ABSTRACT
To observe three-dimensional changes of dentigerous cyst-associated maxillary canines (DCAMC) in adolescents after marsupialization by using cone beam computed tomography (CBCT). Methods: A total of 34 DCAMC patients with dentigerous cyst aged 10-14 were divided into central type and lateral type, while canines on the non-cyst side served as a control. A three-dimensional reference frame was set up to analyze the position, angle changes and influential factors for DCAMC by using CBCT before operation and in 3-6 month after operation. Results: 1) Compared with pre-operation, there was significant vertical movement in DCAMC after marsupialization. Tip of tooth moved labially while tooth axis inclined mesiodistally; 2) Horizontal, vertical movement and mesiodistal inclination of DCAMC were significantly greater than those in the health side; 3) Compared with the lateral type DCAMC, the central type DCAMC showed a significant changes in labial inclination; 4) Horizontal movement, mesiodistal and labial inclination of lateral type DCAMC were all evidently greater than those of the central type DCAMC; 5) Vertical movement and inclination of DCAMC after marsupialization were significantly correlated to the time interval (r=0.354, 0.374, both P<0.05), while vertical movement of cuspid in health side was significantly negative correlated with the patients' age and the level of root formation (r=-0.506, -0.721, both P<0.01). Conclusion: DCAMC in adolescents can obtain obvious changes in position and angles after marsupialization regardless of the level of root formation, which is beneficial for further orthodontic treatment.
Subject(s)
Adolescent , Child , Humans , Cone-Beam Computed Tomography , Cuspid , Dentigerous Cyst , MaxillaABSTRACT
Objective:To investigate the effect of different crown heights of lateral incisor and canine on smile esthetics perception between orthodontists and patients.Methods:A total of 31 orthodontists and 56 patients on smile aesthetics perception were investigated.We adjusted the height of lateral incisor and canine to get 20 kinds of anterior tooth area morphology by Photoshop and asked interviewees to grade.Scores of satisfaction were recorded by Likert method.Results:Subjects in the 2 groups preferred smiles with upper anterior teeth edge parallel to lower lip.There was better acceptance for longer canines and less satisfaction at shorter lateral incisors in patients.Patients also got higher discrete degree of evaluation results and more rigorous about smile esthetics than orthodontists.Conclusion:Orthodontists and patients have different satisfaction at esthetics of anterior teeth.Esthetics preference should be considered in orthodontic treatment schedule.
ABSTRACT
Objective:To explore the influence of gender and age on the measurement of cone beam CT (CBCT) in normal and occluded craniofacial hard tissues for Han nationality in Changsha area.Methods:A total of 80 CBCT data of normal and occluded craniofacial hard tissues for Han nationality in Changsha area were collected,including 40 adults [16 males and 24 females,aged (17.57±1.83) years] and 40 children[16 males and 24 females,age (11.50±1.26) years].Threedimensional cephalometric measurements were carried out by Dolphion Imaging software,and the influence of gender and age was compared.Results:The symmetry of craniofacial hard tissues in male and female in the adults was good (the maximum asymmetric rate R was 6.39％ and the minimum asymmetric rate R was 0.08％).There was no significant differencein the anterior palatal width,palatal width,the upper incisor protrusion distance,the lower incisor protrusion distance,hyoid-mandibular plane,basal epiglottis width,and palatal plane airway width between the males and females (all P＞0.05);while the remaining indicators were significantly higher in males than those in females (all P＜0.05).There was no significant gender difference in angle indicators (all P＞0.05).There were significant differences in the posterior height,the maxillary length,the lower incisor protrusion,and the mandibular plane angle between the adults and the children(all P＜0.05);but the rest of indicators were not significant difference (all P＞0.05).Conclusion:The symmetry of craniofacial hard tissues for Han nationality in Changsha area is good.The gender and age affect the line space measurements but not affect the most of the angle measurements.
ABSTRACT
To investigate three-dimensional morphological features of temporomandibular joint in skeletal malocclusion Class III with different vertical skeletal facial types. Methods: A total of 46 adults with skeletal malocclusion Class III were enrolled and allocated into a normal-angle, a high-angle and a low-angle groups. All patients were undergone cone beam computed tomography (CBCT). Images of temporomandibular joint were reconstructed and analyzed by Invivo 5. Nine measurements relevant to the positions and forms of condyle as well as joint spaces were performed. Results: Significant differences were not observed between the 2 sides of each group among skeletal malocclusion Class III (P>0.05). Compared with the high-angle and normal-angle patients, the low-angle patients had larger superior spaces, bigger gradients of the articular tublecle, longer condyle, and larger internal spaces between the condyle and the fossa. Compared with the low-angle and normal-angle patients, the high-angle patients had smaller condylar antero-posterior diameters. Conclusion: Class III malocclusion patients with different vertical skeletal patterns have different positions and forms of condyles, which should be paid attention to in clinic.