BACKGROUND: Pattern of dental anomalies encountered in cleft patients shows subtle signs of genetic involvement. This study aimed to evaluate the prevalence and pattern of tooth agenesis and supernumerary teeth in Thai cleft population according to the cleft type.
METHODS: Data collected from patients with cleft lip and palate, who had been treated at Tawanchai Cleft Center, Khon Kaen University, Thailand, available during year 2012-2022, were investigated. Records from 194 patients with non-syndromic clefts met the inclusion criteria. Standard dental records, and at least either orthopantomogram (OPG) or cone beam computed tomography (CBCT), were examined. Statistical analysis was performed using chi-square and binominal test (p ≤ 0.05).
RESULTS: Prevalence of tooth agenesis was higher (77.3%) than that of supernumerary teeth (5.7%) and was more common in bilateral cleft lip and palate (BCLP) (88.1%) than in unilateral cleft lip and palate (UCLP) (72.6%) (p = 0.017). The upper lateral incisor was more frequently affected (46.4%), followed by the upper second premolar. The number of missing teeth observed on the left side was significantly higher. Patients with left UCLP (ULCLP) had the highest prevalence of tooth agenesis. A total of 41 tooth agenesis code (TAC) patterns was found. The prevalence of supernumerary teeth was comparable with 6.6% of ULCLP, 5.1% of BCLP, and 4.5% of URCLP. Tooth-number anomalies were observed more often in the BCLP and were most likely to occur on the left side of the maxilla. Both types of anomalies could be featured in a small proportion of cleft patients.
CONCLUSIONS: More than half of the patients with non-syndromic cleft lip and palate in this study, presented with tooth-number anomalies. Tooth agenesis was approximately 10-time more prevalent than supernumerary teeth. Tooth agenesis was likely to appear on the left-side of the maxilla regardless of the laterality of the cleft.

UNASSIGNED: The association between psychiatric disorders and dentofacial deformities has attracted widespread attention. However, their relationship is currently unclear and controversial.
UNASSIGNED: A two-sample bidirectional MR analysis was performed to study the causal relationship between dentofacial deformity and eight psychiatric disorders, including major depressive disorder, panic disorder, schizophrenia, bipolar disorder, attention deficit hyperactivity disorder, Alzheimer\'s disease, autism spectrum disorder, and neuroticism. Inverse variance weighted, weighted median, MR-Egger regression, weighted mode four methods, and further sensitivity analyses were conducted.
UNASSIGNED: The major depressive disorder affected dentofacial deformity, with an OR = 1.387 (95% CI = 1.181-1.629, P = 6.77×10-5). No other psychiatric disorders were found to be associated with dentofacial deformity. In turn, dentofacial deformity were associated with neuroticism, with an OR = 1.050 (95% CI = 1.008-1.093, P = 0.018). And there was no evidence that dentofacial deformity would increase the risk of other psychiatric disorders.
UNASSIGNED: Major depressive disorder might elevate the risk of dentofacial deformities, and dentofacial deformity conditions would increase the risk of the incidence of neuroticism.

BACKGROUND: 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.

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.
METHODS: 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.

This study aimed to compare the pre- and post-operative temporomandibular joint (TMJ) condylar position in dentofacial deformity (DFD) patients who had orthognathic surgeries using cone beam computed tomography (CBCT). A retrospective study evaluating the pre- and post-operative CBCT for 79 DFD patients (equivalent to 158 TMJs) (mean age = 26.62 ± 9.5 years) with a bilateral sagittal split osteotomy with or without Le Fort I surgeries (n = 29 Class II DFD, n = 50 Class III DFD) was performed. This included the compartmental measurement of TMJ spaces, in addition to the measurement of intercondylar distances and angles. Condylar position centricity was assessed using the Pullinger and Hollender formula. Clinical data were analysed for DFD class, the type of surgery and post-operative CBCT timing. Pre- and post-operative measurements were compared statistically using a paired t-test, Wilcoxon signed-rank test, and Stuart-Maxwell test. TMJ condyles tended to relocate post-operatively in a posterosuperior position with internal rotation in Class II DFD and a superior position with internal rotation in Class III DFD. However, the overall changes were within <0.5 mm translation and <4° rotation and the number of concentrically positioned condyles (according to the Pullinger and Hollender formula) did not change significantly. Orthognathic surgery is associated with minor post-operative translational and rotational condylar positional changes in Class II and III DFDs.

With the growing demand for orthognathic surgery and other facial treatments, the accurate identification of anatomical landmarks has become crucial. Recent advancements have shifted towards using three-dimensional radiologic analysis instead of traditional two-dimensional methods, as it allows for more precise treatment planning, primarily relying on direct identification by clinicians. However, manual tracing can be time-consuming, mainly when dealing with a large number of patients. This study compared the accuracy and reliability of identifying anatomical landmarks using artificial intelligence (AI) and manual identification. Thirty patients over 19 years old who underwent pre-orthodontic and orthognathic surgery treatment and had pre-orthodontic three-dimensional radiologic scans were selected. Thirteen anatomical indicators were identified using both AI and manual methods. The landmarks were identified by AI and four experienced clinicians, and multiple ANOVA was performed to analyze the results. The study results revealed minimal significant differences between AI and manual tracing, with a maximum deviation of less than 2.83 mm. This indicates that utilizing AI to identify anatomical landmarks can be a reliable method in planning orthognathic surgery. Our findings suggest that using AI for anatomical landmark identification can enhance treatment accuracy and reliability, ultimately benefiting clinicians and patients.

Sagittal split ramus osteotomy (SSRO) is a versatile orthognathic procedure for correcting mandibular deformities. Various complications can possibly occur when performing SSRO, and it can even cause serious adverse consequences because of the complexity of anatomy and operative procedures. The types of complications and their accompanying clinical manifestations are closely related to the choice of diagnosis and treatment strategies and clinical outcomes. To discuss the causes, prevention, and treatment measures of various common complications of SSRO, domestic orthognathic surgery experts prepared this consensus to increase the awareness of SSRO complications, thereby ensuring safe surgical procedure and good results.
下颌支矢状骨劈开术（SSRO）是正颌外科中最为常用的一类矫治下颌骨畸形的手术。由于局部解剖和操作步骤的复杂性，SSRO出现各类并发症的可能性较大，甚至可能造成严重的不良后果。诊疗策略的选择及转归与并发症的类型及其临床表现密切相关。为此，国内相关专家编写本共识，对SSRO各类常见并发症的原因、预防、处置措施进行阐述，以期提高广大同行对SSRO并发症的认识，确保手术安全进行并获得良好效果。.

Facial symmetry refers to a complete coincidence of each facial component on the sagittal plane, while asymmetry refers to the bilateral difference between these components. The presence of perfect bilateral symmetry is almost never present in human, so it is more common for individuals to predominate facial asymmetry. However, this condition can result from functional and esthetic problems. This research seeks to determine the alternatives, diagnosis and ideal treatment plan for the correction of each type of facial asymmetry through orthognathic surgery. For this purpose, a review of articles published between 2015 to date was carried out. Selecting those that were focused on describing or evaluating facial and dentofacial symmetry and asymmetry, type of diagnosis or treatment plan, including clinical cases. The Google search engine, SciELO and databases of medical interest, such as PubMed, PMC and Medigraphic were used. According to the research and treatments carried out during the last few years in the dental clinic, it has been proven that orthognathic treatment accompanied by previous planning is the best option for the management of skeletal facial asymmetries.

The aim of this study was to investigate the impact of orthognathic therapy on patients\' quality of life. Therefore, a systematic review was conducted including all prospective studies that compared pretherapeutic and posttherapeutic Oral Health Impact Profile (OHIP) or Overall Quality of Life (OQOL) questionnaire scores. Studies in patients with congenital deformities, clefts, or posttraumatic or cancer-associated deformities were excluded. Overall, 23 prospective studies were included; 8 used OHIP, 9 used OQOL and 6 used both questionnaires. A total of 1039 patients were identified (60.29% women, 39.71% men), with a mean age of 45.17 years. All analyzed studies showed in both OHIP and OQLQ an improvement of the quality of life in patients after orthognathic therapy. While improved scores could be observed in all investigated criteria, the studies demonstrated that social and aesthetic aspects showed the most prominent impact. Comparison of different Angle Classes showed, furthermore, that Class III patients had an even greater advantage over those with a Class II deformity. The review confirms that the quality of life in patients with orthognathic therapy improves significantly in all observed aspects. With regard to Angle Classes, Class III patients showed an even greater improvement than Class II patients.

UNASSIGNED: This study is designed to evaluate the need for a greater emphasis on clinical facial analysis over cephalometrics in the diagnosis and treatment planning of patients with dentofacial deformities.
UNASSIGNED: A predetermined questionnaire study was designed to get the thought process of surgeons and consultants involved in orthognathic surgery from various parts of southern India. Two hundred and twenty-eight maxillofacial consultants were involved in the survey. Demographic information, type of professional practice, preferred tool in the diagnosis & treatment planning: Cephalometrics or 3D software solutions and flaw in the available tools were evaluated.
UNASSIGNED: The results of this study revealed that only 36.8% of the consultants felt that cephalometrics is the prime tool and 73.3% of the consultants felt that 3D software solutions were superior to cephalometrics in the diagnosis and treatment planning of patients with dentofacial deformities. However, 46% of the consultants preferred facial analysis as the prime tool with cephalometrics as an adjunct. Pertaining to the clinical outcome of their treated cases of dentofacial deformities, 61.8% of the consultants felt the need to address additional cosmetic issues following an orthognathic procedure. It was observed that 92.1% of the participants felt the need for greater emphasis on clinical facial analysis than cephalometrics.
UNASSIGNED: Human faces should always be evaluated taking into consideration the various esthetic units of the face. Performing corrective jaw surgery merely based on cephalometric values inevitably fails to address the various other innate imbalances of the face. Hence, cephalometric data should only be considered as an adjunct to clinical judgment in the diagnosis and treatment planning of dentofacial deformities.