A blind accuracy assessment of computer-modeled forensic facial reconstruction using computed tomography data from live subjects.

A computer modeling system for facial reconstruction has been developed that employs a touch-based application to create anatomically accurate facial models focusing on skeletal detail. This article discusses the advantages and disadvantages of the system and illustrates its accuracy and reliability with a blind study using computed tomography (CT) data of living individuals. Three-dimensional models of the skulls of two white North American adults (one male, one female) were imported into the computer system. Facial reconstructions were produced by two practitioners following the Manchester method. Two posters were produced, each including a face pool of five surface model images and the facial reconstruction. The face pool related to the sex, age, and ethnic group of the target individual and included the surface model image of the target individual. Fifty-two volunteers were asked to choose the face from the face pool that most resembled each reconstruction. Both reconstructions received majority percentage hit rates that were at least 50% greater than any other face in the pool. The combined percentage hit rate was 50% above chance (70%). A quantitative comparison of the facial morphology between the facial reconstructions and the CT scan models of the subjects was carried out using Rapidform(™) 2004 PP2-RF4. The majority of the surfaces of the facial reconstructions showed less than 2.5 mm error and 90% of the male face and 75% of the female face showed less than 5 mm error. Many of the differences between the facial reconstructions and the facial scans were probably the result of positional effects caused during the CT scanning procedure, especially on the female subject who had a fatter face than the male subject. The areas of most facial reconstruction error were at the ears and nasal tip

Three-dimensional study of facial changes in children aged 11-14 years

Conclusions: The following conclusions could be drawn from this study of facial morphology: 1. The three-dimensional laser capture technique described is both valid and reliable. 2. The study has shown that the use of three-dimensional imaging is a feasible method in the analyzing and perceiving of changes to the face over time. 3. Males and females show differing facial morphology. 4. The magnitudes of surface changes are larger in males than in females. 5. There is a significant difference in the timing of the surface changes in males than in females, with males exhibiting later changes. 6. There is forward growth particularly occurring in the nose, brows, lios and vertical dimensions of the face. 7. There seems to be a deepening of the eyes and flattening of the cheeks. 8. Clinicians should be aware of three-dimensional surface changes that result from growth and treatment. 9. Growth has been shown to be variable in this age group of 11-14 year olds. Some children have illustrated significant growth changes whilst others very little, and this may depend on the period of capture related to their growing period. 10. There was a difference between the facial morphology of females who received and did not receive orthodontic treatment. These differences were seen particularly in the upper and lower lip regions. 11. However, there was very little difference in individuals who received and did not receive orthodontic treatment. 12. Asymmetric growth patterns were seen occurring in 35% of the cohort studied with right sided differences being more than left sided differences.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Three-dimensional analysis of facial morphology surface changes in untreated children from 12 to 14 years of age

The developing face is of interest to orthodontists, especially if orthodontic treatment can influence the outcome of facial growth. New 3-dimensional (3D) modalities have enabled clinicians to better understand the facial changes in a developing child. Methods: Fifty-nine children with normal body mass indexes were evaluated with a previously validated 3D laser imaging device over a 2-year period. Surface changes were evaluated on normal and average faces. These changes were seen as mean surface changes and color maps. Results: The results suggest that the surface areas of change in average faces were generally downward and forward with respect to the nose and soft-tissue nasion. The lips also translated in a downward direction as the nose grew, and there was a general increase in the vertical dimension. Some subjects were in the "great changes" category, boys significantly more so than girls. Conclusions: The following conclusions can be made from this 3D study of changes of facial morphology in children: (1) surface changes are greater in boys than in girls; (2) differences in the timing of surface changes in boys and girls are clinically significant, with boys exhibiting more changes later; (3) positive surface changes occur in the nose, brows, lips, and vertical dimensions of the face; (4) the eyes deepen, and the cheeks become flatter; and (5) 3D imaging is a useful tool in analyzing changes to the face over time. (Am J Orthod Dentofacial Orthop 2008; 134: 751-60

Three-dimensional imaging for orthodontics and maxillofacial surgery

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A 3-Dimensional evaluation of post-operative swelling following orthognathic surgery at 6 months

Background: Advances in three-dimensional technology have enabled applications for the clinical setting to be created and used in routine diagnosis, treatment planning, and patient education. The objectives of this prospective clinical trial were to determine the volume changes associated with facial swelling following orthognathic surgery. Methods: Twelve subjects requiring orthognathic surgery were recruited for the study. Laser scanned images of the subjects were obtained under a reproducible, controlled environment with two laser-scanning devices assembled as a stereo pair. Three-dimensional laser scans were recorded over six time periods, as follows: T1, presurgical scan; T2, 1 day postoperatively; T3, 1 week postoperatively; T4, 1 month postoperatively; T5, 3 months postoperatively; and T6, 6 months postoperatively. Results: The results showed a clinical difference in the mean shell deviations between bimaxillary and single-jaw orthognathic surgery. Furthermore, the results suggest that the mean volume of swelling was reduced by approximately 60 percent within the first month after surgery. Finally, the amounts of swelling following surgery were greater in bimaxillary cases. The recovery in the swelling was also faster in this group of patients. Conclusions: Three-dimensional imaging has opened up new avenues of patient care and treatment evaluation. The results have shown that the laser scanning device and the method described are a reliable and accurate measure of facial swelling following surgery

The fabrication of a customized occlusal splint based on the merging of dynamic jaw tracking records, cone beam computed tomography, and CAD-CAM digital impression

OBJECTIVES: The aim of this case report was to present the procedure of fabricating a customized occlusal splint, through a revolutionary software that combines cone beam computed tomography (CBCT) with jaw motion tracking (JMT) data and superimposes a digital impression. MATERIALS AND METHODS: The case report was conducted on a 46-year-old female patient diagnosed with the temporomandibular disorder. A CBCT scan and an optical impression were obtained. The range of the patient's mandibular movements was captured with a JMT device. The data were combined in the SICAT software (SICAT, Sirona, Bonn, Germany). RESULTS: The software enabled the visualization of patient-specific mandibular movements and provided a real dynamic anatomical evaluation of the condylar position in the glenoid fossa. After the assessment of the range of movements during opening, protrusion, and lateral movements all the data were sent to SICAT and a customized occlusal splint was manufactured. CONCLUSIONS: The SICAT software provides a three-dimensional real-dynamic simulation of mandibular movements relative to the patient-specific anatomy of the jaw; thus, it opens new possibilities and potentials for the management of temporomandibular disorders

An Evaluation of Jaw Tracking Movements in Patients with Total Joint Replacements versus a Control Group

Background and Objectives: One form of treatment for degenerative temporomandibular joint diseases such as osteoarthritis, rheumatic arthritis, TMJ ankylosis, and condylar resorption is total joint replacement. The aim of this study was to examine the function of the temporomandibular joint after prosthetic joint replacement. Materials and methods: Fifteen patients with unilateral or bilateral TMJ total joint replacements and 15 healthy controls were evaluated via a SICAT JMT+ device. This non-invasive system measures 3D position and linear movements in all degrees of freedom and allows undisturbed functional mandibular movements to provide a quantitative evaluation. In addition, a TMJ questionnaire consisting of the subjective symptoms was also obtained. To date, no similar studies have been cited in the literature. Results: Mandibular movements after prosthetic joint replacement were recorded during opening, closing, protrusion, and lateral excursive movements and were all significantly decreased compared to those of controls. In the treatment group, the maximum incisal opening was 33.46 ± 5.47 mm, left lateral movement was 1.91 ± 2.7 mm, right lateral movement was 1.74 ± 1.74 mm, and protrusive movement was 2.83 ± 2.05 mm. The p-value comparison study and control group indicated significant difference (p < 0.0001) between the two groups. The study group stated a high level of satisfaction with the total joint replacement. Conclusion: Within the limitations of the study, the following conclusions can be drawn: (1) TMJ replacement patients showed significantly limited jaw movements compared to the control group; (2) a small percentage of TMJ replacement patients still present low levels of pain but improved chewing ability and quality of life

Extractions as a form of interception in the developing dentition: a randomized controlled trial

Objective: To determine if the extractions of lower primary canines are an effective procedure to relieve crowding of the labial segment. Study design: randomized controlled trial. Subject sample: 83 cases were collected in clinics in Italy, Germany and Wales. The groups were followed over a 2-year period. Method: Subjects were randomly allocated to a primary canine non-extraction or extraction group. Dental casts of the patients were collected at the start and at the recall period of the trial. The outcome measures recorded were lower incisor crowding, arch length, intermolar width, overbite, overjet, lower clinical crown heights and lower incisor inclinations. Statistics: The Mann–Whitney test was used to compare the differences between the extraction and non-extraction groups. Results: In both groups, crowding reduced 1.27 mm in the non-extraction group and 6.03 mm in the extraction group. The difference between the 2 groups was 4.76 mm (P<0.05). The arch perimeter decreased more in the extraction group by 2.73 mm (P<0.05). As the incisor inclination stayed essentially the same, the loss in arch length was attributed to the molars moving forward. The net gain from extracting deciduous canines was 2.03 mm. Conclusions: There was a reduction in lower incisor crowding as a result of lower primary canine extraction. However, arch perimeter decreased more in the extraction group leaving less space for the eruption of the lower secondary canines