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Background: Factors like medical and periodontal conditions, implant location and smoking can affect marginal bone loss (MBL) of basal implants. Objectives: The purpose of this study is to explore the association of MBL with multiple variables including gender, age, smoking status, diabetes, implant placement protocol, location of implant, and type of prosthesis. Material and Methods: A total of 156 single-piece basal implants (Dr. Ihde Dental AG in Gommiswald, Switzerland) were placed in 44 patients. Dental panoramic tomographs were obtained postoperatively and following a one-year of service to determine MBL on mesial and distal sides. The association of MBL with the multiple variables was analysed using the multivariate and the random forest analysis. Results: The mean mesial and distal MBL was 0.64 millimetres. None of the implants presented MBL exceeding 1 millimetre. All implants were retained without complications during the firstyear of service. The MBL was remarkably associated with the smoking status, diabetes, location of implant and implant placement protocol. Diabetes mellitus is the most vital parameter in predicting MBL. Conclusion: The mean MBL of all implants did not exceed the threshold of 1 millimetre during the first year of service. When placing implants in patients who smoke and have diabetes, care should be taken.
Antecedentes: Factores como las condiciones médicas y perio-dontales, la ubicación del implante y el tabaquismo pueden afectar la pérdida marginal de hueso (PMH) de los implantes basales. Objetivo: La finalidad de este estudio es explorar la asociación de PMH con múltiples variables, incluido el sexo, la edad, el tabaquismo, la diabetes, el protocolo de colocación del implante, la ubicación del implante y el tipo de prótesis. Material y Métodos: Se colocaron 156 implantes basales de una sola pieza (Dr.Ihde Dental AG, Gommiswald, Suiza) en 44 pacientes. Se obtuvieron tomografías panorámicas dentales después de la operación y después de un año de servicio para deter-minar la MBL en los lados mesial y distal. La asociación de la PMH con las múltiples variables se analizó mediante el análisis multivariado y de bosque aleatorio. Resultados: La PMH media mesial y distal fue de 0,64 milímetros. Ninguno de los implantes presentó PMH superior a 1 milímetro. Todos los implantes se mantuvieron sin complicaciones durante el primer año de servicio. La PMH se asoció nota-blemente con el tabaquismo, la diabetes, la ubicación del implante y el protocolo de colocación del implante. La diabetes mellitus es el paráme-tro más importante para predecir la MBL. Conclusion: La PMH media de todos los implantes no superó el umbral de 1 milímetro durante el primer año de servicio. Se debe tener especial cuidado al colocar implantes en pacientes que fuman y tienen diabetes.
Subject(s)
Humans , Male , Female , Radiography, Panoramic , Dental Implants , Dental Implantation, Endosseous , Tobacco Use Disorder/complications , Alveolar Bone Loss , Diabetes Mellitus , Mandible/diagnostic imagingABSTRACT
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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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 establish a mathematical model to describe the skeletal class Ⅲ malocclusion of patient dental and basal bone arch form, for providing a data reference and basis for further study. Methods Thirty-five patients with skeletal classⅢmalocclusion were selected in this study for computed tomography CBCT. The data of 3-D image were analyzed, and dental arch marker (Fa) and base bone arch marker (Ba) were determined. The reference plane was determined by least square method. Software Matlab 7.0 was used to calculate two-dimensional coordinate system. Based on this, a mathematical model was established to describe the dental and basal bone arch form and then to validate the mathematical model. Results (1) The mathematical model can be used to describe the dental arch form of skeletal classⅢmalocclusion, maxillary:Y=46.12 [1-(2X/70.99)2]1.052;mandibular:Y=39.16 [1-(2X/64.51)2]1.038. (2) The mathematical model can be used to describe the basal bone arch form of skeletal classⅢmalocclusion, maxillary:Y=43.14 [1-(2X/75.09)2]1.061;mandibular:Y=39.03 [1-(2X/60.63)2]1.021. (3) Fa was located at Ba labial side in the maxilla, the distance was positive. Fa was located at Ba lingual side in the mandibular, and the distance was negative. (4) The fitting correlation coefficient of beta-function curve and each tooth on the dental and basal bone arch of skeletal class Ⅲ malocclusion were greater than 0.7 (P<0.05). Conclusion In this study, the mathematical model can be used to describe the dental and basal bone arch form of the skeletal classⅢmalocclusion, which can guide further research.
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Humans , Facial Bones , Intubation , Intubation, Intratracheal , Surgery, Oral , TracheostomyABSTRACT
Objective: To investigate the roles of tooth mass and bon e mass in dental crowding. Methods: Tooth mass and basal bone mass were measured with electronic vernier and a computer aided dental cast measurem ent and analysis system developed by faculty of stomatology of Kunming Medical C ollege in 91 individuals with normal occlusion and 101 with dental crowding aged from 16 to 26 years old(on the average age of 21). Ttest was applied in st atistic analysis. Results :Teeth width was bigger (P05), PMBAW U and PMBAW L were smaller (P
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PURPOSE: The aim of this study was to analyze radiologically the location and course of the mandibular canal and to observe the alveolar and basal bone changes during the remodeling procedures of atrophic mandible. MATERIALS AND METHODS: CT scanning was performed on dry 30 edentulous or partially dentulous mandibles. In 48 edentulous lower halves, measuring areas were determined by three points in the length of the mandibular canal. The distance from the mandibular canal towards cranial and caudal edges, buccal and lingual external borders of the body of the mandible were measured. A statistical comparison between the mean values of different classes of mandibular body was carried out in the selected areas. RESULTS: The distance between the mandibular canal and caudal borders of the body of the mandible and lingual borders dose not change in the atrophic process of mandible. The mandibular canal within the mandible courses downwards from mandibular foramen towards mesial and subsequently it gets to the mental foramen. The distance between the mandibular canal and buccal external border of basal bone changes similar to the change of cranial borders of alveolar bone in the atrophic process of mandible. CONCLUSION: CT scanning was very effective and practicable to analyze the location and course of the mandibular canal and to observe the alveolar and basal bone changes of atrophic mandible. Also more detailed investigation of basal bone changes observed during the remodeling procedures of atrophic mandibles seems reasonable to rely on the massive anthropologic collections of atrophic mandibles combined with CT scanning.
Subject(s)
Mandible , Tomography, X-Ray ComputedABSTRACT
This study has been performed to determine whether significant differences in the maxillary basal bone pattern exist between skeletal Class ill malocclusion and normal occlusion. Mterials for the skeletal Class ill sample consisted of lateral cephalometric roentgenograms and maxillary cast models of 29 adult individuals, 15 males and 14 females. The average age was 19.75 years with a range from 16.4 to 29.1 years. A normal control sample consisted of lateral cephalometric roentgenograms and maxillary cast models of 24 adult individuals, 13 males and 11 females. The average age was 24.25 years with a range from 20.8 to 29.4 years. The results of this study can be summarized and concluded as like follows. 1. In comparing sexual difference of maxillary basal bone morphology in skeletal Class III malocclusion, the following parameters of males were found to be significally larger than those of females : inter first premolar width, inter molar width, oblique canine height, oblique molar height and maxillary basal bone perimeter. 2. In comparing sexual difference of maxillary basal bone morphology in normal occlusion, the following parameters of males were found to be significally larger than those of females : inter canine width, inter first and second premolar width, inter molar width, oblique canine height and oblique molar height. 3. In comparing maxillary basal bone morphologic difference between skeletal Class III malocclusion and normal occlusion in males, the following parameters were found to be significally larger in normal occlusion : inter canine width, inter canine height, inter molar height, oblique canine height and oblique molar height. 4. In comparing maxillary basal bone morphologic difference between skeletal Class III malocclusion and normal occlusion in females, the following parameters were found to be significally larger in normal occlusion : inter canine height, inter molar height, oblique canine height, oblique molar height and maxillary basal bone perimeter.