To investigate the association between maxillofacial morphology and mandibular bone volume in patients with skeletal malocclusion.
Subjects were 118 adult Japanese (58 males and 60 females). Skeletal ...malocclusion was classified, based on cephalometric analysis, into skeletal Classes I (-1° ≤ ANB < 4°), II (ANB ≥ 4°), and III (ANB < -1°). Using cone-beam computed tomography and three-dimensional image analysis software, the dental crowns and mandible were separated, with only the mandible extracted. This was then reconstructed as a three-dimensional model, from which the mandibular volume was measured.
No significant difference in mandibular volume was noted among skeletal Classes I, II, and III, nor was there any significant correlation between mandibular volume and the ANB, SNB, or mandibular plane angles. There was occasional and limited correlation between mandible volume and gonial angle and certain cephalometric distance parameters.
We conclude that proper understanding of the three-dimensional maxillofacial morphology requires not only cephalometric radiographic tracings but also high-resolution analysis of the mandibular area, width, and volume.
The aim of this study was to evaluate the differences in sella dimensions and shape between growing patients with Class I, Class II, and Class III skeletal malocclusions, evaluated through ...morphometric analysis. Seventy-eight subjects aged between 9 and 13 years were selected and assigned to either the Class I, Class II, or Class III groups according to the measured ANB angle (the angle between the Nasion, skeletal A-point and skeletal B-point). Six landmarks were digitised to outline the shape of the sella turcica. Linear measurements of the sella length and depth were also performed. Procrustes superimposition, principal component analysis, and canonical variate analysis were used to evaluate the differences in sella shape between the three groups. A one-way MANOVA and Tukey's or Games-Howell tests were used to evaluate the presence of differences in sella dimensions between the three groups, gender, and age. The canonical variate analysis revealed a statistically significant difference in sella shape between the Class I and the Class II groups, mostly explained by the CV1 axis and related to the posterior clinoidal process and the floor of the sella. No differences were found regarding linear measurements, except between subjects with different age. These differences in sella shape, that are present in the earlier developmental stages, could be used as a predictor of facial growth, but further studies are needed.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Introduction The aim of this study was to evaluate the effect of rapid maxillary expansion on the volume of the nasal cavity by using computed tomography. Methods The sample consisted of 24 patients ...(10 boys, 14 girls) in the permanent dentition who had maxillary constriction and bilateral posterior crossbite. Ten patients had skeletal Class I and 14 had Class II relationships. Skeletal maturity was assessed with the modified cervical vertebral maturation method. Computed tomograms were taken before expansion and at the end of the 3-month retention period, after active expansion. The tomograms were analyzed by Mimics software (version 10.11, Materialise Medical Co, Leuven, Belgium) to reconstruct 3-dimensional images and calculate the volume of the nasal cavities before and after expansion. Results and Conclusions A significant ( P = 0.000) average increase of 11.3% in nasal volume was found. Sex, growth, and skeletal relationship did not influence measurements or response to treatment. A significant difference was found in the volume increase between the Class I and Class II patients, but it was attributed to the longer expansion period of the latter. Therefore, rapid maxillary expansion induces a significant average increase of the nasal volume and consequently can increase nasal permeability and establish a predominant nasal respiration pattern.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The objective of the study was to elucidate the association between cranial base (Bjork-Jarabak analysis), midsagittal cross-sectional area of the airway in the pharyngeal region (MCSA-PR) data and ...pharyngeal-airway volume (PAV) and develop a model that could help clinicians predict PAV using two-dimensional (2D) data (Bjork polygon and MCSA-PR).
Pre-treatment lateral cephalometric radiographs and magnetic resonance imaging (MRI) scans of 82 women were categorized into three anteroposterior skeletal groups based on ANB angle: Class I (n = 29), 1.5° ≤ ANB≤5.1°; Class II (n = 26), ANB >5.1°; Class III (n = 27), ANB <1.5°. The Bjork polygon, MCSA-PR data from cephalograms and PAV data from MRI scans were examined. Intergroup comparisons were performed using the Kruskal-Wallis test and one-way analysis of variance (ANOVA), with pairwise comparisons conducted using the Bonferroni-corrected Mann-Whitney U-test for the Kruskal-Wallis test and Bonferroni-corrected multiple comparison test for one-way ANOVA. Forward multiple linear regression was used to create model equations for predicting PAV.
MCSA-PR and anterior (N-S) and posterior (S-Ar) cranial-base lengths were positively correlated with the PAV. We developed four models; three operated at the group level, and one encompassed the entire sample. Notably, all models could effectively explain the variance in the PAV data. The model for the Class I group was the strongest (adjusted R
= 0.77).
Our findings indicate the remarkable potential of the MCSA-PR, N-S and Bjork sum angles (BSA) as predictors of the PAV and the relevance of 2D cephalometric and cranial-base parameters in predicting the three-dimensional (3D) pharyngeal-airway size.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
To establish an objective method for evaluating facial attractiveness from a set of orthodontic photographs.
One hundred eight malocclusion patients randomly selected from six universities in China ...were randomly divided into nine groups, with each group containing an equal number of patients with Class I, II, and III malocclusions. Sixty-nine expert Chinese orthodontists ranked photographs of the patients (frontal, lateral, and frontal smiling photos) before and after orthodontic treatment from "most attractive" to "least attractive" in each group. A weighted mean ranking was then calculated for each patient, based on which a three-point scale was created. Procrustes superimposition was conducted on 101 landmarks identified on the photographs. A support vector regression (SVR) function was set up according to the coordinate values of identified landmarks of each photographic set and its corresponding grading. Its predictive ability was tested for each group in turn.
The average coincidence rate obtained for comparisons of the subjective ratings with the SVR evaluation was 71.8% according to 18 verification tests.
Geometric morphometrics combined with SVR may be a prospective method for objective comprehensive evaluation of facial attractiveness in the near future.
To evaluate the dentoskeletal effects and effectiveness of the eruption guidance appliance in Class III patients in the mixed dentition.
The experimental group comprised 22 patients with Class III ...malocclusion and anterior cross-bite (12 males, 10 females, mean age 7.63 ± 0.96 years) treated with the eruption guidance appliance over a mean period of 1.72 ± 0.48 years. The control group comprised 22 untreated subjects (12 males, 10 females, mean age 7.21 ± 0.60 years) with Class III malocclusion. Lateral cephalometric radiographs were obtained at pretreatment (T1) and posttreatment (T2). Intergroup comparisons were performed with Mann-Whitney and t-tests (P < .05).
In the experimental and control groups, the anteroposterior relationship between the maxilla and mandible (ANB angle) remained stable during the treatment period (T1 to T2). The mandibular plane angle decreased in the experimental group and increased in the control group. In the experimental group, the lower anterior face height increase and maxillary molar vertical development were significantly smaller compared to controls. Positive overjet was achieved in 54% of the experimental group.
The eruption guidance appliance produced no change in the skeletal anteroposterior relationship. The anterior cross-bite/edge-to-edge relationship was corrected in only about half of the treated subjects.
The surgery-first approach indicates that the orthognathic surgery precedes the orthodontic treatment, whereas the orthodontics-first approach indicates that the orthodontic treatment precedes the ...orthognathic surgery. The conventional approach is an orthodontics-first approach. The purposes of this article are to introduce the concept of the surgery-first approach and to report the guidelines for orthodontic management and model surgery without presurgical orthodontic decompensation. The surgery-first approach treats facial esthetics first and then occlusion, whereas the conventional approach treats occlusion first and then facial esthetics. The surgery-first approach uses osteotomy to solve both skeletal problems and dental compensation, and a “transitional” occlusion is set up postoperatively. Orthodontics in the surgery-first approach is a postoperatively adjunctive treatment to transfigure the transitional occlusion into the solid final occlusion. The advantages of the surgery-first approach are that 1 ) the patient's chief complaint, dental function, and facial esthetics are achieved and improved in the beginning of the treatment; 2 ) the entire treatment period is shortened to 1 to 1.5 years or fewer depending on the complexity of orthodontic treatment; and 3 ) the phenomenon of postoperatively accelerated orthodontic tooth movement reduces the difficulty and treatment time of orthodontic management in the surgery-first approach.
Objectives
Given that current literature largely dissociates dental malocclusion and bruxism, the objective of this study was to gather, through a systematic review, scientific evidence to support ...their relationship.
Methodology
This study was performed according to the PECO strategy (where P = general population; E = dental malocclusion; C = no dental malocclusion; and O = bruxism). Literature searches were conducted without language or date restrictions in the following databases: PubMed, Scopus, the Web of Science, the Cochrane Library, LILACS/BBO via VHL and the grey literature. The search strategy included Medical Subject Headings/DECs, synonyms and free terms relevant to each database, with no age restrictions applied. Once the relevant data were extracted from the articles, the Fowkes and Fulton guidelines were followed to assess the quality and risk of bias. For quantitative analysis, dental malocclusions were divided into groups according to their type in order to perform odds ratio (OR) meta‐analyses with 95% confidence intervals (CI) using the Review Manager software program (Cochrane, London, UK). The level of certainty of evidence was demonstrated through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE).
Results
After 1,502 studies found, 10 studies were included for qualitative analysis and nine for quantitative synthesis. Four studies presented high methodological quality. Five meta‐analyses suggested a non‐association between bruxism and Angle class I (OR: 1.05, 95% CI: 0.41‐2.69; P = .92; I2 = 84%), Angle class II (OR: 1.49, 95% CI: 0.77‐2.87; P = .23; I2 = 71%) or Angle class III (OR: 0.77, 95% CI: 0.31‐1.93; P = .58; I2 = 0%). Bruxism was associated with children who did not present with a posterior crossbite (OR: 0.70, 95% CI: 0.51‐0.96; P = .03; I2 = 27%) and present crowding (OR: 1.53, 95% CI: 1.03‐2.26; P = .03; I2 = 0%). The GRADE analysis presented a very low quality of evidence.
Conclusion
Individuals who present with bruxism have a greater chance of crowding. However, bruxism is not associated with the presence of any of the other malocclusions evaluated.
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BFBNIB, CMK, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The purpose of this systematic review was to analyze the available literature about the influence of breastfeeding in primary and mixed dentition on different types of malocclusions.
Preferred ...Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) guidelines were used to perform the present review. The following electronic databases were searched: Pubmed, Evidence-Based Medicine Reviews (EBMR), Embase, Cochrane Library, Medline, Web of Science and Ovid.
A primary research found a total of 279 articles. Two more papers were also considered from the gray literature. Two hundred sixty-three articles were excluded as they were deemed irrelevant on the basis of: duplicates, title, abstract, methods and/or irrelevant contents. Eighteen papers were selected and included in the qualitative analysis.
breastfeeding is a positive factor that seems to reduce the incidence of posterior crossbite, skeletal class II and distoclusion in primary and mixed dentition. A sort of positive relationship between months of breastfeeding and risk reduction seems to exist. More longitudinal research is needed to avoid bias in the results, with data collected prospectively on the months of exclusive breastfeeding, by means of specific questionnaires and successive clinical evaluation of the occlusal condition at the primary dentition, mixed dentition and permanent dentition stages.
Correcting severe scissor bite in an adult Baik, Un-Bong; Kim, Yunji; Sugawara, Junji ...
American journal of orthodontics and dentofacial orthopedics,
July 2019, 2019-Jul, 2019-07-00, 20190701, Volume:
156, Issue:
1
Journal Article
Peer reviewed
Scissor bite often remains unnoticed by patients although it can adversely affect facial symmetry, jaw growth, and mastication. This case report illustrates the efficacy of temporary skeletal ...anchorage devices (TSADs) and a modified lingual arch in correcting severe scissor bite. A 28-year-old woman presented with severe scissor bite in the mandibular right posterior segment. To treat this condition, TSADs were used for maxillary posterior intrusion and a modified lingual arch for buccally uprighting mandibular posterior teeth. Long-term retention records demonstrate stable treatment results.
•Severe scissor bite correction.•TSADs were used for maxillary posterior intrusion and a modified lingual arch for buccally uprighting mandibular posterior teeth.•6-year retention.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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