ABSTRACT
Purpose@#Intraoral scanners, desktop scanners, and cone-beam computed tomography (CBCT) are being used in a complementary way for diagnosis and treatment planning. Limited patient-based results are available about dimensional reproducibility among different three-dimensional imaging systems. This study aimed to evaluate dimensional reproducibility among patient-derived digital models created from an intraoral scanner, desktop scanner, and two CBCT systems. @*Materials and Methods@#Twenty-nine arches from sixteen patients who were candidates for implant treatments were enrolled. Different types of CBCT systems (KCT and VCT) were used before and after the surgery. Polyvinylsiloxane impressions were taken on the enrolled arches after the healing period. Gypsum casts were fabricated and scanned with an intraoral scanner (CIOS) and desktop scanner (MDS). Four test groups of digital models, each from CIOS, MDS, KCT, and VCT, respectively, were compared to the reference gypsum cast group. For comparison of linear measurements, intercanine and intermolar widths and left and right canine to molar lengths were measured on individual gypsum cast and digital models. All measurements were triplicated, and the averages were used for statistics.Bland–Altman plots were drawn to assess the degree of agreement between each test group with the reference gypsum cast group. A linear mixed model was used to analyze the fixed effect of the test groups compared to the reference group (α=0.05).Result: The Bland–Altman plots showed that the bias of each test group was –0.07 mm for CIOS, –0.07 mm for MDS, –0.21 mm for VCT, and –0.25 mm for KCT. The linear mixed model did not show significant differences between the test and reference groups (P>0.05). @*Conclusion@#The linear distances measured on the digital models created from CIOS, MDS, and two CBCT systems showed slightly larger than the references but clinically acceptable reproducibility for diagnosis and treatment planning.reproducibility for diagnosis and treatment planning.plots showed that the bias of each test group was –0.07 mm for CIOS, –0.07 mm for MDS,
ABSTRACT
OBJECTIVE@#The aims of the present study were to evaluate the changes in the maximum lip-closing force (MLF) after orthodontic treatment with or without premolar extractions and verify the correlation of these changes with dentoskeletal changes.@*METHODS@#In total, 17 women who underwent nonextraction orthodontic treatment and 15 women who underwent orthodontic treatment with extraction of all four first premolars were included in this retrospective study. For all patients, lateral cephalograms and dental models were measured before (T0) and after (T1) treatment. In addition, MLF was measured at both time points using the Lip De Cum LDC-110R® device. Statistical analyses were performed to evaluate changes in clinical variables and MLF and their correlations.@*RESULTS@#Both groups showed similar skeletal patterns, although the extraction group showed greater proclination of the maxillary and mandibular incisors and lip protrusion compared to the nonextraction group at T0. MLF at T0 was comparable between the two groups. The reduction in the arch width and depth and incisor retroclination from T0 to T1 were more pronounced in the extraction group than in the nonextraction group. MLF in the extraction group significantly increased during the treatment period, and this increase was significantly greater than that in the nonextraction group. The increase in MLF was found to be correlated with the increase in the interincisal angle and decrease in the intermolar width, arch depth, and incisor–mandibular plane angle.@*CONCLUSIONS@#This study suggests that MLF increases to a greater extent during extraction orthodontic treatment than during nonextraction orthodontic treatment.
ABSTRACT
Background@#Dental studies of precocious puberty have focused on examination of jaw and dentition growth. The aim of the study was to analyze the relationship between precocious puberty and maxillary dental developmental abnormalities (DDAs). @*Methods@#This retrospective study was conducted on the Korean patients in whom dental panoramic and hand-wrist radiographs had been taken before they were 15 years of age. The maxillary DDAs were assessed as mesiodens, congenital missing teeth, peg-shape lateral incisors, or impacted teeth. The chronological ages of the control group members were within the normal range of the hand-wrist bone age. Others with a peak luteinizing hormone of ≥ 5 and < 5 IU/L were allocated to central precocious puberty (CPP) and peripheral precocious puberty (PPP), respectively. @*Results@#Of the enrolled 270 patients, 195, 52, and 23 were allocated to the control, CPP, and PPP groups, respectively. The maxillary DDAs were significantly more prevalent in the CPP group than in the other groups. Among those with maxillary DDA, the mesiodens predominated. Age- and sex-adjusted multivariate analysis revealed maxillary DDA (odds ratio, 3.36; 95% CI, 1.60-7.05) and especially mesiodens (odds ratio, 5.52; CI, 2.29-13.28) to be significantly associated with CPP. @*Conclusions@#Maxillary DDAs were significantly more prevalent in the CPP group than in the PPP or control groups. Among the many types of maxillary DDAs, mesiodens was significantly associated with CPP and may be considered a predictor of the development of CPP.
ABSTRACT
Background@#Dental studies of precocious puberty have focused on examination of jaw and dentition growth. The aim of the study was to analyze the relationship between precocious puberty and maxillary dental developmental abnormalities (DDAs). @*Methods@#This retrospective study was conducted on the Korean patients in whom dental panoramic and hand-wrist radiographs had been taken before they were 15 years of age. The maxillary DDAs were assessed as mesiodens, congenital missing teeth, peg-shape lateral incisors, or impacted teeth. The chronological ages of the control group members were within the normal range of the hand-wrist bone age. Others with a peak luteinizing hormone of ≥ 5 and < 5 IU/L were allocated to central precocious puberty (CPP) and peripheral precocious puberty (PPP), respectively. @*Results@#Of the enrolled 270 patients, 195, 52, and 23 were allocated to the control, CPP, and PPP groups, respectively. The maxillary DDAs were significantly more prevalent in the CPP group than in the other groups. Among those with maxillary DDA, the mesiodens predominated. Age- and sex-adjusted multivariate analysis revealed maxillary DDA (odds ratio, 3.36; 95% CI, 1.60-7.05) and especially mesiodens (odds ratio, 5.52; CI, 2.29-13.28) to be significantly associated with CPP. @*Conclusions@#Maxillary DDAs were significantly more prevalent in the CPP group than in the PPP or control groups. Among the many types of maxillary DDAs, mesiodens was significantly associated with CPP and may be considered a predictor of the development of CPP.
ABSTRACT
OBJECTIVES: This study was performed to evaluate patterns of failure time after insertion, failure rate according to loading time after insertion, and the patterns of failure after loading. MATERIALS AND METHODS: A total of 331 mini-implants were classified into the non-failure group (NFG) and failure group (FG), which was divided into failed group before loading (FGB) and failed group after loading (FGA). Orthodontic force was applied to both the NFG and FGA. Failed mini-implants after insertion, ratio of FGA to NFG according to loading time after insertion, and failed mini-implants according to failed time after loading were analyzed. RESULTS: Percentages of failed mini-implants after insertion were 15.79%, 36.84%, 12.28%, and 10.53% at 4, 8, 12, and 16 weeks, respectively. Mini-implant failure demonstrated a peak from 4 to 5 weeks after insertion. The failure rates according to loading time after insertion were 13.56%, 8.97%, 11.32%, and 5.00% at 4, 8, 12, and 16 weeks, respectively. Percentages of failed mini-implants after loading were 13.79%, 24.14%, 20.69%, and 6.9% at 4, 8, 12, and 16 weeks, respectively. CONCLUSION: Mini-implant stability is typically acquired 12 to 16 weeks after insertion, and immediate loading can cause failure of the mini-implant. Failure after loading was observed during the first 12 weeks.
Subject(s)
Dental Implants , Immediate Dental Implant Loading , Orthodontic Anchorage ProceduresABSTRACT
OBJECTIVE: The purpose of this study was to compare the longitudinal treatment effects of facemask with rapid maxillary expansion (FM/RME) and chincup (CC) therapy followed by fixed orthodontic treatment (FOT) in Class III malocclusion (CIII) patients. METHODS: The samples consisted of twenty-one CIII patients who had similar skeletal and dental characteristics before FM/RME or CC therapy and good retention results (Class I molar/canine relationship and positive overbite/overjet) after FOT (Group 1, FM/RME, n = 11; Group 2, CC, n = 10). Lateral cephalograms were taken before (T0) and after FM/RME or CC therapy (T1), and after FOT and retention (T2). Skeletal and dental variables were measured. Mann-Whitney U-test and Wilcoxon signed-rank test were used for statistical analysis. RESULTS: During T0-T1, FM/RME therapy induced forward movement of point A, and labioversion of the upper incisors. Both groups showed posterior repositioning of the mandible. FM/RME resulted in increase of the vertical dimension; however, CC caused an increase in articular angle and decrease in gonial angle. During T1-T2, both groups exhibited forward growth of point A. Group 1 showed forward growth and counterclockwise rotation of the mandible and increase of IMPA; however, Group 2, showed increase of ANS-Me/N-Me and decrease of overbite. CONCLUSIONS: The key factor for successful FM/RME and CC therapy and good retention results might be a harmonized forward growth of the maxilla that could keep pace with the growth and rotation of the mandible.
Subject(s)
Humans , Incisor , Malocclusion , Mandible , Maxilla , Overbite , Palatal Expansion Technique , Retention, PsychologyABSTRACT
Subject(s)
Axis, Cervical Vertebra , Displacement, Psychological , Finite Element Analysis , Imidazoles , Nitro Compounds , Orthopedics , TractionABSTRACT
OBJECTIVE: The purpose of this study was to evaluate the stress distribution in bone and displacement distribution of the miniscrew according to the length and number of the miniscrews used for the fixation of miniplate, and the direction of orthodontic force. METHODS: Four types of finite element models were designed to show various lengths (6 mm, 4 mm) and number (3, 2) of 2 mm diameter miniscrew used for the fixation of six holes for a curvilinear miniplate. A traction force of 4 N was applied at 0degrees, 30degrees, 60degrees and 90degrees to an imaginary axis connecting the two most distal unfixed holes of the miniplate. RESULTS: The smaller the number of the miniscrew and the shorter the length of the miniscrew, the more the maximum von Mises stress in the bone and maximum displacement of the miniscrew increased. Most von Mises stress in the bone was absorbed in the cortical portion rather than in the cancellous portion. The more the angle of the applied force to the imaginary axis increased, the more the maximum von Mises stress in the bone and maximum displacement of the miniscrew increased. The maximum von Mises stress in the bone and maximum displacement of the miniscrew were measured around the most distal screw-fixed area. CONCLUSIONS: The results suggest that the miniplate system should be positioned in the rigid cortical bone with 3 miniscrews of 2 mm diameter and 6 mm length, and its imaginary axis placed as parallel as possible to the direction of orthodontic force to obtain good primary stability.
Subject(s)
Axis, Cervical Vertebra , Displacement, Psychological , Finite Element Analysis , TractionABSTRACT
The maxillary protraction headgear has been widely used in the treatment of skeletal Class III children with maxillary deficiency. A variety of treatment objectives which allow dentoalveolar movements may be established, but when only maxillary protraction without dentoalveolar movement is needed, one of the limitations in maxillary protraction with conventional tooth-borne anchorage is the loss of dental anchorage. This is because a bone remodeling occurs not only at circummaxillary sutures but also within the periodontal tissues. During protraction treatment in the mixed dentition phase, in older children or for the patient with multiple congenitally missing teeth, it is not uncommon to observe undesirable mesial movement of maxillary teeth. Such a side effect can be eliminated or minimized using absolute anchorage such as skeletal anchorage. The purpose of this case report is to introduce a new technique of the maxillary protraction headgear treatment using surgical miniplates.
Subject(s)
Child , Humans , Bone Remodeling , Dentition, Mixed , Sutures , ToothABSTRACT
Subject(s)
Congenital Abnormalities , Dental Arch , Dentofacial Deformities , Esthetics , Magnetic Resonance Imaging , Maxilla , Orthognathic Surgery , Vertical DimensionABSTRACT
Although the submentovertex radiograph and surface EMG are not often used due to the difficulty of interpretation, they are accepted as useful diagnostic and analytic aids for skeletal asymmetry. There have been reports which state that they were also useful for the evaluation of vertical skeletal relations. The purpose of this study was to evaluate the correlations between EMG data, measurements from submentovertex radiographs, facial types and facial asymmetry following examination of 60 asymmetric patients. The radiographic corpus length were greater in the nonaffected sides (p < 0.001), gonion to interspinosum axis were greater in the affected sides and the mandibular condyle and gonion were located more anteriorly in the non-affected sides than in the affected sides but not significant (p=0.07). The activity of the anterior temporal muscle in rest position was higher in the affected sides than in the non-affected sides (p < 0.01). The activity of the masseter muscle at maximum clenching was found to be nonsignificant but it was higher in the affected sides than in the non-affected sides (p=0.09). There was positive correlation between facial index and the intercondylar axes angle (p < 0.01). There was positive correlation between masseter muscle activity in maximum occlusion and facial index in the affected and non-affected sides (p < 0.05). The results demonstrate that the submentovertex radiograph and EMG can provide useful information for the evaluation of horizontal and vertical skeletal relations.
Subject(s)
Humans , Axis, Cervical Vertebra , Facial Asymmetry , Mandibular Condyle , Masseter Muscle , Temporal MuscleABSTRACT
The purpose of this study was to investigate cephalometrically the short term static velopharyngeal changes in 25 patients (10 boys and 15 girls, aged from 5 years 9 months to 12 years 10 months in the beginning of treatment) with skeletal Class III malocclusions who underwent nonsurgical maxillary protraction therapy with a facemask. The linear, angular and ratio measurements were made on lateral cephalograms. Only the change in hard palatal plane angle was negatively correlated with the change in maxillary depth or N-perp to A (p < 0.01). The change in velar angle showed a statistically significant increase (p < 0.001). This change was influenced more by the soft palatal plane angle than by the hard palatal plane angle (p < 0.001). The changes in soft tissue nasopharyngeal depth and hard tissue nasopharyngeal depth showed statistically significant increases (p < 0.001). Correlations between the changes in soft tissue (or hard tissue) nasopharyngeal depth and the change in soft palatal plane angle were significant (p < 0.05). The increase in hard palate length was statistically significant (p < 0.001). The change in hard palate length was negatively correlated with the change in soft tissue nasopharyngeal depth (p < 0.05). The change in need ratio S (C) showed a statistically significant increase (p < 0.001). But this difference was within the normal range reported by previous studies. These findings indicate that the velopharyngeal competence was maintained even if the anatomical condition of the static velopharyngeal area were changed after maxillary protraction.
Subject(s)
Female , Humans , Malocclusion , Mental Competency , Palate, Hard , Reference ValuesABSTRACT
This study is aimed at providing the variables associated with adolescent compliance in orthodontic treatment, and identifies the salient predictors of cooperative behaviors over the course of treatment. Orthodontic attitude scale, orthodontic locus of control scale and demographics data were obtained for 60 adolescent orthodontic patients who had been in treatment a minimum of 10 months. This data was then analyzed in relation to their sex, school age and treatment compliance. The following results were obtained. 1. The scoring of external-powerful others-parents, subscale of the Orthodontic Locus of Control scale, found a statistically significant difference between sex differences (p<0.05). The score of boys was higher than that of girls. 2. The external-powerful others-parents score from the Orthodontic Locus of Control scale showed a significantly positive correlation (p<0.05) with the level of compliance. 3. The salient factors associated with compliance were the adolescent patients' own cognition and decisions. 4. There was a statistically significant correlation between the length of treatment and patient compliance (p<0.05). Thus, there was a substantial decrease in the cooperation of orthodontic patients over time. 5. Other independent variables including age, sex, family environment, religion, academic standing, parents' occupation and education, and brushing frequency were investigated and did not yield any significant relationships. Patient compliance is a critical factor in the efficacy of orthodontic treatment. Individuals vary greatly in their perceptions and attitudes of orthodontic treatment, sociodemographic environments and personality characteristics. In assessing the level of compliance attainable by each individual patient it is advisable to pay sufficient attention not only to the technical matters but also to the psychologic aspects of the treatment progress.
Subject(s)
Adolescent , Female , Humans , Cognition , Compliance , Cooperative Behavior , Demography , Education , Internal-External Control , Occupations , Patient Compliance , Sex CharacteristicsABSTRACT
We have analyzed 27 cases(38.8%) of scapho-lunate(SL) dissociation which were the most com- mon type of total 72 cases of post-traumatic wrist instabilities since 1985. As a result, SL dissociations associated with wrist fracture were 23 cases, more common than simple dynamic SL dissociation(4 cases). Early diagnosis and treatment influenced on their prognosis, and both wrist PA roentgenograms were useful for the confirmative diagnosis of SL dissociation. In 16 cases with early diagnosis, closed reduction, 2 or 3 K-wires fixation under C-arm image and short arm cast for 8 weeks were effective. But in 11 cases with neglected diagnosis and with wrist fractures showed poor results. Excessive wrist ligamentous reconstruction in chronic cases should be avoided because of osteoporosis and wrist stiffness. Conclusively, clinical wrist symptoms are more important than radiological changes in wrist insta- bilites. So if the symptoms are not so severe, we must consider the patient's age, occupation and their social activities etc. to decide the proper way of treatment.