Background/objectives: Facial soft tissues changes during growth roughly tend to mimic the underlying hard tissues, but not completely. The aim of this mixed longitudinal study was to assess facial growth among pre-pubertal and pubertal subjects without malocclusion using a noninvasive three-dimensional laser scanning system. Subjects/methods: Fifty-nine subjects (30 females and 29 males) aged at baseline 5.4-8.9 years with normal occlusion were clustered into the younger, older pre-pubertal, and pubertal groups according to age and the absence/presence of a standing height growth spurt. Three-dimensional facial images were obtained using laser scanners for five consecutive years. Several transversal, sagittal, and vertical parameters were assessed for between and within group comparisons. Results: Significant overall changes of almost all parameters were seen within each group (P ( 0.05) without any group differences (P ) 0.05). The younger pre-pubertal group showed greater annual growth rates of lip prominence; both pre-pubertal groups showed greater rates in facial middle third height. The pubertal group showed greater annual rates in facial profile angle changes during the growth peak. Limitations: A high standing height increment (7 cm) was used as the threshold for subject allocation in the pubertal group. Conclusions: Soft tissue facial growth has generally similar amounts and rates irrespective of the pubertal growth spurt. Pre-pubertal subjects show greater annual rates of facial middle third height changes while pubertal subjects show greater annual rates of chin protrusion.
COBISS.SI-ID: 32498649
The purpose of this study is to compare 3-dimensional facial averages of Asians (Koreans and Chinese) and Houstonian white faces using a (3-dimensional) surface imaging system. Methods: Three-dimensional images of Korean adults (Seoul, Korea) with class I malocclusion captured using the 3dMDface. The images of 138 Koreans were processed to generate average male and female facial shells using Rapidform 2006 plus pack 2 software and then superimposed and compared with the average shells of Chinese adults (Xi' An, China) and white adults (Houston, Tex.). Results: The average Korean male and female faces were wider with prominent malar and zygomatic areas when compared with the white faces. The average white male and female faces showed more protrusion in the glabella, nasion, rhinion, and the soft-tissue pogonion than the Korean faces. The average Korean male face was retrusive at masseteric region while having more prominent lips, nasal tip, and supraglabella than the Chinese counterpart. The average Korean female face was narrower than the average Chinese female face, but there was more protrusion in the periorbital, nasal tip, and malar region seen in the Korean female face. Concluisons: Although the average faces of Chinese and Korean populations in this study showed remarkable similarities, there were distinct differences seen in the facial morphology of the 2 Asian groups. Three-dimensional imaging can be effectively used to establish population facial norms and to quantify the variations seen between different ethnicities. This information may be used in the clinical environment for plastic, oral, and maxillofacial surgery and orthodontics.
COBISS.SI-ID: 32882905
The aim of this study was to evaluate an advanced magnetic resonance imaging (MRI) method, apparent diffusion coefficient (ADC) mapping, in the functional assessment of carious teeth. 38 extracted human teeth with scores of 0, 3 and 6 according to International Caries Detection and Assessment System (ICDAS) criteria were screened and subsequently analyzed by MRI at 2.35 T. Histology sectioning of teeth was used for the gold standard by analyzing two extreme cases (intact and severely decayed). ADC maps of the same teeth were calculated from corresponding diffusion-weighted images and used to obtain ADC distributions along dental pulp as functions of the relative pulp length measured from the occlusal pulp side. The measured distributions were analyzed for the best fit by a four-parameter three-segment linear regression model for ADC distribution along the pulp. MRI results were in good agreement with findings in histological sections of identical teeth. The best fit model parameters, relative decayed region depth, relative transition region width and ADC values of intact and decayed pulp tissue, showed statistically significant differences between the ADC values of intact and decayed pulp tissue (1.0 % 10-9 m2/s vs. 0.74-0.89 % 10-9 m2/s) and the relative decayed region depth progressing with ICDAS score (3 vs. 46% with ICDAS 3 vs. ICDAS 6). The results of this feasibility study confirmed relevance of ADC mapping for the discrimination and localization of intact and decayed regions in dental pulps of carious teeth.
COBISS.SI-ID: 1673595
Skeletal anterior open bite (AOB) or apertognathism is characterized by the absence of contact of the anterior teeth and affects articulation parameters, chewing, biting and voice quality. The treatment of AOB consists of orthognatic surgical procedures. The aim of this study was to evaluate the effects of treatment on voice quality, articulation and nasality in speech with respect to skeletal changes. The study was prospective; 15 patients with AOB were evaluated before and after surgery. Lateral cephalometric x-ray parameters (facial angle, interincisal distance, Wits appraisal) were measured to determine skeletal changes. Before surgery, nine patients still had articulation disorders despite speech therapy during childhood. The voice quality parameters were determined by acoustic analysis of the vowel sound /a/ (fundamental frequency-F0, jitter, shimmer). Spectral analysis of vowels /a/, /e/, /i/, /o/, /u/ was carried out by determining the mean frequency of the first (F1) and second (F2) formants. Nasality in speech was expressed as the ratio between the nasal and the oral sound energies during speech samples. After surgery, normalizations of facial skeletal parameters were observed in all patients, but no statistically significant changes in articulation and voice quality parameters occurred despite subjective observations of easier articulation. Any deterioration in velopharyngeal insufficiency was absent in all of the patients. In conclusion, the surgical treatment of skeletal AOB does not lead to deterioration in voice, resonance and articulation qualities. Despite surgical correction of the unfavourable skeletal situation of the speech apparatus, the pre-existing articulation disorder cannot improve without professional intervention.
COBISS.SI-ID: 32152537
Objectives: The aim of this study was to characterize facial and jaw morphology of children with Class III malocclusion in early mixed dentition. Methods: This study was conducted on 7- to 8-year-old Caucasian children, 48 children with Class III malocclusion and 91 children with normal occlusion. Surface images of faces and study casts were obtained using laser scanning. Two average facial templates were constructed for the males and females in the control group. The facial images were superimposed on the corresponding average templates. Facial parameters, palatal volumes, and gingival surface areas were measured and group differences were quantified. The analysis of variance was used for statistical evaluation of the measured parameters. Results: The results revealed shorter lower face height (P ( 0.001), concave facial profile (P ( 0.001), retruded maxilla (P ( 0.001), protruded mandible (P ( 0.001), retrusive mid-face restricted area (P ( 0.001), reduced gingival surface area of the maxilla (P = 0.013), and reduced maxilla/mandible gingival surface area ratio (P ( 0.001) in the Class III group compared to the control group. There were no differences between the groups in upper face height, restricted areas of the upper and lower face, palatal volume, and gingival surface area of the mandible (P ) 0.05). Limitations: Regardless of the fact that the prevalence of Class III malocclusion is rather small, the sample size could be larger. Conclusions: Class III subjects show clinically relevant facial and jaws characteristics in pre-pubertal growth period. A comprehensive diagnosis should include transverse dimension analysis.
COBISS.SI-ID: 31716825