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Objective:This study aimed to investigate the change of the position of the tongue before and after combined treatment of maxillary expansion and orofacial myofunctional therapy in children with mouth-breathing and skeletal class Ⅱmalocclusion. Methods:A total of 30 children with skeletal class Ⅱ malocclusion and unobstructed upper airway were selected. The 30 children were divided into mouth-breathing group（n=15） and nasal-breathing group（n=15） and CBCT was taken. The images were measured by Invivo5 software. The measurement results of the tongue position of the two groups were analyzed by independent samples t-test. 15 mouth-breathing children with skeletal class Ⅱ malocclusion were selected for maxillary expansion and orofacial myofunctional therapy. CBCT was taken before and after treatment, the measurements were analyzed by paired sample t test with SPSS 27.0 software package. Results:The measurement of the tongue position of the mouth-breathing and nasal-breathing groups were compared, the differences were statistically significant（P<0.05）. The measurement of the tongue position showed significant difference after the combined treatment of maxillary expansion and orofacial myofunctional therapy in children with mouth-breathing and skeletal class Ⅱmalocclusion（P<0.05）. Conclusion:Skeletal class Ⅱ malocclusion children with mouth-breathing have low tongue posture. The combined treatment of maxillary expansion and orofacial myofunctional therapy can change the position of the tongue.
Subject(s)
Child , Humans , Myofunctional Therapy/methods , Mouth Breathing/therapy , Palatal Expansion Technique , Tongue , Malocclusion/therapyABSTRACT
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.
Subject(s)
Humans , Malocclusion, Angle Class III , Malocclusion, Angle Class II/surgery , Facial Bones , Incisor , Orthognathic Surgical Procedures , Cone-Beam Computed Tomography , MandibleABSTRACT
OBJECTIVES@#This study aimed to conduct a meta-analysis of the efficacy of mandibular advance clear alig-ners with traditional functional appliances as the control group.@*METHODS@#PubMed, Web of Science, Embase, Cochrane Library, China Biomedical Abstracts Database, China Knowledge Network Database, Wanfang Database, and Weipu Database were used in this study. The two groups of researchers screened the literature and extracted data based on the inclusion and exclusion criteria established by PICOS entries, and used the ROBINS-I scale for quality evaluation. Revman 5.4 and Stata 17.0 software were used for meta-analysis.@*RESULTS@#Nine clinical controlled trials were included in this study with a total sample size of 283 cases. No significant difference was found in SNA, SNB, ANB, Go-Pog, U1-SN, Overjet, and other aspects between the invisible group and the traditional group in the treatment of skeletal class Ⅱ ma-locclusion patients; there was a 0.90° difference in mandibular plane angle between the two groups; the growth of the mandibular ramus (Co-Go) in the traditional group was 1.10 mm more than that in the invisible group; the lip inclination of the lower teeth in the invisible group was better controlled, 1.94° less than that in the control group.@*CONCLUSIONS@#The invisible group can better control the lip inclination of the mandibular anterior teeth when guiding the mandible. Furthermore, the mandibular plane angle (MP-SN) can remain unchanged, but the growth of the mandibular ramus is not as good as the traditional group, and auxiliary measures should be taken to improve it in clinical practice.
Subject(s)
Humans , Malocclusion, Angle Class II/therapy , Mandibular Advancement , Orthodontics, Corrective , Orthodontic Appliances, Functional , Mandible , Orthodontic Appliances, Removable , CephalometryABSTRACT
Objective@#To evaluate the effects of non-bracket invisible appliance mandibular advance(MA) on skeletal Class Ⅱ growing patients with mandibular retrusion.@*Methods@#Nineteen skeletal Class Ⅱ growing patients with mandibular retrusion who were treated in the department of stomatology of Changshu traditional Chinese medicine hospital from January 2018 to May 2021 were selected. They had an average age of (12.32±1.51) years old. The treatment group consisted of 10 children who were treated with MA. The control group consisted of 9 children who refused to treat their malocclusion. Cephalometrics of all patients were taken before and after the observation or treatment. The cephalometric data of two groups were analyzed. @*Results@#Compared with the control group, in the treatment gruop SNB angle, L1-NB angle, L1-NB distance, L6-MP distance, Z angle increased significantly (P<0.05);Co-Go distance, Co-Gn distance, SL increased more greatly than the control group; ANB angle, U1-SN angle, U1-NA angle, U1-NA distance, L1-MP distance, FCA angle decreased significantly (P<0.05); SE did not change significantly in the treatment group, but increased significantly in the control group (P<0.05).@*Conclusion @# MA can promote mandibular growth and improve lateral profile. The angle of the lower teeth and the angle of the mandible plane can be controlled by MA appliance.
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Objective@# To compare the hyoid bone position among patients with different sagittal skeletal malocclusions to provide a reference for clinicians to formulate treatment plans.@*Methods@#Lateral cephalograms of 284 orthodontic patients were selected. According to ANB angles, the types of skeletal malocclusion of patients were determined as follows: Class Ⅰ (1° ≤ ANB ≤ 5°), Class Ⅱ (ANB>5°) and Class Ⅲ (ANB<1°). Ten parameters were used to determine hyoid positions. After comparing the hyoid positions of the three groups, stratified analyses based on sex and age were conducted. @*Results @# No significant differences in demographic and vertical facial type features among skeletal Classes Ⅰ, Ⅱ and Ⅲ patients were observed (P>0.05). The angle between the Gonion-hyoid point line and the hyoid point-Menton line (Go-Hy-Me) of Class Ⅱ patients was significantly smaller than that of Class Ⅰ patients, and the angle between the most anterior and inferior point of the third cervical vertebra-hyoid point line and the hyoid point-Sella line (C3-Hy-S) of Class Ⅲ patients was smaller than that of Class I patients (P<0.05). Age-stratified analysis showed that in the juvenile group, the C3-Hy-S of Class Ⅲ patients was significantly smaller than that of Class Ⅰ patients in males and females (P<0.05). In the adult female group, the Go-Hy-Me of Class Ⅱ patients was significantly smaller, and the distance from the hyoid point to the mandibular plane (Hy-MP) was larger than that noted in Class Ⅰ patients (P<0.05); no significant difference in hyoid position between male Class Ⅱ and I patients was observed (P>0.05).@*Conclusions@#Compared with Class Ⅰ patients, the hyoid bone of Class Ⅱ patients in adult females was farther away from the mandible and that of Class Ⅲ patients in juveniles was farther away from the cervical vertebra and posterior cranial base.
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OBJECTIVE@#To compare temporomandibular joint (TMJ) morphology and position among skeletal class Ⅱ female adolescents with different vertical patterns using cone-beam CT (CBCT).@*METHODS@#Diagnostic CBCT images of 80 female patients aged 11 to 14 years were assessed retrospectively. According to subspinale-nasion-supramental angle (ANB) and Frankfort horizontal plane-gonion-gnathion angle (FH-GoGn), the participants were categorized into four groups (20 subjects each), i.e. class Ⅰ normal angle (group 1, 0°≤ANB < 4°, 22°≤FH-GoGn≤32°), class Ⅱ low (group 2, ANB≥4°, FH-GoGn < 22°), normal (group 3, ANB≥4°, 22°≤FH-GoGn≤32°) and high angle (group 4, ANB≥4°, FH-GoGn > 32°). Cephalometrics, morphology and position of TMJ were measured in Dolphin software. Using paired-samples t test to analyze TMJ symmetry, One-way analysis of variance (One-way ANOVA) and Chi-square tests to detect differences among the groups. The correlations between cephalometrics and TMJ measurements were also analysed within the skeletal class Ⅱ patients.@*RESULTS@#(1) Analysing TMJ morphologic symmetry, some measurements differed statistically although the mean diffe-rences were negligibly relative to their values. No statistically significant difference was found among the groups though group 4 showed the highest probability of condylar position asymmetry (65%). (2) Comparing group 1 with group 3, statistical difference was found in condylar position (χ2=6.936, P < 0.05) instead of morphologic measurements. Anterior and concentric condylar position were more frequently observed in group 1, yet posterior position was more prevalent in group 3. (3) In groups 2, 3, and 4, statistically, group 2 had the deepest glenoid fossa depth (H2&4=10.517, P=0.002), biggest superior (LSD-t2&3=3.408, LSD-t2&4=5.369, P < 0.001) and lateral (LSD-t2&3=2.767, LSD-t2&4=3.350, P=0.001) joint spaces, whereas group 4 showed the shortest condylar long axis diameter (H2&4=13.374, P < 0.001), largest glenoid fossa vertical distance (LSD-t2&4=4.561, P < 0.001, LSD-t3&4=2.713, P=0.007), smallest medial (LSD-t2&4=-4.083, P < 0.001) and middle (LSD-t2&4=-4.201, P < 0.001) joint spaces. The posterior condylar position proportion gradually increased from groups 2 to 3 to 4. Correlation analysis revealed ANB correlated with anterior joint space positively (r=0.270, P=0.037) and condylar long axis angle negatively (r=-0.296, P=0.022). FH-GoGn correlated with superior (r=-0.488, P < 0.001), posterior (r= -0.272, P=0.035), mesial (r=-0.390, P=0.002), middle (r=-0.425, P=0.001), and lateral (r=-0.331, P=0.010) joint spaces, articular eminence inclination (r=-0.259, P=0.046), as well as condylar long axis diameter (r=-0.327, P=0.011) negatively, and glenoid fossa depth (r=0.370, P=0.004) positively.@*CONCLUSION@#TMJ characteristics of skeletal class Ⅱ sagittal pattern mainly reflected in condylar position rather than morphology. TMJs of different vertical patterns differed more in joint spaces, position of condyle and glenoid fossa than in morphologic measurements. Vertical position of glenoid fossa and proportion of posterior condyle increased gradually from hypodivergent to hyperdivergent. Highest glenoid fossa position, maximum ratio of posterior positioned condyle, smallest joint spaces, shallowest glenoid fossa depth, and narrowest condylar long axis diameter were found in skeletal class Ⅱ high angle group, which means that patients with this facial type have considerable joint instable factors, and we should especially pay attention when orthodontic treatment is carried out on them.
Subject(s)
Adolescent , Child , Female , Humans , Cephalometry , Cone-Beam Computed Tomography , Malocclusion, Angle Class II/diagnostic imaging , Mandibular Condyle/diagnostic imaging , Retrospective Studies , Temporomandibular Joint/diagnostic imagingABSTRACT
OBJECTIVE@#To analyze the morphological changes in the upper airway of obstructive sleep apnea syndrome (OSAS) patients treated with oral appliance in skeletal class Ⅱ malocclusion with different vertical features by using cone beam CT (CBCT).@*METHODS@#Thirty-six patients diagnosed with OSAS by polysomnography and daytime sleepiness scale and skeletal class Ⅱ malocclusion were treated with oral appliance for 4 months. The changes based on CBCT in the morphology of glossopharyngeal and palatopharyngeal before and after treatment in OSAS patients with different vertical features were compared.@*RESULTS@#After treatment with oral appliance, the glossopharyngeal and palatopharyngeal morphologies of patients with mild OSAS showed significant changes. After treatment with oral appliance, the glossopharyngeal morphology of all patients showed significant changes (P<0.05). The palatopharyngeal morphology of patients in the lower and average groups also exhibited significant changes (P<0.05). Sagittal changes in the glossopharyngeal measurements of high-angle patients demonstrated significant difference, whereas the other measured values showed no significant difference.@*CONCLUSIONS@#The morphological changes in the upper airway were significant in OSAS patients with lower and average vertical patterns when treated with oral appliance, but the changes in high vertical patterns were not significant.
Subject(s)
Humans , Cone-Beam Computed Tomography , Malocclusion, Angle Class II , Polysomnography , Sleep Apnea, ObstructiveABSTRACT
Objective@#To explore the correlation between the parameters of the mandible and parameters of cervical vertebrae and craniofacial bone in class Ⅱ skeletal patients in Northeast China and to establish correlation equations expressing the relationship between the mandible and cervical vertebrae and craniofacial bone directly and quantitatively for the clinical diagnosis and treatment of orthodontics and orthognathics and for prediction. @*Methods @#The mandible, cranial facial bone and cervical vertebrae of 201 children and adolescents aged 8 to 20 years were measured using digital cranial lateral tablets. All of the cases were divided into male (n=75) and female (n=126) groups using a sensitivity analysis method based on genetic algorithms to select the craniofacial bone and cervical bone with strong sensitivity to mandible parameters and to establish relevant equations. @*Results @#Through sensitivity analysis, the parameters with the strongest correlation between the measured values of the mandible were H4 and SN, those with a strong correlation were SN-Ar, the anterior and posterior high ratio SGo/NGn, the Y axis angle and mandibular angle Ar-Go-Gn. The established equation was as follows: males: Ar-Pg=28.415+1.818×H4+0.746×SN(r2=0.056 8, P < 0.001); females: Ar-Pg=15.168+1.706×H4+0.675×SN+0.31×SN-Ar-0.29×Y axis angle (r2=0.611, P < 0.001). No significant difference was found between the predicted values obtained by the established equations and measured values (P > 0.05). @*Conclusion @#The mandibular length equation established by sensitivity analysis and genetic algorithms is statistically significant and can predict a certain degree of growth and development.
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Objective To study the variation of the dental and basal arch forms before and after orthodontic treatment of patients with skeletal class Ⅱ malocclusion by tooth extraction.Methods The mandibular dental casts of 25 skeletal class Ⅱ patients were laser scanned before and after treatment.The facial axis (FA) points,which were used to represent the dental arch,and the WALA point,which were used to represent the basal bone,were identified for each tooth from the right first molar to the left first molar.We constructed the curve with points of projection of the FA and WALA point on the reference plane,and compared the curve of dental arch and basal bone before and after treatment.Results The width of anterior middle and posterior of the basal arch increased (0.835± 1.259) mm,(1.700±1.280) mm and (2.170±1.227) mm,respectively.While the dental arch had a wider width (1.110±1.566) mm in posterior segment but a narrower one in anterior (3.345±2.907) mm.Conclusions The width of middle and posterior of basal bone represented by WALA ridge becomes wider after orthodontic treatment with tooth extraction in patients with skeletal class Ⅱ malocclusion,while the dental arch turns to a new form,which is more coordinated to the basal bone.
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Objective:To study the influence of Cm-Sn-Ls and Li-Sm-Pg angle change on facial 3D aesthetics and to compare the aesthetic evaluation difference between orthodontic professionals and non-professionals.Methods:Facial photographs of a skeletal class Ⅱ and a class Ⅲ subject were respectively obtained and 3D head inodels were created by 3DMAX.Then 16 head models were obtained for each subject by changing Cm-Sn-Ls and Li-Sm-Pg angles.30 othodontic professionals and 60 non-professionals were chosen to score the models by NRS.Results:For class Ⅱ subject,the 2 groups gave lowest score to original profile,Cm-Sn-Ls and Li-Sm-Pg angle change of + 15°,-15°;the professionals gave highest score to(+ 10°,0)、(+ 15°,0),while non-professionals gave highest score to (+ 5 °,-5 °) and (+ 5°,-10°).For class Ⅲ subject,the 2 groups selected original profile,(0,+ 15 °) and (0,+ 10°) for lowest score,and professionals selected (-5°,+ 15°) 、(-10°,+ 15°) for highest score,while non-professionals choose (-10°,+5°) 、(-15°,0) for highest score (between groups,P ＜ 0.05).Conclusion:Both orthodontic professionals and non-professionals like the profile with appropriate compensation for skeletal class Ⅱ and class Ⅲ patients,but there is some aesthetic difference about the amount of compensation between the two groups.
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Objective To adopt the cone beam computed tomography(CBCT) to analyze the bone thickness of infrazygomatic crest with different vertical skeletal facial types in teenagers.Methods Sixty teenagers of skeletal class were collected,including each 20 cases of high angle,average angle and low angle.The CBCT scanning data of oral maxillofacial region were collected.The bone thickness at different coronary slices in buccal side of infrazygomatic crest region at 13,15,17 mm above the maxillary occlusal plane was measured.The measured data were analyzed statistically.Results The bone thickness of infrazygomatic crest was gradually thinned from down to up,and the difference was statistically significant(P＜0.05);the bone thickness(except 3 points at 13 mm from maxillary plane) at each measured point in the high,average and low angle groups showed the change trend of low angle ＞average angle＞high angle,the difference was not statistically significant(P＞0.05).Conclusion In teenagers,the bone thickness of infrazygomatic crest in skeletal class Ⅱ is gradually thinned from cranial direction and rearward,the high angle is thinnest and the low angle is thickest.
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Objective:To establish the quantitative relationship equation of the crantiofacial vertical points in the skeletal classⅡ malocclusion patients with various vertical types by using genetic algorithms method,and to express the measured values in the patients with different gender with the same formula.Methods:A total of 155 skeletal class Ⅱ malocclusion patients without treatment,aged from 10 to 18 years old,were selected and divided into high-angle group(n=50),average-angle group(n=58),low-angle group(n=47);5 samples were randomly selected in each group as the test samples,the rest as the experimental sample.The cephalometic radiographs were performed and measured.The relevant influencing factors of craniofacial structure were ensured.The genetic algorithm was used to optimize the equation parameters to obtain the correlation equation.The error between the predicted value and the measured value was compared.Results:The various parameters had no significant differences between different gender in high-angle,average-angle and low-angle groups(P>0.05);then the men and the women with same type were combined,most of the indicators had statistically significant differences between three groups (P0.05).Conclusion:The quantitative relationship equation of the crantiofacial vertical points in the skeletal class Ⅱmalocclusion patients with various vertical types established with genetic algorithms may show the vertical quantitative relationship and predict the growth to a certain degree.
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Objective @#To investigate the effect of orthodontic and orthognathic treatment on patients with skeletal Class Ⅱ malocclusionby studying the changes of soft and hard tissues in maxillofacial region, to analyze the correlation between soft and hard tissues in patients with skeletal classⅡ in order to provide reference and guidance for combination therapy.@*Methods @#23 patients with skeletal classⅡmalocclusion treated by combined orthodontic and surgical treatment were selected, 21 parameters that can reflect the soft and hard tissue and the facial appearance were recorded in the imaging data before and after orthodontic-orthognathic treatment, The correlation between the soft and hard tissue of the patients before treatment was analyzed.@*Results @#There were significant differences between the before and after orthodontic-orthgnathic treatment in the 19 of above mentioned parameters, except for ANS-Me/N-Me(%) and Pg-Pg′ (mm). By analyzing the correlation between the hard tissue index and the soft tissue profile of the patients before treatment, it can be found that the facial aesthetics is influenced by many hard tissue parameters.@*Conclusion @# The effect of orthodontic and orthognathic technique in the treatment of skeletal ClassⅡ malocclusion is considerable. Hard tissue profile of patients with skeletal ClassⅡ malocclusion forms the basis and support of soft tissue profile. At the same time, soft tissue has some independence. However, the exact quantitative relationship remains to be further studied.
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Objective:To study the alveolar bone morphology in the anterior teeth area of the skeletal Class Ⅱ malocclusion subjects with different vertical skeletal types.Methods:64 patients with skeletal Class Ⅱ malocclusion and 15 subjects with normal occlusion were included.The alveolar bone structure of the anterior teeth were observed using CBCT.Results:The labial and lingual alveolar bone height and the alveolar bone thickness of the incisors of the patients were much lower than those of the normal controls.The height of labial and lingual alveolar bone and the alveolar bone thickness of anterior teeth in high-angle subgroup were lower than those in low-angle subgroup.Conclusion:The thickness of the anterior teeth alveolar bone of skeletal Class Ⅱ malocclusion is low,espe-cially in the high-angle group.
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Objective:To investigate the effects of corticotomy assisted orthodontic treatment for mild skeletal Class Ⅱ malocclusion. Methods:7 adult patients with mild skeletal Class Ⅱ division 1 malocclusion were included and underwent corticotomy assisted ortho-dontic treatments.3D measurements and analysis of CBCT data before and after treatment were conducted.Results:The average dura-tion of upper anterior teeth retraction was 3.2 months.After treatment,obvious retraction of up incisiors with the retraction of maxillary alveolar bone and the upper lip backward and downward movement were observed.Conclusion:Corticotomy assisted orthodontic treat-ment is effective in the treatment of mild skeletal Class Ⅱ malocclusion by the retraction of uper anterior teeth,alveolarar bone and soft-tissue profile improvement.
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Objective:To investigate the structure of alveolar bone around incisors in patients with verical facial type of skeletal ClassⅡ by CBCT.Methods:60 skeletal Class Ⅱ patients were divided into low angle,average angle and high angle cases(n =20)by FMA.CBCT scanning was made and the thickness of the labial and lingual alveolar bone around the incisors in each subject was meas-ured.The measurements were analyzed using ANOVA.Results:The total width of alveolar bone at the root apical level of maxillary and mandibular incisors,the lingual thickness of alveolar bone at the root midpoint of maxillary incisors and labial thickness of alveolar bone at the root midpoint of mandibular incisors in the high angle cases were thinner than that in the average and low angle cases(P <0.05),but there was no significant difference in labial thickness of alveolar bone at the crest among 3 groups.Conclusion:The alveo-lar bone thickness around incisors of high angle patients is thinner,more attention should be paid for the alveolar bone absorpation and tooth root exposure in these patients.
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BACKGROUND:The incidence rate of cervical abnormalities of the patients with skeletal class Ⅱ and normal occlusion has been studied abroad, but the researches on the incidence of cervical abnormalities in different malocclusion patients is rare at home. OBJECTIVE:To observe the imaging of patients with cervical abnormalities and to statistics the incidence of cervical abnormalities in different malocclusion patients through analyzing the lateral cephalogram of different malocclusion patients. METHODS:Skeletal class Ⅱ group was consisted of 93 patients, 41 male (aged 18-40 years) and 52 female (aged 22-35 years), with the A point-nasion-B point angle>5°. Class Ⅰ group was consisted of 45 patients, 31 female (aged 20-36 years) and 14 male (aged 17-38 years), with the 1°