Changes in lateral standing posture following orthognathic surgery: a cohort study.

Altering neuromuscular and musculoskeletal relationships also affects standing body posture, particularly in the head and neck areas. This prospective cohort study assessed the effects of orthognathic surgery on head posture in the lateral standing view. Thirty-one patients who underwent single-jaw orthognathic mandibular surgery were included. The patients underwent cephalometric and photographic evaluations of their habitual posture before and 6 months after surgery. The craniovertebral angle and Frankfort angle were determined and measured using MB-Ruler software. Mandibular positional changes were also measured by superimposing lateral cephalograms and recording changes in the menton point. All data were analysed by paired t-test. The craniovertebral angle increased significantly in patients with Class II malocclusion (P = 0.001) and decreased significantly in Class III patients (P = 0.004). Furthermore, the Frankfort angle was significantly increased in both Class II (P = 0.005) and Class III (P = 0.012) patients. The tendency towards forward head posture decreased in Class II patients, and the neck posture improved. Conversely, a slight but significant tendency towards a forward head posture was observed in Class III patients after surgery. Furthermore, the natural head position changed in both study groups, leading to a more upright head posture.

The efficacy of Platelet and Leukocyte Rich Fibrin (L-PRF) in the healing process and bone repair in oral and maxillofacial surgeries: a systematic review.

INTRODUCTION: The search to optimize the healing and bone repair processes in oral and maxillofacial surgeries reflects the constant evolution in clinical practice, driven by the demand for increasingly satisfactory results and the need to minimize postoperative complications. OBJECTIVE: To evaluate the efficacy of Platelet and Leukocyte Rich Fibrin (L-PRF) in the healing and bone repair process in oral and maxillofacial surgeries. MATERIALS AND METHODS: The systematic review protocol for this study included the definition of the research question, the domain of the study, the databases searched, the search strategy, the inclusion and exclusion criteria, the types of studies to be included, the measures of effect, the methods for screening, data extraction and analysis, and the approach to data synthesis. Systematic literature searches were carried out on Cochrane databases, Web of Science, PubMed, ScienceDirect, Embase and Google Scholar. RESULTS: The strategic search in the databases identified 1,159 studies. After removing the duplicates with the Rayyan© software, 946 articles remained. Of these, 30 met the inclusion criteria. After careful evaluation based on the inclusion and exclusion criteria, 8 studies were considered highly relevant and included in the systematic review. CONCLUSION: Platelet and Leukocyte Rich Fibrin (L-PRF) has a positive effect on the healing process and bone repair in oral and maxillofacial surgeries.

Trigeminal Cardiac Reflux During Le Fort I Osteotomy: A Case Report.

The trigeminocardiac reflex (TCR) is marked by significant cardiovascular reactions, such as bradycardia and asystole, triggered by trigeminal nerve stimulation. It is described as a brief episode of bradycardia, hypotension, or even cardiac arrest resulting from trigeminal nerve stimulation. The exact cause of TCR is not yet fully understood, but it is believed to involve the release of neurotransmitters, including acetylcholine, and the involvement of central neuronal integration. In this case report, we present an occurrence of trigeminal cardiac reflux during a Le Fort I osteotomy procedure in a patient with no medical issues.

What comes first: teeth or face? Recommendations for an interdisciplinary collaboration between facial esthetic surgery and dentistry.

OBJECTIVE: The aim of the present study was to provide recommendations in order to facilitate communication between dental professionals and surgeons who are collaborating in the field of dentofacial esthetics. CLINICAL CONSIDERATIONS: Smile esthetics are beyond the scope, both of the surgeons who are collaborating with facial esthetics and of the dentists, as a wide range of treatment options from both sides is available. It can be difficult for the surgeon or the dentist that first comes in contact with the patient to conduct an individualized global treatment plan, in order to find out how the various phases of the treatment can be sequenced, as a workflow for an efficient interaction between facial surgery and dentistry still does not exist in the scientific literature. CONCLUSIONS: Facial cosmetic procedures and dental treatment have to be planned as individual elements of the whole dentofacial esthetic rehabilitation. The treatment has to be initiated with the design of the smile and the intraoral mock-up, followed by the required surgical interventions, and to be finished with the delivery of the definitive dental restoration. CLINICAL SIGNIFICANCE: Dentofacial esthetics require comprehensive communication between surgeons and dentists. Following the proposed recommendations, an individualized interdisciplinary treatment plan can be conducted, defining the role of each specialty.

Post-condylectomy orthodontic treatment for a severe asymmetrical open bite in a condylar hyperplasia patient.

A satisfactory treatment of an 18-year-old lady was reported with right combination-type condylar hyperplasia (CH) in active phase. The chin severely deviated to the left, with the right gonial angle locating at a lower level. Intraorally, the lower centre line shifted to the left, the scale of which reached the width of one lower incisor. The right molar relation was mesial. Right maxillary second molar over-erupted without contact to lower teeth. There had been 2.5-mm anterior open bite (AOB) before surgery (T1) due to the tongue-spitting habit. After judging the benefits and disadvantages of all treatment alternatives, the decision was made to perform a right condylectomy and post-surgery orthodontics. Before orthodontics (T2) when the chin was positioned centred, an asymmetrical open bite occurred, caused by pre-contact between the right maxillary and mandibular second molars. Meanwhile, the AOB at T2 became 11.5mm. Orthodontic-related treatment included four premolars extraction and intrusion of bilateral maxillary molars using four miniscrews. Finally, this treatment achieved a clinically centred chin with two gonial angles at the same level. Post-condylectomy, the large AOB was resolved, together with a bilateral neutral molar relationship and alignment of the incisor midlines. Besides, the resected right condyle was covered by a continuous cortex bone and returned to the glenoid fossa. In sum, a high-challenging combined-type CH case was accomplished with impressive improvement in facial and occlusal symmetry, thanks to condylectomy and post-surgery miniscrew-assisted orthodontics.

Three-dimensional assessment of root changes after Le Fort I osteotomy.

The study aim was to assess the volumetric, linear, and morphological changes of the maxillary incisor, canine, and premolar roots following Le Fort I osteotomy. Sixty patients (585 teeth) were included retrospectively from among individuals who underwent combined orthodontics and orthognathic surgery. The study group comprised 30 patients who underwent orthodontics and one-piece Le Fort I osteotomy, while the control group consisted of 30 patients who underwent orthodontics and bilateral sagittal split osteotomy but no maxillary surgery. CBCT scans were obtained at four time points: preoperative, 6 months, 1 year, and 2 years postoperative. A fully automated three-dimensional evaluation protocol was utilized to assess root changes of the maxillary teeth. Significant differences in the apical and middle parts of the teeth were observed between the study and control groups at 1 and 2 years postoperative, with greater percentage changes in the study group (all P < 0.05). Greater root remodelling in the canines, first and second premolars was observed in the study group (all P < 0.005). Spearman correlation analysis indicated a positive relationship between root remodelling and maxillary advancement, with larger advancements contributing to increased root remodelling in the apical and middle root parts (both P < 0.05). These findings can be valuable for surgeons and orthodontists in evaluating root changes.

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

Background/purpose: Many 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 methods: This 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. Results: Substantial 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. Conclusion: Considerable 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.

Systematic review of the histological and functional effects of botulinum toxin A on masticatory muscles: Consideration in dentofacial orthopedics and orthognathic surgery.

INTRODUCTION: Botulinum toxin type A causes muscle paralysis and is widely used in the masticatory muscle for stomatognathic diseases, such as temporomandibular disorder, bruxism, or masseteric hypertrophy. Nonetheless, its muscular effect remains unclear. Better understanding could aid improved use and perhaps new indications, particularly in dentofacial orthopaedics and orthognathic surgery. METHODS: This systematic review explored the histologic and functional effects of botulinum toxin in animal and human masticatory muscles and was conducted in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The MEDLINE, Web of Science, and Cochrane Library electronic databases were searched for relevant articles. The inclusion criteria were human or animal masticatory muscle analysis after botulinum toxin injection(s) AND histological structural/ultrastructural analysis by optical or electronic microscopy OR functional effect analysis by bite force evaluation (occlusal force analyzer) and muscle activity (electromyography). RESULTS: Of an initial 1578 articles, 44 studies were eventually included. Botulinum toxin injection in the masticatory muscle altered its histological structure and functional properties. The human and animal studies revealed ultrastructural change, atrophy, and fiber type modifications of the masticatory muscles after one injection. Botulinum toxin decreased bite force and muscle activity, but recovery was uncertain. CONCLUSIONS: Muscle forces applied on the skeleton is a key feature of facial growth. Masticatory muscle paralysis changes mechanical stress on bones, which rebalances the force applied on facial bones. This new balance could benefit dental deformity or surgical relapse. Therefore, botulinum toxin could limit the orthognathic effect of the masticatory muscles in such patients. Given the uncertain recovery, multiple injections should be avoided, and usage should not deviate from established consensus.

Augmentation genioplasty using discarded bone fragments following proximal segment osteotomy of the ramus in intraoral vertical ramus osteotomy (IVRO).

BACKGROUND: Based on a three-dimensional (3D) orthognathic simulation, this technical report introduces a method for augmentation genioplasty using a proximal bone fragment of the mandible, which is typically discarded in intraoral vertical ramus osteotomy (IVRO). RESULTS: A 43-year-old female patient diagnosed with Class III malocclusion, presenting with a protruding mandible and long facial height, underwent surgical treatment. The surgical plan involved mandibular setback position using IVRO and augmentation genioplasty. The 3D orthognathic surgery including augmentation genioplasty simulation was performed. An excessively elongated proximal segment was sectioned following IVRO. The inferior part of the sectioned proximal bone fragment of the mandible was positioned to align with the requirements of advancement genioplasty. After ensuring that the placement of the fragment matched that of the simulated surgery, each bone fragment was fixed. At 1.5 years post-surgery, the grafted bone on the augmentation genioplasty was well maintained, with slight bone resorption. CONCLUSIONS: Augmentation genioplasty using the proximal bone fragment of the mandible, which is typically discarded in IVRO, reduces the surgical complications associated with chin osteotomy. When a secondary genioplasty is required, genioplasty with osteotomy, movement of the cut bone fragments, partial bone-shaving osteotomy, and additional bone grafting are viable options.

Appraising mandibular prognathism in class III malocclusion following orthognathic surgery: Patient-reported and cephalometry-based outcomes.

Patients with class III malocclusion often exhibit mandibular prognathism and complain of "prognathic appearance". The overall positive effects of orthognathic surgery on facial appearance have been demonstrated using patient-reported outcome measures (PROMs), but studies investigating the correlation between subjective PROMs results and objective measurements of imaging studies are sparse in the literature. This study recruited consecutive patients with skeletal class III malocclusion who underwent two-jaw orthognathic surgery between January 2016 and January 2021. The PROMs survey was conducted focusing on subjective perception of mandibular appearance. Lateral cephalometric images were measured to examine the correlation with the PROMs results. A total of 96 patients were eligible for this study. Of these, 74 patients (77.1%) reported complete correction of prognathic appearance postoperatively, whereas 22 patients (22.9%) perceived residual prognathic appearance. In a comparison of postoperative measurements between completely and incompletely satisfied patients, there were significant differences in SNB, ANB, convexity, facial angle, Nv-B, Nv-Pog, SN'B', soft tissue facial angle, lip-chin-throat angle, N'v-B', and N'v-Pog'. The PROM results were significantly associated with the objective measurements of imaging studies. Investigating the correlation between PROMs and objective measurements enables integration of patients' perception of the outcomes into future therapeutic strategy and surgical planning, contributing to the enhancement of patient satisfaction.

Novel GNAI3 mutation in a Chinese family with auriculocondylar syndrome and treatment of severe dentofacial deformities: a 5-year follow-up case report.

BACKGROUND: Auriculocondylar syndrome (ARCND) is an extremely rare autosomal dominant or recessive condition that typically manifests as question mark ears (QMEs), mandibular condyle hypoplasia, and micrognathia. Severe dental and maxillofacial malformations present considerable challenges in patients' lives and clinical treatment. Currently, only a few ARCND cases have been reported worldwide, but most of them are related to genetic mutations, clinical symptoms, and ear correction; there are few reports concerning the treatment of dentofacial deformities. CASE PRESENTATION: Here, we report a rare case of ARCND in a Chinese family. A novel insertional mutation in the guanine nucleotide-binding protein alpha-inhibiting activity polypeptide 3 (GNAI3) was identified in the patient and their brother using whole-exome sequencing. After a multidisciplinary consultation and examination, sequential orthodontic treatment and craniofacial surgery, including distraction osteogenesis and orthognathic surgery, were performed using three-dimensional (3D) digital technology to treat the patient's dentofacial deformity. A good prognosis was achieved at the 5-year follow-up, and the patient returned to normal life. CONCLUSIONS: ARCND is a monogenic and rare condition that can be diagnosed based on its clinical triad of core features. Molecular diagnosis plays a crucial role in the diagnosis of patients with inconspicuous clinical features. We present a novel insertion variation in GNAI3, which was identified in exon 2 of chromosome 110116384 in a Chinese family. Sequential therapy with preoperative orthodontic treatment combined with distraction osteogenesis and orthognathic surgery guided by 3D digital technology may be a practical and effective method for treating ARCND.

Anatomic and functional masseter muscle adaptation following orthognathic surgery-MRI analysis in 3 years of follow-up.

BACKGROUND: Orthodontic and surgical technical advances in recent years have resulted in treatment opportunities for a whole range of craniofacial skeletal disorders either in the adolescent or adult patient. In the growing child, these can include myofunctional orthodontic appliance therapy or distraction osteogenesis procedures, while in the adult, the mainstay approach revolves around orthognathic surgery. The literature agrees that for a change in craniofacial morphology to remain stable, the muscles acting upon the facial skeleton must be capable of adaptation in their structure and, therefore, their function. Failure of the muscles to adapt to the change in their length or orientation will place undesirable forces on the muscle attachments leading to potential instability of the skeleton. Adaptation can occur through various processes including those within the neuromuscular feedback mechanism, through changes within muscle structure or through altered muscle physiology, and through changes at the muscle/bone interface. It is now accepted that because there is no single method of assessing masticatory function, several measures should be taken, and whenever possible, simultaneously. METHODS: This investigation was designed to apply several, newly developed and more sophisticated methods of measuring muscle structure and function to a situation where adaptation of muscle is pivotal to the success of a therapeutic approach. Patients attending the combined orthodontic/orthognathic surgery clinic at the Clitrofa - Centro Médico, Dentário e Cirúrgico, in Trofa, Portugal, were screened. Ten patients scheduled for a bimaxillary osteotomy involving a combination of maxillary Le Fort I impaction procedure coupled with a sagittal split advancement of the mandible were selected to form the study group. The patients have MRI of the masseter muscle to evaluate the masseter muscle volume and fibre orientation changes. This exam was taken before surgery (T0), 6 to 12 months after surgery (T1), and 3 years after surgery (T2), by two independent observers, according to the protocol jointly developed between the Eastman Dental Institute - University of London and the MRI Centre - Department of Radiology at John Radcliffe Hospital - University of Oxford. RESULTS: Significant differences (p < 0.05) have been identified between Time 0 (pre-op) and Time 1 (6-12 months post-op) regarding the masseter area (mm2). The differences against Time 0 (pre-op) seem to disappear at Time 2 (3 years post-op). CONCLUSIONS: MRI therefore seems to be a valid tool for measuring differences in the masseter muscle area and volume associated with high-severity occlusal deformities, although showing not to be as efficient in detecting the same differences in cases of low-severity occlusal deformities.

Cephalometric evaluation of skeletal stability and pharyngeal airway changes after mandibular setback surgery: Bioabsorbable versus titanium plate and screw fixation.

Purpose: This study compared sequential changes in skeletal stability and the pharyngeal airway following mandibular setback surgery involving fixation with either a titanium or a bioabsorbable plate and screws. Materials and Methods: Twenty-eight patients with mandibular prognathism undergoing bilateral sagittal split osteotomy by titanium or bioabsorbable fixation were randomly selected in this study. Lateral cephalometric analysis was conducted preoperatively and at 1 week, 3-6 months, and 1 year postoperatively. Mandibular stability was assessed by examining horizontal (BX), vertical (BY), and angular measurements including the sella-nasion to point B angle and the mandibular plane angle (MPA). Pharyngeal airway changes were evaluated by analyzing the nasopharynx, uvula-pharynx, tongue-pharynx, and epiglottis-pharynx (EOP) distances. Mandibular and pharyngeal airway changes were examined sequentially. To evaluate postoperative changes within groups, the Wilcoxon signed-rank test was employed, while the Mann-Whitney U test was used for between-group comparisons. Immediate postoperative changes in the airway were correlated to surgical movements using the Spearman rank test. Results: Significant changes in the MPA were observed in both the titanium and bioabsorbable groups at 3-6 months post-surgery, with significance persisting in the bioabsorbable group at 1 year postoperatively (2.29°±2.28°; P<0.05). The bioabsorbable group also exhibited significant EOP changes (-1.21±1.54 mm; P<0.05) at 3-6 months, which gradually returned to non-significant levels by 1 year postoperatively. Conclusion: Osteofixation using bioabsorbable plates and screws is comparable to that achieved with titanium in long-term skeletal stability and maintaining pharyngeal airway dimensions. However, a tendency for relapse exists, especially regarding the MPA.

"The impact of orthognathic surgery on articulation proficiency and speech intelligibility in skeletal Class III malocclusion: 18 months follow up".

Introduction: Orthognathic surgery results in the positional change of the maxilla and mandible that may affect speech. The present study evaluated the effect of combined maxillary advancement and mandibular setback surgery on articulation proficiency and speech intelligibility in patients with non-syndromic skeletal Class III malocclusion. Methods: In this prospective study, twenty-five patients with skeletal class III malocclusion and consecutively treated with Lefort-1 maxillary advancement and mandibular setback (BSSO) orthognathic surgery were included in this study. The speech sample was recorded with a digital audio tape recorder one day before surgery and at 3, 6, 9, 12 and 18 months after surgery. Three qualified and experienced speech and language pathologists evaluated articulation errors and intelligibility of speech samples. Repeated One-way analysis of variance was used to compare articulation proficiency and speech intelligibility at different time intervals. Results: The substitution, omission, distortion and addition errors showed no significant changes at 3 months and 6 months. The total articulation errors decreased to zero at 9 months and no significant increase was observed till 18 months (P < 0.05). Speech intelligibility showed statistically non-significant improvement at any time interval. Cephalometric skeletal parameters SNA and N l A°. were significantly correlated with addition and total articulation errors at 18 months follow up. Conclusions: The ortho-surgical treatment improves speech (decreases. articulation errors) in most of the patients usually 6-9 months post-surgery. Speech intelligibility is not affected by bimaxillary orthognathic surgery in skeletal class III patients. The articulation errors were correlated to changes in position of maxilla.

Comparison of smile attractiveness in cases with gummy smile treated with botulinum toxin and maxillary impaction surgery: A retrospective study.

This study aimed to compare the smile's attractiveness in patients submitted to the treatment of gummy smiles with botulinum toxin or maxillary impaction surgery. The retrospective sample comprised 26 patients divided into two groups: Group 1 (BTX): 13 patients (12 females and 1 male) with a mean age of 28.06 years (s.d. = 6.09) and mean gingival exposure during smile of 5.18 mm (s.d. = 1.51) treated with botulinum toxin; Group 2 (SURGICAL): 13 patients (9 females and 4 males) with a mean age of 30.59 years (s.d. = 5.72) and mean gingival exposure during smile of 5.21 mm (s.d. = 1.55) treated with orthognathic maxillary impaction surgery. The group of evaluators comprised 317 participants, divided into 143 orthodontists (85 females and 58 males) with a mean age of 41.40 (s.d. = 9.30); 62 dentists (47 female and 15 male) with a mean age of 35.44 (s.d. = 10.44), and 112 lay people (74 female and 38 male) with a mean age of 46, 91 (s.d. = 10.11) in a questionnaire on Google Forms. Without knowing the therapy used, the evaluators assigned scores to the photographs of the posed smile taken before (T1) and after (T2) treatment. Intergroup comparison of smile attractiveness was performed using the t-independent, one-way ANOVA, and Tukey tests. There was a significant improvement in smile attractiveness with treatment in both groups; however, the improvement was significantly better in the surgical group than in the BTX group. Orthodontists rated smile attractiveness significantly higher than dentists and laypersons for the final phase of the BTX and surgical groups. There was a significant improvement in the smile attractiveness with botulinum toxin application and orthodontic-surgical treatment. However, orthognathic surgery promoted a greater improvement in smile attractiveness than the application of botulinum toxin.

3D evaluation model of facial aesthetics based on multi-input 3D convolution neural networks for orthognathic surgery.

BACKGROUND: Quantitative evaluation of facial aesthetics is an important but also time-consuming procedure in orthognathic surgery, while existing 2D beauty-scoring models are mainly used for entertainment with less clinical impact. METHODS: A deep-learning-based 3D evaluation model DeepBeauty3D was designed and trained using 133 patients' CT images. The customised image preprocessing module extracted the skeleton, soft tissue, and personal physical information from raw DICOM data, and the predicting network module employed 3-input-2-output convolution neural networks (CNN) to receive the aforementioned data and output aesthetic scores automatically. RESULTS: Experiment results showed that this model predicted the skeleton and soft tissue score with 0.231 ± 0.218 (4.62%) and 0.100 ± 0.344 (2.00%) accuracy in 11.203 ± 2.824 s from raw CT images. CONCLUSION: This study provided an end-to-end solution using real clinical data based on 3D CNN to quantitatively evaluate facial aesthetics by considering three anatomical factors simultaneously, showing promising potential in reducing workload and bridging the surgeon-patient aesthetics perspective gap.

Risk Factors Contributing to Symptomatic Miniplate Removal following Orthognathic Surgery: Systematic Review and Meta-Analysis.

Background/Objectives: The use of miniplates for stabilizing bones post orthognathic surgery has surged in popularity due to their efficacy in ensuring stability and hastening recovery. However, controversy exists regarding what should be done with these miniplates after surgery. Some surgeons advocate for their removal, while others suggest leaving them in place. This study sought to assess the frequency, causes, and potential risk factors linked with miniplate removal in orthognathic procedures. Methods: A thorough meta-analysis was conducted by scrutinizing studies from various databases including PubMed, Google Scholar, Embase, and Scopus, focusing on publications spanning from 1989 to 2023. Results: Ten studies meeting the inclusion criteria, encompassing 1603 patients, were chosen for inclusion in the meta-analysis. The male-to-female ratio varied from 0.7:1 to 4:1. Overall, 5595 miniplates were inserted, with 294 (5.3%) being subsequently removed. Primary reasons for miniplate removal included infection (161 cases, 2.9%), exposure of miniplates (34 cases, 0.6%), and palpable plates (23 cases, 0.4%). Other indications comprised pain, patient preference, and temperature sensitivity. Less frequent causes for miniplate removal included sinusitis, secondary surgery, and dental pathology. The mean duration of miniplate removal was 5.5 months, with the majority (56.1%) being removed from the mandible rather than the maxilla. In conclusion, this meta-analysis underscores the importance of miniplate removal when hardware causes complications and physical discomfort. The primary reasons for removing miniplates were infection and plate exposure, with the mandible being the most common removal site. Conclusions: These findings emphasize the need for continued monitoring to assess the fate of miniplates in orthognathic surgery and provide valuable information for future clinical decision-making.

Obstructive sleep apnea: What is an orthodontist's role?

BACKGROUND: The American Association of Orthodontists white paper on obstructive sleep apnea and orthodontics remains the most authoritative statement on the topic. This was produced in 2019 due to increasing orthodontic interest in obstructive sleep apnea (OSA) and the lack of formal guidelines for orthodontists. Since the white paper's release, advocacy for contrarian ideas and practices remain. Orthodontists are sometimes acting as primary care providers for OSA. Procedures appropriate only for screening are sometimes being used for diagnosis. The side effects of effective treatments such as mandibular advancement devices need further consideration. Also, research has clarified the effectiveness and ineffectiveness of treatments such as palatal expansion. RESULTS: Part of an orthodontist's role is screening for OSA. The correct action when this is suspected remains referral to the appropriate physician specialist for diagnosis and treatment or coordination of treatment. Orthodontists may participate in the treatment of patients with OSA as a member of a multi-disciplinary team. Effective orthodontic treatments may include orthognathic surgery with maxillomandibular advancement and mandibular advancement devices. The negative effects of the latter make this a choice of last resort. Current research indicates that OSA alone is not sufficient indication for palatal expansion. CONCLUSIONS: Orthodontists should appropriately screen for obstructive sleep apnea. This may be done as part of our health histories, our clinical examination, and review of radiographs taken for purposes other than the diagnosis and screening for OSA. Orthodontic treatment for OSA can be helpful and effective. However, this may be done only after referral to the appropriate physician specialist, as part of a multi-disciplinary team, with consideration of the likely effectiveness of treatment, and after all likely and potential negative consequences have been considered and thoroughly discussed with the patient.

Artificial Intelligence Used for Diagnosis in Facial Deformities: A Systematic Review.

AI is included in a lot of different systems. In facial surgery, there are some AI-based software programs oriented to diagnosis in facial surgery. This study aims to evaluate the capacity and training of models for diagnosis of dentofacial deformities in class II and class III patients using artificial intelligence and the potential use for indicating orthognathic surgery. The search strategy is from 1943 to April 2024 in PubMed, Embase, Scopus, Lilacs, and Web of Science. Studies that used imaging to assess anatomical structures, airway volume, and craniofacial positions using the AI algorithm in the human population were included. The methodological quality of the studies was assessed using the Effective Public Health Practice Project instrument. The systematic search identified 697 articles. Eight studies were obtained for descriptive analysis after exclusion according to our inclusion and exclusion criteria. All studies were retrospective in design. A total of 5552 subjects with an age range between 14.7 and 56 years were obtained; 2474 (44.56%) subjects were male, and 3078 (55.43%) were female. Six studies were analyzed using 2D imaging and obtained highly accurate results in diagnosing skeletal features and determining the need for orthognathic surgery, and two studies used 3D imaging for measurement and diagnosis. Limitations of the studies such as age, diagnosis in facial deformity, and the included variables were observed. Concerning the overall analysis bias, six studies were at moderate risk due to weak study designs, while two were at high risk of bias. We can conclude that, with the few articles included, using AI-based software allows for some craniometric recognition and measurements to determine the diagnosis of facial deformities using mainly 2D analysis. However, it is necessary to perform studies based on three-dimensional images, increase the sample size, and train models in different populations to ensure accuracy of AI applications in this field. After that, the models can be trained for dentofacial diagnosis.

Changes in Maxillary Sinus Volume and Mucosal Thickness Post Bimaxillary Advancement Procedures: A Retrospective Study.

Background: Bimaxillary surgery is an elemental procedure in the field of cranio-maxillofacial surgery. It allows for the correction of even the most challenging cases of maxillomandibular disorders, malocclusion, facial asymmetry, and disproportion. The osteotomies and maneuvers carried out during the procedure result in changes to the surrounding tissues, including the maxillary sinuses (MS). The aim of this study was to assess the change in the maxillary sinus volume and the thickness of the mucosa after maxillomandibular advancement (MMA) surgeries. Methods: A group of 25 patients who underwent MMA surgery were included in the study. Computed tomography (CT) of the head and neck region was performed 2 weeks preoperatively and 6 months postoperatively. Acquired Digital Imaging and Communications in Medicine (DICOM) files were analyzed using different software programs to calculate the medium MS mucosa thickness and MS volume. Results: A statistically significant reduction in MS volume was observed (p = 0.015). The change in the median thickness of the MS mucosa was not statistically significant. The median sella-nasion-A point angle (SNA angle) value of the group increased from 80.2 to 83.4 degrees. A weak negative correlation between the SNA delta and the MS volume delta was observed. Spearman's rank coefficient: (ρ s = -0.381, p = 0.060). Conclusions: The MMA surgery results in a reduction in the MS volume. The amount of forward movement of the maxilla may be correlated with the extent of the MS volume reduction.