredictable fracture of the osteotomy. Postoperative complications included proximal segment rotation, defined as displacement of the proximal segment of the osteotomy from the glenoid fossa; nonunion of the osteotomy, defined as the formation of fibrosis between bone segments that caused occlusal instability; and nerve dysfunction, defined as decreased sensation of the skin innervated by the inferior alveolar nerve (IAN). This last complication was analyzed subjectively. When mandibular osteotomy was to be performed in a patient, 3 options were given. These options were bilateral sagittal split osteotomy, IVRO, and IVSRO. Each mandibular technique was explained to the patients, who chose their technique. Bilateral sagittal split osteotomy involved the risk of permanent injury to the IAN, but maxillomandibular fixation (MMF) was not necessary. The IVRO has minimal risk of damaging the IAN but a minimum of 15 days of MMF would be necessary. The IVSRO was presented as having the same characteristics of IVRO, but with better bone contact, and therefore, improved healing. Thus, the patients’ choice was usually made on the basis of either having their jaws wired together for some period, with minimal risk of lower lip sensory disturbances, or opening the mouth in the immediate postoperative period, with a greater risk of lower lip sensory disturbances. All operations were performed by the same surgeon, and all patients received preoperative and postoperative orthodontic treatment, seeking a stable postoperative result. Surgery was performed when stable occlusion had been achieved; thus, no postoperative splint was used during the MMF period. The IVSROs were performed according to the description by Fujimura et al.3 After periosteal elevation of the lateral aspect of the mandible through an intraoral approach, a corticotomy line was established from the mid-sigmoid notch to the antegonial notch, followed by decortication of the lateral aspect of the ramus using a cylindrical bur, parallel to the original

sagittal plane and anterior to the corticotomy line, until the bone marrow was exposed. A vertical osteotomy was performed along the original sagittal plane with an osteotome, from the corticotomy line to the medial posterior border of ramus, until a complete split of the mandible was achieved. MMF was applied with wires before suturing and was kept in place for 15 days postoperatively. Rigid fragment fixation was not performed on any patient. After the fifteenth postoperative day, the patients were put in heavy elastics for at least 4 weeks to guide the function of the mandible. After this phase, the patient was kept in light elastics until the osteotomy had stabilized. When the osteotomy was stable, the patients were referred to finish their orthodontic treatment. None of the patients were put in light elastics or underwent physiotherapy in the immediate postoperative period. The proximal segment of the mandible was not fixated in any patient, with either wires or plate and screws.

Results A total of 40 patients, accounting for 80 IVSROs, underwent surgery from October 1, 2004, to December 31, 2007. The mean patient age was 25.4 years. The mean follow-up period was 18 months (range 6 to 24). Of the 40 patients, 15 were male and 25 were female. Mandibular protrusion was the most common deformity treated (25 patients), followed by mandibular protrusion and asymmetry, in both genders. Bimaxillary surgery was performed in 26 patients, and mandibular single-jaw surgery was performed in 4. The diagnosis and postoperative follow-up results of all patients are listed in Table 1. The mean range of movement of the distal segments in the 80 sides is listed in Table 2. The mean amount of mandibular movement in the horizontal direction was 2 mm at the incisor and 3 mm at the right molar for setback. For mandibular advancement, the mean amount of movement was 2 mm at the lower incisor and right molar. The mean movement of the lower incisor in the horizontal plane was 2 mm. For vertical movement, the mean movement of the lower incisor was 3 mm in the counterclockwise rotations and 1 mm in the clockwise rotations. Counterclockwise rotations were associated with greater movement. Although greater movement was done, the mean amount during mandibular advancement and setback was 2 mm. The mean period of MMF with wires was 15 days, followed by therapy with heavy elastics for 4 weeks. Transoperative complications occurred more frequently than postoperative complications. Of the 5 complications, 4 were excessive bleeding and bad splits. Condylar dislocation occurred in 1 patient. The

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Table 3. COMPLICATIONS ASSOCIATED WITH IVSRO

Table 1. PATIENT CHARACTERISTICS

Characteristics

Value

Complication

Patients (n)

Patients (n) Mean age (yr) Maxillomandibular fixation period (d) Mean Range Postoperative mouth opening (mm) Male Mandibular protrusion Mandibular retrusion Mandibular retrusion and asymmetry Mandibular protrusion and asymmetry Mandibular asymmetry Single-jaw/2-jaw surgery Female Mandibular protrusion Mandibular retrusion Mandibular retrusion and asymmetry Mandibular protrusion and asymmetry Mandibular asymmetry Single-jaw/2-jaw surgery

40 (80 sides) 25.4

Hemorrhage Condylar dislocation Nerve dysfunction Bad split

2 (0.8) 1 (0.4) 0 (0.0) 2 (0.8)

15.2 13-25 42.8 11 (22 sides) 0 2 (4 sides) 2 (4 sides) 0 1/14 14 (28 sides) 2 (4 sides) 0 7 (14 sides) 2 (4 sides) 3/22

Monteiro et al. Intraoral Verticosagittal Ramus Osteotomy. J Oral Maxillofac Surg 2009.

complication rate was low, with 80% occurring during surgery (Table 3).

Discussion The IVSRO has 3 advantages: the condylotomy effect, the large contact area between the proximal and distal segments, and the low incidence of complica-

Table 2. DIRECTION AND AMOUNT OF MOVEMENT IN IVSRO

Movement Setback Incisor Right molar Left molar Advancement Incisor Right molar Left molar Rotation Counterclockwise Incisor Right molar Left molar Clockwise Incisor Right molar Left molar

Mean (mm)

Maximum (mm)

2 3 2

6 7 7

2 2 2

5 6 4

3 4 3

9 8 8

1 4 2

1 4 2

Abbreviation: IVSRO, intraoral verticosagittal ramus osteotomy. Monteiro et al. Intraoral Verticosagittal Ramus Osteotomy. J Oral Maxillofac Surg 2009.

Data in parentheses are percentages. Monteiro et al. Intraoral Verticosagittal Ramus Osteotomy. J Oral Maxillofac Surg 2009.

tions, especially injury to the IAN. The indications for IVSRO result from the condylotomy effect associated with the larger contact area between segments, making it possible to treat patients with mandibular deficiency associated with temporomandibular disorders using an osteotomy that does not rigidly fixate the condyle.3 If the contact area is considered, patients who require small-to-moderate mandibular advancement will benefit from this osteotomy, because it does not risk injury to the IAN and allows osseous healing in mandibular advancement. Fujimura et al4 have reported on the usefulness of the IVSRO to treat most types of dentofacial deformities. Hashemi5 reported his experience with the IVSRO, but he rigidly fixed the condyle and missed the condylotomy effect. The MMF period ranged from 15 to 21 days, similar to that in previously published studies.3,4,6 The MMF period was similar to that used for IVRO, but the contact area between the segments of the osteotomy permitted improved osseous healing. After the MMF period with wires, heavy elastics were used to guide the mandible. Fujimura et al4 did not report their period of MMF, but elastics were used for 3 months after releasing the MMF. The use of wire semirigid fixation instead of MMF was not offered to our patients because the condylotomy effect would have been lost. After MMF, the patients used elastics to guide the occlusion and underwent physical therapy to improve their mouth opening and reduce facial swelling. The elastics were used until stable occlusion had been achieved. Fujimura et al4 reported 1 case of a mandible withdrawing from the influence of the suprahyoid muscles when the MMF was released. They prolonged the MMF period for an additional week. These movements were also seen in our patients; however, instead of using 1 more week of MMF, we decided to use elastics to guide the occlusion. A stable occlusion was attained in all patients using this method. In our institution, interocclusal splints are used only in cases in which premature contact cannot be removed before surgery or in cases of segmental maxillary surgery. Fujimura et al4 reported the use of a splint in all their patients. However, because all patients concluded the treatment

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with a balanced occlusion, the use of a splint in the postoperative period might not have influenced the final result. Its use is a question of surgical training. Regarding the mouth opening, the mean value at the third postoperative month was 42.8 mm, a slight decrease compared with the preoperative value, but without trismus at the evaluation. These results are similar to those reported in published studies.3,4 The amount of movement of the mandible was smaller than that reported. In the past decade, mandibular setback surgery has declined in frequency to less than 10% of Class III patients. In contrast, bimaxillary surgery has been used in about 40% of Class III patients.7 Therefore, a tendency to share the amount of movement between the jaws has been observed. Maxillary Le Fort I osteotomy was much more frequently associated with verticosagittal osteotomy (Table 1). Although large movements are not indicated for IVSRO, the contact area between the proximal and distal segments allows the dentate mandibular segment to move in any direction.3 Fujimura et al3 reported an overall complication rate of 14% (6 of 42 sides). Their experience was similar to the experience in our center (Table 3). They reported complications of 2 hemorrhages from the maxillary artery, 1 bad split, 1 joint dislocation, and 2 transitory neurosensory alterations. The 2 cases of hemorrhage in our series occurred during the midsigmoid osteotomy. The bleeding occurred because the maxillary artery approaches very close to the medial aspect of the sigmoid notch.8 Although the surgical procedure was stopped, compression was sufficient to treat this complication. A condylar dislocation was discovered in the first postoperative week, and a bad split occurred at the proximal segment, near the angle of the mandible. Recently, Hashemi5

reported an overall complication rate of 11%, with injury to the IAN in 3.8%. The complications were similar to those reported in the present study, including a bad split and bleeding. However, our patients did not experience injury to the IAN. These data suggest a low morbidity associated with the IVSRO. The IVSRO is a versatile and efficient osteotomy with a low rate of complications. This osteotomy should be included in the list of possible procedures used to treat dentofacial deformities, including mildto-moderate mandible advancement and setback.

References 1. Choung PH: A new osteotomy for the correction of mandibular prognathism: Techniques and rationale of the intraoral verticosagittal ramus osteotomy. J Craniomaxillofac Surg 20:153, 1992 2. Choung PH, Nam IW: An intraoral approach to treatment of condylar hyperplasia or high condylar process fractures using the intraoral vertico-sagittal ramus osteotomy. J Oral Maxillofac Surg 56:563, 1998 3. Fujimura K, Segami N, Sato J, et al: Advantages of intraoral verticosagittal ramus osteotomy in skeletofacial deformity patients with temporomandibular joint disorders. J Oral Maxillofac Surg 62:1246, 2004 4. Fujimura K, Segami N, Sato J, et al: Comparison of the clinical outcomes of patients having sounds in the temporomandibular joint with skeletal mandibular deformities treated by verticosagittal ramus osteotomy or vertical ramus osteotomy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 99:24, 2005 5. Hashemi HM: Evaluation of intraoral verticosagittal ramus osteotomy for correction of mandibular prognathism: A 10-year study. J Oral Maxillofac Surg 66:509, 2008 6. Choi YS, Yun KI, Kim SG: Long-term results of different condylotomy designs for the management of temporomandibular joint disorders. Oral Med Oral Pathol Oral Radiol J Endod 93:132, 2002 7. Busby BR, Bailey LJ, Proffit WR, et al: Long-term stability of surgical class III treatment: A study of 5-year postsurgical results. Int J Adult Orthodon Orthognath Surg 17:159, 2002 8. Fujimura K, Segami N, Kobayashi S: Anatomical study of the complications of intraoral verticosagittal ramus osteotomy. J Oral Maxillofac Surg 64:384, 2006

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