OBJECTIVE: To evaluate the changes of periodontal phenotype (width of keratinized gingiva, thickness and height of alveolar bone) of lower anterior teeth in patients with skeletal class Ⅲ malocclusion before and after the periodontal-orthodontic-orthognathic combined treatment. METHODS: In the study, 20 patients with skeletal class Ⅲ malocclusion (6 males and 14 females) completed the periodontal-orthodontic-orthognathic combined treatment were included from March 2017 to June 2022, with 39 central incisors, 40 lateral incisors and 40 canines. The mean age was (25.40±4.27) years (20-34 years). The mean follow-up time was (3.70±1.05) years from the beginning of periodontal corticotomy regenerative surgery (PCRS) to the end of the combined treatment. Cone-beam computed tomography (CBCT) was used to measure the thickness, area and height of alveolar bone by the same researcher, taken before the PCRS (T0), 6 months after the PCRS (T1), 12 months after the PCRS (T2), before the orthognathic surgery (T3), and after the periodontal-orthodontic-orthognathic combined treatment (T4). The periodontal clinical parameters were used to evaluate changes in the soft tissue by another researcher, measured before the PCRS (T0) and after the combined treatment (T4). Changes of soft and hard tissue were evaluated by the periodontal phenotype. RESULTS: The width of keratinized gingiva increased significantly (all P < 0.001) in lower anterior teeth, the central incisors, lateral incisors and canines increased by (1.82±1.57) mm, (2.03±1.48) mm and (2.05±1.27) mm, respectively. The proportion of thick periodontal biotype in the central and lateral incisors increased significantly (all P < 0.001), while the changes of periodontal biotypes in the lower canines were not obvious. The thickness of labial alveolar bone of lower anterior teeth all increased significantly after periodontal corticotomy regenerative surgery and the combined treatment (all P < 0.001). The area of labial alveolar bone of lower anterior teeth also increased significantly after the combined treatment (all P < 0.001). The whole area of labial and lingual alveolar bone of central and lateral incisors increased (P < 0.001), while the whole area of canines remained the same. All The height of the alveolar bone increased (all P < 0.001) on the labial side after the treatment. CONCLUSION The periodontal phenotypes of lower anterior teeth were significantly improved after the periodontal-orthodontic-orthognathic combined treatment in patients with skeletal Angle class Ⅲ malocclusion. The improvement was long-termly stable, and the periodontal risk was reduced.
Male ; Female ; Humans ; Malocclusion, Angle Class III/surgery* ; Oral Surgical Procedures ; Incisor ; Cone-Beam Computed Tomography/methods*

OBJECTIVE: To evaluate the decompensation effectiveness and alveolar bone remodeling of mandibular anterior teeth after preoperative orthodontic treatment in high-angle patients with skeletal class Ⅱ malocclusion using lateral cephalogram and cone-beam computed tomography (CBCT). METHODS: Thirty high-angle patients with skeletal class Ⅱ malocclusion who had received preoperative orthodontic treatment and orthognathic surgery in Peking University School and Hospital of Stomatology between Ja-nuary 2017 and August 2022 and had taken lateral cephalogram and CBCT before and after preoperative orthodontic treatment were selected. Items were measured with lateral cephalogram including: The lower central incisor (L1)-Frankfort plane angle (L1-FH), the L1-mandibular plane angle (L1-MP), the L1-nasion-supramental angle (L1-NB) and the vertical distance from the incisal edge of lower central incisor to NB line (L1-NB distance), etc. The incidence of dehiscence/fenestration and the length of dehiscence at labial side (d-La) and lingual side (d-Li) were measured using CBCT. Pearson correlation analysis was used to evaluate the correlation between the changes of d-Li of L1 and age, duration of preoperative orthodontic treatment and the cephalometric measurements before preoperative orthodontic treatment to screen out risk factors affecting the periodontal risk of preoperative orthodontic treatment in high-angle patients with skeletal class Ⅱ malocclusions. RESULTS: After preoperative orthodontic treatment, L1-FH, L1-MP, L1-NB and L1-NB distances changed by 11.56°±5.62°, -11.13°±5.53°, -11.57°±5.43° and (-4.99±1.89) mm, respectively, and the differences were all statistically significant (P < 0.05). Among the 180 measured mandibular anterior teeth, 45 cases with labial dehiscence/fenestration before preoperative orthodontic treatment (T0) had no longer labial dehiscence/fenestration after preope-rative orthodontic treatment (T1); 142 cases without lingual dehiscence/fenestration at T0 had lingual dehiscence/fenestration at T1. After preoperative orthodontic treatment, the d-La of lower lateral incisors (L2), lower canines (L3) and lower anterior teeth (L1+L2+L3) decreased by (0.95±2.22) mm, (1.20±3.23) mm and (0.68±2.50) mm, respectively, and the differences were statistically significant (P < 0.05); the d-Li of L1, L2, L3 and L1+L2+L3 increased by (4.43±1.94) mm, (4.53±2.35) mm, (3.19±2.80) mm and (4.05±2.46) mm, respectively, and the differences were statistically significant (P < 0.05). The increase of d-Li of L1 was positively correlated with L1-FH (r=0.373, P=0.042). CONCLUSION This study showed that high-angle patients with skeletal class Ⅱ ma-locclusion could achieve ideal decompensation effect of mandibular anterior teeth after preoperative orthodontic treatment with bilateral mandibular first premolars extracted, but the lingual periodontal risk of mandibular anterior teeth was increased. This risk could be correlated to L1-FH before preoperative orthodontic treatment, which should be paid more attention in the design of orthodontic-orthognathic surgical treatment.
Humans ; Malocclusion, Angle Class III ; Malocclusion, Angle Class II/surgery* ; Facial Bones ; Incisor ; Orthognathic Surgical Procedures ; Cone-Beam Computed Tomography ; Mandible

Objective:To explore the effects of mouth opening breathing for different reasons on children's maxillofacial development. Methods:One hundred and fifty-one children were selected as the research objects of this experiment. They were divided into 49 cases of adenoid hypertrophy group（group A）, 52 cases of tonsillar hypertrophy group（group B） and 50 cases of adenoid with tonsillar hypertrophy group（Group C）. Healthy children in the same period were selected as the control group, a total of 45 cases. The reflex nasopharyngeal measurement parameters, facial development indexes and cephalometric parameters of group A, group B, group C and control group were analyzed, and the incidence of Angle ClassⅡand Angle Class Ⅲ in group A, group B and group C were studied. Results:Compared with the control group, the reflex nasopharyngeal measurement parameters in group A, group B and group C was significantly different（P<0.05）, and the cephalometric parameters changed with variation in groups（P<0.05）. The incidence of Angle Class Ⅱ facial pattern in group A and group C was higher, but the incidence of Angle Class Ⅲ facial pattern in group B and group C was higher（P<0.05）. Conclusion:Adenoid hypertrophy leads to mandibular retraction; tonsil hypertrophy leads to anterior mandibular arch; adenoid hypertrophy and tonsil hypertrophy are easy to lead to clockwise rotation of the mandible. In clinical practice, to avoid children's uncoordinated maxillofacial development, we should correct the maxillofacial situation of children as soon as possible.
Child ; Humans ; Maxillofacial Development ; Malocclusion, Angle Class III/complications* ; Nasopharynx ; Adenoids ; Palatine Tonsil ; Mouth Breathing/etiology* ; Hypertrophy/complications* ; Mouth

OBJECTIVE: To assess three-dimensional (3D) changes of circummaxillary sutures following maxillary protraction with alternate rapid palatal expansions and constrictions (RPE/C) facemask protocol in maxillary retrusive children, and to investigate the relationship between the changes of circum-maxillary sutures and zygomaticomaxillary suture (ZMS) maturation, and to explore the factors of maxilla forward movement with RPE/C and facemask. METHODS: In the study (clinical trial registration No: ChiCTR2000034909), 36 maxillary retrusive patients were recruited and block randomized to either the rapid palatal expansion (RPE) group or the RPE/C group. Patients aged 7 to 13 years, Class Ⅲ malocclusion, anterior crossbite, ANB less than 0°, Wits appraisal less than -2 mm, and A-Np less than 0 mm were included in the study. The RPE group received rapid palatal expansion, whereas the RPE/C group received alternate rapid palatal expansions and constrictions, and both with facemask protraction. Head orientations of cone-beam computed tomography (CBCT) images were implemented by Dolphin 11.7. 3D measurements of circummaxillary sutures on CBCT images were evaluated using Mimics 10.01 before (T0) and after treatment (T1). The changes were analyzed with independent t test, two-way ANOVA, Pearson correlation and regression analysis. RESULTS: Two subjects in the RPE/C group were lost to follow-up. A total of 34 patients reached the completion criteria and were analyzed. Compared with the RPE group, sagittal changes of circummaxillary sutures were significantly increased in the RPE/C group with 1.21 mm advancement of zygomaticotemporal suture, 2.20 mm of ZMS, 1.43 mm of zygoma-ticofrontal suture (P < 0.05, respectively). Except for the zygomaticotemporal suture, the rest forward sagittal changes of other circummaxillary sutures showed no major difference in terms of the ZMS maturation. The Spearman's correlation in RPE/C indicated a strong positive correlation of sagittal changes between ZMS and point A (P < 0.01) with a regression analysis R²=42.5%. CONCLUSION RPE/C might be more effective on the treatment of maxillary retrusive children. As one of the major mechanical loading sutures during orthopedic therapy, ZMS showed a strong positive correlation with point A on sagittal changes.
Cone-Beam Computed Tomography/methods* ; Constriction ; Humans ; Malocclusion, Angle Class III/therapy* ; Maxilla/diagnostic imaging* ; Palatal Expansion Technique ; Sutures

OBJECTIVE: To explore the method of measuring root volume with cone-beam computed tomography (CBCT) three-dimensional reconstruction technology, and to study root length and root volume of upper and lower central incisors in patients with skeletal Class Ⅲ malocclusion treated by surgical orthodontic treatment. METHODS: Twenty patients with skeletal Class Ⅲ malocclusion undergoing surgical orthodontic treatment were selected. CBCT data at three time points, before decompensation treatment (T0), after decompensation treatment (before orthognathic surgery, T1), and the end of post-operative orthodontic treatment (T2) were collected. Three-dimensional reconstruction technology was used to measure the root length and root volume of the upper and lower central incisors (including total root volume, cervical root and apical root), calculate the percentage of reduction volume, and measure the distance of tooth movement after orthodontic treatment. Data were statistically analyzed by SPSS 20.0 software. Least significant difference (LSD) method was used for pair comparison between the groups subject to normal distribution, and non-parametric test was used for comparison between the groups not subject to normal distribution. The differences of root length and root volume of upper and lower incisors were compared, and the characteristics of root absorption were analyzed. RESULTS: Root length and root volume of the upper and lower central incisors were reduced during the surgical orthodontic treatment (P < 0.05) in cases. Both the root volume of cervical root and apical root were significantly reduced (P < 0.05), the reduction of apical root was more significant. The percentage of root volume reduction of the upper central incisor was (30.51±23.23)%, and lower central incisor (23.24±11.96)%. Compared with the upper central incisor, the root volume reduction amount and percentage of the lower central incisor were smaller, and apical root volume reduction of the upper central incisor was greater than that of the lower central incisor, which was statistically significant (P < 0.05). During pre-surgical orthodontic treatment, maxillary central incisor palatal moving was in a controlled tipping manner, and the mandibular central incisor tipped labially. CONCLUSION In patients with skeletal Class Ⅲ malocclusion, root length and total root volume of upper and lower central incisors decreased during surgical orthodontic treatment. Root volume measurement indicated that the cervical root also had root resorption. The difference in root resorption of the upper and lower central incisors might be related to the distance and direction of teeth movement. CBCT three-dimensional reconstruction will compensate for the limitation of root length measurement in evaluating root resorption.
Cone-Beam Computed Tomography/methods* ; Humans ; Incisor/diagnostic imaging* ; Malocclusion, Angle Class III/surgery* ; Maxilla/surgery* ; Root Resorption/etiology*

OBJECTIVE: To measure the distance from cemento-enamel junction (CEJ) to alveolar crest (AC) of labial side of anterior teeth on skeletal Angle class III patients under direct vision during periodontal bone augmentation surgery and to make relevant analysis to find the relevant factors. METHODS: In the study, 46 skeletal Angle class III patients (10 males and 36 females) received periodontal bone augmentation surgery of anterior teeth were included, with 67 jaws (27 maxillae and 40 mandibles) and 400 anterior teeth (161 maxillary anterior teeth and 239 mandibular anterior teeth). The mean age was 23.65 years. Maxillary anterior teeth consisted of 54 central incisors, 53 lateral incisors and 54 canines. Mandibular anterior teeth consisted of 79 central incisors, 80 lateral incisors and 80 canines. CEJ-AC was measured in three sites (mesial sites, central sites and distal sites) by Williams periodontal probes during periodontal bone augmentation surgery under direct vision by the same researcher. RESULTS: The average CEJ-AC of 400 anterior teeth was (2.21±1.48) mm. The average CEJ-AC of maxillary anterior teeth was (1.72±1.13) mm, more than (2.54±1.60) mm of mandibular anterior teeth (P<0.05). The average CEJ-AC of canines was (2.42±1.78) mm, more than (2.06±1.27) mm of central incisors or (2.16±1.32) mm of lateral incisors (P<0.05). The average CEJ-AC of central sites was (3.04±2.01) mm, more than (1.79±0.86) mm of mesial sites or (1.81±0.89) mm of distal sites (P<0.05). CEJ-AC of 233 anterior teeth was more than 2 mm, accounting for 58.25%, and 117 anterior teeth with dehiscence were found, accounting for 29.25%. Multilevel and multivariate Logistic regression showed age, jaw, tooth and site were the relevant factors to the position of alveolar crest. CONCLUSION The position of alveolar crest of skeletal Angle class III patients who received periodontal bone augmentation surgery was lower than that of the general population, causing periodontal risks during decompensation orthodontics therapy before orthognathic surgery. The position of alveolar crest was lower in older patients than in younger patients, in mandibular teeth than in maxillary teeth, in canines than in central incisors or lateral incisors, and in central sites than in mesial sites or distal sites of labial side, which showed much higher risk.
Alveolar Process ; Cone-Beam Computed Tomography ; Female ; Humans ; Male ; Malocclusion, Angle Class III ; Mandible ; Maxilla ; Young Adult

OBJECTIVE: This study aimed to investigate the therapeutic effects and advantages of skeletal class Ⅲ malocclusion treatment by transmission straight wire technique. METHODS: Ninety-seven patients who received treatment for skeletal class Ⅲ malocclusion at the Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2012 to January 2017 were selected for this retrospective study. All these patients refused surgery. They were divided into two groups in accordance with the type of skeletal malocclusion: mild-to-moderate skeletal malocclusion group (-4°≤ANB <0°) and severe skeletal malocclusion group (-8°≤ANB<-4°). Each of the two groups was divided further into two small groups in accordance with the technique used: T group (transmission straight wire technique) and M group (MBT technique). RESULTS: The crossbite of all 59 patients in the mild-to-moderate skeletal malocclusion group was successfully treated. The molars were classified as classⅠrelationship, and the facial profile improved. Significant differences were found in the values of U1/SN angle, L1/MP angle, and Lip-Diff between the T and M groups before and after the treatment (P<0.05). The extent of incisor root resorption was lighter in the T group than in the M group (P<0.05). In the severe skeletal malocclusion group, the crossbite of all 38 patients was cured or partially cured. Fourteen patients showed severe lower anterior teeth inclination (five in the T group and nine in the M group), and the profiles did not significantly improve. Significant differences were observed in the values of U1-NA value, U1/SN angle, L1-NB value, L1/MP angle, LLP, and Lip-Diff between the T and M groups before and after the treatment (P<0.05). The extent of incisor root resorption was lighter in the T group than in the M group (P<0.05). CONCLUSIONS Relative to the MBT technique, the transmission straight wire technique has great advantages in improving facial profile, reducing the compensatory inclination of the upper and lower anterior teeth, and reducing the risk of root resorption in the treatment of skeletal class Ⅲ malocclusion.
Cephalometry ; Humans ; Malocclusion ; Malocclusion, Angle Class II ; Malocclusion, Angle Class III ; Maxilla ; Retrospective Studies

OBJECTIVE: To assess the efficacy of bone anchorage and maxillary facemask protraction devices in treating skeletal class Ⅲ malocclusion in adolescents. METHODS: Articles relating to the use of bone anchorage and maxillary facemask protraction devices for treating skeletal class Ⅲ malocclusion in adolescents were searched from the databases of Cochrane Library, PubMed, EmBase, CNKI, and Wanfang database. Several inclusion and exclusion criteria were developed for the article screening. The clinical data were extracted, and the quality of the selected articles was evaluated. A Meta-analysis of SNA, SNB, ANB, ANS-Me, Wits, and U1-PP change was performed by using RevMan 5.3. RESULTS: Seven studies (264 patients) were included in the Meta-analysis. Among these studies, three were randomized controlled trials, and four were non-randomized controlled trials. Compared with the maxillary facemask protraction device group, the bone ancho-rage device group had higher SNA changes and lower ANS-Me, Wits, and U1-PP changes (P<0.05). No significant differences were observed in the SNB and ANB changes between these two groups. CONCLUSIONS Compared with the maxillary facemask protraction device, the bone anchorage device can increase the extent of protraction of the maxilla and has better controls for the labial inclination of the maxillary anterior teeth in treating skeletal class Ⅲ malocclusion among adolescents. However, additional high-quality randomized controlled trials must be performed to verify the results.
Adolescent ; Cephalometry ; Extraoral Traction Appliances ; Humans ; Malocclusion, Angle Class III ; Maxilla ; Palatal Expansion Technique

OBJECTIVE: To investigate the effect of pre-surgical orthodontic treatment on temporomandibular joint (TMJ) in patients with skeletal class Ⅲ malocclusion treated with orthodontic-orthognathic surgical treatment. METHODS: Twenty-four patients with skeletal class Ⅲ malocclusion who underwent orthodontic-orthognathic surgical treatment were included in the study. Before and after the completion of orthodontic treatment, the symptoms of TMJ were examined and recorded, and the short- and the long-axis diameter of the condylar (d), condylar height (h), joint space (L) at different angles, bilateral condylar spacing (R), and the condylar angles were measured, with scanning performed by using cone-beam computed tomography (CBCT). Then, the changes of TMJ symptoms and bone structure at different periods were analyzed. RESULTS: No significant changes were observed in the joint symptoms before and after the pre-surgical orthodontic treatment. No significant changes were found in the measurements of the bone structure of TMJ in the dimensional direction (P>0.05). CONCLUSIONS In the orthodontic-orthognathic surgical treatment procedure, the pre-surgical orthodontic process does not have a significant effect on TMJ.
Cone-Beam Computed Tomography ; Humans ; Malocclusion, Angle Class II ; Malocclusion, Angle Class III ; Mandibular Condyle ; Temporomandibular Joint

OBJECTIVE: To investigate stability of skeletal hard tissues, dental hard tissues and soft tissues after orthodonticorthognathic treatment in a long term. This study reviewed longitudinal changes in orthodontic-orthognathic patients of skeletal class III malocculsion, using lateral cephalometric radiographs in 3-12 years after treatment in comparison to treatment finishing. METHODS: Twenty-two patients with skeletal Class III malocclusion following orthodontic-orthognathic surgery in Peking University School and Hospital of Stomatology from January 1, 2000 to January 1, 2009 were observed. The lateral cephalometric radiographs of the following stages were collected: treatment finishing (T1), 3 to 12 years after treatment (T2). Statistical analyses of cephalometrics were evaluated. Paired student t test was performed by SPSS 17.0. RESULTS: Data of all the 22 patients were studied in longitudinal timeline after treatment and 3-12 years after treatment. From T1 to T2, we evaluated 11-SN (angle between the upper incisors axis and SN plane), 11-NA angle (angle between the upper incisors axis and NA plane), 11-NA mm (perpendicular distance from upper incisors to NA plane), 11-41 (angle between the upper incisors axis and lower incisors axis), 41-NB angle (angle between lower incisors and NB plane), 41-NB (perpendicular distance from lower incisors to NB plane), 41-MP angle (angle between lower incisors and GoGn plane), and IMPA [angle between lower incisor and mandibular plane (tangent line to submandibular border)]. Most hard tissues of the teeth remained stable but upper anterior teeth angulations decreased, indicating by significantly reducing 11-SN (T1: 110.98°±6.77°; T2: 109.21°±5.80°; P=0.005); reducing 11-NA (T1: 28.31°±6.80°; T2: 26.49°±6.18°; P=0.002); increasing 11-41 (T1: 123.51°±8.14°; T2: 125.7°±10.01°; P=0.035). From T1 to T2, we also evaluated SNA (angle of sella-nasion-A-point), SNB (angle of sella-nasion-B-point), ANB (angle of A-point-nasion-B-point), GoGn-SN (angle between GoGn and SN plane), GoGn-FH (angle between GoGn and Frankfort plane), Y axis (angel between Sella-Gn and Frankfort plane), N-ANS (distance from nasion point to ANS point), ANS-Me (distance from ANS point to Menton point), N-Me (distance from nasion point to Menton point), ANS-Me/N-Me% (proportion of ANS-Me to N-Me), and FMA (angle between Frankfort and mandibular plane), Wits appraisal (horizontal distance between points A and B on functional occlusal plane). Skeletal hard tissues also remained relatively stable, only N-Me value changed significantly with a decreasing facial height (T1: 124.98°±11.98°; T2: 122.4°±11.05°; P=0.024). From T1 to T2, we finally evaluated FH-NsPg angle (angle between NsPg and Frankfort plane), H angle (angel between H line and NB), FH-A'UL angle (angle between A'UL and Frankfort plane), FH-B'LL angle (angle between B'LL and Frankfort plane), UL-LL (angle between UL and LL), UL-EP (distance between UL and E line), LL-EP (distance between LL and E line), Sn-H (perpendicular distance between Sn point and H line), Nls-H (distance of nose-lip-sulcus to H line), Li-H (lower lip to H line), Si-H (lower lip sulcus to H line), and NLA (nasolabial angle, angle of Cm-Sn-UL-point). Soft tissues changes were observed in decreasing UL-EP [T1: (-2.78±2.20) mm; (-3.29±2.44) mm; P=0.02] and H angle (T1: 8.27°±3.71°; 7.32°±3.83°; P=0.006). Other soft tissues remained relatively stable by retruding upper lip position and chin changes with no statistical significance. CONCLUSION Orthodontic-orthognathic treatment can improve esthetics and occlusal function in patients of skeletal class III malocclusion with a stable long-term outcome.
Cephalometry ; Facial Bones ; Humans ; Malocclusion, Angle Class III ; Mandible ; Maxilla ; Orthognathic Surgical Procedures