OBJECTIVE: To establish a similarity measurement model for patients with dentofacial deformity based on 3D craniofacial features and to validate the similarity results with quantifying subjective expert scoring. METHODS: In the study, 52 cases of patients with skeletal Class Ⅲ malocclusions who underwent bimaxillary surgery and preoperative orthodontic treatment at Peking University School and Hospital of Stomatology from January 2020 to December 2022, including 26 males and 26 females, were selected and divided into 2 groups by sex. One patient in each group was randomly selected as a reference sample, and the others were set as test samples. Three senior surgeons rated the similarity scores between the test samples and the reference sample. Similarity scores ranged from 1 to 10, where 1 was completely different, and 10 was exactly the same. Scores larger than 7.5 was considered as clinically similar. Preoperative cone beam computed tomography (CBCT) and 3D facial images of the patients were collected. The three-dimensional hard and soft tissue features, including distances, angles and 3D point cloud features were extracted. The similarity measurement model was then established to fit with the experts' similarity scoring by feature selection algorithm and linear regression model. To verify the reliability of the model, 14 new patients were selected and input to similarity measurement model for finding similar cases. The similarity scoring of these similar cases were rated by experts, and used to evaluate the reliability of the model. RESULTS: The similarity metric models indicated that the features of the middle and lower craniofacial features were the main features to influence the craniofacial similarity. The main features that were related to the expert' s similarity scoring included distance of anterior nasal spine-menton (ANS-Me), distance of right upper canion point-Frankfurt horizontal plane (U3RH), distance of left superior point of the condyle-left gonion (CoL-GoL), distance of left gonion-menton (CoL-Me), distance of pogonion-midsagittal plane (Pog-MSP), distance of right alar base-left alar base (AlR-AlL), angle of pronasale-soft tissue pogonion-labrale inferius (Pn-Pog' -Li), distance of trichion-right tragus (Tri-TraR), distance of left exocanthion-left alar base (ExL-AlL), lower 1/3 of skeletal face, middle and lower 2/3 of skeletal face and upper lip region of soft tissue. Fourteen new patients were chosen to evaluate the model. The similar cases selected by the model had an average experts' similarity scoring of 7.627± 0.711, which was not significantly different with 7.5. CONCLUSION The similarity measurement model established by this model could find the similar cases which highly matched experts' subjective similarity scoring. The study could be further used for similar cases retrieval in skeletal Ⅲ malocclusion patients.
Humans ; Male ; Female ; Imaging, Three-Dimensional/methods* ; Cone-Beam Computed Tomography ; Malocclusion, Angle Class III/surgery* ; Orthognathic Surgical Procedures/methods* ; Face/anatomy & histology* ; Cephalometry/methods* ; Adult ; Adolescent ; Dentofacial Deformities/surgery* ; Young Adult

OBJECTIVES: This study aims to compare the effects of two orthodontic treatment modalities for skeletal class Ⅲ malocclusion on specific changes in airway volume, morphology, palatal angle, mandibular rotation, and bone displacement. Results provide scientific evidence for the selection of orthodontic treatment plans and reduce the risk of developing obstructive sleep apnea hypopnea syndrome (OSAHS). METHODS: Thirty-six patients diagnosed with skeletal class Ⅲ malocclusion at the Department of Orthodontics, the Affiliated Stomatological Hospital of Nanjing Medical University from September 2018 to December 2023 were divided into two groups: orthodontic-orthognathic treatment group (18 patients) and camouflage orthodontic treatment group (18 patients). Changes in airway volume, cross-sectional area, palatal angle, mandibular, and tongue positions were observed through pre- and post-operative cone beam computed tomography and 3D cephalometric measurements. RESULTS: In the camouflage orthodontic treatment group, nasopharyngeal volume and oropharyngeal volume statistically increased after treatment (P<0.05). In the orthodontic-orthognathic treatment group, changes in nasopharyngeal volume, nasopharyngeal airway, distance from posterior tongue to pharyngeal wall, palatal angle, mandibular rotation, and hyoid bone displacement were statistically significant after surgery (P<0.05). In the comparison between the two groups after treatment, changes in the distance from posterior tongue to pharyngeal wall, palatal angle, and distance from hyoid bone to sella turcica point were statistically significant (P<0.05). CONCLUSIONS Patients in the orthodontic-orthognathic treatment group showed significantly greater changes in oropharyngeal cross-sectional area, palate angle, and tongue position compared with patients in the camouflage orthodontic treatment group. As individuals susceptible to OSAHS often exhibit mandibular retrusion and decreased minimum airway cross-sectional area, special attention should be paid to airway morphology changes when adopting orthodontic-orthognathic treatment to avoid adverse consequences.
Humans ; Hyoid Bone/diagnostic imaging* ; Malocclusion, Angle Class III/therapy* ; Male ; Female ; Cone-Beam Computed Tomography ; Cephalometry ; Orthodontics, Corrective/methods* ; Adult ; Mandible ; Pharynx/diagnostic imaging* ; Sleep Apnea, Obstructive/etiology* ; Orthognathic Surgical Procedures

PURPOSE: The purpose of the study is to compare the surgical access and post-operative outcome of two intra-oral incisions used for approaching a mandibular body fracture. METHODS: This clinical trial involved 60 patients with mandibular body fractures who were randomly allocated to control and study groups. The fractures were approached using the routine vestibular incision in the control group and crevicular incision with vertical release in the study group. The effects of incision design on the post-surgical outcome variables like swelling, trismus, paresthesia, wound healing and gingival recession were statistically analysed with non-parametric tests by using SPSS 22.0 software. Comparison of continuous variables between the groups and time points was done using Mann Whitney test and Friedman test respectively. Chi-square test was used to compare proportions between groups. Dunn's test with Bonferroni correction was used for pair wise comparisons. RESULTS: The study group demonstrated favourable surgical outcome in the immediate postoperative phase as compared to the control group. The difference in mouth opening, swelling and neurosensory impairment between the two groups was found to be statistically significant (p < 0.05). CONCLUSION Crevicular incision was found to be an ideal alternative to vestibular incision in achieving surgical access and fixation of mandibular body fractures with reduction in postoperative patient discomfort and better surgical outcome.
Adult ; Female ; Fracture Fixation, Internal ; methods ; Humans ; Male ; Mandibular Fractures ; physiopathology ; surgery ; Middle Aged ; Open Fracture Reduction ; methods ; Orthognathic Surgical Procedures ; methods ; Surgical Wound ; Treatment Outcome ; Young Adult

The presence of a large palatal or maxillary defect after partial or total maxillectomy for tumor, trauma or congenital deformation poses a challenge to prosthodontists, particularly when the use of an implant cannot be considered. This case report described the use of an air valve in a hollow silicone obturator to manufacture an inflatable obturator that could be extended further into undercut area to retain itself. The inflatable obturator exhibited adequate retention, stability and border sealing, thereby improving the masticatory,pronunciation and swallowing functions of patients. It may be a suitable alternative treatment option to an implant-retained obturator.
Dental Impression Technique ; Dental Prosthesis Design ; Dental Prosthesis Retention ; Denture Retention ; Denture, Complete, Upper ; Fibrous Dysplasia of Bone ; rehabilitation ; surgery ; Humans ; Male ; Maxilla ; surgery ; Orthognathic Surgical Procedures ; instrumentation ; methods ; rehabilitation ; Palatal Obturators ; Silicones ; Treatment Outcome ; Young Adult

OBJECTIVETo sum up the various procedures for skeleton and soft tissue contour reconstruction in severe progressive hemifacial atrophy.

METHODSFrom Jan 2004 to May 2012, 25 patients with severe progressive hemifacial atrophy underwent the procedures of lipoinjection, microsurgical flap transplantation, dermis grafting, distraction osteogenesis, orthognathic surgery and so on for both skeleton and soft tissue reconstruction.

RESULTSAmong them, zygomatic augmentation and lipoinjection were performed in 24 cases, anterolateral thigh adipofascial flap in 10 cases and latissimus dorsi flap in one case, orthognathic surgery in 17 cases, including Le Fort I osetoectomy in 3 cases, genioplasty in 4 cases, mandibular distraction osteogenesis combined with secondary Le Fort I osteotomy in 3 cases, genioplasty combined with mandibular augmentation with Medpor implant in 7 cases. The patients were followed up for 6 months to 5 years. Through skelton and soft tissue reconstruction, the oblique occlusion plane and malocclusion were corrected with great improvement in face asymmetry.

CONCLUSIONSFor severe progreassive hemifacial atrophy, comprehensive procedures should be adopted for both skelton and soft tissue reconstruction to achieve good results.

Adipose Tissue ; transplantation ; Facial Asymmetry ; surgery ; Facial Hemiatrophy ; surgery ; Humans ; Mandible ; surgery ; Orthognathic Surgical Procedures ; Osteogenesis, Distraction ; methods ; Osteotomy, Le Fort ; methods ; Reconstructive Surgical Procedures ; methods ; Skin Transplantation ; methods ; Surgical Flaps ; transplantation

Computer Simulation ; Computer-Assisted Instruction ; methods ; Dental Models ; Humans ; Oral Surgical Procedures ; education ; Orthognathic Surgical Procedures ; education ; User-Computer Interface

OBJECTIVETo restore good occlusion and face profile, the orthognathic operation and orthodontics were used to correct the dento-maxillofacial deformities following the repair of cleft lip and palate.

METHODS21 patients (7 males and 14 females, mean age of 20.6 years) were included in this study. Their dento-maxillofacial deformities following the repair of cleft lip and palate have been corrected in our hospital since 1996. Of them, 17 patients received pre- and postoperative orthodontic treatments. 21 cases underwent the following surgical procedures: Le Fort I osteotomy in 7 cases, multisegmental Le Fort I osteotomy in 5 cases, Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) in 4 cases, Le Fort I osteotomy and mandibular body osteotomy in 2 cases, BSSRO and genioplasty in 2 cases, BSSRO in 1 case. Rigid internal fixation was used in all patients. After multisegmental Le Fort I osteotomy, the rigid fixed palatine splint was used for 6 approximately 8 weeks.

RESULTSOsteotomy segments healed well in all cases without severe complications. 14 patients were followed-up for an average of 25.6 months. There was no evident relapse. 12 patients who received pre- and postoperative orthodontic treatments had satisfactory occlusion and face profile.

CONCLUSIONSOrthognathic operation combined with orthodontics can be used satisfactorily to correct the dento-maxillofacial deformities following cleft lip and palate repair.

Adolescent ; Adult ; Cleft Lip ; surgery ; Cleft Palate ; surgery ; Female ; Follow-Up Studies ; Humans ; Male ; Maxillofacial Abnormalities ; etiology ; surgery ; Orthodontics, Corrective ; Orthognathic Surgical Procedures ; methods ; Osteotomy ; Postoperative Complications ; surgery ; Young Adult