Amount Of Maxillary Advancement Research Articles

Speech following Le Fort I Maxillary Advancement in Cleft Maxillary hypoplasia - an objective and subjective outcome analysis.

To objectively evaluate the effect of maxillary advancement on speech and VPI using video-fluoroscopy (VFS), direct nasoendoscopy, and speech evaluation and subjectively assess patients and their peer's perception regarding their speech outcome. 27 cleft patients who underwent Lefort 1 maxillary advancement were divided into 2 groups- Group A with 4-7mm of advancement and Group B with 8-13mm advancement. VFS in lateral view, nasoendoscopy, and speech recordings were performed pre and 6 months postoperatively. VFS assessed the relative position of velum in relation to the pharyngeal wall, speech was evaluated for changes in nasal emission, resonance, and articulation along with nasal endoscopy to assess the overall function of the velopharyngeal valve. Subjective speech evaluation was done with a Patient-Reported Outcome Measure [PROM] questionnaire. As per VFS, for every 1mm maxillary advancement, the velopharyngeal gap at rest increased by 1.75mm in group A and 1.58mm in group B. The compensatory changes in group B were more pronounced. Post-operative VFS showed velar closure remained the same as preoperative closure in 86.7%, and worsened in 13.3% in group A whereas it remained unchanged in 66.7%, improved in 25%, and worsened in 8.3% in group B. In nasoendoscopy, the closure pattern showed no change in 86.6%, improved in 6.7%, and deteriorated in 8.3% in group A while there was no change in 83.4%, improved in 8.3%, and deteriorated in 8.3% in group B. Dental and labiodental articulation statistically improved [p < 0.05] after surgery. PROM reported 85.7% of patients with improved speech, 82.1% improved sound quality along with 89.3% improvement in articulation. The primary cause for functional impairment and poor aesthetics in cleft deformity is the maxillary hypoplasia and therefore, should be the focus during correction. The pre-operative VP status or the amount of maxillary advancement could not predict the postoperative VP status. Maxillary advancement over 10mm did not seem to significantly affect the final VP status. Articulation improves due to increased tongue space and favorable dental segment positioning. Mild to moderate immediate post op changes in nasality improves or even reverts to their preoperative status in the majority of the cases in about six months.

Subregional pharyngeal changes after orthognathic surgery in skeletal Class III patients analyzed by convolutional neural networks-based segmentation

ObjectivesTo evaluate the accuracy of fully automatic segmentation of pharyngeal volume of interests (VOIs) before and after orthognathic surgery in skeletal Class III patients using a convolutional neural network (CNN) model and to investigate the clinical applicability of artificial intelligence for quantitative evaluation of treatment changes in pharyngeal VOIs. Methods310 cone-beam computed tomography (CBCT) images were divided into a training set (n = 150), validation set (n = 40), and test set (n = 120). The test datasets comprised matched pairs of pre- and post-treatment images of 60 skeletal Class III patients (mean age 23.1 ± 5.0 years; ANB<-2⁰) who underwent bimaxillary orthognathic surgery with orthodontic treatment. A 3D U-Net CNNs model was applied for fully automatic segmentation and measurement of subregional pharyngeal volumes of pre-treatment (T0) and post-treatment (T1) scans. The model's accuracy was compared to semi-automatic segmentation outcomes by humans using the dice similarity coefficient (DSC) and volume similarity (VS). The correlation between surgical skeletal changes and model accuracy was obtained. ResultsThe proposed model achieved high performance of subregional pharyngeal segmentation on both T0 and T1 images, representing a significant T1–T0 difference of DSC only in the nasopharynx. Region-specific differences amongst pharyngeal VOIs, which were observed at T0, disappeared on the T1 images. The decreased DSC of nasopharyngeal segmentation after treatment was weakly correlated with the amount of maxillary advancement. There was no correlation between the mandibular setback amount and model accuracy. ConclusionsThe proposed model offers fast and accurate subregional pharyngeal segmentation on both pre-treatment and post-treatment CBCT images in skeletal Class III patients. Clinical significanceWe elucidated the clinical applicability of the CNNs model to quantitatively evaluate subregional pharyngeal changes after surgical-orthodontic treatment, which offers a basis for developing a fully integrated multiclass CNNs model to predict pharyngeal responses after dentoskeletal treatments.

Skeletal Stability of Two-Jaw Surgery Without Bone Grafting in Patients With Cleft Lip and Palate.

The purpose of this study was to evaluate the postoperative skeletal stability of orthognathic surgery performed without a bone graft in cleft lip and palate patients. Nineteen cleft lip and palate patients that underwent orthognathic surgery from July 2008 to August 2019 at the Department of Oral and Maxillofacial Surgery of Pusan National University Dental Hospital were selected. None of these patients underwent bone grafting during orthognathic surgery. Lateral cephalograms were taken 1 month before surgery (T0), immediately after surgery (T1), and 6 months after surgery (T2). Lateral cephalograms were analyzed using the V-Ceph program. The analysis was performed using SPSS for Windows version 26.0. The analysis was conducted by repeated-measures analysis of variance. A total of 19 patients were included in this retrospective study (9 males/10 females of overall mean age 22 ± 4.89 years). Mean maxillary depth values at the 3-time points were 85.37° ± 2.62° (T0), 90.13° ± 2.77° (T1), and 89.29° ± 2.91° (T2). Mean McNamara-N Perpend values were -5.52 ± 3.19 mm (T0), 0.09 ± 3.10 mm (T1), and -0.83 ± 3.14 mm (T2). Mean sella nasion point A (SNA) values were 75.42° ± 2.98° (T0), 79.19° ± 2.94° (T1), and 78.45° ± 2.84° (T2). Mean relapse rates were maxillary depth 20.15%, McNamara-N Perpend 17.95%, and SNA 18.74%. Mean horizontal advancement was 5.61 ± 2.32 mm based on McNamara vertical to A point, mean horizontal relapse was -0.92 ± 0.56 mm, and the mean horizontal relapse rate was 17.95%. Favorable skeletal stability can be obtained without bone graft when the amount of maxillary advancement is less than 6 mm in cleft patients.

Le Fort I Osteotomy in Cleft Patients: Maxillary Advancement and Articulation.

Maxillary advancement may affect speech in cleft patients. To examine whether the amount of maxillary advancement and preoperativecephalometric skeletal and dentoalveolar relationships are associated with articulation errors of the Finnish alveolar consonants /s/, /l/, and /r/ in cleft patients. Fifty-seven nonsyndromic cleft patients who underwent Le Fort I or bimaxillary osteotomies were evaluated retrospectively. Pre- and post-operative lateral cephalometric radiographs and standardized speech video recordings were analyzed. The Aspin-Welch unequal variance t test, Student t test sign test, intraclass correlation and Kappa statistics were used in the statistical analyses. The mean advancement of the maxilla (point A) was 4.65 mm horizontally (range -2.80 to 11.30) and -3.82 mm vertically (range -14.20 to 3.90). The overall articulation (especially the sounds /s/ and /l/) improved significantly postoperatively, but the amount of maxillary advancement did not affect the articulation. The preoperative mean percentages of /s/, /l/, and /r/ errors were 32%, 33%, 46% and the postoperative percentages 23%, 19%, 40%, respectively. Preoperative articulation errors of /s/ were related to palatal inclination of the upper incisors. Orthognathic surgery may improve articulation errors. The amount of maxillary advancement is not related to the improvement.

Biomechanical evaluation of two miniplate fixations applied in the anterior region after Le Fort I osteotomy: an experimental study

The aim of this experimental study was to evaluate the reliability of two-plate fixations applied to the anterior region of the maxilla after Le Fort I osteotomy in terms of stability. Twenty polyurethane-based skull models were used to evaluate two fixation techniques. Two groups consisting of four and two L-shaped titanium miniplates were tested. Each group was tested with the application of vertical forces in the anteroposterior direction using a servohydraulic testing unit. The displacement values in each group at each stage (from 10 N - 120 N) were compared using the Mann-Whitney U test. The displacement values for the two groups were not statistically significant up to 20 N, but differed significantly between 20 N and 120 N (p < 0.05). The results showed that the biomechanical behaviour of fixation with four miniplates was better than that of two after a load of 20 N. It can be concluded that when the amount of maxillary advancement is increased to 10 mm or more, fixation with only two plates does not provide sufficient stability experimentally.

Videofluoroscopic Findings as Predictors of Velopharyngeal Insufficiency After Orthognathic Surgery in Patients With Cleft Lip and Palate.

Midface retrusion is a common problem in patients with cleft lip and palate owing to the lack of adequate growth of the maxilla. Midface advancement surgery is a definite treatment for midface retrusion; however, the subsequent oropharyngeal airway changes might result in velopharyngeal insufficiency (VPI) in affected patients. Determining the predictors of VPI beforehand and modifying the surgical procedure would be beneficial. A retrospective review of 42 patients with cleft lip and palate who underwent orthognathic surgery from 2013 to 2014 was performed. A total of 25 patients met the inclusion criteria and had undergone complete pre- and postsurgery videofluoroscopy, nasopharyngoscopy (NPS), and speech assessment. We compared 2 groups of patients, those who showed NPS finding changes of more than 0.1 (8 patients) and those without changes (17 patients), by measuring the distances of the contact point to the tip of the velum, gap size at maximum closure (MC) and rest, contact area length, lateral wall closure rate, closure velocity, and 2 angles (from the velum to the hard palate and genu) at MC and rest. The amount of maxillary advancement was also recorded. Among the 8 patients with NPS finding changes, 3 underwent Furlow palatoplasty for VPI. No significant difference was found in the amount of maxillary advancement between the groups (5.8 vs 5.7 mm). Significant differences were found in the preoperative gap size at MC and angle at the genu at MC (P = 0.035 and .012). These could be considered as the predictors before surgery. After surgery, a significant difference was found in the contact area, lateral wall closure rate, and gap size at MC (P = 0.005, 0.018, and 0.01). Videofluoroscopy is a relatively applicable method of determining dynamic changes in the velum function. By performing videofluoroscopy before midface advancement surgery in patients with cleft lip and palate, we may predict the risk of VPI and consider alternative surgical strategies.

The Prediction Capacity 3-D Software, on a 2-D Analysis, in Planning the Positioning of the Upper Lip After Maxillary Advancement.

The maxillary advancement using Le Fort I osteotomy directly affects in the positioning of the upper lip (UL) and the nasolabial angle (NLA), which plays an important role in facial expression and aesthetics, because of this, the aim of this study was to evaluate the ability of Dolphin Imaging 11.8 software in predicting changes to the UL position and NLA in patients undergoing maxillary advancement. It was a retrospective cohort study. Predictive and final tracings using pre- and postoperative Cone beam computed tomography (CBCT) of 24 patients undergoing maxillary advancement, regardless of mandibular movement, were compared. Whether the amount of advancement changes this predictability was also analyzed. The predictive and the 12-month postoperative data were evaluated using Dolphin Imaging 11.8 software and compared. Student t test was used to get the results. The vertical analysis of the incisal tip and cementoenamel junction of the upper central incisor (UCI) and of the UL were statistically significant (P = .001 for all). The horizontal measurements of the same variables (P = .238, P = .516, P = .930, respectively) and the NLA (P = .060) showed no statistical significance. The amount of advancement did not interfere with the variables analyzed, except for the exposure (P = .009) and inclination of the UCI (P = .010). It was concluded that the amount of maxillary advancement does not interfere with the UL prediction; the prediction capacity of the software was good for the horizontal measurements, but had a significant error index for vertical measurements.

Correlation Between Speech Outcomes and the Amount of Maxillary Advancement After Orthognathic Surgery (Le Fort I Conventional Osteotomy and Distraction Osteogenesis) in Patients With Cleft Lip and Palate.

The purpose of this study is to evaluate the factors affecting the speech outcome following Le fort I conventional osteotomy(CO) or Le Fort I distraction osteogenesis(DO) in patients with cleft lip and palate at a single institution. Records of cleft lip and palate patients who underwent orthognathic surgery between 2010 and 2015 were reviewed. Data included age at orthognathic surgery, sex, cleft lip and palate type, type of orthognathic surgery, the amount of maxillary advancement, and speech assessment. Speech outcomes were classified into 2 categories. Compared with the pre and post-operative Pittsburgh Weighted speech scale scores, in case that the post-operative total score is increased the authors define it as "Speech deterioration" and if not, the authors define it as "Speech preservation." The 44 patients were identified, 33 patients underwent CO and 11 patients underwent DO. The mean age was 19.4 ± 1.4. The mean period time of speech evaluation after orthognathic surgery was 1.0 ± 0.46 year. The mean amount of maxillary advancement was 7.2 ± 3.2 mm and show significant correlation with speech outcomes. (P = 0.012) . In CO group, the patients who had the maxilla 1∼5 mm advancement maintained their speech completely and 44% of patients with 6∼8 mm deteriorated their speech. In DO group, patients with 9∼10 mm maintained their speech completely, 50% of patients with 11∼12 mm deteriorated their speech and 100% of patients with 13∼16 mm deteriorated their speech. According to the relationship between the amount of maxillary advancement and speech outcomes, there was a statistically significant correlation in both CO and DO groups. (P = 0.04, 0.029). It was found that speech of the patients with more amount of maxillary advancement tended to get worse. Also, it was observed that there exist some stable ranges of maxillary advancement for speech safety which does not effect on speech. (1∼5 mm in CO group and 9∼10 mm in DO group).

Maxillary distraction osteogenesis for correction of maxillary retrognathia in cleft lip and palate patients: a case series

&lt;p class="abstract"&gt;The treatment protocol of patients having maxillary retrognatia is presented in this case series. Maxillary expansion, secondary alveolar bone grafting and/or oronasal fistula closure were performed in 6 cleft lip and palate patients. Preoperative simulation of Le Fort I osteotomy and adaptation of maxillary distractors were realized with stereolytographic cranium models. Intraoral maxillary distraction was applied under general anesthesia. A single unit acrylic occlusal splint was ligated to maxillary dental arch and worked as a guide during entire activation and consolidation period of distraction osteogenesis. Rigid internal fixation plates were placed in the osteotomy sites at the end of consolidation period. The amount of maxillary advancement was between 5-14 mm. Satisfying occlusal and skeletal relationships were obtained in all patients. Advancement of maxilla by distraction osteogenesis resulted in gradual formation of bone at the osteotomy line and enhanced treatment outcome in patients with cleft lip and palate.&lt;/p&gt;

Impact of orthognathic surgery on velopharyngeal function by evaluating speech and cephalometric radiographs

Maxillary retrognathia is a well-known consequence of abnormal facial growth in patients with cleft lip and palate. Orthognathic surgery improves facial appearance and occlusion but may induce velopharyngeal insufficiency. The aim of this study was to evaluate the effect of orthognathic surgery on velopharyngeal function by using speech analysis and lateral cephalometric radiographs. We conducted a retrospective study of 47 patients who underwent maxillary advancement ± mandibular setback between 2006 and 2016. Preoperative and 1 year postoperative audio recordings were blinded for scoring by three trained speech therapists. Preoperative and 1 year postoperative lateral cephalometric radiographs were used to obtain information about skeletal movement and its relationship with the velopharyngeal area. Correlations between speech outcomes and cephalometric radiographs were determined. Hyponasality improved significantly after surgery (p < 0.05), whereas hypernasality deteriorated significantly only in patients who underwent maxillary advancement alone (p < 0.05). No difference in speech parameters was found between patients with hypernasality or patients who had a pharyngoplasty preoperatively and the rest of the group. No correlation was found between the amount of maxillary advancement and hypernasality. A significant correlation (r < -0.49, p < 0.05) was found between the preoperative velar length and hypernasality postoperatively. Maxillary advancement has a negative impact on velopharyngeal function, whereas bimaxillary surgery seems to protect from deterioration. No difference was found in the amount of maxillary advancement or in velopharyngeal measurements between the Le Fort I group and the bimaxillary group. A short soft palate is a predictor of hypernasality after orthognathic surgery.

Impact of the Distance of Maxillary Advancement on Horizontal Relapse After Orthognathic Surgery.

The maxillary horizontal relapse following Le Fort I advancement has been estimated to be 10% to 50%. This retrospective review examines the direct association between the amounts of maxillary advancement and relapse. We hypothesize that the greater the advancement, the greater the relapse amount. Patients with class III skeletal malocclusion underwent maxillary advancement with either a Le Fort I or a Le Fort I with simultaneous mandibular setback (bimaxillary surgery) from 2008 to 2015. Patients were assessed for a history of cleft lip or cleft palate. Patients with known syndromes were excluded. Cephalometric analysis was performed to compare surgical and postsurgical changes. Of 136 patients, 47.1% were males and 61.8% had a history of cleft. The mean surgery age was 18.9 (13.8-23) years and 53.7% underwent a bimaxillary procedure. A representative subgroup of 35 patients had preoperative, immediate postoperative, and an average of 1-year postoperative lateral cephalograms taken. The mean maxillary advancement was 6.3 mm and the horizontal relapse was 1.8 mm, indicating a 28.6% relapse. A history of cleft and amount of maxillary advancement were directly correlated, whereas bone grafting of the maxillary osteotomy sites was inversely correlated with the amount of relapse ( P < .05). Our data suggest positive correlation between amount of maxillary advancement and horizontal relapse as well as a positive correlation between history of cleft and horizontal relapse. Bone grafting of the maxillary osteotomy sites has a protective effect on the relapse.

Velopharyngeal changes after maxillary distraction in cleft patients using a rigid external distraction device: A retrospective study.

To evaluate early and late velopharyngeal changes in cleft lip and palate (CLP) patients after use of the Rigid External Distractor (RED) device and to correlate these changes to the amount of maxillary advancement. Thirty Class III CLP patients were included in the study. Maxillary advancement was performed using the RED device in combination with titanium miniplates and screws for anchorage. Lateral cephalograms, nasometer, and nasopharyngoscope records were taken before distraction, immediately after distraction, and 1 year after distraction. A paired t-test was used to detect differences at P < .05. SNA angle and A point and ANS to Y axis were significantly increased after maxillary distraction (P = .0001). Statistically significant increases in nasopharyngeal and oropharyngeal depths, velar angle, and need ratio were also found (P = .0001). Nasalance scores showed a significant increase (P = .008 for nasal text and .044 for oral text). A significant positive correlation was observed between the amount of maxillary advancement and the increase in nasopharyngeal depth and hypernasality (P = .012 and .026, respectively). Nasopharyngeal function was deteriorated after maxillary advancement in CLP patients. There was a significant positive correlation between the amount of maxillary advancement and the increase in nasopharyngeal depth and hypernasality.

Clinical and radiographic evaluation of maxillary central incisors exposure in patients undergoing maxillary advancement.

Introduction: Patients with dentofacial deformities may undergo orthodontic or orthodontic-surgical treatment. Both modalities can affect esthetics. Objective: This study aims to evaluate clinical and radiographic changes in exposure of maxillary central incisors occurring after orthognathic surgery for maxillary advancement. Methods: A total of 17 patients who underwent orthognathic surgery for maxillary advancement between September, 2010 and July, 2011 were selected. Exposure of maxillary central incisors was evaluated clinically and by lateral cephalograms. Measurements were taken one week before and three months after surgery. Data were paired in terms of sex, age, nasolabial angle, height and thickness of the upper lip, the amount of maxillary advancement, clinical exposure and inclination of maxillary central incisor by statistical tests (CI 95%). Results: After maxillary advancement, incisor clinical exposure had increased even with relaxed lips and under forced smile. Moreover, there was a mean increase of 23.33% revealed by lateral cephalograms. There was an inverse correlation between upper lip thickness and incisors postsurgical exposure revealed by radiographic images (p = 0.002). Conclusions: Significant changes in the exposure of maxillary central incisors occur after maxillary advancement, under the influence of some factors, especially lip thickness.

Ostéotomie d’avancée maxillaire dans les séquelles de fente labio-maxillo-palatine : dilemme entre l’occlusion et l’esthétique du profil

Maxillary hypoplasia is a common sequela of cleft lip and palate. Its surgical treatment consists in a maxillary advancement by distraction or by conventional orthognathic surgery but morphological results are unpredictable. Our goal in this study was to see if the esthetical results (on the lip and the nose) of maxillary advancement were correlated to the preservation of lateral incisor space of the cleft side. This retrospective study included 38patients operated between 2002 and 2013. Unilateral clefts were studied independently from bilateral clefts. Profile aesthetics was evaluated independently and subjectively by two surgeons and scored on an 8-point scale. The result was classified as "good" if the score was superior or equal to 6. The score was correlated to the following parameters: amount of maxillary advancement, upper incisor axis, preservation of the missing lateral incisor space. In the "good result" group, the space of the lateral incisor was less often preserved. The nasolabial angle was more open and the upper central incisor axis more vertical. These results were more pronounced in bilateral clefts, but also found in unilateral clefts. Under reservation of the subjective evaluation and of the small number of patients, it seemed that lateral incisor space closure improved the profile of patients treated by maxillary advancement for cleft lip and palate sequelae.

Assessment of three-dimensional nasolabial response to Le Fort I advancement

Le Fort I advancement induces soft tissue changes to the nasolabial region. The correlation of sagittal skeletal movement to soft tissue alteration has been studied using 2D methods. However, the influence of maxillary advancement has not been adequately assessed using three-dimensional means. The purpose of this study is to analyze nasolabial changes following Le Fort I advancement using 3D photometric measurements. Patient demographic information and their amount of advancement were tabulated. Pre- and postoperative 3D photographs (3D VECTRA photosystem, Canfield, Fairfield, NJ) were recorded. Nasolabial anthropometric measurements were performed using the corresponding 3D post-processing software (Mirror). Six month minimum follow-up elapsed before final evaluation. Forty-four 3D photo data sets were included. Mean maxillary advancement was 5.5 (±1.9) mm. Male/female ratio was 0.7 with a mean age of 16.7 years. Significant increases (p < 0.0001) were seen in the alar base, alar widths, nostril width, and in the soft triangle and lateral alar angles. Significant decreases (p < 0.0001) were noted in the nasofrontal angle and in nostril height. A significant (p < 0.05) increase of the nasal tip, columella and upper lip projection was seen. Philtral height showed no significant changes (p > 0.05) after maxillary advancement. No significant correlation (p > 0.05) between the degree of soft tissue changes and the amount of maxillary advancement was found. Le Fort I advancement significantly impacts the nasolabial soft tissue envelope. The 3D soft tissue changes are predictable and similar for any advancement up to 10 mm.

Stability of maxillary advancement using external rigid distractors in cleft lip and palate patients

Purpose: To evaluate the skeletal changes associated with maxillary advancement using the external rigid distractor in cleft lip and palate patients after distraction and to assess the stability of these changes. Patients and Methods: Eight cleft lip and palate patients with maxillary hypoplasia underwent maxillary distraction osteogenesis using external rigid devise. Lateral cephalometric records were obtained before distraction T1 and after completing active distraction T2. After a three month follow up period a final lateral cephalometric record was evaluated T3. Results: The maxilla was significantly advanced as indicated by the increase in maxillary depth angle and effective maxillary length (median difference, 10 mm). The palatal plane angle showed a significant increase (median difference, 5o), showing clockwise rotation. At T3 there was a slight decrease in maxillary depth angle (median difference, 3o). Effective maxillary length decreased significantly at T3 (median difference, 2 mm). The palatal plane angle decreased (median difference, 3o) and almost returned to its original position, showing a counterclockwise rotation. Conclusion: Maxillary advancement using external rigid distractor resulted in clockwise rotation of maxilla with increase in palatal plane angle and slight increase in mandibular plane angle. The amount of maxillary advancement was slightly reduced during follow up and the palatal plane almost returned to its original position. These changes showed good stable clinical results.

Soft-tissue changes after maxillomandibular advancement surgery assessed with cone-beam computed tomography

The purpose of this study was to quantify anteroposterior and transverse facial soft-tissue changes with respect to underlying skeletal movements after maxillomandibular advancements by using cone-beam computed tomography. Thirty white patients were treated by maxillomandibular advancements after LeFort I osteotomies and bilateral sagittal split osteotomies. The patients were scanned by using cone-beam computed tomography within 1 week before the surgery, within 1 week after the surgery, and a minimum of 8 weeks postsurgery. We measured the differences between the first and last images and calculated ratios for anteroposterior and transverse soft-to-hard tissue movements. Changes in the greatest interalar width were also measured. There was a statistically significant difference in the greatest interalar width change between patients receiving maxillary advancements greater than 4 mm and those having advancements less than or equal to 4 mm (P <0.023). Mean ratios of anteroposterior soft-to-hard tissue movements were 84.9% +/- 38.0% in the malar region, 96.1% +/- 15.5% in the chin, and 101.1% +/- 27.3% in the subcommissural region. Mean ratios of transverse soft-to-hard tissue movements were 39.4% +/- 19.7% in the malar region and 82.5% +/- 56.7% in the subcommissural region. The amount of maxillary advancement most likely plays a role in the postsurgical increase in interalar width. In addition, facial soft tissues appear to respond more to anterior movement of the jaws than to an increase in transverse dimensions after maxillomandibular advancements.

超音波画像を用いた片側性口唇裂・口蓋裂症例に対する上顎骨延長術後の骨形成の評価

Objective: Ultrasonographic (US) observation was carried out in order to investigate bone formation and remodeling after distraction osteogenesis (DOG) using the rigid external distraction (RED) system.Patients and method: The patients were seven cases of unilateral cleft lip and palate treated using the RED system: six males and one female with the mean age of 19 years. The amount of maxillary advancement by DOG ranged from 7.5 to 17.5mm and the timing of US observation was from 2.2 to 6.9 years post-DOG. B mode US examination of the distracted maxillary anterior wall was performed with a 14-MHz transducer. Bone formation and remodeling were assessed on both cleft and non-cleft sides by evaluating bone continuity and smoothness of the distracted bony gap, respectively.Results: Continuity of the cortical bone was recognized in six cases, but was, not detectable in one case. On the other hand, the distraction gap was not recognizable in one case on both sides; was obvious in four cases on both sides; and was obvious on the cleft side and detectable on the non-cleft side in two cases.Conclusion: The diverse aspects of bone formation and remodeling suggest that continuous monitoring is needed after maxillary DOG using the RED system.

Speech Outcome and Velopharyngeal Function in Cleft Palate: Comparison of Le Fort I Maxillary Osteotomy and Distraction Osteogenesis—Early Results

To compare speech outcome and velopharyngeal (VP) status of subjects with repaired cleft palate who underwent either conventional Le Fort I osteotomy or maxillary distraction osteogenesis to correct maxillary hypoplasia. Prospective randomized study with blind assessment of speech outcome and VP status. Twenty-two subjects were randomized into conventional Le Fort I osteotomy and Le Fort I distraction groups. All were native Chinese (Cantonese) speakers. Perceptual judgment of resonance and nasal emission, study of VP structures by nasoendoscopy, and instrumental measurement by nasometry. Assessments were performed preoperatively and at 3 months postoperatively. Assessment of VP closure, perceptual rating of hypernasality and nasal emission, nasalance, and amount of maxillary advancement. There was no statistical difference in any of the outcome measures between the 10 subjects with conventional Le Fort I osteotomy and the 12 subjects with maxillary distraction: hypernasality (chi-square = 3.850, p = 0.221), nasal emission (chi-square = 0.687, p = 0.774), VP gap size (chi-square = 1.527, p = 0.635, and nasalance (t = -0.145, p = 0.886). There was no correlation between amount of maxillary advancement and any of the outcome measures (p = .05 for all). Changes in VP gap size and resonance are described. Results need to be interpreted with caution because of the small sample size and early follow-up. However, this study utilized an assessment protocol involving a variety of outcome measures and careful consideration of reliability factors, which can be a model for further and follow-up studies.

Prediction of Deterioration of Velopharyngeal Function Associated with Maxillary Advancement Using Electromyography of Levator Veli Palatini Muscle

The purpose of the present study was to examine the possibility that postoperative velopharyngeal function following maxillary advancement could be predicted using preoperative electromyography of the levator veli palatini. Levator muscle electromyography was recorded preoperatively during speech and blowing. Levator activity was expressed as a percentage relative to the maximum value observed throughout the experiment. Postoperative velopharyngeal function was evaluated by means of perceptual judgment and nasoendoscopy. The subjects were four patients with repaired cleft palates who underwent maxillary advancement, two by osteotomy and two by distraction osteogenesis. None of the subjects presented with preoperative hypernasality, and nasoendoscopy demonstrated complete velopharyngeal closure in all subjects prior to maxillary advancement. Preoperative levator activity for speech of two subjects was similar to that for normal speakers (< 60% of total range), and postoperative nasality and nasoendoscopic findings revealed no detectible changes. For the other two subjects, levator activity for speech exceeded 60% of the total range, similar to that of speakers with velopharyngeal incompetence. These subjects showed increased hypernasality and deteriorated velopharyngeal closure following maxillary advancement. The deterioration of velopharyngeal function associated with maxillary advancement was demonstrated for subjects whose levator activity was at higher levels during speech in comparison with maximal activity observed during blowing, regardless of the amount of maxillary advancement. Preoperative levator muscle electromyography could be a predictor in identifying patients at higher risk of postsurgical deterioration of velopharyngeal function.