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

Dentofacial deformities secondary to condylar hyperplasiais a kind of disease presenting facial asymmetry, malocclusion, temporomandibular joint dysfunction, and other symptoms caused by non-neoplastic hyperplasia of the condyle. The etiology is still unknown, and currently, pre- and post-operative orthodontics accompanied by orthognathic surgery, temporomandibular joint surgery and jawbone contouring surgery are the main treatment methods. A personalized treatment plan was developed, considering the active degree of condyle hyperplasia, the severity of the jaw deformity, and the patient's will, to correct deformity, obtain ideal occlusal relationship, and regain good temporomandibular joint function. Combined with the author's clinical experience, the etiology, clinical and imageological features, treatment aims, and surgical methods of condylar hyperplasia and secondary dentofacial deformities were discussed in this paper.
Humans ; Dentofacial Deformities/pathology* ; Hyperplasia/pathology* ; Mandibular Condyle/surgery* ; Orthognathic Surgical Procedures ; Temporomandibular Joint/surgery*

Treating dentofacial deformities secondary to condylar resorption is a remarkable clinical challenge. Combined orthodontic treatment and orthognathic surgery is currently the main treatment scheme and is often integrated with temporomandibular joint surgery or conservative treatment according to the severity of condylar resorption. This paper discussed the etiology, clinical features, imaging features, treatment options, and prophylaxis of condylar resorption.
Bone Resorption ; Dentofacial Deformities ; Humans ; Mandibular Condyle ; Orthognathic Surgery ; Orthognathic Surgical Procedures ; Temporomandibular Joint

BACKGROUND: Fibrous dysplasia (FD) is characterized by the replacement of normal bone by abnormal fibro-osseous connective tissue and typically treated with surgical contouring of the dysplastic bone. When dysplastic lesions involve occlusion, not only is surgical debulking needed, orthognathic surgery for correction of dentofacial deformity is mandatory. However, the long-term stability of osteotomized, dysplastic bone segments is a major concern because of insufficient screw-to-bone engagement during surgery and the risk of FD lesion re-growth. CASE PRESENTATION: This case report reviewed two patients with non-syndromic FD that presented with maxillary occlusal canting and facial asymmetry. Le Fort I osteotomy with recontouring of the dysplastic zygomaticomaxillary region had been performed. The stability of osseous segments were favorable. However, dysplastic, newly formed bone covered the previous plate fixation site and mild bony expansion was observed, which did not influence the facial profile. Including the current cases, 15 cases of orthognathic surgery for FD with dentition have been reported in the literature. CONCLUSION: The results showed that osteotomy did not appear to significantly reduce the long-term stability of the initial fixation insufficiency of the screw to the dysplastic bone. However, based on our results and those of the others, long-term follow-up and monitoring are needed, even in cases where the osteotomized segment shows stable results.
Connective Tissue ; Dentition ; Dentofacial Deformities ; Facial Asymmetry ; Follow-Up Studies ; Humans ; Orthognathic Surgery ; Osteotomy

A 28-year-old male patient with right maxillar, zygomatic arch, orbital wall, and nasal bone fractures had an orthognathic and nasal surgery. Naso-endotracheal intubation is the first choice during surgical correction of dentofacial deformities in an orthognathic surgery; however, its presence can interfere with concomitant surgical procedures on the nose. Traditionally, the naso-endotracheal tube will be removed and replaced with an oro-endotracheal tube. We changed the endotracheal tube from nasal to oral by using an airway exchange catheter.
Adult ; Catheters* ; Dentofacial Deformities ; Humans ; Intubation ; Male ; Nasal Bone ; Nasal Surgical Procedures* ; Nose ; Orbit ; Orthognathic Surgery ; Zygoma

surgery serves to combine the total or segmental maxillary and mandibular correction of the dentofacial deformities with concurrent procedures to provide immediate repositioning to the dento-osseous elements. In addition, splitting the palate may often be necessary to correct a functionally poor relationship of the maxilla to the mandible or the facial skeleton by realigning the maxillary arch. In this case, the discrepancy in a bimaxillary horizontal relationship and the space between the 2nd premolar and 2nd molar was retained after lengthy preoperative orthodontic treatment. However, we could correct these dento-osseous discrepancies immediately by performing midpalatal expansion, anterior segmental osteotomy and symphyseal osteotomy with bimaxillary osteotomies. If the blood supply to each segment segments was maintained and primary closure of the operation site was feasible, multiple segment osteotomy was considered as a very effective technique for treating dentofacial deformities in vertical, transverse, and sagittal dimensions with differential repositioning of all segments.]]>
Bicuspid ; Dentofacial Deformities ; Mandible ; Maxilla ; Molar ; Orthognathic Surgery ; Osteotomy ; Palate ; Skeleton

OBJECTIVES: This study was performed in order to evaluate the occurrence of temporomandibular joint disorder after surgical correction of skeletal class II malocclusion. MATERIALS AND METHODS: This study included 21 patients who underwent orthognathic surgery for the correction of dentofacial deformities by a single surgeon at Mokdong Hospital, Ewha Womans University from 2000 to 2010. They underwent bilateral sagittal split ramus osteotomy for the treatment of undesirable mandibular advancement. The temporomandibular disorder (TMD) symptoms prior to surgery were recorded and the radiographic evaluation (panorama, bone scan, and magnetic resonance imaging [MRI]) of the post-surgery temporomandibular joint (TMJ) were assessed in order to evaluate condylar resorption, remodeling and disc displacement. The minimum follow-up period, including orthodontic treatment, was 12 months. Orthognathic procedures included 1-jaw surgery (n=8 patients) and 2-jaw surgery (n=13 patients). The monocortical plate was used for bilateral sagittal split ramus osteotomy fixation. RESULTS: Among class II malocclusion patients with TMD symptom, clicking improved in 29.1%, and maximum mouth opening increased from 34.5+/-2.1 mm to 37.2+/-3.5 mm. The differences were not statistically significant, however. Radiographic changes in bone scan improved slightly based on the report by radiologist but not in TMJ dynamic MRI. CONCLUSION: No particular improvements were found in patients with joint sound only. Patients with limitation of mouth opening showed an increase in the degree of opening, but the difference was not statistically significant (P>0.05).
Dentofacial Deformities ; Displacement (Psychology) ; Female ; Follow-Up Studies ; Humans ; Joints ; Magnetic Resonance Imaging ; Malocclusion ; Mandibular Advancement ; Mouth ; Orthognathic Surgery ; Osteotomy, Sagittal Split Ramus ; Temporomandibular Joint ; Temporomandibular Joint Disorders

deformities. To achieve the goal of the surgery, the maxilla should be repositioned based on the precisely planned position during surgery. The internal reference points (IRPs) and the external reference points (ERPs) are usually used to determine vertical dimension of maxilla, which is an important factor for confirming maxillary position. However, the IRPs are known to be inaccurate in determining the vertical dimension. In this study, we investigated the correlation of positional change of the modified IRPs with repositioned maxilla.METHODS: The study group consisted of 26 patients with dentofacial deformities. For the simulation of the surgery, patient maxillary CT data and 3-D virtual surgery programs (V-Works(R) and V-Surgery(R)) were used. IRPs of this study were set on both the lateral wall of piriform aperture, inferior margin of both infraorbital foramen, and the labial surfaces of the canine and first molar. The distance from the point on lateral wall of the piriform aperture to the point on the buccal surface of the canine was defined as IRP-C, and the distance from the point on the inferior margin of the infraorbital foramen to the point on the buccal surface of the 1st molar was defined as IRP-M. After the virtual simulation of Le Fort I osteotomy, the changes in IRP-C and IRP-M were compared with the maxillary movement. All measures were analyzed statistically.RESULTS: With respect to vertical movements, the IRP-C (approximately 98%) and the IRP-M (approximately 96%) represented the movement of the canine and the 1st molar. Regarding rotating movement, the IRPs changed according to the movement of the canine and the 1st molar. In particular, the IRP-C was changed in accordance with the canine.CONCLUSION: IRPs could be good indicators for predicting vertical movements of the maxilla during surgery.]]>
Congenital Abnormalities ; Dentofacial Deformities ; Humans ; Maxilla ; Molar ; Orthognathic Surgery ; Osteotomy ; Osteotomy, Le Fort ; Vertical Dimension

INTRODUCTION: In the management of dentofacial deformities, variable movement of the maxilla can be made possible by a Le Fort I osteotomy. Posterior impaction of the maxilla necessary for rotation of the maxillomandibular complex enhances the functions and esthetic results. In cases of posterior impaction of the maxilla, an increase in the figure of the occlusal plane angle and incisor inclination can occur. This study reports the relationship between the amount of posterior impaction and the change in the occlusal plane angle and incisor inclination in a Le Fort I osteotomy by preoperative and postoperative lateral cephalograms. MATERIALS AND METHODS: Twenty patients who had undergone orthognathic surgery in Dong-A University Medical Center participated in this study. Lateral cephalometrics, within 3 weeks prior to surgery and 3 days after surgery, were used for analysis. Pre and postoperative measurements of the occlusal plane angle and incisal inclination based on the Frankfort horizontal (FH) plane were performed. X and Y were defined as the amount of vertical change in the upper incisor tip and the amount of vertical change in the upper first molar mesial cup tip through the operation. The amount of final posterior maxillary impaction was determined by subtracting Y from X, which is the difference in vertical height. According to the amount of posterior maxillary impaction, the change in the occlusal plane angle and incisal inclination was measured. RESULTS: The average posterior maxillary impaction was 2.91 mm and the average change in the occlusal plane angle and incisal inclination was 6.54degrees after surgery. As a result, each mm of posterior maxillary impaction changed the occlusal plane angle and incisal inclination by 2.25degrees. Statistically, there was high significance. Two cases were observed: one with the same amount of posterior maxillary impaction performed on both the right and left showing 2.20degrees, and the other with a different amount of posterior maxillary impaction performed showing 2.35degrees. In this case, there was no significance difference between the two cases. CONCLUSION: Each mm of posterior maxillary impaction changes the occlusal plane angle and incisal inclination by an average of 2.25degrees. In posterior maxillary impaction, there was no significant difference in the amount of change in the occlusal plane angle and incisal inclination regardless of whether there was an equal amount of posterior maxillary impaction on both sides. This study is expected to help in the presurgical orthodontic preparation and presurgical treatment planning.
Academic Medical Centers ; Dental Occlusion ; Dentofacial Deformities ; Humans ; Incisor ; Malocclusion ; Maxilla ; Molar ; Orthognathic Surgery ; Osteotomy ; Osteotomy, Le Fort ; Tooth, Impacted

surgery with simultaneous maxillomandibular procedures especially including maxillary posterior impaction and advancement.STUDY DESIGN: Forty patients with dentofacial deformities were randomly assigned into titanium (4 males and 6 females) and absorbable (17 males and 13 females) fixation group. All patients had undergone surgical alterations of maxilla with posterior impaction and advancement. A comparison study of the change in the maxillary position after the simultaneous surgery was performed with 1-day, 6-months postoperative lateral cephalograms compared to preoperative lateral cephalogram by tracing. Wilcoxon rank sum test was used for statistical analysis.RESULT: The position of the maxilla was stable after surgery and was not changed significantly from 1 day to 6 month after the simultaneous maxillomandibular surgery both in the experimental (absorbable plates) and control (titanium plates).CONCLUSION: This study suggests that application of absorable plating system in the fixation of maxillary segment in the simultaneous maxillomandibular procedures, leads to a predictable short-term postoperative skeletal stability comparable to the titanium plating system. Long term follow-up and further studies will be needed.]]>
Dentofacial Deformities ; Follow-Up Studies ; Humans ; Male ; Maxilla ; Orthognathic Surgery ; Titanium