Surgical Orthodontic Treatment Research Articles

Does artificial intelligence predict orthognathic surgical outcomes better than conventional linear regression methods?

ABSTRACT Objectives To evaluate the performance of an artificial intelligence (AI) model in predicting orthognathic surgical outcomes compared to conventional prediction methods. Materials and Methods Preoperative and posttreatment lateral cephalograms from 705 patients who underwent combined surgical-orthodontic treatment were collected. Predictors included 254 input variables, including preoperative skeletal and soft-tissue characteristics, as well as the extent of orthognathic surgical repositioning. Outcomes were 64 Cartesian coordinate variables of 32 soft-tissue landmarks after surgery. Conventional prediction models were built applying two linear regression methods: multivariate multiple linear regression (MLR) and multivariate partial least squares algorithm (PLS). The AI-based prediction model was based on the TabNet deep neural network. The prediction accuracy was compared, and the influencing factors were analyzed. Results In general, MLR demonstrated the poorest predictive performance. Among 32 soft-tissue landmarks, PLS showed more accurate prediction results in 16 soft-tissue landmarks above the upper lip, whereas AI outperformed in six landmarks located in the lower border of the mandible and neck area. The remaining 10 landmarks presented no significant difference between AI and PLS prediction models. Conclusions AI predictions did not always outperform conventional methods. A combination of both methods may be more effective in predicting orthognathic surgical outcomes.

Surgical Orthodontic Treatment for Skeletal Maxillary Protrusion in Sturge-Weber Syndrome: A Case Report and Review of the Literature

Surgical Orthodontic Treatment for Skeletal Maxillary Protrusion in Sturge-Weber Syndrome: A Case Report and Review of the Literature

Impact of Orthodontic-Surgical Treatments on the Signs and Symptoms of Temporomandibular Disorders: A Systematic Review.

Some patients exhibit temporomandibular joint or muscular disorders of the masticatory system before, during, or after orthognathic surgery (OS). These are collectively referred to as temporomandibular disorders (TMDs). This systematic literature review aimed to determine the relationship between orthodontic-surgical treatment and TMDs. An electronic search of the PubMed database, supplemented by a manual search, was performed; the search included any studies published between 2021 (date of the last search in a systematic review of the literature on the subject) and June 2023 that evaluate the prevalence of TMDs during orthodontic-surgical treatment. The diagnosis of TMDs had to be established using the diagnostic algorithm "diagnostic criteria for temporomandibular disorders (DC/TMDs)", and the diagnosis of disc displacement had to be confirmed using magnetic resonance imaging (MRI). The data were extracted and statistically analyzed. Of the 100 results, seven eligible articles were included, representing a total of 529 cases undergoing orthodontic-surgical treatment. A reduction in joint noises (64.8%), arthralgia (57 to 77%), and myalgia (73 to 100%) was found after orthodontic-surgical treatment despite the fact that a minority of patients exhibited these signs and symptoms even though they were asymptomatic before treatment. The effects of OS on disc position were objectively unpredictable. After surgery, the presence of headaches decreased without significance and the risk of their occurrence was very low (1%). The studies converged toward a reduction in the amplitudes of mouth opening and lateral/protrusion movements. Finally, after the treatment, mandibular function was improved. Under the conditions of this study, OS seems to have a positive impact on the signs and symptoms of TMDs; however, it is not possible to predict the consequential effects on the position of the TMJ disc, whether it is initially in a normal position or displaced.

An automated method for assessing condyle head changes in patients with skeletal class II malocclusion based on CBCT images.

Currently, there is no reliable automated measurement method to study the changes in the condylar process after orthognathic surgery. Therefore, this study proposes an automated method to measure condylar changes in patients with skeletal class II malocclusion following surgical-orthodontic treatment. Cone-beam computed tomography (CBCT) scans from 48 patients were segmented using the nnU-Net network for automated maxillary and mandibular delineation. Regions unaffected by orthognathic surgery were selectively cropped. Automated registration yielded condylar displacement and volume calculations, each repeated three times for precision. Logistic regression and Linear regression were used to analyze the correlation between condylar position changes at different time points. The Dice score for the automated segmentation of the condyle was 0.971. The Intraclass correlation coefficients (ICCs) for all repeated measurements ranged from 0.93 to 1.00. The results of the automated measurement showed that 83.33% of patients exhibited condylar resorption occurring six months or more after surgery. Logistic regression and Linear regression indicated a positive correlation between counterclockwise rotation in the Pitch plane and condylar resorption(p < 0.01). And a positive correlation between the rotational angles in both three planes and changes in the condylar volume at six months after surgery(p ≤ 0.04). This study's automated method for measuring condylar changes shows excellent repeatability. Skeletal class II malocclusion patients may experience condylar resorption after bimaxillary orthognathic surgery, and this is correlated with counterclockwise rotation in the sagittal plane. This study proposes an innovative multi-step registration method based on CBCT, and establishes an automated approach for quantitatively measuring condyle changes post-orthognathic surgery. This method opens up new possibilities for studying condylar morphology.

Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children.

Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children.

Changes in smile parameters after surgical-orthodontic treatment for skeletal Class III malocclusion

Background/purposeMany patients pursue attractive smiles, and surgical-orthodontic treatment is a common method. We aimed to analyze the changes in smile parameters after surgical-orthodontic treatment in patients with skeletal Class III pattern and identify factors influencing postoperative outcomes. Materials and methodsThis retrospective study comprised 34 patients with skeletal Class III malocclusion and pure mandible prognathism who received surgical-orthodontic treatment. Hard and soft tissue parameters were assessed through lateral cephalometry, and smile esthetics were evaluated through extraoral photography. Postoperative changes in smile parameters and between-parameter correlations were analyzed. Random forest and decision tree deep learning models were used to identify factors influencing postoperative changes. ResultsSubstantial postoperative changes were observed in the buccal corridor, upper lip height, and smile index. Significant between-sex differences were noted in the upper midline and right chelion. Strong, positive correlations were found between upper lip height and upper lip ratio and between lower lip height and lower lip ratio. By contrast, strong negative correlations were observed between lower teeth exposure and smile index and between interlabial gap and smile index. The highest degrees of postoperative changes were noted in asymmetry-associated smile parameters: lower lip area, interlabial gap, smile index, buccal corridor, and arc ratio. ConclusionConsiderable changes were noted in skeletal, dental, and soft tissue parameters after surgical-orthodontic treatment. However, the changes in smile esthetics were less prominent from the frontal view. As for chin asymmetry, the most to least prominent changes were in the lower lip area, interlabial gap, smile index, buccal corridor, and arc ratio, respectively.

Changes in masseter muscle morphology after surgical-orthodontic treatment in patients with skeletal Class III malocclusion with mandibular asymmetry: The automatic masseter muscle segmentation model

This study evaluated the masseter muscle changes after surgical-orthodontic treatment in patients with a skeletal Class III malocclusion using automatic segmentation. Images of 120 patient with skeletal Class III malocclusion were obtained and reconstructed at T0 (pretreatment), T1 (presurgery), and T2 (6-12-month postsurgery). The patients were divided into symmetrical and asymmetrical groups. The volume, major axis length, maximum cross-sectional area, horizontal cross-sectional area 5 mm above the mandibular foramen (CSAF), and orientation were calculated automatically. In the asymmetrical group, the volume and major axis length on the deviated side were lower than on the nondeviated side at T0, T1, and T2 (P<0.05). There were no significant differences in maximum cross-sectional area and CSAF bilaterally. The orientation was coronally more vertical and sagittally more forward on the deviated side (both P<0.001). In the symmetrical group, there were no significant bilateral differences at T0, T1, and T2. The volume, major axis length, and CSAF decreased, and the coronal orientation was more vertical on the nondeviated side at T2 than at T0 in both groups (P<0.05). The coronal plane orientation was more inclined on the deviated side at T2 than at T0 in the asymmetrical group (P<0.05). The smaller volume on the deviated side at T2 indicates the need for myofunctional training after surgery. The masseter muscle volume and the cross-sectional area did not recover to the preorthodontic levels. Studies with longer follow-up durations are needed to confirm these findings.

Orthodontic-Surgical Correction of a Skeletal Class III Malocclusion: Case Report

Introduction: Class III malocclusions and anterior crossbites are disturbing for patients because they are very apparent and often cause aesthetic and functional damage. Description: The clinical case describes a 19-year-old patient in good general health attended the dento-facial orthopedics service at the Rabat Hospital Center for Dental Consultation and Treatment presenting an anterior crossbite. The clinical examination and the cephalometric analysis showed that the patient had a Class III malocclusion of maxillary and mandibular origin with hyperdivergent facial type. An orthodontic-surgical treatment was well indicated for correction of the skeletal discrepancy in three phases: presurgical orthodontic preparation, orthognathic surgery and orthodontic finishing. Results: In reviewing the patient’s final records, the major goals set at the beginning of treatment were successfully achieved; the facial profile and proportion were significantly improved with solid functional occlusion Conclusion: In class III malocclusion when facial aesthetics is altered, the surgical-orthodontic treatment is the most indicated for patients who do not present facial growth.

Surgical treatment of the dento-maxillary anomalies in the sagittal plane

Orthognathic surgery involves all surgical interventions to correct musculoskeletal, dental and soft tissue deformities of the jaws, being the treatment method of choice for severe dento–maxillary anomalies, which cannot be rehabilitated by orthodontic treatment alone. The purpose. Evaluation of the particularities of diagnosis and treatment of patients with jaw anomalies in sagittal plane. Material and methods: 22 patients aged between 20 and 46 years, during the period 2016—2021. The surgical stage occurred in stationary conditions, and the clinical and paraclinical evaluation of the patients took place in dental clinic through photostatic examination, study models, radiological examination, intraoral scanning. Results: Predominance of patients with skeletal Class III (77.3%), compared to Class II (22,7%). Osteotomies used: Le Fort 1 for maxilla, osteotomy of the mandibular ramus Obwegeser — Dal Pont for the lower jaw and genioplasty for repositioning the chin. The unavoidable surgical trauma for the correct positioning of the jaws leads to intraoperative hemorrhages, hematomas and postoperative conditions acceptable from the point of view of the endured trauma. Conclusions. The orthodontic–surgical treatment is a safe method of rehabilitating patients with anomalies in sagittal plane, with postsurgical results superior to intraoperative risks and complications.

Surgical treatment of the dento-maxillary anomalies in the sagittal plane

Introduction. Orthognathic surgery involves all surgical interventions to correct musculoskeletal, dental and soft tissue deformities of the jaws, being the treatment method of choice for severe dento–maxillary anomalies, which cannot be rehabilitated by orthodontic treatment alone. The purpose. Evaluation of the particularities of diagnosis and treatment of patients with jaw anomalies in sagittal plane. Material and methods: 22 patients aged between 20 and 46 years, during the period 2016—2021. The surgical stage occurred in stationary conditions, and the clinical and paraclinical evaluation of the patients took place in dental clinic through photostatic examination, study models, radiological examination, intraoral scanning. Results: Predominance of patients with skeletal Class III (77.3%), compared to Class II (22,7%). Osteotomies used: Le Fort 1 for maxilla, osteotomy of the mandibular ramus Obwegeser — Dal Pont for the lower jaw and genioplasty for repositioning the chin. The unavoidable surgical trauma for the correct positioning of the jaws leads to intraoperative hemorrhages, hematomas and postoperative conditions acceptable from the point of view of the endured trauma. Conclusions. The orthodontic–surgical treatment is a safe method of rehabilitating patients with anomalies in sagittal plane, with postsurgical results superior to intraoperative risks and complications.

Orthodontic Treatment and Mini Wing Osteotomy: A Case Report of Changes in Facial Aesthetic

For correction of dentofacial deformities, orthosurgical treatment is recommended and often involves bi-maxillary orthognathic surgery. The chin area is an important key for a harmonious facial profile and plays an important role. The present case (of a 38- year-old female) describes one successful surgical-orthodontic treatment. The treatment consisted of the use of an Edgewise fixed appliance (0.022”×0.028”), mini Wing osteotomy (mWo), correction of the deviated nasal septum, and rhinoplasty. The treatment resulted in a better facial harmony and aesthetic with greater definition and lengthening of the submental region, adipose tissue elimination, and an upturned nose due to the correction of the deviated nasal septum associated with rhinoplasty. The Class I canine and molar relationship, the upper and lower midlines coincident with the facial midline, and the compensatory projection of the lower incisors were maintained. A satisfactory overbite and overjet, and leveled curve of Spee were obtained. In conclusion, the orthodontic treatment associated with mWo, correction of the deviated nasal septum, and rhinoplasty surgery provided satisfactory functional and aesthetic results.

Facial asymmetry correction with surgical-orthodontic treatment: Challenges of the surgical and postsurgical phases

Asymmetry is commonly diagnosed in orthodontic clinical practice and is more or less perceived depending on its severity. In more severe cases, orthodontic-surgical treatment is the only treatment option. Although presurgical orthodontics is fundamental, occasionally, the occlusion obtained after surgery is far from that planned, and the orthodontist must decide between surgical re-intervention or orthodontic finishing. This clinical report describes the case of an 18-year-old man, presenting a severe facial asymmetry with class III malocclusion, who underwent a surgical-orthodontic treatment. One week after orthognathic surgery, the patient was reoperated because the intercuspation was different from the one obtained at the end of surgery. However, after the second surgery, the intercuspation was still far from what was planned. Despite that, at the end of treatment, a functional and stable occlusion was obtained, associated with a significant improvement in facial harmony and function.

Three-dimensional assessment of periodontal support of lower incisors for skeletal Class II malocclusion undergoing presurgical orthodontic treatment with different vertical skeletal patterns

BackgroundThe aim of the present study was to compare periodontal support changes during retraction of mandibular anterior teeth for skeletal Class II malocclusion with different facial divergence and to analyze relevant factors influencing bone remodeling by applying three-dimensional (3D) cone-beam computed tomography (CBCT) reconstruction technology.MethodsForty-eight patients with Class II malocclusion requiring surgical orthodontic treatment enrolled in the study were divided into the hyperdivergent group (n = 16), normodivergent group (n = 16) and hypodivergent group (n = 16) according to their vertical skeletal patterns. Cone-beam computed tomography (CBCT) scans were obtained before treatment (T1) and after presurgical orthodontic treatment (T2). The two-dimensional (2D) alveolar bone morphology, movement of mandibular central incisors and volume of the alveolar bone around incisors were measured on the labial and lingual sides by 3D CBCT reconstruction technology. Statistical analyses were performed with one-way ANOVA, paired t tests and multiple linear regression.ResultsDuring presurgical orthodontic treatment, the alveolar bone height on the labial side of the hyperdivergent group decreased significantly (P ≤ 0.05), but was maintained in the normodivergent and hypodivergent groups (P > 0.05). However, the alveolar bone volume, alveolar bone thickness at each level and alveolar bone height on the lingual side decreased significantly for all the groups. Apart from the initial morphometric measurements at T1, the morphology of lingual alveolar bone at T2 was significantly influenced by the direction and amount of tooth movement. Horizontal retraction and vertical protrusion of the root apex were negatively related to the alveolar bone on the lingual side after presurgical orthodontic treatment.ConclusionFor Class II malocclusion patients undergoing presurgical orthodontic treatment, the changes in the periodontal support of the lower central incisors varied in different vertical skeletal patterns. There exists a great periodontal risk of alveolar bone resorption on the lingual side for various vertical types. To avoid alveolar bone deterioration, it is essential to investigate the bone remodeling of patients with different alveolar bone conditions and cautiously plan tooth movement prior to orthodontic treatment. Moreover, 3D measurements based on CBCT construction can provide complementary information to traditional 2D measurements.

COMBINED ORTHODONTIC AND SURGICAL TREATMEN IN PATIENT WITH MANDIBULAR PROGNATHISM

The aim of this case was to present a combined orthodontic-surgical treatment for a 30-year-old patient. The initial clinical examination revealed a Class III malocclusion, concave profile, 4.5mm overjet, and 2mm overbite. The treatment plan included orthodontic preparation with fixed appliances, surgical correction of skeletal discrepancies, and post-surgical orthodontic treatment. Lateral cephalograms were taken before the orthodontic therapy, just before the surgical intervention, and after the treatment, following the removal of fixed appliances. On the initial lateral cephalogram SNB angle was 88°, ANB -5°, SpP/MP 28°, total Bjork’s polygon angle 405°, I/SpP 71°, i/MP 111° and mandibular corpus length was increased by +11mm. On the final post-surgical lateral cephalogram, after the intervention and appliance removal the SNB angle was 81°, ANB 3°, SpP/MP 25°, total Bjork’s polygon angle 398°, I/SpP 64°, i/MP 96° and man- dibular corpus length was increased by +3mm. The pre-surgical orthodontic treatment lasted 12 months, followed by bimaxillary surgery. The post-surgical orthodontic treatment lasted 12 months. After appliance removal, a retentive phase with night-time wear of retainers was implemented. The result was stable Class I occlusion, satisfactory profile appearance, 2.5mm overbite, and 2mm overjet.

Costs and duration of orthodontic-surgical treatment with mandibular advancement surgery.

The aim was to analyse the costs and duration of orthodontic-surgical treatment with mandibular advancement in the public health care sector in Finland. The study was conducted as a retrospective registry study in a public district hospital on all nonsyndromic patients that were ethnic Finns and treated with full fixed appliances and mandibular advancement surgery in 2016-2020. The mean treatment duration of the included 45 patients was 28.1 months, including 18.9 months pre and 9.2 months postoperative orthodontics. The median number of visits was 27, including 17 visits before and 9 visits after surgery. The mean total treatment time was 14.5 h. The mean total direct costs per course of treatment were 7574 € to the municipality and 947 € to the patient. The costs positively correlated with the duration of the treatment (rho = 0.71, P = .000), but were not associated to gender or age of patient. The mean surgery time was 78 minutes, and significantly less with an experienced surgeon (P = .002). It was calculated that the mean minimum treatment costs would be 45% of the present total, achievable with a patient with optimum dental arches at the start of treatment. The major limitation of the study is the relatively small number of study subjects. A 55% share of the costs is influenced by case- and operator-dependent factors. This indicates that the complexity and performance of the orthodontic phases of treatment are important determinants in the cost structure.

The impact of orthodontic-surgical treatment on facial expressions—a four-dimensional clinical trial

ObjectiveThe objective of this clinical trial was to compare facial expressions (magnitude, shape change, time, and symmetry) before (T0) and after (T1) orthognathic surgery by implementing a novel method of four-dimensional (4D) motion capture analysis, known as videostereophotogrammetry, in orthodontics.MethodsThis prospective, single-centre, single-arm trial included a total of 26 adult patients (mean age 28.4 years; skeletal class II: n = 13, skeletal class III: n = 13) with indication for orthodontic-surgical treatment. Two reproducible facial expressions (maximum smile, lip purse) were captured at T0 and T1 by videostereophotogrammetry as 4D face scan. The magnitude, shape change, symmetry, and time of the facial movements were analysed. The motion changes were analysed in dependence of skeletal class and surgical movements.Results4D motion capture analysis was feasible in all cases. The magnitude of the expression maximum smile increased from 15.24 to 17.27 mm (p = 0.002), while that of the expression lip purse decreased from 9.34 to 8.31 mm (p = 0.01). Shape change, symmetry, and time of the facial movements did not differ significantly pre- and postsurgical. The changes in facial movements following orthodontic-surgical treatment were observed independently of skeletal class and surgical movements.ConclusionsOrthodontic-surgical treatment not only affects static soft tissue but also soft tissue dynamics while smiling or lip pursing.Clinical relevanceTo achieve comprehensive orthodontic treatment plans, the integration of facial dynamics via videostereophotogrammetry provides a promising approach in diagnostics.Trial registration numberDRKS00017206.

Association of scoliosis with skeletal jaw asymmetry

ObjectiveThe objective of this study was to evaluate the relationship between scoliosis and skeletal jaw asymmetry. MethodsThe subjects were one hundred and thirty-eight (43 male, 95 female) patients with jaw deformity, who underwent surgical orthodontic treatment at Cyubu Rosai Hospital from April 2017 to March 2022, without congenital disease or scoliosis treatment history. Posteroanterior cephalograms and posteroanterior chest radiographs obtained before surgery were used to evaluate horizontal displacement of the jawbone, Cobb angle of scoliosis, respectively. Actual values of spines curved to the right and left of the body and of displacement of the mandible in these directions were both deemed positive and negative, respectively. Correlations between absolute values of spine and jaw displacement, namely values without regard to their direction, and correlations between actual values of spine and jaw displacement were analyzed using Spearman, non-parametric, and Pearson, parametric, tests respectively. ResultsTwenty-two patients (15.9 %) had Cobb angle > 10°. Although there was no significant correlation between Cobb angle and Me angle in the actual values (p = 0.606), there was a significant correlation in the absolute values (p = 0.023). ConclusionsThis study suggests a relationship between horizontal deviation of the mandible and scoliosis in patients with jaw deformity, albeit not necessarily in the same direction.

Assessing the Impact of Maxillomandibular Difference on the Success of Orthodontic Decompensation Preparation in Orthognathic Surgical Skeletal Class-III Patients

Background: Combined orthodontic-surgical treatment includes a thorough diagnosis and analysis of dental and facial deformities. Cephalometric analysis is a common tool for this, in which measurements of specific anatomical landmarks are performed. In order to achieve a successful surgery, orthodontic teeth preparation is mandatory, including dental decompensation before surgery. This should be planned and adequately executed to allow the surgeon to move the jaws to the correct ideal position. Aim: The current study aimed to check if the orthodontic decompensation amount is influenced and compromised by the maxillomandibular difference and if there is a correlation between the deformity’s severity and the orthodontist’s difficulty in achieving an accurate result in the orthodontic decompensation preparation. Methods: The study consisted of 50 pre-operational cephalometric radiographs of patients with Class-III (prognathic) deformity. The measurements included the angles of the upper incisor (U1) longitudinal axis to the Frankfort plane (FH) and palatal plane (PP), lower incisor (L1) longitudinal axis to the lower mandibular plane (MP), overjet (OJ), effective maxillary length, effective mandibular length, and the maxilla–mandibular difference (Diff); Pearson correlation coefficient was applied. Results: There was a significant correlation between the maxilla–mandibular difference and U1 to FH angle (r = 0.254, p = 0.037), U1 to PP angle (r = 0.447, p &lt; 0.001), OJ (r = (−0.426), p &lt; 0.001). There was no statistical significance for Diff and L1 to MP angle (p = 0.342). Conclusions: In Class-III patients, achieving adequate decompensation is more challenging with the maxillary incisors rather than with the mandibular incisors, especially in more severe cases.

Skeletal Class III Surgical-Orthodontic Treatment and Remote Digital Monitoring during COVID-19 Pandemic: A Case Report

Skeletal Class III Surgical-Orthodontic Treatment and Remote Digital Monitoring during COVID-19 Pandemic: A Case Report

Long-term stability of surgical orthodontic treatment for patients with asymmetric mandibular prognathism: a retrospective comparison study on surgical methods

ABSTRACT Purpose To consider long-term postoperative stability, and its contributing factors in surgical orthodontic treatment for asymmetric mandibular prognathism by comparing a sagittal split ramus osteotomy (SSRO) and a combination of Le Fort I osteotomy and SSRO. Materials and Methods Patients with asymmetric mandibular prognathism had undergone SSRO (14 patients; one-jaw surgery group) or a combination of Le Fort I osteotomy and SSRO (15 patients; two-jaw surgery group) were enrolled. Cephalometric analyses were performed at five time points: initial visit (T0), pre-surgery (T1), several months after surgery (T2), start of retention (T3) and more than 5 years after surgery (T4). Factors were evaluated by measuring two groups at each time point, comparing changes in measurements during each time period, correlating mandibular changes between each period, and correlating changes in lower first molar and ramus inclination with T2-T4 measurements. Results The two-jaw surgery group had significantly smaller transverse changes of menton (Me) at T3–T4 and T2–T4 compared to the one-jaw surgery group. In the one-jaw surgery group, transverse changes in Me at T2–T4 were positively correlated with changes in transverse inclination of mandibular ramus at the deviated side observed at T1–T2. Vertical change of pogonion at T2–T4 was positively correlated with change in bucco-lingual inclination of lower first molar at T0–T1. Conclusions Two-jaw surgery is suggested to be more effective than one-jaw surgery in achieving long-term stability of mandibular position in the transverse and anteroposterior dimensions after surgical orthodontic treatment for asymmetric mandibular prognathism. Long-term follow-up is necessary to monitor potential mandibular relapse.