Assessment of lateral pterygoid muscle and temporomandibular joint disc after Le Fort I osteotomy with and without intentional pterygoid plate fracture and sagittal split ramus osteotomy in class II and class III patients

The aim of the study was to examine lateral pterygoid muscle (LPM) and temporomandibular joint (TMJ) disc before and after Le Fort I osteotomy with and without intentional pterygoid plate fracture and sagittal split ramus osteotomy (SSRO) in class II and class III patients.Le Fort I osteotomy and SSRO were performed in class II and class III patients. LPM measurements using oblique sagittal computed tomography (CT) images and TMJ disc position using magnetic resonance imaging (MRI) were examined. Statistical comparisons were performed for the LPM and TMJ between class II and class III patients and between those with and without intentional pterygoid plate fracture in Le Fort I osteotomy.The subjects comprised 60 female patients (120 sides), with 30 diagnosed as class II and 30 as class III. Preoperatively, the width of the condylar attachment, width at eminence, length of the LPM, angle of the LPM, and square of the LPM were significantly smaller in the class II group than in the class III group (p < 0.05). After 1 year, the width of the condylar attachment, width at eminence, and angle of the LPM remained significantly smaller in the class II group than in the class III group (p < 0.0001). TMJ disc position was significantly related to the width of the condylar attachment of the LPM, both pre- and postoperatively (p < 0.0001). However, postoperative disc position did not change in all patients. Next, the class II patients (60 sides) were divided into two groups who underwent Le Fort I osteotomy with or without intentional pterygoid plate fracture. Changes in all measurements of the LPM showed no significant differences between these two groups.Our study suggested that TMJ disc position classification could be associated with the width of condylar attachment of the LPM before and after surgery, while the surgical procedure, including Le Fort I osteotomy with intentional pterygoid plate fracture, might not affect postoperative LMP or disc position in class II patients.     

Postoperative computed tomography study of pterygomaxillary separation during the Le Fort I osteotomy

Computed tomography (CT) was used postoperatively to assess the pterygomaxillary region in 12 orthognathic surgery patients who had had a Le Fort I osteotomy. Although pterygomaxillary separation was successful in all cases, in only 41.6% of the sides did fractures of the plate not occur. The incidence of low pterygoid plate fracture was 37.5% and that of high pterygoid plate fracture was 25%; 4.2% of sides showed a maxillary tuberosity fracture. Multiple fractures were observed in 8.3% of separated plates. Of 17 pterygoid plates judged clinically to be intact, only 10 were intact as assessed by CT. The significance of these findings and application of CT to evaluation of modifications to the Le Fort I osteotomy is discussed.     

Assessment of bone healing and hypoesthesia in the upper lip after Le Fort I osteotomy with self-setting α-tricalcium phosphate and absorbable plates

PurposeThe purpose of this study was to evaluate hypoesthesia of the upper lip and bone formation using self-setting α-tricalcium phosphate (Biopex^®) between the segments following Le Fort I osteotomy with bent absorbable plate fixation.Subjects and methodsThe subjects were 47 patients (94 sides) who underwent Le Fort I osteotomy with and without mandibular osteotomy. They were divided into a Biopex^® group (48 sides) and a control group (46 sides). The Biopex^® was inserted into the anterior part of the gap between the segments in the Biopex^® group. Trigeminal nerve hypoesthesia at the region of the upper lip was assessed bilaterally by the trigeminal somatosensory-evoked potential (TSEP) method. The area of the Biopex^® at the anterior part in the maxilla was assessed immediately after surgery and 1 year postoperatively by computed tomography (CT).ResultsThe mean measurable period and standard deviation were 13.2 ± 18.5 weeks in the control group, 14.5 ± 17.9 weeks in the Biopex^® group, and there was no significant difference in TSEP. The area of the Biopex^® after 1 year was significantly smaller than that immediately after surgery (right side: P = 0.0024, left side: P = 0.0001) and bone defects between the segments could not be found in the Biopex^® group. In the control group, although the areas of bone defect after 1 year were significantly smaller than that immediately after surgery on the right side (P = 0.0133) and left side (P = 0.0469) in the frontal view, complete healing of the bone defects could be seen in 12 of 46 sides after 1 year.ConclusionThis study suggested that inserting Biopex^® in the gap between the maxillary segments was useful for new bone formation and it did not prevent the recovery of upper lip hypoesthesia after Le Fort I osteotomy with absorbable plate fixation.     

Role of Le Fort type I osteotomy approach in juvenile nasopharyngeal angiofibroma

Le Fort type I osteotomy is a fracture that extends from the pyriform aperture to each of the pterygoid plates, resulting in the detachment of the upper jaw from the cranial base. A retrospective study was conducted on 12 patients with juvenile nasopharyngeal angiofibroma (JNA) who underwent the Le Fort type I approach. Preoperatively, all cases were investigated with computed tomographic scans with contrast and angiography with embolisation. This paper highlights the surgical technique, results and treatment morbidity. The average age of the patients was 21 years, average duration of surgery was 3.2h and average blood loss was 550 ml. All cases had significant symptomatic improvement postoperatively. At 1 year follow up, the authors encountered dental malocclusion in one case and no recurrence of JNA. The Le Fort I osteotomy approach is an excellent approach for the excision of JNA because it allows good surgical exposure, better haemostasis, is cosmetically more acceptable and has a very low morbidity.     

Le Fort I osteotomy using an ultrasonic bone curette to fracture the pterygoid plates

PURPOSE: The purpose of this study was to evaluate the advantageous use of an ultrasonic bone curette and to assess the mobilization of the pterygoid process after a Le Fort I osteotomy. MATERIAL AND METHODS: 14 Japanese adults (ranging in age from 17 to 30 years, mean 22.4) with jaw deformities diagnosed as mandibular prognathism or bimaxillary asymmetry underwent Le Fort I osteotomy with bilateral sagittal split ramus osteotomy or intraoral vertical ramus osteotomy. During the Le Fort I osteotomy, the Sonopet UST-2000 ultrasonic bone curette was used to fracture the pterygoid process slightly above the level of the maxillary osteotomy without damaging the descending palatine artery or other blood vessels and nerves. After surgery, the pterygoid process osteotomy and its mobility were evaluated from three-dimensional computed tomographic images. RESULTS: In all cases, the mobility of the pterygoid process could be achieved by using the device safely with minimal bleeding and no notable complications. The maxillary segment could be fixed in an ideal position and in all 14 cases, an ideal profile was achieved. CONCLUSION: Ultrasonic bone curette offers a safe procedure for performing pterygoid process fractures without damaging the surrounding tissue such as the descending palatine artery.     

Le Fort I osteotomy with sparing fracture of lateral pterygoid plate

This study aimed to clarify the relation between the anatomical variations of the pterygomaxillary region and fracture of the pterygoid plate during Le Fort I osteotomy. We present a secure method to separate maxillary tuberosities from pterygoid plates without injuring the pterygoid plates. Thirty specimens of hemisection of Korean skulls were used for the study. The maxilla was sectioned transversely on the floor of the pyriform aperture and posteriorly to the lateral pterygoid plate with a mechanical saw. The section was 5 to 6 mm above the tooth roots. The pterygomaxillary junction was separated with a curved osteotome in two steps: initially with light tapping of the shallow groove 2 to 3 mm anterior to the pterygomaxillary fissure at a half right angle and then changing the course of forceful tapping to more than 60 degrees. The maxillary tuberosity separated from the medial and lateral pterygoid plates during the procedure was grouped into the "disjunction group" (24 of 30, 80%) and the pterygoid plates fractured were grouped into the "fracture group" (6 of 30, 20%). The thickness of the pterygomaxillary region (T) was significantly greater in the disjunction group than in the fracture group (P = 0.034). The concavity of the pterygomaxillary fissure (C) was significantly deeper in the disjunction group than in the fracture group (P = 0.020). There was no significant difference of width of the pterygomaxillary fissure between the disjunction group and the fracture group (P = 0.169). The thin pterygomaxillary region and less concave pterygomaxillary fissure on the preoperative computed tomography scan draw precautionary attention to vulnerable pterygoid plates fractured in the procedure of Le Fort I osteotomy.     

Cranial nerve injury after Le Fort I osteotomy

A Le Fort I osteotomy is widely used to correct dentofacial deformity because it is a safe and reliable surgical method. Although rare, various complications have been reported in relation to pterygomaxillary separation. Cranial nerve damage is one of the serious complications that can occur after Le Fort I osteotomy. In this report, a 19-year-old man with unilateral cleft lip and palate underwent surgery to correct maxillary hypoplasia, asymmetry and mandibular prognathism. After the Le Fort I maxillary osteotomy, the patient showed multiple cranial nerve damage; an impairment of outward movement of the eye (abducens nerve), decreased vision (optic nerve), and paraesthesia of the frontal and upper cheek area (ophthalmic and maxillary nerve). The damage to the cranial nerve was related to an unexpected sphenoid bone fracture and subsequent trauma in the cavernous sinus during the pterygomaxillary osteotomy.     

Pattern of pterygomaxillary disarticulation associated with Le Fort I maxillary osteotomy

Pterygomaxillary disarticulation (PMD) contributes to surgical complications of Le Fort 1 osteotomy and is associated with undesirable fractures of the pterygoid plates. The aim of this paper was to investigate the patterns of PMD in Le Fort I osteotomies using Rowe's disimpaction forceps, and to evaluate correlations with age and anatomical measurements. Cone-beam computed tomography (CBCT) scans of 70 consecutive orthognathic patients were retrospectively evaluated to study four patterns of PMD: Type 1 - PMD at, or anterior to, the pterygomaxillary junction (PMJ); Type 2 - PMD posterior to the PMJ; Type 3 - PMJ separation with comminuted fracture of the pterygoid plates; Type 4 - disarticulation of the maxilla involving the pterygoid plates above the level of the osteotomy line. The preoperative anteroposterior and mediolateral thicknesses of the PMJ and the length of the medial and lateral pterygoid plates were assessed. Satisfactory PMD was achieved in all cases and no severe complications were reported, including vascular, dental, mucosal, or neural damage. The most common PMD was Type 1 (54.3%), followed by Type 2 (40%). Comminuted fracture of the pterygoid plates was limited to 5.7% of cases, and no Type 4 was detected. A weak correlation was detected between PMJ thickness and PMD pattern (p = 0.04). No statistically significant correlation was detected between patients’ age and type of PMD. PMD of Le Fort I maxillary osteotomy using a Smith spreader and Rowe's disimpaction forceps proved safe, with minimal damage to the pterygoid plates.     

Pterygoid plate fractures caused by the Le Fort I osteotomy

Le Fort I osteotomies have been carried out on eight cadavers to determine whether pterygomaxillary dysjunction with a curved chisel causes fractures of the pterygoid plates. Fractures occurred on 12 of the 16 sides, were either at the level of the osteotomy cut or near to the base of the skull, and were sometimes multiple. There was no apparent correlation between the presence, type or extent of pterygoid plate fracture and whether or not that side of the osteotomy was completed first.     

Altering the angulation of a curved osteotome--does it have effects on the type of pterygomaxillary disjunction in Le Fort I osteotomy? An experimental study.

A standard Le Fort I osteotomy was performed on 12 cadavers to determine whether the incidence of pterygoid plate fractures could be reduced by increasing the angle of the curved osteotome relative to the sagittal plane. In the group where an osteotome with the usual angulation was employed, fractures occurred on 9 of 12 sides. In the increased angulation group, 5 of 12 pterygoid plates were fractured. All fractures were restricted to the level of the horizontal osteotomy cut. It is concluded that increased angulation of a curved osteotome can decrease the incidence of fractures of the pterygoid plates. This procedure, however, is not recommended because it can cause fracture of the palatine bone or displacement of the fractured pterygoid plate fragment posteriorly.     

Upper lip length after V-Y versus continuous closure for Le Fort I level maxillary osteotomy

PURPOSE: The purpose of this report is to document changes in lip length and thickness after Le Fort I maxillary osteotomy by using continuous versus V-Y closure.Materials and Methods: This is a retrospective analysis of 18 patients who underwent Le Fort I maxillary osteotomy. Ten patients had a single midline V-Y closure and 8 patients had simple continuous closure. Lateral cephalometric analysis was performed, and preoperative and 12-month postoperative changes in lip dimensions were calculated. Lip length and thickness were analyzed at 5 points: A-point (A), subnasale (Sn), cervical margin of incisor (C), stomion superius (Ss) and labrale superius (Ls). The lengths from A to Sn, C to Ls, and Sn to Ss were calculated. RESULTS: After 12 months, there was no significant difference in lip length (P =.39) or thickness of the upper lip in its upper (P =.75) or lower (P =.19) parts, between the 2 groups. CONCLUSION: Lip length and width show no significant differences before surgery versus after surgery with either closure technique after Le Fort I osteotomy.     

Le Fort I截骨术治疗上颌骨折咬合错乱

目的根据正颌外科技术要点,应用模型外科、Le Fort I型截骨术及钛板坚固内固定治疗上颌骨折移位咬合错乱.方法笔者经治的颌面部骨折患者8例,取模型按模型外科设计骨切开线,制作咬合板并行单颌牙弓夹板预备.采用Le Fort I型截骨恢复咬合关系后行坚固内固定.结果所有病例均为一期愈合,7例术后咬合关系恢复良好,2例术后开口度明显改善,其余病例开口度恢复正常.颜面外形恢复良好.结论按模型外科设计,行Le Fort I型截骨术是矫治上颌骨折咬合紊乱较为理想的方法,咬合板有利于(牙合)关系的恢复和稳定.     

Maxillary stability following Le Fort I osteotomy in combination with sagittal split ramus osteotomy and intraoral vertical ramus osteotomy: a comparative study between titanium miniplate and poly-L-lactic acid plate.

PURPOSE: The purpose of this study was to compare changes in maxillary stability after Le Fort I osteotomy with titanium miniplate and poly-L-lactic acid (PLLA) plate (Fixsorb-MX; Takiron Co, Osaka, Japan). PATIENTS AND METHODS: The subjects were composed of 47 Japanese patients with diagnosed jaw deformity: 24 underwent Le Fort I osteotomy and sagittal split ramus osteotomy (SSRO); and 23 underwent Le Fort I osteotomy intraoral vertical ramus osteotomy without internal fixation. Each group was divided into titanium plate and PLLA plate groups. Time course changes between plate groups were compared using lateral and posteroanterior cephalography. RESULTS: Significant differences were identified between titanium plate and PLLA plate groups in A point after Le Fort I osteotomy and SSRO (P < .05). Significant differences existed between titanium plate and PLLA plate groups in vertical component of posterior nasal spine after Le Fort I osteotomy in both combinations with SSRO and intraoral vertical ramus osteotomy (P < .05). However, no significant differences were identified in measurements on posteroanterior cephalography. CONCLUSION: These results suggest a slight tendency for vertical impaction after Le Fort I osteotomy both in combination with SSRO and intraoral vertical ramus osteotomy with PLLA plates, although differences in time course changes were not clinically apparent, and normal occlusion was established in all patients.     

Comparison of maxillary setback by maxillary tuberosity removal or intentional pterygoid plate fracture in Le Fort I osteotomy: a long-term evaluation

The purpose of the study was to investigate the clinical application and long-term stability of maxillary setback in Le Fort I osteotomy using maxillary tuberosity removal or intentional pterygoid plate fracture (IPPF). Eighty adult class II patients who underwent Le Fort I osteotomy with bilateral sagittal split ramus osteotomy by the same surgeon between January 2013 and January 2019 were included in this retrospective study. Traditional maxillary tuberosity removal was performed in 40 patients (group I), and the other 40 patients (group II) underwent IPPF to set back the maxilla according to surgeon preference. An obvious change in profile was observed for all of the patients, with no significant relapse at 1 year postoperative. The operation time and intraoperative blood loss were significantly higher in group I than in group II (P =  0.037 and P =  0.021, respectively). In group II, the most superior point of the fracture line was at a mean distance of 12.25 ± 2.04 mm above the most inferior point of the pterygoid plate. More bone fragments were noted when the fracture level was low than when it was high. In conclusion, both maxillary tuberosity removal and IPPF resulted in sufficient and stable maxillary setback, with IPPF showing less blood loss and a shorter operative time.     

Strain distribution during separation of the pterygomaxillary suture by osteotomes. Comparison between Obwegeser's osteotome and swan's neck osteotome

In the Le Fort I type osteotomy, separation of the pterygomaxillary suture is a dangerous manoeuvre which must be carried out during the surgical procedure. To determine the osteotome best suited for safe separation of the pterygomaxillary suture, we measured the strain distribution over the surrounding bone structures during the osteotomy, employing two types of osteotomes. In both the Obwegeser osteotome group and swan's neck osteotome group, a large strain was measured at the medial pterygoid plate on the side of osteotome application. The intensity of the strain at the medial pterygoid plate was higher in the Obwegeser osteotome group than in the swan's neck group. With the Obwegeser osteotome which is routinely and commonly used in orthognathic surgery, safe separation of the suture cannot be accomplished unless the blade is correctly applied to the suture and superoposterior compression of the pterygoid process is avoided.     

Transient abducens nerve palsy following a Le Fort I maxillary osteotomy: report of a case

A case of transient abducens nerve palsy following Le Fort I maxillary osteotomy is reported. The results of the CT scan strongly suggest the cause was a fracture of the body of the sphenoid bone but the cause of the fracture is unclear. The palsy occurred on the first postoperative day and recovery took approximately 5 months. The most likely explanation for the complication is a transmittal of force from the osteotome used to fracture through the pterygoid plates extending superiorly through the medial surface of the cavernous sinus. This case clearly demonstrates the importance of care in positioning of the pterygomaxillary osteotome.     

Comparing the effects of V-Y advancement versus simple closure on upper lip aesthetics after Le Fort I advancement.

PURPOSE: The aim of this study was to compare upper lip movement and its dimensional changes after maxillary advancement via Le Fort I osteotomy, using V-Y advancement versus simple continuous closure. The study investigates dimensional changes in the superior and inferior portions of the upper lip, as well as changes in lip length, resulting from the procedure. PATIENTS AND METHODS: The study group consisted of 35 patients who had undergone 1-piece Le Fort I osteotomy for maxillary advancement of 3 to 6 mm with less than 3 mm of vertical changes. Fixation was performed by rigid monocortical plating. Closure of soft tissue was achieved using V-Y advancement in 17 patients and simple continuous suturing in 18 patients. Lateral cephalometric radiographs were taken and measured preoperatively and then 6 months after surgery. RESULTS: The magnitude of upper lip movement was 88.89% of the maxillary advancement in the simple continuous suturing group and 90.77% in the V-Y advancement group. The superior portion of the upper lip thickened by 2.08 mm and 2.35 mm in the 2 groups, respectively. The inferior portion of the upper lip thickened by -1.94 mm and -1.14 mm, respectively. The upper lip shortened by 0.79 mm in the simple continuous suturing group and lengthened by 1.10 mm in the V-Y advancement group. CONCLUSIONS: Upper lip movement and dimensional changes differ when simple continuous suturing and V-Y advancement closure are used.     

Frequency of Le Fort I osteotomy after repaired cleft lip and palate or cleft palate.

OBJECTIVE: Diminished maxillary growth is a consequence of labiopalatal repair, and many patients with cleft lip and palate require Le Fort I advancement. The goal of this study was to determine the frequency of maxillary hypoplasia as measured by need for Le Fort I. SUBJECTS: Retrospective cohort study of males born before 1987 and females before 1989. Records of 173 patients with cleft lip and palate and 34 with cleft palate were reviewed. METHODS: Documented age, gender, cleft type, and need for Le Fort I. Pearson chi-square and Fischer's exact analyses were performed to evaluate the frequency of Le Fort I. RESULTS: Of 217 patients with cleft lip and palate or cleft palate, 40 were syndromic; of the remaining 177 patients, 69 had cleft lip, 78 had cleft lip and palate, and 30 had cleft palate. Thirty-seven of 177 patients (20.9%) required Le Fort I, subcategorized by cleft type: 0/69 for cleft lip, 37/78 for cleft lip and palate, and 0/35 for cleft palate (p<.0001). Of the 37/78 (47.4%) cleft lip and palate patients, the frequency of Le Fort I correlated with severity: 5/22 unilateral incomplete cleft lip and palate; 16/33 unilateral complete cleft lip and palate; 1/2 bilateral incomplete cleft lip and palate; 2/4 bilateral asymmetric complete/incomplete cleft lip and palate; 13/17 bilateral complete cleft lip and palate (p<.05). CONCLUSION: Overall frequency of Le Fort I was 20.9% in patients with cleft lip and palate and cleft palate. Of those with cleft lip and palate, 47.7% required maxillary advancement, but none with isolated cleft lip or cleft palate required correction. Frequency of Le Fort I osteotomy correlated with the spectrum of severity of labiopalatal clefting.     

Orbitofrontal monobloc advancement for Crouzon syndrome

IntroductionUsually, patients suffering from Crouzon syndrome have synostosis of coronal sutures, exophthalmia, hypertelorism, and hypoplasia of the middle third of face. Sometimes maxillary retrusion is absent, so these patients have class I or II relationship. In these cases, frontofacial monobloc advancement, which is the gold standard, increases the maxillo-mandibular dysmorphia. Therefore we propose orbitofrontal monobloc advancement minus dental arch, without splits of the pterygoid plates.Case reportA 12-year-old girl with Crouzon syndrome had intracranial hypertension, exophthalmia, a middle third retrusion and a class II occlusion. We achieved orbitofrontal monobloc advancement which is frontofacial monobloc advancement minus maxillary dental arch. Four distractors KLS Martin were used. After 20 days of distraction, the final advancement was 10.2 mm for cranial distractors and 10.5 mm at fronto-zygomatic. Distractors were removed after 8 months.DiscussionWe offer patients suffering from Crouzon syndrome with class I or II relationship a change from the classic frontofacial monobloc advancement leaving the maxillary dental arch in place, thus avoiding the worsening of the maxillo-mandibular dysmorphia related to surgery. The idea of associating Le Fort I osteotomy with a frontofacial monobloc advancement or Le Fort III osteotomy has already been described, mainly by Tessier and Obwegeser, however they probably achieved a complete Le Fort I osteotomy while we don't split the pterygoid plates.The patient's morphology and his surgical history determine the choice between Le Fort III and monobloc advancement. Dental occlusion needs to be taken into account for surgical indication.     

Soft tissue profile changes after Le Fort I osteotomy in UCLP patients.

The changes in soft tissue profile after Le Fort I osteotomy were evaluated cephalometrically in 38 consecutive UCLP patients (25 males, 13 females) operated on between 1987 and 1995. Mean age at operation was 23.5 years. The one-piece Le Fort I osteotomy was fixed with titanium plates and the osteotomy site was bone grafted. Neither intermaxillary fixation nor occlusal splints were used postoperatively. Soft tissue changes were analyzed both horizontally and vertically by cephalograms taken shortly before surgery, 6 months and 1 year postoperatively. The mean maxillary skeletal advancement (point A) during surgery was 3.8 mm and mean vertical lengthening 4.4 mm. One year postoperatively the horizontal change in the upper lip profile (point a) was 80% of the skeletal change. Vertically, the soft tissue change in the upper lip was smaller 40%, but increased significantly (to 58%) if V-Y plasty was used. The V-Y plasty also increased the anteroposterior thickness of the upper lip. No significant soft tissue changes were observed between 6 months and 1 year postoperatively.