3D follow-up study of facial asymmetry after developmental dysplasia of the hip.

OBJECTIVES: To evaluate the change in facial asymmetry among subjects treated for developmental dysplasia of the hip (DDH) from childhood to adolescence. SETTING AND SAMPLE POPULATION: A total of 39 adolescents (26 females and 13 males), born and treated for DDH during 1997-2001, participated in the first examination in 2007 (T1; at the age of 8.2) and in the follow-up in 2016 (T2; at the age of 16.6). MATERIAL AND METHODS: In this longitudinal study, three-dimensional (3D) images were taken using a 3DMD face system based on a stereophotogrammetric method. Facial asymmetry was determined as the average distance (mm) calculated between the original and superimposed mirrored face and the symmetry percentage (%) calculated as the face area where the distance between the original face and the mirrored surface does not exceed 0.5 mm. RESULTS: Results showed increased asymmetry from T1 to T2. The average distance increased for whole face (from 0.51 mm to 0.59 mm, P = .001), upper face (from 0.41 mm to 0.49 mm, P = .005), mid-face (from 0.48 mm to 0.57, P = .002) and lower face (from 0.74 mm to 0.85 mm, P = .147). Facial symmetry percentage decreased for whole face from 61.23% to 55.38% (P = .011), for upper face from 69.27% to 62.24% (P = .005) and for mid-face from 62.29% to 55.63% (P = .007) and for lower face from 43.37% to 42.19% (P = .66). CONCLUSION: Facial asymmetry increases from childhood to adulthood in subjects treated for DDH. Orthodontic treatment does not eliminate this asymmetric facial growth.

Bench, Boundaries, and Benefits: Negotiating the Maze to a Successful Product in the United States.

KNOWLEDGE TRANSFER STATEMENT:: The information in this commentary will allow clinicians and inventors to better translate ideas in the commercial realm. It has a direct impact to improving clinical care and the patient experience.

Comparison of facial morphologies between adult Chinese and Houstonian Caucasian populations using three-dimensional imaging.

The objective of this study was to compare the facial morphologies of an adult Chinese population to a Houstonian white population. Three-dimensional (3D) images were acquired via a commercially available stereophotogrammetric camera system, 3dMDface™. Using the system, 100 subjects from a Houstonian population and 71 subjects from a Chinese population were photographed. A complex mathematical algorithm was performed to generate a composite facial average (one for males and one for females) for each subgroup. The computer-generated facial averages were then superimposed based on a previously validated superimposition method. The facial averages were evaluated for differences. Distinct facial differences were evident between the subgroups evaluated. These areas included the nasal tip, the peri-orbital area, the malar process, the labial region, the forehead, and the chin. Overall, the mean facial difference between the Chinese and Houstonian female averages was 2.73±2.20mm, while the difference between the Chinese and Houstonian males was 2.83±2.20mm. The percent similarity for the female population pairings and male population pairings were 10.45% and 12.13%, respectively. The average adult Chinese and Houstonian faces possess distinct differences. Different populations and ethnicities have different facial features and averages that should be considered in the planning of treatment.

Facial morphology of Finnish children with and without developmental hip dysplasia using 3D facial templates.

BACKGROUND: Developmental dysplasia of the hip (DDH) is a condition that affects the femoral head and the acetabulum and leads to hip subluxation and dislocation. Infants with DDH are usually treated using splints that immobilize their hip joint and are forced on their back for long periods of time. The link between positioning and facial asymmetries is poorly understood. OBJECTIVE: To compare the facial morphologies of children with DDH to a group of healthy controls. SUBJECTS AND METHODS: Fifty-six Finnish patients born with DDH were matched on the basis of gender and age to a control group. Three-dimensional surface images were captured using the 3dMDface system. Using RF6 PP2 software, anthropometric landmarks were plotted and used to calculate asymmetry based on 3D co-ordinates in a reference framework. RESULTS: There was statistically significant difference between all paired facial shells. Relative to the control group, DDH boys and girls presented a chin-point deviation to the right, a more prominent left orbital ridge, a more protrusive nose and upper lip. The gender-specific subgroups show a similarity of 66.54 and 65.22% in girls and boys, respectively. CONCLUSIONS: Patients with DDH present a facial asymmetry when compared to healthy controls. Gender characteristics are marked whether subjects are affected with DDH or not. Three-dimensional surface imaging is a powerful diagnostic and research tool.

Facial templates: a new perspective in three dimensions.

PURPOSE: This paper describes the use of adult facial template in gender-specific facial analysis. SUBJECTS AND METHODS: Eighty adults, mean age 24.5, were selected for the study. Laser-scanned images of the subjects were obtained under a reproducible and controlled environment with two Minolta Vivid 900 (Osaka, Japan) optical laser-scanning devices assembled as a stereo-pair. A set of left and right scanned images was taken for each subject and each scan took an average of 2.5 s. These scanned images were processed and merged to form a composite three-dimensional soft tissue reproduction of the subjects using commercially available reverse modelling software. The differences in facial morphology were measured using shell deviation colour maps. The facial template was used to compare differences between males vs. females groups and two subjects with facial disproportions. RESULTS: The difference between the male and female facial templates was 1.28 +/- 1.02 mm. The areas of greatest deviation were at the nasal, zygomatic area and lower jaw line. The results of the surface deviation maps between the templates and subjects with facial disproportion showed that the results could be applied for orthodontic diagnosis. CONCLUSIONS: The construction of the adult facial templates provides an interesting perspective into measuring changes in groups of patients and also acts as a useful template for the comparison of skeletal disproportion.

A new method for the 3D measurement of postoperative swelling following orthognathic surgery.

OBJECTIVE: To describe a new method for measuring facial swelling following orthognathic surgery using a 3D laser-scanning device. DESIGN: Prospective clinical trial. Setting and Sample Population -- University Dental Hospital, Wales College of Medicine, Biology Life and Health Sciences. Three subjects requiring bi-maxillary orthognathic surgery were recruited for the study. EXPERIMENTAL VARIABLES: Laser-scanned images of the subjects were obtained under a reproducible and controlled environment with two Minolta Vivid 900 (Osaka, Japan) optical laser-scanning devices assembled as a stereo-pair. A set of left and right scanned images was taken for each subject and each scan took an average of 2.5 s. 3D laser scans were recorded over six time periods (T1 -- pre-surgical scan, postoperatively: T2 -- 1 day, T3 -- 1 week, T4 -- 1 month, T5 -- 3 months and T6 -- 6 months). OUTCOME MEASURE: Facial scans from different time periods were overlaid onto the baseline (T6) facial scan to determine the reduction and changes in swelling following orthognathic surgery. RESULTS: The results showed that swelling could be accurately quantified following surgery. Furthermore, there was a significant reduction in the amount of swelling 1 month postoperatively. Furthermore, the facial morphology returned to approximately 90% of the baseline facial scan at 3 months. CONCLUSION: The 3D laser-scanning device and the method described was a reliable and accurate measure of facial swelling following surgery.

Three-dimensional cone beam computerized tomography in orthodontics.

There has been an escalating interest in three-dimensional imaging devices over the last decade. Orthodontists are beginning to appreciate the advantages that the third dimension gives to clinical diagnosis, treatment planning and patient education. This article focuses on the cutting edge technology of cone beam CT, which utilizes conventional X-ray technology and computerized volumetric reconstruction to reproduce a three-dimensional image. A variety of applications and range of issues associated with this technology will be discussed.

The investigation of the changing facial appearance of identical twins employing a three-dimensional laser imaging system.

OBJECTIVE: An investigation to determine the changing facial appearance of identical twins. DESIGN: Clinical study. MATERIALS AND METHODS: Two Minolta Vivid 900 3D optical laser scanners were placed as a stereo pair to capture the soft tissues of a pair of identical twins. Each scan took approximately 2.5 s. The scanned whole faces were superimposed to determine changes in facial morphologies at different time intervals. OUTCOME MEASURES: The shell deviations between left and right scans of each patient were recorded and analysed for differences. Furthermore, final merged faces were overlaid to determine the changes in facial morphology over time. RESULTS: The results showed that changes in height and weight correlated with changes in facial morphology. CONCLUSION: The 3D laser scanning device is a clinically useful tool in the study of facial growth and facial morphology in a pair of twins.

The dental management of a patient with hyperimmunoglobulinemia E syndrome: a case report.

Hyperimmunoglobulinemia E recurrent infection syndrome (also known as Job's syndrome) is a rare multi-system primary immunological disorder in which non-immunological abnormalities of the dentition, bones and connective tissue are also seen. A previous study has reported the occurrence of dental abnormalities in three-quarters of individuals diagnosed as suffering from this condition. The present authors report the case of a boy whose prolonged retention of the primary dentition was associated with delayed eruption of permanent teeth. They emphasize the need for early intervention in order to help minimize later orthodontic problems.

The feasibility of measuring three-dimensional facial morphology in children.

OBJECTIVE: An investigation to determine the feasibility of measuring soft tissue morphology in children using a three-dimensional laser-scanning device. DESIGN: Prospective clinical trial. SETTING AND SAMPLE POPULATION: University of Wales, College of Medicine and one secondary school in the South Wales region. Sixty live subjects (30 adults, 30 children) were recruited in the study. EXPERIMENTAL VARIABLES: Laser scanned images of the subjects were obtained under a reproducible and controlled environment with two Minolta Vivid 900 (Osaka, Japan) optical laser-scanning devices assembled as a stereo-pair. A set of left and right scanned images was taken for each subject and each scan took an average of 2.5 s. These scanned images were processed and merged to form a composite three-dimensional soft tissue reproduction of the subjects using commercially available reverse modelling software. OUTCOME MEASURE: The shell deviations between left and right scan of each patient were recorded and analysed for differences. These differences determined whether the subjects could remain still during the time of the scans. RESULTS: The results showed that the mean differences between shell deviations for the adult scans and children scans were 0.25 +/- 0.09 and 0.30 +/- 0.09 mm, respectively. Paired t-tests showed that the mean error between subject groups was 0.05 +/- 0.15 mm indicating that there was no difference between the two subject groups (p = 0.18). CONCLUSION: The technique as described is clinically reproducible for children and adults and can be used for studies assessing facial changes due to growth or clinical intervention.

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. METHODS: 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.

Tooth agenesis: a report of missing molars in two generations.

A recent review has suggested that tooth agenesis is becoming more evident in society, though it is not known whether this observation is related to better detection methods and patient awareness or whether there is a real trend towards an increase in prevalence. In this paper we report developmental absence of permanent molars in two generations, and discuss the possible clinical implications of this pattern of tooth agenesis.

Repair of new-generation tooth-colored restoratives: methods of surface conditioning to achieve bonding.

The shear bond strength of repaired resin-modified glass-ionomer cements and polyacid-modified composite resins after different methods of surface conditioning was studied. For the resin-modified glass-ionomer cement, none of the surface treatment methods had a significantly higher repair bond strength than the control. For the polyacid-modified composite, the application of low-viscosity resin after treatment with maleic acid, polyacrylic acid, and air abrasion appeared to be of paramount importance, for it enhanced bonding of the repaired specimens.