Assessment of facial soft-tissue profiles based on lateral photographs versus three-dimensional face scans.

OBJECTIVES: The purpose of this study was to compare two-dimensional (2D) lateral photographs versus three-dimensional (3D) face scans in analyzing facial profiles using Schwarz's concept of the jaw profile field (JPF) in its original 2D and in a modified 3D version. In addition, the distribution of the facial profile types described by Schwarz were examined. MATERIALS AND METHODS: Of 75 adult volunteers recruited specifically for this study, we obtained both photographs (Nikon D 300S; Nikon, Düsseldorf, Germany) and scans (FaceSCAN3D Scientific Photolab 60 Hz; 3D-Shape, Erlangen, Germany) in a standardized setting. Four raters analyzed the pertinent measurements using image analysis software (Onyx Ceph 3; Image Instruments, Chemnitz, Germany). Statistical analysis was conducted using the R suite environment (v. 3.2.1; R Foundation for Statistical Computing, Vienna, Austria). RESULTS: Intraobserver reliability was substantial for two raters (κ = 0.61-0.8), moderate for one (κ = 0.41-0.60), and almost perfect for one (κ = 0.81-1.00). As for interobserver reliability, we observed moderate agreement between the two basic technologies tested, but internal agreement was only moderate even within the 2D view modes (average κ = 0.51) versus almost perfect within the 3D view modes (κ = 0.84-0.94). Forward-slanting anteface was clearly the most common (43.27%) and straight retroface the least common (0.3%) diagnosis. Only a minority of patients (18.38% of women and 16.15% of men) had straight as opposed to slanting profiles. CONCLUSIONS: Given our findings of acceptable agreement between 3D scanning and 2D lateral photography, in combination with almost perfect internal agreement between different 3D view modes, it appears useful to adapt Schwarz's method of facial profile assessment for clinical use in 3D virtual environments.

Long-term neuromuscular status in overdenture and complete denture patients with severe mandibular atrophy.

PURPOSE: The long-term neuromuscular status of edentulous patients with severe mandibular atrophy who wore complete dentures (CDs) or implant-supported overdentures (ISOs) was investigated in the present study. MATERIALS AND METHODS: Eleven CD patients and 11 patients with ISOs supported by two implants took part in the study. All patients had used their dentures for more than a decade. All patients (average age, 76 years) suffered from severe mandibular atrophy, which was to be quantified using panoramic radiographs and computer software. Kinesiographic parameters such as opening and extension movements as well as opening and closing velocities were recorded by means of a sirognathograph during test food chewing on the left and right sides. Simultaneously, electromyographic recording of masseter and temporalis activities was performed using surface electrodes. RESULTS: The kinesiographic values obtained from ISO patients were higher than those for CD patients: 12.65 mm for vertical opening (CD, 11.79 mm) and 5.66 mm for horizontal extension (CD, 5.11 mm). Opening velocity values were 100.93 mm/s and 91.74 mm/s, respectively. Closing velocity of 78.16 mm/s in ISO patients was significantly different from that measured in CD patients (58.45 mm/s). With regard to electromyographic activities, the increase was significant for the masseter during chewing on the working side (ISO: 189.79 µV, CD: 78.05 µV) and on the nonworking side (ISO: 130.53 µV, CD: 47.25 µV). For the temporalis, values of 194.11 µV and 119.02 µV in the ISO and CD patients, respectively, were observed for working side chewing. Nonworking side values reached 155.48 µV for ISO subjects and 78.35 µV for CD subjects, which was significantly different. The degree of atrophy in both groups did not differ statistically. CONCLUSIONS: The use of two interforaminal implants with an overdenture can provide long-term neuromuscular benefits for edentulous patients.