MRI susceptibility artefacts caused by orthodontic wire.

OBJECTIVES: To evaluate magnetic susceptibility artefacts produced by orthodontic wires on MRI and the influence of wire properties and MRI image sequences on the magnitude of the artefact. METHODS: Arch form orthodontic wires [four stainless steels (SS), one cobalt chromium (CC) alloy, 13 titanium (Ti) alloys] were embedded in a polyester phantom, and scanned using a 1.5-T superconducting magnet scanner with an eight-channel phased-array coil. All wires were scanned with T1-weighted spin echo (SE) and gradient echo (GRE) sequences according to the American Society for Testing and Materials (ASTM) F2119-07 standard. The phantom also scanned other eight sequences. Artefacts were measured using the ASTM F2119-07 definition and OsiriX software. Artefact volume was analysed according to metal composition, wire length, number of wires, wire thickness, and imaging sequence as factors. RESULTS: With SE/GRE, black/white artefacts volumes from all SS wires were significantly larger than those produced by CC and Ti wires (P < .01). With the GRE, the black artefacts volume was the highest with the SS wires. With the SE, the black artefacts volume was small, whereas white artefacts were noticeable. The cranio-caudal extent of the artefacts was significantly longer with SS wires (P < .01). Although a direct relationship of wire length, number of wires, and wire thickness with artefact volume was noted, these factors did not influence artefact extension in the cranio-caudal direction. CONCLUSIONS: Ferromagnetic/paramagnetic orthodontic wires create artefacts due to local alteration of magnetic field homogeneity. The SS-type wires produced the largest artefacts followed by CC and Ti.

Three-dimensional changes in the cranial base associated with soft-diet feeding.

BACKGROUND: Masticatory activity affects the morphology of the maxillo-mandibular complex, however, its influence on the cranial base remains to be elucidated. The recent integration of quantitative morphometric analysis with 3D imaging enabled a comprehensive and high-resolution morphological characterization of the craniofacial complex. We aimed to investigate the influence of masticatory activity on the morphology of the growing cranial base by three-dimensional (3D) geometric morphometric approach using micro-CT. METHODS: The micro-CT data was reanalyzed to illustrate the 3D shape of the cranial base, and wireframe models were generated by connecting landmarks on the images. In the original study, mice were fed a soft diet (SD) of powdered pellets or a conventional hard diet (HD) for 6 weeks from 3 to 9 weeks of age, immediately after weaning. A principal component (PC) analysis analyzed shape variations and assessed their significance, while canonical variate (CV) analysis facilitated the comparison and differentiation of groups based on shape, unveiling meaningful shape distinctions. RESULTS: Three PCs were extracted that significantly separated the SD and HD groups among those explaining variations in shape. These PCs were related to the length of the sphenoid bone, the width of the anterior part of the sphenoid bone, and the length of the cranial base. Furthermore, one CV effectively distinguished SD from HD, and CV analysis showed that the sphenoid was shortened in the length and narrowed at the border of the temporal bone in SD mice. CONCLUSIONS: Masticatory loading affects the skeletal development of the cranial base. The morphology of the sphenoid bone was affected in both the sagittal and transverse axes.

Facial soft-tissue shape changes after fixed edgewise treatment with premolar extraction in individual artificial-intelligence-classified facial profile patterns.

OBJECTIVE: To examine the patterns of pretreatment facial soft tissue shape in orthodontic cases with premolar extraction using artificial intelligence (AI) and to investigate the corresponding changes. METHODS: One hundred and fifty-two patients who underwent orthodontic treatment with premolar extraction were enrolled. Lateral cephalograms were obtained before and after the treatment. For each record, the outlines of the nose-lip-chin profile and corresponding 21 cephalometric variables were extracted. The AI method classified pretreatment records into three subject groups based on the feature variables extracted from the outline. Dentoskeletal and soft tissue facial form changes observed after treatment were compared statistically (P < 0.05) between the groups using ANOVA. Multivariate regression models were used for each group. RESULTS: Group 1 (n = 59) was characterized by Class II high-angle retrognathic mandible with an incompetent lip, group 2 (n = 55) by Class I malocclusion with retruded and thin lips, and group 3 (n = 38) by Class I malocclusion with an everted superior lip before treatment. The ratios of anteroposterior soft tissue to hard tissue movements in Group 1 were 56% (r = 0.64) and 83% (r = 0.75) for the superior and inferior lips, respectively, whereas those in Group 2 were 49% (r = 0.78) and 91% (r = 0.80), and 40% (r = 0.54) and 79% (r = 0.70), respectively, in Group 3. CONCLUSIONS: The modes of facial form changes differed depending on the pre-treatment profile patterns classified by the AI. This indicates that the determination of the pre-treatment profile pattern can help in the selection of soft tissue to hard tissue movement ratios, which helps estimate the post-treatment facial profile with a moderate to high correlation.

Oral frailty is a risk factor for body weight loss after gastrectomy: a single-center, retrospective study.

BACKGROUND: Body weight loss (BWL) is a serious complication of gastrectomy in patients with gastric cancer (GC). Nutritional intervention alone is inadequate for preventing BWL, and a new approach is needed. Oral frailty among older adults has recently attracted attention. This study aimed to investigate masticatory ability and BWL after gastrectomy. METHODS: This was a single-center, retrospective study. Functional tooth units (FTU) were used to measure masticatory ability. Patients with FTU < 4 were defined as low FTU group and FTU ≥ 4 as high FTU group. The BWL was compared between the two groups. RESULTS: Sixty patients who underwent distal gastrectomy for GC from March 2022 to January 2023 were enrolled in this study. The median FTU was 3 (range 0-12). The low-FTU group (FTU < 4) included 29 patients, while the high-FTU group (FTU ≥ 4) included 31 patients. The %BWL in the low FTU group was significantly higher than that in the high-FTU group at 1 and 3 months (p = 0.003 and p = 0.017, respectively). The risk factors associated with a %BWL > 5 at 1 and 3 months after gastrectomy were analyzed using logistic regression analysis. Only FTU < 4 was an independent risk factor after gastrectomy for GC in univariate and multivariate analyses (p = 0.028 and p = 0.006, respectively). CONCLUSIONS: Low FTU in patients with preoperative GC was a risk factor for %BWL 1 and 3 months postoperatively. Appropriate oral interventions may be useful in improving the postoperative nutritional status after gastrectomy.

Relationship Between Stigma Experience and Self-Perception Related to Facial Appearance in Young Japanese Patients with Cleft lip and/or Palate.

OBJECTIVE: To examine the relationship between stigma experience related to facial appearance in Japanese youths with cleft lip and/or palate (CL/P) and their self-perception. DESIGN: A cross-sectional study. PARTICIPANTS: Sixty-nine Japanese youths with CL/P (11-18 years old). OUTCOME MEASURES: The participants' stigma experience in relation to facial appearance (measured with 7 single contextual scale items) and their self-perception (measured with 5 domain scores based on 30 perceptual items) were assessed using the Japanese version of the Youth Quality of Life Instrument-Facial Differences Module. Participants were categorized into high and low self-perception subgroups with a threshold of 1 standard deviation for each domain. The frequency of stigma experiences was compared between the following 2 subgroups: age, sex, cleft palate only versus other cleft, and high versus low self-perception. Correlations between the responses regarding stigma and all domain scores were examined. RESULTS: Sixteen percent of the participants reported experiencing stigma. Hearing others say something about their face occurred significantly more frequently in youths 15 to 18 years of age than in youths 11 to 14 years of age. Stigma frequency was not found to differ by sex or cleft type. Stigma experiences were significantly more frequent for youth with higher scores across negative self-perception domains as well as higher coping skills. Significant correlations were identified between responses regarding stigma items and all domain scores (r = 0.27-0.63, p < .05). CONCLUSIONS: It was found that stigma experiences related to facial appearance may influence negative self-perceptions of facial differences as well as higher coping skills among Japanese youths with CL/P.

Prognostic Factors for Orthognathic Surgery in Children With Cleft Lip and/or Palate: Dentition and Palatal Morphology.

To determine dental and palatal morphology in children with cleft lip and/or palate (CL/P) and identify morphological prognostic factors for orthognathic surgery (OGS).Retrospective cohort study.Orthodontic department of a university dental hospital.This study included 80 patients with bilateral and unilateral CL/P who had lateral cephalograms at the ages of 7 (T1), 15 (T2) years, and a dental plaster model at T1.Plaster models at T1 were scanned with a three-dimensional (3D) scanner. Morphological features were extracted from 3D models with geometric morphometrics software as principal components (PCs). The combinations of the PCs and other predictive factors (ie, the No. of clefts in the lip and alveolus, the palatal repair method, sex, cephalometric variables at T1, and the No. of missing teeth) were examined by logistic regression to determine the predictability for OGS. The need for OGS and skeletal and dental discrepancies at T2 were examined as outcomes.Shrinkage of the palate, including vertical shallowing and transverse narrowing of the posterior maxilla and cleft-side asymmetry of the anterior maxilla at T1, as well as the No. of clefts in the lip and alveolus, the palatal repair method, male sex, several cephalometric variables for the sagittal and vertical dimensions, and the No. of missing teeth, were found to be predictive factors for OGS.Morphological prognostic factors for OGS in children with CL/P were determined.

Morphologic variations in the craniofacial structures in Japanese adults and their relationship with sex differences.

INTRODUCTION: The morphology of the human face varies broadly, with genetic and environmental factors determining these variations. Examining variations in the 3-dimensional (3D) craniomandibular morphology and identifying related factors (eg, sex differences) are important in orthodontic clinics. This study observed shape variations in the 3D facial morphology of Japanese adults showing skeletal Class 1 malocclusion and examined the association of sexual dimorphism with shape variations. METHODS: Sixty cone-beam computed tomography images of Japanese adults (30 males and 30 females) with skeletal Class I malocclusion were employed. In each cone-beam computed tomography image, wire mesh fitting was conducted as previously described. A principal component (PC) analysis after Procrustes registration and the PC clustering method was conducted to observe the shape variations. A PC regression analysis was conducted to determine the sexual morphologic characteristics. RESULTS: Nine PCs depicting 62% of the morphology were determined. Four typical phenotypes were found, mainly related to mandibular protrusion (PC1) and the vertical divergence of the face (PC2). PCs related to sex determination were PC3 (robustness of the mandibular angle in males), PC5 (greater size and shape of the coronoid and mastoid processes in males), and PC7 (greater maxillary width in males), accounting for 16% of total variations. CONCLUSIONS: The major shape variations in skeletal Class 1 subjects were related to nonsexual dimorphic characteristics (ie, mandibular protrusion and facial divergence). Sexual dimorphic characteristics were evaluated in detail and accounted for 16% of total morphologic variations.

Comparison of 3-D mandibular surfaces generated by MRI and CT.

OBJECTIVE: The purpose of this study was to evaluate the errors of three-dimensional mandibular surfaces generated using magnetic resonance imaging (MRI) when computed tomography (CT) was set as the gold standard. SETTINGS AND SAMPLE POPULATION: Seven patients with orthognathic deformities who had undergone CT and MRI scans were included in the study. MATERIALS AND METHODS: Mandibular surfaces were generated on each CT and MR image by the surface-rendering method. Intra-individual reliability between CT and MRI was statistically tested by the confidence limits of agreement (LOA) for systematic error, 95% confidence interval minimal detectable change (MDC95 ) for random error and intra-class correlation coefficient (ICC). RESULTS: The average total error was 1.6 mm. The greatest MDC95 was observed in the coronoid region in all directions. The other regions showed MDC95 values of < 1.8 mm (transvers direction), 3.5 mm (vertical direction) and 1.7 mm (antero-posterior direction). ICCs showed 'almost perfect' agreement with respect to all regions. CONCLUSION: Random errors were quantified for 3-D rendering of the mandible from MRI data. Although the coronoid region showed the greatest errors, the other regions of the mandibular surfaces generated using MRI were able to be evaluated.

Evaluation of Facial Appearance-Related Quality of Life in Young Japanese Patients With Cleft Lip and/or Palate.

OBJECTIVE: (1) To confirm the reliability of a Japanese version of the Youth Quality of Life Instrument-Facial Differences Module (YQOL-FD); (2) to assess the quality of life (QoL) related to facial difference in Japanese youths with cleft lip and/or palate (CL/P) using this instrument; and (3) to examine the QoL differences according to age, sex, and cleft type. DESIGN: A cross-sectional study. SETTING: Japanese youths with CL/P were recruited through our hospital and asked to complete the YQOL-FD. PARTICIPANTS: Sixty-nine Japanese youths (age, 11-18 years) with CL/P. OUTCOME MEASURES: The domain scores of stigma, negative consequences, negative self-image, positive consequences, and coping in the YQOL-FD, and the reliability of such scores were evaluated. RESULTS: The instrument showed an acceptable internal consistency (Cronbach α = 0.74-0.92) and test-retest reliability (intraclass correlation coefficient = 0.94-0.98), except for the coping domain. The individual's domain scores were spread out from the lowest score to the high scores among all domains, thus indicating the negative and positive impacts of living with facial differences regarding their QoL may vary among individuals with CL/P. All domain scores in the 15- to 18-year-old group were significantly higher than those in 11- to 14-year-old group; there were no significant differences according to sex or cleft type. CONCLUSIONS: The instrument showed acceptable reliability, except for the coping domain. There were individual variations in QoL concerning the facial difference among Japanese youths with CL/P as measured by the YQOL-FD, suggesting the importance of individual evaluations. Perceptions were influenced by age, but not sex or cleft type.

Comparison of clinical outcomes between Invisalign and conventional fixed appliance therapies in adult patients with severe deep overbite treated with nonextraction.

INTRODUCTION: The use of aligner therapy for orthodontic treatment has increased substantially in the past decade. However, no study has compared treatment outcomes between the conventional fixed appliance and Invisalign therapies in patients with a severe deep overbite. METHODS: This study included 50 consecutive adult patients who underwent treatment with either Invisalign (n = 25; mean age, 23.3 ± 8.5 years) or a conventional fixed appliance (n = 25; mean age, 23.1 ± 6.5 years) to correct overbite >5 mm and >60% deep overbite. Cephalometric analysis and peer assessment rating was used to compare the clinical outcome between groups. RESULTS: Cephalometric analysis showed significant differences in N-Me (P = 0.0005) and Mp-L6 (P = 0.0001) between Invisalign and fixed appliance treatment groups. No significant differences were observed in the peer assessment rating analysis or total treatment duration between the 2 groups. CONCLUSIONS: Both Invisalign and conventional fixed appliances were effective in treating patients with a severe deep overbite. Invisalign therapy may be preferable over conventional fixed appliance therapy in patients with high angle and deep overbite. However, because this study had a retrospective design, the results should be viewed with caution.

The validation of orthodontic artificial intelligence systems that perform orthodontic diagnoses and treatment planning.

AIM: This study was aimed to evaluate two artificial intelligence (AI) systems that created a prioritized problem list and treatment plan, and examine whether the performance of the aforementioned systems was equivalent to orthodontists. MATERIALS AND METHODS: A total of 967 consecutive cases [800: training; 67: validation; 100: evaluation (40: randomly selected for the clinical evaluation)] were used. We used a stored document that describes (1) the patient's clinical information, (2) the prioritized list, and (3) a treatment strategy without digital tooth movement. Sentences of (1) were vectorized according to the bag of words method (V); sentences of (2) and (3) were relabelled with 423 and 330 labels, respectively. AI systems that output labels for the prioritized list (subtask 1) and treatment planning (subtask 2) based on the vectors V were developed using a support vector machine and self-attention network, respectively, while the system was trained to improve precision and recall. Clinical evaluations were conducted by four orthodontists (no faculty or residents; peer group) in two sessions: in the first session, peer group and the developed AI systems created problem lists and treatment plans; in the second session, two of the peer group (not AI) evaluated these lists and plans, including the lists and plans of the AIs, by scoring them using 4-point scales [unacceptable (1) to ideal (4)]. Scores were compared among the system and peer group (Wilcoxon signed-rank test, P < 0.05). RESULTS: The precision after system training was 65% and 48% for subtasks 1 and 2 respectively, with recall of 55% and 48%, respectively. The clinical evaluation of the AI system for subtask 1 showed a mid-rank. For subtask 2, the AI system had a significantly lower score than the three panels but the same rank with one panel. CONCLUSIONS: Two AI systems that output a prioritized problem list and create a treatment plan were developed. The clinical system ability of the former system showed a mid-rank in the peer group, and the latter system was almost equivalent to the worst orthodontist.

Determination of prognostic factors for orthognathic surgery in children with cleft lip and/or palate.

OBJECTIVE: To determine the prognostic factors for orthognathic surgery (OGS) in children with cleft lip and/or palate (CL/P) using artificial intelligence (AI) systems. DESIGN: Retrospective cohort study. SETTING: An orthodontic department at a university dental hospital. PARTICIPANTS: This study included 126 patients with bilateral and unilateral CL/P for whom lateral cephalograms were obtained at three time points: 7 (T1), 10 (T2) and 15 (T3) years of age. MAIN OUTCOME MEASURES: Cleft type, severity of lip separation at birth, number of missing teeth, sex, palatal repair methods and surgeons, cephalometric variables at T1 and T2, and the total duration of orthodontic treatment were examined as predictors. The need for OGS and skeletal and dental discrepancies at T3 was examined as outcomes. RESULTS: A total of six models were developed, with a mean area under the receiver operating characteristic curve of 0.93. Multiple prognostic factors for OGS were identified. In particular, the number of clefts in the lip and alveolus showed relatively high odds ratios, as did anterior crossbite at T3. Achieving palatal closure with the push-back method, rather than Furlow's method, was also found to be a predictive factor for anterior crossbite at T3, with high odds ratios. CONCLUSIONS: The prognostic factors for OGS determined by the AI systems were the number of clefts in the lip and alveolus, the palatal repair method, male sex, several cephalometric variables for the sagittal and vertical dimensions, growth patterns and the number of missing teeth.

Clinical applicability of automated cephalometric landmark identification: Part II - Number of images needed to re-learn various quality of images.

AIM: To estimate the number of cephalograms needed to re-learn for different quality images, when artificial intelligence (AI) systems are introduced in a clinic. SETTINGS AND SAMPLE POPULATION: A total of 2385 digital lateral cephalograms (University data [1785]; Clinic F [300]; Clinic N [300]) were used. Using data from the university and clinics F and N, and combined data from clinics F and N, 50 cephalograms were randomly selected to test the system's performance (Test-data O, F, N, FN). MATERIALS AND METHODS: To examine the recognition ability of landmark positions of the AI system developed in Part I (Original System) for other clinical data, test data F, N and FN were applied to the original system, and success rates were calculated. Then, to determine the approximate number of cephalograms needed to re-learn for different quality images, 85 and 170 cephalograms were randomly selected from each group and used for the re-learning (F85, F170, N85, N170, FN85 and FN170) of the original system. To estimate the number of cephalograms needed for re-learning, we examined the changes in the success rate of the re-trained systems and compared them with the original system. Re-trained systems F85 and F170 were evaluated with test data F, N85 and N170 from test data N, and FN85 and FN170 from test data FN. RESULTS: For systems using F, N and FN, it was determined that 85, 170 and 85 cephalograms, respectively, were required for re-learning. CONCLUSIONS: The number of cephalograms needed to re-learn for images of different quality was estimated.

Clinical applicability of automated cephalometric landmark identification: Part I-Patient-related identification errors.

OBJECTIVES: To determine whether AI systems that recognize cephalometric landmarks can apply to various patient groups and to examine the patient-related factors associated with identification errors. SETTING AND SAMPLE POPULATION: The present retrospective cohort study analysed digital lateral cephalograms obtained from 1785 Japanese orthodontic patients. Patients were categorized into eight subgroups according to dental age, cleft lip and/or palate, orthodontic appliance use and overjet. MATERIALS AND METHODS: An AI system that automatically recognizes anatomic landmarks on lateral cephalograms was used. Thirty cephalograms in each subgroup were randomly selected and used to test the system's performance. The remaining cephalograms were used for system learning. The success rates in landmark recognition were evaluated using confidence ellipses with α = 0.99 for each landmark. The selection of test samples, learning of the system and evaluation of the system were repeated five times for each subgroup. The mean success rate and identification error were calculated. Factors associated with identification errors were examined using a multiple linear regression model. RESULTS: The success rate and error varied among subgroups, ranging from 85% to 91% and 1.32 mm to 1.50 mm, respectively. Cleft lip and/or palate was found to be a factor associated with greater identification errors, whereas dental age, orthodontic appliances and overjet were not significant factors (all, P < .05). CONCLUSION: Artificial intelligence systems that recognize cephalometric landmarks could be applied to various patient groups. Patient-oriented errors were found in patients with cleft lip and/or palate.

Surface-based 3-dimensional cephalometry: An objective analysis of cranio-mandibular morphology.

INTRODUCTION: The purpose of this study was to apply a previously reported homologous model for quantifying and visualizing the three-dimensional (3D) cranio-mandibular morphology. METHODS: Twenty-eight 3D cone-beam computed tomography (CBCT) images of Japanese patients (7 to 13 years of age) showing skeletal Class 1 malocclusions were used in this study. Wire mesh fitting was conducted for each patient based on the assignment of landmarks to each 3D surface (homologous modeling). Cranial and mandibular images were generated using surface rendering of the CBCT images. The mean and standard deviation of each point on the wire mesh were calculated as the normative mean. Two operators conducted the process twice for seven patients, with a one-week interval between fittings. The intra- and inter-examiner reliability were determined using the 95% confidence interval minimal detectable change (MDC95) for random error and intra-class correlation coefficients (ICCs). RESULTS: The intra- and inter-examiner reliability of the mesh fitting method were almost perfect. Normative ranges of the cranial and mandibular surfaces of Japanese were determined. CONCLUSIONS: A clinical method that enables practitioners to quantify and visualize the hard tissues of a patient's face in three dimensions with almost perfect reliability is presented. This method allows practitioners to evaluate how patients' skeletal characteristics differ from normative means in three dimensions.

Three-dimensional changes in the craniofacial complex associated with soft-diet feeding.

BACKGROUND AND OBJECTIVES: The masticatory force affects craniofacial development. We aimed to quantify the topological deviation of the growing craniofacial structure due to soft-food diet feeding and to map the region where the phenotypes appeared on three-dimensional (3D) images. MATERIAL AND METHODS: Mice were fed a powdered soft diet (SD) or conventional hard diet (HD) of regular rodent pellets at 3 weeks of age until 9 weeks of age. The heads, excluding the mandibles, were scanned by micro-computed tomography. The topographic deviation of the bony surface was quantitatively assessed by a wire mesh fitting analysis. The actual displacement and significant differences were mapped and visualized in each x-, y-, and z-axis on the 3D craniofacial image. On these reconstructed images, two-dimensional linear measurements between the landmark points confirmed the 3D skeletal displacement. RESULTS: In the transverse direction, the zygomatic arches and the region in which the temporal muscle attaches to the parietal and temporal bones were narrow in the SD group. The temporal muscle attachment regions significantly shifted anteriorly, and consequently, the sagittal zygomatic arch shortened. Although the cranial sagittal length was not affected, the vertical height was also reduced in the SD group compared to the HD group. CONCLUSIONS: Our 3D surface-based analysis demonstrated that SD feeding resulted in reduced 3D bony development at the region where the chewing muscles attach to the zygomatic arches and the temporal and parietal bones. Interestingly, SD feeding induced an anterior shift in the temporal and parietal bone regions, which can affect the skeletal inter-jaw relationship.

The Elimination of Dental Crowding and Development of a Proper Dental Arch by Maxillary Anterior Segmental Distraction Osteogenesis for a Patient With UCLP.

OBJECTIVE: This report describes the case of a male patient with a complete unilateral cleft lip and palate who presented with midface deficiency and an anteroposteriorly constricted maxilla. DESIGN: Case report Interventions: Correction involved anterior distraction of the segmented maxilla. RESULTS: The present case demonstrates that elongation of the maxilla with anterior distraction is an effective way to develop a proper dental arch, correct anterior and posterior crowding, and improve a midface deficiency.

Efficacy of Maxillary Anterior Segmental Distraction Osteogenesis in Patients With Cleft Lip and Palate.

OBJECTIVES: To evaluate the effects of maxillary anterior segmental distraction osteogenesis (MASDO) in patients with cleft lip and palate (CLP) and to identify risk factors for increased relapse. DESIGN: A retrospective study. PATIENTS: Thirty-one Japanese patients with CLP who underwent MASDO were eligible for study inclusion. MAIN OUTCOME MEASURES: We evaluated lateral cephalograms obtained before (T1), at 3 months (T2), and at 1 year (T3) after MASDO, and measured changes from T1 to T2 (δT1T2), from T2 to T3 (δT2T3), and from T1 to T3 (δT1T3). We also evaluated the risk factors associated with an increased relapse. RESULTS: Overall (δT1T3), MASDO improved retrusion of the maxilla. We measured a significant advancement (6.1 mm) of the anterior maxillary segment in δT1T2 (A-McNamara classification) and increases in the overjet and the SNA, ANB, and nasolabial angles. However, skeletal relapse was evident in δT2T3, and the median percentage of relapse was 10%. To explore the risk factors, we subdivided patients with a δT1T2 of >5 mm into 2 groups based on the percentage of relapse (>15% vs ≤15%). There were significant differences between these groups in the vertical positions of the anterior nasal spine and point A, and the angle formed by the SN and palatal planes (SNPP), suggestive of intraoperative counterclockwise rotation of the maxilla. CONCLUSIONS: MASDO is effective for correcting midfacial deficiencies, but counterclockwise rotation of the maxilla during surgery may cause relapse.

Asymmetric Anterior Distraction for Transversely Distorted Maxilla and Midfacial Anteroposterior Deficiency in a Patient With Cleft Lip/Palate: Two-Stage Surgical Approach.

The present report describes a male patient with a unilateral cleft lip and palate who presented with midfacial anteroposterior and transverse deficiency. Correction involved a two-stage surgical-orthodontic approach: asymmetric anterior distraction of the segmented maxilla followed by two-jaw surgery (LeFort I and bilateral sagittal splitting ramus osteotomies). The present case demonstrates that the asymmetric elongation of the maxilla with anterior distraction is an effective way to correct a transversely distorted alveolar form and midfacial anteroposterior deficiency. Furthermore, successful tooth movement was demonstrated in the new bone created by distraction.