OBJECTIVE: To compare the registration accuracy of three-dimensional (3D) facial scans for the design of full-arch implant supported restoration by five methods and to explore the suitable registration method. METHODS: According to the criteria, ten patients with maxillary edentulous jaw or end-stage dentition requiring implant supported restorations were enrolled in this study. A special rim with individual feature marks reflected appropriate occlusal relationship and esthetic characteristics was made for each patient. Both 3D facial scan data of natural laughter and with opener traction to expose the teeth or occlusal rim of each patient were acquired by facial scan and input to the digital analysis software Geomagic Qualify 2012. The dataset was superimposed by five different methods: seven facial anatomical landmark points alignment, facial immobile area alignment (forehead and nasal area), facial anatomical landmark points and immobile area combining alignment, facial feature points alignment, facial and intraoral feature points alignment with the same local coordinate system. The three-dimensional deviation of the same selected area was calculated, the smaller the deviation, the higher the registration accuracy. The 3D deviation was compared among the three registration methods of facial anatomical landmark points, facial immobile area alignment and the combination of the above two methods. Friedman test was performed to analyze the difference among the three methods (α=0.05). The effect of the aid of the facial and intraoral feature points were evaluated. Paired t test were performed to analyze the difference (P<0.05). RESULTS: The average three-dimensional deviation of the selected area after alignment with the facial anatomical landmarks was (1.501 2±0.406 1) mm, significantly larger than that of the facial immobile area best-fit alignment [(0.629 1±0.150 6) mm] and the combination of the two methods[(0.629 1±0.150 6) mm] (P < 0.001). The aid of the facial feature points could significantly reduce the deviation (t=1.001 3, P < 0.001). There was no significant statistical difference in the remaining groups. CONCLUSION The forehead area of the 3D facial scan can be exposed as much as possible. The establishment of facial characteristic landmark points and the use of the invariant area alignment can improve the accuracy of registration. It should be clinically feasible to apply three-dimensional facial scan to the design of full-arch implant supported restoration with the registration of the immobile area on the face especially the forehead area.
Computer-Aided Design ; Humans ; Imaging, Three-Dimensional ; Jaw, Edentulous/diagnostic imaging* ; Maxilla/diagnostic imaging* ; Radionuclide Imaging

OBJECTIVETo study the edentulous patients facio-maxillary characters, and discuss the base of recording jaw relation by swallowing action.

METHODSForty-three edentulous patients were included in this study, age ranged from 57 to 70 yr, with new comfortable full dentures. Two lateral cephalograms for one patient were taken by SIRONA digital X-ray dental system, one of which was centric occlusion with full denture, another was the end position of swallowing action without denture.

RESULTSThe vertical facial dimensions of male were a little more than that of female. The ratio of lower front facial height/upper front facial height was about 6/5, angle S-N-Po was about 78 approximately 80 degrees. These data may be useful for dentists to make diagnoses if the jaw relation is right or not. Both in vertical or anterior-posterior (horizontal) dimension, the differences between two groups (two actions in one patient) were not significant. It showed that two positions of two actions were the same.

CONCLUSIONSThe SIRONA digital X-ray dental system for cephalometry was swift, and had its own characters. The way of swallowing and occluding is one of efficient methods to record the jaw relation of edentulous patients veraciously and naturally.

Aged ; Cephalometry ; methods ; Deglutition ; Female ; Humans ; Jaw Relation Record ; Jaw, Edentulous ; diagnostic imaging ; Male ; Middle Aged ; Radiography, Dental, Digital

OBJECTIVETo evaluate the mandible angle and to investigate the relationship of angle size to gender, age-group, cortical thickness at the mandibular angle (CTMA), height of mandibular residual body, and edentulous period in the elderly edentulous subjects.

METHODSA total of 356 panoramic radiographs of three groups of subjects were evaluated: the young dentate group, 131 subjects (mean age: 27); the older dentate group, 97 (mean age: 64); and the elderly edentulous group, 128 (ages 76, 81, or 86). Mandibular angle size, CTMA, and height of mandibular residual body were measured from panoramic radiographs. A structured questionnaire was used to determine the history of edentulousness.

RESULTSDifference in angle size was found between dentate men and women (P < 0.05, P < 0.001), but not between the elderly edentulous men and elderly women. The elderly edentulous subjects had larger mandibular angles than did older dentate subjects (P < 0.001). The angle size was negatively related to CTMA only among 76-year-old edentulous women (P < 0.01) and negatively associated with average height of the mandibular residual body in the edentulous men and women (P < 0.01). No association existed between angle size and duration of edentulousness.

CONCLUSIONSElderly edentulous subjects have large mandibular angles and the angle size is correlated with low-height of the mandibular residual body, which suggests that masticatory function of natural dentition and complete denture may influence change of the mandibular angle. The significant relationship of mandibular angle size to CTMA probably indicates the effect of systemic factors on change in the mandibular angle.

Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Alveolar Process ; diagnostic imaging ; pathology ; Cephalometry ; Female ; Humans ; Jaw, Edentulous ; diagnostic imaging ; Male ; Mandible ; diagnostic imaging ; pathology ; Middle Aged ; Radiography

Aged ; Female ; Humans ; Immediate Dental Implant Loading ; methods ; Jaw, Edentulous ; diagnostic imaging ; rehabilitation ; surgery ; Male ; Mandible ; diagnostic imaging ; surgery ; Maxilla ; diagnostic imaging ; surgery ; Middle Aged ; Radiography, Panoramic ; Surgery, Computer-Assisted ; methods

OBJECTIVETo evaluate the long-term clinical outcome of delayed implant placements after maxillary sinus floor augmentation with autologous bone or Bio-Oss grafting.

METHODSEighteen patients underwent maxillary sinus floor augmentation and delayed implant placements from January, 2002 to December, 2008. Bone grafting and sinus floor augmentation were performed in 21 sides of maxilla and 46 implants were placed 6 - 8 months later. Residual bone height was less than 4 mm. The cases were divided to 2 groups and different materials (autologous bone + Bio-Oss and Bio-Oss alone) were grafted relatively. The bone resorption was assessed by panoramic X-ray and the stability of the implant was reviewed postoperatively.

RESULTSThe average follow-up time was 54 months. Only one implant was lost and the implant survival rate was 98%. X-ray showed that the bone resorption was observed in both groups. The absorption ratio of autologous bone + Bio-Oss group was 18.65% and that of the Bio-oss group was 1.93%. The difference was significantly different.

CONCLUSIONSThe result of maxillary sinus floor augmentation with bone grafting was predictable. More bone absorption occurred in the Bio-Oss than in autologous bone + Bio-Oss.

Adult ; Bone Substitutes ; therapeutic use ; Bone Transplantation ; methods ; Collagen ; therapeutic use ; Dental Implantation, Endosseous ; methods ; Female ; Follow-Up Studies ; Humans ; Jaw, Edentulous, Partially ; diagnostic imaging ; surgery ; Male ; Maxilla ; diagnostic imaging ; Middle Aged ; Minerals ; therapeutic use ; Radiography, Panoramic ; Sinus Floor Augmentation ; methods ; Young Adult