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Objective:To analyze the symmetry of different reference planes in the surgical simulation design of patients with protrusive jaw deformity with high and low eyes.Methods:Fifteen patients with partial jaw deformity were selected from January 2019 to June 2020, including 3 males and 12 females, aged 18-26 years, with average 23.78 years. Inclusion criteria were that the patients, aged more than 18 years, were diagnosed as protrusive jaw deformity with maxillary occlusal plane tilt and high and low eyes by clinical and imaging analysis. Three different 3D reference plane systems were established by different modeling methods. The distance between the landmarks of soft and hard tissues and the median sagittal plane was measured. The symmetry of skull was qualitatively analyzed by mirror image technique. The difference of three reference planes in surgical simulation symmetry of patients with protrusion jaw and high and low eyes was evaluated by one-way ANOVA.Results:Qualitative analysis showed that in the three measurement planes, the symmetry of the third reference plane was the best, and the symmetry of the second and the first was poor. Quantitative analysis showed that in measurement index of hard tissue, there was statistical difference between the distance of each landmark in the reference plane established by Method 3 and Method 1, Method 2 [(1.65±1.19) mm; (3.37±1.58) mm; (3.26±2.36) mm, P<0.05], but there was no statistical difference between Method 1 and Method 2 (P > 0.05). The measurement result of soft tissue was consistent with that of hard tissue, and the distance of each landmark in Method 3 from the median sagittal plane was very small, and the mean error was less than 0.5 mm, which was consistent with the clinical results. Conclusions:Digital model surgery technology can assist orthognathic surgeons in the design and prediction of surgical scheme, especially for patients with special partial jaw deformity.
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Objective@# To establish a three-dimensional coordinate system that can accurately measure the recurrence rate after orthognathic surgery, and evaluate and analyze the degree of recurrence.@*Methods @#Data from patients who underwent orthognathic surgery in a hospital were selected to reconstruct three-dimensional images with spiral CT. The two researchers used the multiplane assisted positioning method to fix the points three times and screened them using intra-andintreclass correlation coefficients (ICC). Reproducible and accurate landmark points were drawn to establish different coordinate systems and calculate the facial asymmetry index (AI) to determine the coordinate system with the best mid-sagittal plane symmetry. This coordinate system and lateral radiographs were used to separately measure the recurrence rate, and evaluate and analyze the three-dimensional recurrence degree of orthognathic surgery.@*Results @#Ten landmark points that may be repeatedly fixed were obtained, including N (nasion), K (K point), ANS(anterior nasal spine), PNS (posterior nasal spine), Ptm(pterygomaxillary fissure), Gn (gnathion), IZ(IZ point), MZ (MZ point), Ms (mastoideale), Cor (coronion) and and Go (gonion). Three coordinate systems were established, and the most suitable coordinate system was the upper edge point of the left infraorbital foramen. The inner upper edge of the right infraorbital foramen and both sides of the midpoint of the ear points constituted the horizontal plane (HP), which passed through the outermost point of the left zygomatic frontal suture and the outermost point of the right zygomatic frontal suture and was perpendicular to the horizontal plane to constitute the coronal plane (CP). It was perpendicular to the two planes to form a sagittal plane (SP). Two-dimensional and three-dimensional measurements of recurrence were performed on 112 patients, and new three-dimensional recurrence evaluation results were obtained. Less than 40% had low recurrence, 40% to 61% had moderate recurrence, and greater than 61% had high recurrence.@*Conclusion@#This study established a three-dimensional coordinate system suitable for measuring the recurrence rate after orthognathic surgery, obtained a new three-dimensional recurrence evaluation result, and provided a clinical experimental basis for evaluating the effect of orthognathic surgery and improving stability.
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Objective@#To analyze the correlation between skeletal vertical patterns and mandibular dental arch width, basal arch width and the dental buccolingual inclination of patients with skeletal ClassⅠ@*Methods@#The CBCT data of 62 skeletal ClassⅠ malocclusion patients were collected and divided into a high-angle group with 19 cases, a mean-angle group with 22 cases, and a low-angle group with 21 cases according to the GoGn-SN angle. Mandible 3D reconstruction of the three groups was performed using Dolphin software, and dental arch widths, basal arch widths and buccolingual inclination of canines, first premolars and first molars, were measured and statistically analyzed respectively. @*Redults@#Mandibular dental arch width showed no significant difference among the three groups (P>0.05). The basal arch widths of mandibular canines and first premolars in low-angle group were larger than those in the other groups (P<0.05). The buccolingual inclinations of mandibular canines and first premolars in high-angle group were larger than those in the other groups (P<0.05). The buccolingual inclination and basal arch width of the first molars among the three groups showed no significant differences (P>0.05). Pearson correlation tests showed that the basal arch widths of mandibular canines and first premolars were negatively correlated with GoGn-SN angle. Excluding the influence of dental arch width and basal arch width, there was still a significant positive correlation between the buccolingual inclination of mandibular canines and first premolars and the GoGn-SN angle (P<0.05).@*Conclusion@#The width of the basal bone arch between different skeletal vertical patterns mainly differs in the canine segment and the premolar segment, and the difference in the buccolingual inclination of the teeth is mainly to compensate for the difference in the GoGn-SN angle. In clinical practice, individualized therapy should be adopted according to the differences to achieve the long-term efficacy of correction.
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OBJECTIVES@#At present, the research on clear aligner of molar distalization mainly focuses on the upper jaw, while the research on mandibular molars is few.This study aims to evaluate the therapeutic effect of mandibular molars distalization with clear aligner via cone beam CT (CBCT) and Dolphin software.@*METHODS@#Twenty cases of mandibular molars with clear aligner were included according to the inclusion and exclusion criteria. CBCT was taken before treatment (T0) and when the first molar was moved in place (T1). Dolphin software was used to measure the effectiveness of molar distalization. Three-dimensional changes in direction and the impact on the incisors and facial soft and hard tissues were evaluated.@*RESULTS@#The effective rates of crown and root distalization of the second and first mandibular molars were 74%, 49%, and 71%, 47%, respectively. The second and first molars were both the distal buccal cusp with the largest distalization [(2.15 ± 0.91) mm and (1.85±1.09) mm], respectively, with significant difference between the T0 and T1 (@*CONCLUSIONS@#Clear aligner can effectively move mandibular molars farther, the crown is more effective than the root, and it is tilted. The second mandibular molar is more effective than the first mandibular molar in its distant displacement and three-dimensional changes. Molar distalization causes minor changes in mandibular incisors and facial soft and hard tissues.
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Cephalometry , Maxilla , Molar , Orthodontic Appliances, Removable , Tooth Movement TechniquesABSTRACT
Objective • To evaluate nasolabial soft tissue changes of Chinese patients with malocclusion after maxillary anterior movement by Le Fort osteotomy with three-dimensional measurement. Methods • From Jan. to Dec. 2017, 37 patients with skeletal Class III malocclusion from Department of Oral and Craniomaxillofacial Surgery of Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, who underwent maxillary Le Fort osteotomy for anterior movement and bilateral sagittal split ramus osteotomy (bi-maxillary orthognathic surgery), were included. A full cranial spiral CT scan and three-dimensional facial soft tissue images were performed within 1 week before and 6 months after operation. Landmarks, relative distance and angle of nasolabial soft tissue were located and measured by 3dMD vultus software, and the differences before and after operation were compared. Results • After bi-maxillary orthognathic surgery, the alar width increased by an average of 0.82 mm, the subalar width increased by an average of 1.07 mm, the upper lip length increased by an average of 1.41 mm, the nasolabial angle increased by an average of 3.09, and the pronasal angle decreased by an average of 1.51(all P<0.05), while nasal height, nasal length and nasal frontal angle were basically stable. Conclusion • After the maxillary Le Fort I osteotomy for anterior movement, the face of patient with malocclusion is improved, and the nasolabial soft tissue is also changed.
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OBJECTIVE@#To study the developmental and morphological characteristics of the mandible in patients with impacted mandibular second molar and to predict the possible trend of mandibular development via three-dimensional (3D) measurement and analysis.@*METHODS@#A total of 88 cases of impacted group and 88 cases of control group were screened out. 3D measurements were performed by using Mimics software. A total of 23 landmark points and 17 measurements were determined. The measurements were analyzed by t-test.@*RESULTS@#The mandible length, the space between the first molars, the space between mandibular angles, and the width between the first molars in the impacted group were lower than those in the control group (P<0.05). Moreover, the value of the submandibular angle was higher than that in the control group (P<0.05).@*CONCLUSIONS@#The impacted mandible of patients with mandibular second molar showed lack of sagittal and width development, and the impacted mandibular second molar was a manifestation of its degeneration.
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Humans , Mandible , Molar , Molar, Third , Software , Tooth, ImpactedABSTRACT
Objective@#To measure and analyze the bone volume and thickness of mandibular angle area by computer-assisted CT.@*Methods@#From January 2010 to January 2016, 94 female patients with mandibular angle hypertrophy and bilateral mandibular angle osteotomy were selected. Twenty female patients with non-mandibular surgery were selected as control group (patient examined after nasal augmentation surgery), aged 18 to 37 years, with an average of 27.5 years. Three dimensional CT data of maxillofacial bone of patients were collected. The three dimensional reconstruction and measurement software Mimics 16.0 was used. A three-dimensional model of mandibular angle region was established. The thickness and volume of mandibular angle were measured and analyzed. The total difference between hypertrophic group and normal group was compared by two independent t-test.@*Results@#The thickness of mandibular angle area and mandibular angle area in hypertrophic group were (9.39±1.48) mm and (3 065.25±720.1) mm3 respectively, and the thickness of mandibular angle area and mandibular angle region in control group were (7.48±0.92) mm and (1 276.57±265) mm3, respectively. There was a significant difference between the two groups (P < 0.05).@*Conclusions@#Based on CT scanning data, a method of measuring the bone volume and thickness of mandibular angle region is established, which is helpful to the three-dimensional measurement and analysis of mandibular shape in patients with mandibular angle hypertrophy.
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Objective@#To investigate the influence of condylar fractures on the growth of condylars after conservative treatments by three-dimensional measurement.@*Methods@#Twenty three children with unilateral condylar fracture followed-up for at least 1 year in Shanghai Ninth People's Hospital were included from June 2016 to March 2017. CT scans were performed for each patient. Three-dimensional virtual skulls were reconstructed and measuring points were defined with Simplant 11.04 software. The depth of glenoid fossa, height of articular eminence, width, height and depth of condylar, deviation of pogonion were measured. Statistical analyses were conducted to assess difference between the bifid group and the normal group.@*Results@#No difference was observed in the vertical position of crest of the articular eminence between two groups (P=0.110). The vertical position of roof of the glenoid fossa in bifid side was significantly superior than the one in normal side (P=0.010). Bifid side had a shorter (P=0.002) and wider(P=0.002) condylar than normal side did. No difference was observed in the depth of condylar between two groups (P=0.071). The average deviation of pogonion was (0.69±1.75) mm (P=0.072) from sagittal plan.@*Conclusions@#This short-termed study indicates that children's growth potential of condylar is under average after conservative treatments. Because the bone hyperosteogeny of glenoid fossa compensates the hypotrophy of condylar, no deviation of pogonion is detected.
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Objective The aim of our work is to characterize individual normal occlusions to establish appropriate treatment standards for different vertical facial types. Methods A total of 30 patients with near-normal occlusion were grouped into high-angle group (eight cases), medium-angle group (12 cases), and low-angle group (10 cases) according to vertical facial skeletal type. Invivo5 software was used and digital imaging and communications in medicine data were rebuilt to measure the ∠L1/MP, ∠L6/MP, axis corner of L6, cant of occlusion plane, Balkwill angle, and Bonwill triangle of each group. Results Among the groups, the low-angle group had the smallest ∠L6/MP (P<0.05) and largest cant of occlusion. No significant difference was observed among the three groups with regard to the other parameters (P>0.05). Conclusion Patients with low-angle vertical facial skeletal type requires a modified treatment standard. In this group, the treatment standard must ensure that the cant of occlusion plane is more parallel to the Frankfurt horizontal plane compared with those of the other groups, and the axis of L6 is tilted distally relative to the mandibular plane.
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Objective To aesthetically evaluate the mandible,to position the gonion landmark of the aesthetic female with digital techniques and to establish three-dimensional mandibular measurements database of the aesthetic female.Methods 14 aesthetic volunteers were chosen by plastic surgeons and ordinary people based on the identical view of esthetic mandible.The heads were scanned by a spiral CT scanner,and the data were imported into Mimics 18.0 to generate the 3D skull images.Distance,angle and ratio measurements,which could represented the aesthetic characters of the mandible,were made on the images.All the data were transferred into the SPSS 22.0 software to perform statistical analysis.A two-tailed t test was used to compare the symmetry of bilateral mandibles.Dynamic database of aesthetic mandibles was established.The mean,standard deviation,standard error and 95％ confidence interval of data were calculated by statistical software automatically.Results The results suggested that the mean of aesthetic mandibular angle was 123.91°,and the mean of mandibular plane angle was 27.03°.The ratio between the mandibular body and ramus approximated to 2 ∶ 1,and the ratio of the distance between gonion and mental foramen to ramus was close to 1.4.Conclusions The study of mandibular esthetics contributes to positioning the new gonion accurately for patients with prominent mandibular angle and gonion reconstruction,and it can assist surgeons in surgical designing,simulating and performing.
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Objective To evaluate recurrence after mandibular distraction osteogenesis in adult patients with hemifacial microsomia using the digital three dimensional measurement.Methods Nine adult hemifacial microsomia patients were evaluated using the method of digital measurements with three dimensional computed tomography.Three observation points were studied:pre-operation (T0),post-operation (T1) and follow-up (T2).The length of ramus (H for normal side and h for affected side),the length of body (L for normal side and l for affected side) and distance between pogonion and facial midline (D) were measured and the recurrence rate (R) was calculated.Results Percentages of h/H at T0,T1,T2 were (58.19±12.06)％,(87.09±17.92)％and (81.13±30.57)％,which had statistical significance respectively.2.Percentage of l/L at T0,T1,T2 were (87.70±7.86)％,(90.69± 5.77) ％ and (90.11±5.62)％,respectively,which had statistical significance between T0 and T1.3.Lengths of D at T0,T1,T2 were (13.66±3.28) mm,(4.926±1.75) mm and (6.616±1.82) mm,respectively,which had statistical significance between T0,T1 and T0,T1.4.Average R was (22.80± 9.73) ％.Conclusions Varying degrees of recurrence do happen in both ramus and body of mandibular after distraction osteogenesis.While it is demonstrated that the mandible grows obviously after operation compared to that pre-operation,Meanwhile,the facial symmetry is also improved significiantly.
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<p><b>OBJECTIVE</b>This study analyzed the alveolar changes of complete unilateral cleft lip (UCCL) patients after pre-surgical nasoalveolar molding (PNAM) treatment using a three-dimensional method.</p><p><b>METHODS</b>Palate impressions of thirty UCCL patients who underwent PNAM treatment in the Affiliated Stomatology Hospital of Guangxi Medical University were taken pre- and post-PNAM. The plaster impressions were scanned using cone beam computed tomography (CBCT). The DICOM files were exported and 3D models reconstructed in Mimics 15.0. The following parameters were analyzed in SPSS 17.0: cleft alveolar gap width, alveolar arch end width, upper lip frenulum-median plane distance, alveolar shift distance, and length of alveolar section.</p><p><b>RESULTS</b>After PNAM treatment, the cleft alveolar gap width and upper lip frenulum-median plane distance decreased significantly (P<0.05). No statistically significant change was observed in the alveolar arch end width (P>0.05). Alveolar shift distances for both sides increased significantly (P<0.05), and the shift distance of major alveolar sec-tion had a more significant increase than the minor alveolar section. The lengths of the alveolar section of both sides increased significantly (P<0.05) with the length of the major alveolar section increasing more significantly than the minor alveolar section.</p><p><b>CONCLUSIONS</b>The impression-CBCT method supply accurate three-dimensional data of the alveolar process. The PNAM treatment can significantly correct alveolar deformity and improve appearance.</p>
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Humans , Alveolar Process , Cleft Lip , Cleft Palate , Hospitals , Preoperative Care , UniversitiesABSTRACT
Objective:To discuss the changing position in three dimensions of maxillary dentition magnetic arch expansion after.Methods: Thirty patients who were in-patient cases were selected, and received three-dimensional data measured before and after treatment it its spiral CT, observed the three-dimensional position of maxillary dentition before and after treatment, and the angle of landmarks change data paired sign test for comparison.Results: Patients in the vertical position of maxillary dentition before and after treatment, sagittal and horizontal direction are changed. First premolars, first molars occurred cheek overall movement and dumping; the maxillary first premolar region is the largest widening position; three-dimensional position of the maxillary central incisor forward, the next move.Conclusion: Patients before and after the change of maxillary dentition MPE can be clearly presented in accordance with spiral CT, lay the foundation for further research MPE mechanism.
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Objective:To study the 3D accuracy of 4 impression materials.Methods:A metal mould with a custom tray was prepared for the measurement.Impression samples of 2 alginate and 2 rubber impression materials were prepared in the metal mould(n =3)re-spectively.The length of three tagged lines,along X,Y,Z axis directions of the samples was measured with a 3D optical scanner.Re-sults:120 min after sampling the variable rates of the length along X,Y,Z axis of Zhermark alginate samples were 3.615%,3.037%and 2.836%,those of CAVEX alginate samples were 2.836%,3.358% and 4.276% respectively;8 h after sampling the variable rates of Impregum Penta polyether rubber samples were 0.039%,0.071% and 0.057%,those of ExpressXT Penta H addition-curing silicone rubber samples were 0.033%,0.088% and 0.084% respectively.Conclusion:The variable rates of the 4 impression materi-als are in accordance with ISO1563∶1990.The variable rate of alginate impression material is greater than that of rubber.
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PURPOSE : The aim of this study was simply assessing linear measurements in the lateral and medial approach, respectively, for bone harvesting using anatomic and three-dimensional (3D) computed tomographic (CT) analyses on a dried cadaveric proximal tibia. In addition, the availability of the three-dimensional computed tomographic (3D-CT) analysis was also estimated. MATERIALS AND METHODS : Ten dried proximal tibia were obtained from five Korean cadavers. Four the reference points, the SM (superior-medial), IM (inferior-medial), SL (superior-lateral), and IL (inferior-lateral) were marked around the tibial tuberosity. The PM (posterior-medial) and PL (posterior-lateral) points were randomly marked at points farthest from the lateral and medial reference points, respectively, in the posterior border of the superior articular surface of both condyles. All measurements were obtained on the dried proximal tibia. After computed tomography had been performed, the three dimensional images were reconstructed using V works 4.0(TM) (Cybermed Inc., Seoul, Korea), and the length between the reference points were measured three dimensionally using the method described above. The error between the mean actual and mean 3D-CT measurements was calculated in order to determine the availability of the three dimensional computed tomographic analysis. RESULTS : The length between the reference points was greatest at the IL-PM, which averaged 65.39 mm+/-10.35. This was followed by the SL-PM with 63.24 mm+/-8.10, the IM-PL with 58.09 mm+/-10.02, and the SM-PL with 51.99 mm+/-9.06. The differences between the IL-PM and SM-PL were 13.4 mm. The mean values were 55.04 mm in the medial approach and 64.32 mm in the lateral approach, and the differences between medial and lateral were 9.28 mm. The error between the mean actual and mean 3D-CT measurements was 0.31% and the standard deviation was 0.28%. CONCLUSION : The anatomical and three dimensional computed tomographic analysis indicates that there was only a 9.28 mm linear difference between the lateral and medial approach. This is consistent with previous studies, which showed that there was little difference between the two approaches in terms of the bone volume. In addition, the error (0.31%) and the standard deviation (0.28%) were considered low, demonstrating high accuracy of 3D-CT. Therefore it can be used in preoperative treatment planning.
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Cadaver , Seoul , TibiaABSTRACT
BACKGROUND AND OBJECTIVES: The caloric test is considered to be one of the most sensitive parameters in the diagnosis of peripheral vestibular disorders, although it can test only the function of the lateral semicircular canals. In this study, the authors measured the eye movements and visual suppression of caloric nystagmus in cats three dimensionally using a magnetic search coil system. MATERIALS AND METHOD: Three-dimensional (3-D) eye movement responses to an ice water caloric stimulus were studied with the six normal cats positioned in an upright position (lateral semicircular canal vertical). Visual suppression of caloric nystagmus was also investigated. RESULTS: All animals showed eye movements in the horizontal, torsional and vertical planes. Of the three nystagmus components, the horizontal component showed the fastest eye velocity during caloric stimulation. In light, a slight, but certain degree of visual suppression in was recognized in cats. CONCLUSION: The caloric nystagmus response involves a complex eye movement response comprising the horizontal, vertical and torsional nystagmus components. The 3-D analysis system with a magnetic search coil is useful to investigate the eye movement during caloric stimulation when the cat is awake.
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Animals , Cats , Caloric Tests , Diagnosis , Eye Movements , Ice , Nystagmus, Physiologic , Semicircular Canals , WaterABSTRACT
BACKGROUND AND OBJECTIVES: Unilateral vestibular dysfunction evokes many bothersome symptoms such as nausea, vomiting, vertigo, ataxia, and positional change. We attempted to understand the vestibular signs after a loss of unilateral vestibular function. MATERIALS & METHOD: We evaluated the serial changes of eye movements and body posture after unilateral labyrinthectomy which was performed on five cats. Data obtained from three of these cats. The eye movements were measured in vertical, horizontal and torsional planes using magnetic search coils, with eyes open in light and eyes open in darkness. The eye movements were recorded with head in neutral, tilted, hanging, and Dix-Hallpike position, and after head was shaken. RESULTS: 1) Spontaneous nystagmus was present for the first three days. 2) Head tilting positional nystagmus was present only on the first day after the operation. Head hanging position produced nystagmus with high slow phase eye velocity for 4 weeks. 3) Positioning nystagmus was recorded for 4 weeks and it was more prominent when labyrinthectomized ear was undermost. 4) Head shaking nystagmus around the pitch and roll axis was evoked within one week, but in the yaw axis it persisted for 4 weeks. When the cat was tilted to the lesion side, the intensitiy of positional and positioning nystagmus was stronger. CONCLUSION: Unusual positions such as head hanging and Dix-Hallpike position evoked prolonged nystagmus. Head shaking in the yaw axis could be used on a long term basis to understand unilateral vestibular dysfunction.
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Animals , Cats , Ataxia , Axis, Cervical Vertebra , Darkness , Ear , Eye Movements , Head , Nausea , Nystagmus, Physiologic , Posture , Vertigo , VomitingABSTRACT
The present study has been performed to evaluate 20 cardiopathy children and 20 healthy children's oral micorbes at the point of antimicrobial susceptibilities for antimicrobial prophylaxis to prevent bacterial endocarditis. The results were as follows: 1. Both groups had similar oral microbes. 2. The antimicrobial susceptibility of S. viridans were: Penicillin< Oxacillin< Ampicillin< Cephalothin< Erythromycin< Clindamycin< Gentamicin< Ciprofloxacin< Vancomycin=Imipenem. The cardiopathy group was slightly lower antimicrobial susceptibility rates than healthy group. 3. The antimicrobial susceptibility of Neisseriaceae were: Clindamycin< Erythromycin< Vancomycin< Penicillin< Gentamicin< Cephalothin< Ciprofloxacin< Imipenem. The antibiotics of bacterial endocarditis antibiotic prophylaxis regimens for dental procedures according to the American Heart Association were generally lower antimicrobial susceptibilities, so they were considered inadequate for the first selective antibiotics and Imipemem was best suitable antimicrobials. Conclusively, when choose antimicrobials for treatment or antimicrobial prophylaxsis for bacterial endocarditis, surveillant culture must be performed to evaluated personal antimicrobial susceptibilities of intraoral microbes for proper antimicrobial choice for dental procedures.