Sagittal Ramus Osteotomy Research Articles

Effect of betamethasone injection into the pterygomandibular space on the neurosensory disturbance after bilateral sagittal split ramus osteotomy: a pilot study

AimThe aim of this study was to evaluate the effect of local betamethasone injection into the pterygomandibular space on postoperative neurosensory deficits.Materials and methodsA prospective controlled clinical study was conducted on 16 patients (6 male, 10 female; mean age, 24.95 ± 9.22 years) who underwent bilateral sagittal ramus osteotomy for mandibular discrepancies. One side of each patient’s mandible was randomly selected as the control side, and the opposite side as the experimental side. On the experimental side, a solution of betamethasone (6 mg/1 ml) was injected into the pterygomandibular space after the completion of wound closure. Neurosensory tests, including light touch, two-point discrimination, direction of movement, thermal sensitivity, and pin-prick discrimination, were performed. The follow-up period ranged between 6 and 12 months, according to the particular sensory test. The Fisher exact test was used to analyse the data.ResultsThe light touch sensation was abnormal in 75% of the control side and 31% of the study side, with the difference being significant (p = 0.03). However, at 6 months, all the study cases regained touch sensation, compared to 69% of the control side. No significant difference in direction movement discrimination was seen; however, at 3 months, the study side showed significantly less direction sensation (19%) compared to the control side (56%) (p = 0.02). There was no significant difference in the two-point discrimination; however, at 3 months, the study side had a significantly less abnormal two-point sensation (13%) than the control side (56%) (p = 0.02). In addition, no significant difference was noted in thermal sensitivity or pin-prick sensation.ConclusionBetamethasone injection into the pterygomandibular space reduces neurosensory disturbances after bilateral sagittal split ramus osteotomies nd leads to faster recovery of sensations.

The Versatility of Extraoral Vertical Ramus Osteotomy for Mandibular Prognathism: A Prospective Study.

Orthognathicsurgery simply means alignment of thejaws.The aim of orthognathic surgery is to normalize the relationship of thejawsbetweenthemselves andtherestof thecraniofacialcomplex. Mandibularprognathism is a common clinical problem all over the world. Currently, sagittal ramus osteotomy is the primary choice for correcting most cases of mandibular retrognathism and prognathism. The surgical option for extreme cases ofmandibular prognathism is extraoral vertical ramus osteotomy (EVRO) or intraoral vertical ramus osteotomy (IVRO) or inverted L osteotomy. The aim of this study was to evaluate the versatility of EVRO for mandibular prognathism. Ten patients with the chief complaint of mandibular prognathism with no history of keloid tendency were included in the study. EVRO was done for all patients. The parameters based on which the outcome of the surgical procedure was assessed weretime taken for the surgical procedure, facial harmony both in frontal and profile views postoperatively, and intraoperativeand postoperative complications, and assessment of the postoperative results was done through orthopantomogram (OPG) and 3D CT scan. Thetime takenfortheentiresurgicalprocedure, startingfrom incisiontoclosure, variedbetween80 and 94 minutes with the average time taken for the surgery being 90 ± 8.80 minutes. It was found that there was a statistically significant difference between preoperative (M = 53.4, SD = 5.854) and postoperative evaluation (M = 47.5, SD = 5.039) of the posterior nasal spine to nasion 1 (PNS-N 1) horizontal plane (HP)(mm) withp < 0.001. Similarly, there was a statistically significant difference between preoperative (M = 81.4, SD = 2.716) and postoperative evaluation (M = 74.4, SD = 3.627) of mandible body length (mm) withp < 0.001. However, no statistically significant difference exists between the preoperative and postoperative evaluation of anterior nasal spine (ANS) to PNS (mm) and ramus height Ar-Go (mm). EVRO is an acceptable surgical procedure owing to the fact that it is relatively simple to carry out, its lack of complications, and its good results.

Correlation between mandibular anatomy and bad split occurrence during bilateral sagittal split osteotomy: a three-dimensional study.

This study aimed to find out the correlation between different anatomical parameters of the mandible and the occurrence of a bad split in patients who had undergone bilateral split sagittal ramus osteotomy (BSSRO). At both the distal roots of the first molar (1) and the retromolar area (2), we measured the distance from the buccal margin of the inferior dental canal (IDC) to the buccal margin of the cortical bone (MCBC), the thickness of both buccal cortical (WBCB) and cancellous bone (WBCA), distance from the superior border of IDC to the alveolar crest (MCAC), buccolingual thickness (BLT), and thickness of cancellous bone (WCA). At the ramus, the distances between the sigmoid notch to the upper part of the lingula (SL) and the inferior border of the mandible (SIBM), the thickness of the ramus at the level of the lingula (BLTR), and the anteroposterior width of the ramus (APWR) were measured. The paired and independent t-tests were used when applicable, and a P-value < 0.05 was considered significant. MCBC1 showed a significant difference between bad and non-bad split sides (P = 0.037). Both WBCA1 and WBCA2 show the same significant difference (P = 0.023, 0.024). Similarly, WCA1 and WCA2 showed a statistical difference between the bad and non-bad split sides (P = 0.027, 0.036). There were no statistically significant differences between the compared sides of WBCB1, WBCB2, MCAC1, MCAC2, SIBM, APWR, SL, and BLTR. Narrow space between IDC and the buccal cortical margin, along with the decrease in the thickness of both buccal cancellous bone and total cancellous bone at the inferior border of the mandible along the course of SSRO, has been implicated in the occurrence of bad split intraoperatively.

Evaluation of bony changes observed in mandibular osteotomy lines and mandibular condyles following bilateral sagittal ramus osteotomy by fractal analysis.

This study aimed to evaluate the surgically impacted trabecular changes in mandibular osteotomy lines and mandibular condyles after bilateral sagittal split ramus osteotomy using the fractal analysis method. The study population consisted of 30 patients (9 male, 21 female) diagnosed with mandibular prognathism and operated with bilateral sagittal split ramus osteotomy under general anesthesia. Fractal analyses observed the alterations on the trabecular structure of osteotomy lines, and mandibular condyles on panoramic radiographs obtained preoperatively, postoperatively, 1st week, 6th month, and 12th month. The box-counting method was used to evaluate the changes in trabecular structure by fractal analysis. P-values of less than 0.05 were considered significant. The fractal dimension values in both osteotomy lines and mandibular condyles were significantly decreased on postoperative 1st week regarding preoperative values. However, fractal dimension values commenced increasing in the following postoperative period. The fractal dimension values of the horizontal and vertical osteotomy lines reached their preoperative values on postoperative 6th and 12th month, respectively. The decreased fractal dimension values observed in the early postoperative period in the right and left condyles reached their preoperative values at the 6th postoperative month. Fractal analyses performed postoperatively can provide information about trabecular changes and bone healing of structures such as osteotomy lines directly affected by bilateral sagittal split ramus osteotomy and indirectly affected mandibular condyles. The results support that fractal analysis can be used together with clinical data in the evaluation of bone healing process.

Influence of the mandibular plane and magnitude of the movement in sagittal split ramus osteotomy: an in vitro study.

The aim of this study was to evaluate fixation resistance in mandibular sagittal split ramus osteotomy in standardized polyurethane hemimandibles with two types of advancement (6 and 12mm), with or without mandibular plane rotation, using a 2.0-mm plate/screw system. Seven groups were evaluated using a vertical compressive load in the first molar region, and the applied force in Newtons was recorded in 1mm, 5mm, and 10mm displacements, as well as the maximum force. There was a statistical intergroup difference and it was observed that increasing the advancement decreased fixation resistance with a single plate, and inserting an additional plate significantly increased osteosynthesis resistance. In the 12mm advancements, clockwise rotation proved to be more resistant when fixed with only one plate. By contrast, counterclockwise rotation was significantly more resistant in stabilizing the mandibular sagittal ramus osteotomy when two plates were used.

Is the Low and Short Medial Horizontal Osteotomy a Predictive Factor for Bad Splits in Sagittal Split Osteotomies?

Statement of the problemThe purpose of this study is to determine whether a low and short medial horizontal osteotomy is a predictive factor for determining bad splits in non-syndromic patients undergoing sagittal split osteotomies for dentofacial disorders. Materials and methodsA retrospective cohort analysis was conducted on subjects who received orthognathic surgery from 2017 to 2019 at Parkland Memorial Hospital. Inclusion criteria were a traditional osteotomy defined by Hunsck and Epker or a low and short osteotomy defined by Posnick.1,2 Exclusion criteria were the diagnosis of a syndromic condition, repeat surgery, or concomitant temporomandibular joint surgery. The predictor variable was the type of osteotomy performed, defined as either a low and short or traditional osteotomy. The primary outcome variable was the occurrence of a bad split. Secondary predictor variables were age and sex, defined as male or female, and faculty side (right side) versus resident side (left side). Descriptive, bivariate, and multiple logistic regression analyses were performed with P < .05 used to determine statistical significance. Results and outcomesFifty-nine patients met the defined inclusion criteria. The average age at the time of surgery was 21 years old. The cohort consisted of 27 males and 32 females. Thirty-six patients were treated with bilateral low and short osteotomies, and 23 patients were treated with bilateral traditional osteotomies. Of the 118 total osteotomies performed, there were a total of 9 bad splits (7.6%). There were 3 right-side bad splits and 6 left-side bad splits. The occurrence of a right-side bad split was 3 for the low and short group and 0 for the traditional group. The occurrence of a left-side bad split was 4 for the low and short group and 2 for the traditional group. There were no significant differences between the type of osteotomy performed and the occurrence of a right-side bad split (P = .1607) or a left-side bad split (P = .7695). There was no significant difference between sex and occurrence of a right-side bad split (P = .6640) or a left-side bad split (P = .2862). There was no significant difference between age and occurrence of a right-side bad split (P = .5233) or a left-side bad split (P = .4492). There was no significant difference between faculty side and resident side with regards to bad splits (P = .4903). Discussion and conclusionThe sagittal split osteotomy (SSO) was first reported by Trauner and Obwegeser in 1955, with the horizontal medial osteotomy further modified by Hunsuck to terminate superior and posterior to lingula.1 Posnick developed an additional modification of the SSO to reduce the frequency of unfavorable splits toward the condyle by modifying the medial horizontal osteotomy to terminate below lingula at the level of the mandibular occlusal plane (low) and anterior to lingula (short).2 The occurrence of bad splits using the traditional osteotomy ranges from 1% to 23%, while the incidence of bad splits reported by Posnick in his retrospective analysis was 0%. The results of the present study suggest a low and short osteotomy is at least as reliable as the traditional osteotomy with regards to intraoperative bad splits. Future prospective studies, including split-mouth study designs by this group, will further elucidate the low and short osteotomy as a reliable alternative to the traditional osteotomy.1.The low medial horizontal osteotomy in patients with atypical ramus morphology undergoing sagittal split osteotomy2.Occurrence of a ‘bad’ split and success of initial mandibular healing: a review of 524 sagittal ramus osteotomies in 262 patients

A novel instrument for the prevention of condylar torque in bilateral sagittal ramus osteotomy when using bicortical screw fixation

When using the bilateral sagittal split osteotomy (BSSO) technique, rigid internal fixation (RIF) remains the standard method to accurately fix the distal and proximal osteotomy fragments. A concern with the use of RIF, especially with bicortical screws, is the increased risk of condylar torque and its functional consequences. This technical note introduces a new method for preventing torque of the mandibular condyles after BSSO, using a sagittal split space maintainer.

Orthognathic Surgery: Past – Present – Future

We owe a great deal of gratitude to pioneer surgeons and orthodontists in the field of orthognathic surgery (OGS).1 Although there have been many giants in both fields, 3 surgeons and 3 orthodontists deserve special mention for their milestone contributions. These surgeons are Hugo Obwegeser, William Bell, and Hans Luhr and the orthodontists are Edward Angle, William Proffit, and Lawrence Andrews. Obwegeser described a safe and practical way to section and reposition the maxilla (i.e., Le Fort I osteotomy), the mandible (i.e., sagittal ramus osteotomies), and the chin (i.e., intraoral oblique osteotomy).

Use of a ‘low and short’ medial cut limits sagittal ramus osteotomy interferences

The traditional ‘high and short’ medial cut of the sagittal ramus osteotomy (Hunsuck modification) is a frequent cause of lingual plate interferences in patients undergoing mandibular yaw or cant corrections. We describe how the modified ‘low and short’ medial cut of the sagittal ramus osteotomy reduces lingual plate interferences with improved passive alignment of the osteotomy segments.

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.

Tongue Numbness and Loss of Taste Following Sagittal Ramus Osteotomy of the Mandible

Lower lip and chin neurosensory disturbance are common following sagittal ramus osteotomy (SRO). Tongue numbness and loss of taste are reported less; however, the subject is studied less or even discussed.

Low-level laser therapy for neurosensory recovery after sagittal ramus osteotomy.

Dento-skeletal deformities are treated combining orthodontic treatment with orthognathic surgery. One of the techniques most used in this type of surgery is the sagittal osteotomy of the mandible. This technique offers many advantages, but within its disadvantages is the inferior alveolar nerve paresthesia. There are various treatments that aim to recovery of the nerve bundle, and one of them is low intensity laser treatment. The aim of this study was to evaluate the effectiveness of low intensity laser therapy in the recovery of neurosensorial tissues after mandibular sagittal osteotomy during orthognathic surgery. Twelve patients submitted to surgery, using mandibular sagittal osteotomy, were treated unilaterally with low intensity infrared (808 nm, GaAIAs active medium) laser, following the inferior alveolar nerve path. The other part of the mandible was treated by placebo. The parameters used were 100 mW of power, irradiancy of 3.6 W/cm2, 2.8J energy per point, an energy density of 100 J/cm2, 28 seconds at each point with a distance of 1.0 cm between points, two sessions per week with a minimum of 10 sessions, starting 48 hours after surgery. Mechanical evaluation was performed in first, fourth, seventh and tenth session. Significant improvement on the treated side was observed. Comparing the behavior among the variables between the treatment (T) group and the control (C) group in the General Recovery was showed a tendency to better results in the T group when compared to the C group, with statistical difference (P≤0.05) after the 10th laser therapy session. The treatment of neurosensorial disorders with infrared low intensity laser could be effective in accelerating recovery, providing greater comfort to the patient, and it presents advantages over other existing methods.

Skeletal changes in patients with mandibular prognathism after mandibular set back and bimaxillary surgery: A comparative cephalometric study

Bacground/Aim. Recently, maxillary and bimaxillary surgery gained the primacy in the surgical correction of class III deformities. The aim of this investigation was to compare the changes in the skeletal relationships in patients with mandibular prognathism after bimaxillary surgery. Methods. The study included 70 subjects divided into three groups. Twenty class III patients of the experimental group 1 underwent bilateral sagittal ramus osteotomy and twenty patients of the experimental group 2 were subjected to bimaxillary surgery. The control group consisted of 30 subjects with skeletal class I and physiological occlusion. Cephalometric research was conducted on 110 lateral cephalometric radiographs made in subjects of the experimental groups 1 and 2 before and after surgery and in subjects of the control group. Using the computer program ?Dr. Ceph?, 30 linear and angular skeletal variables were analyzed on each radiograph. Results. Bimaxillary osteotomies changed most of variables that characterize the mandibular prognathism. The changes in the sagittal plane included the significant increase of sella-nasion to the A point (SNA) angle (by 4? on the average) and the A point to B point (ANB) angle (6?), and significant reduction in angles sellanasion to the B point (SNB) (3?), gonial angle (ArGoMe) (8?), gonial angle inferior (NGoMe) (6.2?), and Bj?rks sum (7?). The vertical relationships were normalized by significant reduction in overall anterior face height N-Me (by 5 mm on the average), the lower anterior face height ANS-Me (4 mm), significant increase in the total posterior face height S-Go (2.5?3 mm), lower posterior face height PNS-Go (4 mm), and significant reduction of the basal and mandibular plane angles. Conclusion. Compared to the isolated mandibular operations, bimaxillary surgery changes more efficiently the sagittal and vertical skeletal relations in patients with class III deformities and harmonizes more successfully the entire skeletal facial profile.

Orthognathic Treatment Using Combination Surgery (Unilateral Sagittal Ramus Osteotomy and Unilateral Intraoral Vertical Ramus Osteotomy) for Skeletal Class III Malocclusion Patient with Facial Asymmetry

This case report describes a successful orthognathic treatment using a combination surgery; unilateral sagittal ramus osteotomy (USSRO) and unilateral intraoral vertical ramus osteotomy (UIVRO). A 23-year-old male patient showing skeletal class III malocclusion with mandibular asymmetry visited our orthodontic department. Characteristics of his facial asymmetry was translation of the mandibular dentition to the left side, without yawing or canting of both jaws. After pre-surgical orthodontic treatment, orthognathic surgery with LeFort I osteotomy in the maxilla and combination surgery in the mandible was performed (USSRO on non-deviation side and UIVRO on deviation side). After 18-month of overall treatment, facial appearance and malocclusion were improved. The combination surgery (USSRO + UIVRO) could be a predictable and better treatment option that overcome the limitations of conventional orthognathic surgery for skeletal class III malocclusion with asymmetry.

How does bone thickness affect the split pattern of sagittal ramus osteotomy?

This study examined the influence of bone thickness on the split pattern of sagittal ramus osteotomy at 62 sites using Dolphin 3D software. Four measurements of thickness were obtained from the preoperative computed tomography scans: measurement A was made 1.5mm above the lingula, using the coronal and sagittal planes; measurement B was made at the same height as measurement A and 1mm from the anterior border of the ramus; measurement C was obtained 5mm distal to the last molar and 5mm below the upper border of the mandible; measurement D was made in the area between the first and second molars, 6mm above the mandibular border. Three-dimensional postoperative images were used to classify the split pattern into types, based on the classification of Plooij et al. The data were analyzed using the Kruskal–Wallis test, followed by Dunn post-hoc test. Thirty-five sagittal splits were type I, one was type II, 19 were type III, and seven were type IV. Type I presented the greatest thickness, whereas type IV presented the lowest. There was a statistically significant difference in thickness only for measurement A, when types I and IV were compared. The results indicate that thinner mandibular rami are more prone to bad splits.

Method of osteotomy fixation and need for removal following bimaxillary orthognathic, osseous genioplasty, and intranasal surgery: a retrospective cohort study

The purpose of this study was to determine the incidence and causes of fixation hardware removal after bimaxillary orthognathic, osseous genioplasty, and intranasal surgery. A retrospective study was performed, involving subjects with a bimaxillary developmental dentofacial deformity (DFD) and symptomatic chronic obstructive nasal breathing. At a minimum, subjects underwent Le Fort I osteotomy, bilateral sagittal ramus osteotomies (SROs), septoplasty, inferior turbinate reduction, and osseous genioplasty. The primary outcome variable studied was fixation hardware removal. Demographic, anatomical, and surgical predictor variables were assessed. Two hundred sixty-two subjects met the inclusion criteria. Their mean age at operation was 25 years (range 13–63 years); 134 were female (51.1%). Simultaneous removal of a third molar was performed in 39.9% of SROs. Three of 262 Le Fort I procedures (1.1%) and two of 524 SROs (0.4%) required hardware removal. There were four cases of ramus wound dehiscence, four of ramus surgical site infection (SSI), one of chin SSI, two of maxillary sinusitis, and one of lingual nerve injury; none of these subjects underwent hardware removal. A limited need for fixation hardware removal after orthognathic procedures was confirmed. There was no statistical correlation between hardware removal and patient sex, age, pattern of DFD, simultaneous removal of a third molar, or occurrence of wound dehiscence, SSI, or lingual nerve injury.

Treatment with Ortognactic Surgery in Patient Class III Skeletal with Lateral Left Mandibular Deviation. Case Report

Class III malocclusion is one of the most complex to treat for healthcare because it presents alterations in skeletal and dental component of patients. Case Report: male patient, 17 years old, had a skeletal Class III malocclusion with mandibular prognathism, facial asymmetry, plus a slightly concave profile, crossbite and posterior left. By orthognathic surgery, using the technique of sagittal ramus osteotomy and segmentation maxillary, Le Fort I, malocclusion, accompanied by the Alexander technique Orthodontics is corrected. Conclusion: the correct application of knowledge in the field of Orthodontics and Maxillofacial Surgery allows patients to become skeletal class II to cephalometric analysis, changes to your profile slightly convex and canine class I is reached on both sides.

Surgical Site Infections Following Bimaxillary Orthognathic, Osseous Genioplasty, and Intranasal Surgery: A Retrospective Cohort Study

Frequency estimates of surgical site infection (SSI) after orthognathic surgery vary considerably. The purpose of this study was to determine the incidence and site of SSIs and associated risk factors after bimaxillary orthognathic, osseous genioplasty, and intranasal surgery. The authors executed a retrospective cohort study of patients with a bimaxillary developmental dentofacial deformity (DFD) and symptomatic chronic obstructive nasal breathing. All patients underwent at a minimum Le Fort I osteotomy, bilateral sagittal ramus osteotomies (SROs), septoplasty, inferior turbinate reduction, and osseous genioplasty. The primary outcome variable studied was the incidence and site of SSI. Predictor variables were type and extent of prophylactic antibiotic used, demographic (age and gender), and anatomic (pattern of DFD, surgical site, and presence of third molar). Two hundred sixty-two patients met the inclusion criteria. Their average age at surgery was 25years (range, 13 to 63yr) and there were 134 female patients (51%). The major presenting patterns of DFD included long face (30%) and maxillary deficiency (25%). Forty percent of patients undergoing an SRO and 47% of those undergoing a Le Fort I osteotomy underwent simultaneous removal of a third molar. Ninety percent of patients received cefazolin or cephalexin antibiotics. Overall, 5 of 1,048 (0.5%) osteotomy sites sustained an infection, including 1 chin and 4 ramus SSIs. There were no delays in bone healing. Fixation hardware removal was not required in any patient who developed an infection. Two of the 25 patients (8%) given clindamycin prophylaxis developed an SSI, whereas 3 of 237 patients (1%) receiving cefazolin did. Three of the 4 patients who developed an SRO SSI underwent simultaneous removal of an erupted or partially erupted mandibular third molar (P < .05). In this study, the incidence of SSI was limited to 1% of patients who were given cefazolin or cephalexin extended for 5days. The removal of an erupted or partially erupted mandibular third molar in conjunction with an SRO was associated with risk of SSI, but the incidence remains low.

Hemimandibular Elongation: Is the Corrected Occlusion Maintained Long-Term? Does the Mandible Continue to Grow?

The purpose of this study was to assess for the maintenance of a corrected occlusion and ongoing mandibular growth in a group of patients younger than 26years with hemimandibular elongation (HME) who underwent bimaxillary orthognathic reconstruction. We conducted a retrospective cohort study of HME patients operated on by a single surgeon at 1 institution between 1999 and 2013. At a minimum, all patients underwent Le Fort I and bilateral sagittal ramus osteotomies. Study exclusions included patients aged 26years or older; those with clefts, craniofacial disorders, or tumors; and those with a history of temporomandibular joint or orthognathic surgery. The study variables included age, gender, side of condylar hyperactivity, premolar extractions, extent of mandibular deformity and malocclusion, planned surgical change, and longitudinal follow-up. The outcome variables studied were the achievement and maintenance of a corrected occlusion and the occurrence of continued mandibular growth after surgery. We compared the occlusion atintervals including the following: before surgery (T1), 5weeks postoperatively (T2), and either 6to24months after surgery (T3) or more than 2years after surgery (T4). Anterior occlusion assessment included evaluation of overjet, overbite, and dental midline position. Posterior occlusion assessment included the Angle classification, first molar vertical position, and first molar transverse position. If the corrected anterior occlusion remained stable and no posterior open bite occurred, then no clinically significant condylar hyperactivity and/or ongoing mandibular growth was judged to have occurred. Seventy-six consecutive patients met the inclusion criteria. Age at operation averaged 18years (range, 14.5 to 25years), and the study included 44 female patients (58%). T3 patients (10 of 76, 13%) had documentation of occlusion at a mean of 19months after surgery. T4 patients (66 of 76, 87%) had documentation of occlusion at a mean of 5years 8months after surgery. Only 1 of the 76 study patients (1%) was judged to have clinically significant ongoing mandibular growth after reconstruction. For all other patients, a corrected anterior occlusion was maintained long-term, and a posterior open bite did not develop in any. In 7 of the 76 patients (9%), there was a recurrent posterior crossbite by 1year after completion of orthodontics but without the need for retreatment. An association was confirmed between mandibular setback and long-term posterior malocclusion even with simultaneous maxillary advancement (P= .05). In HME, a favorable occlusion can be reliably achieved and maintained long-term in most cases using standard bimaxillary orthognathic technique. The need for mandibular setback, even in the presence of simultaneous maxillary advancement, proved to be a factor in the recurrence of long-term posterior malocclusion, although the risk remains low. The results clarify that in patients with HME, by use of the described techniques and timing for surgery, there is no need for an ablative open joint procedure to arrest condylar growth.

Occurrence of a ‘bad’ split and success of initial mandibular healing: a review of 524 sagittal ramus osteotomies in 262 patients

The purpose of this study was to assess the prevalence of a ‘bad’ split after sagittal ramus osteotomies (SRO) and report the results of initial mandibular healing. A retrospective cohort study derived from patients treated by a single surgeon at one institution between 2004 and 2013 was performed. An index group consisting of a series of subjects with a spectrum of bimaxillary dentofacial deformities also involving the chin and symptomatic chronic obstructive nasal breathing was identified. The SRO design, bicortical screw fixation technique, and perioperative management were consistent. Outcome variables included the occurrence of a ‘bad’ split and the success of initial SRO healing. Two hundred sixty-two subjects undergoing 524 SROs met the inclusion criteria. Their average age was 25 years (range 13–63 years) and 134 were female (51%). Simultaneous removal of a third molar was performed during 209 of the SROs (40%). There were no ‘bad’ splits. All subjects achieved successful bone union, the planned occlusion, and return to a chewing diet and physical activities by 5 weeks after surgery. The presence of a third molar removed during SRO was not associated with an increased frequency of a ‘bad’ split or delayed mandibular healing.