Hard Tissue Analysis Research Articles

UTILIZATION OF THE IMAGEJ SOFTWARE CAPABILITIES IN DENTISTRY: A LITERATURE REVIEW

Introduction. The method of digital photometry is rapidly gaining widespread use when it comes to quantitative analysis of the color and structure of soft tissues, which is of particular importance in modern dental practice and research. Image J is one of the most widely used digital photometry tools, especially in medical and dental research. As an open source software developed by the US National Institutes of Health, it provides a wide range of image processing and analysis capabilities, including area, color intensity, texture, and the ability to apply various filters and settings. This allows researchers to analyze tissues in detail, track the dynamics of changes, and detect anomalies that are invisible to the naked eye. The purpose of the literature review is to study the potential of the Image J working tools for paraclinical research in the field of prosthetic dentistry. Methodology. A total of 21 literary sources were analyzed, of which 2 were domestic and 19 were foreign. The functionality of the application was studied on the basis of the software “Image J” 1.54g, by National Institutes of Health; USA. Results and discussion. One of the most important functions of the ImageJ program is the measurement of color indicators within the “Adjust” system, which allows for an objective determination of the color characteristics of enamel, dentin, and the oral mucosa. The “Adjust” function provides researchers with a comprehensive set of tools for modifying image parameters, enabling accurate and reliable analysis of both hard dental tissues and soft tissues of the oral cavity. Key tools within this function include brightness and contrast adjustment, threshold segmentation, and color balance, all of which are critical for high-quality dental tissue photometry. It is worth noting that existing literature does not provide information regarding the application of ImageJ functionality in the field of prosthetic dentistry, particularly for analyzing the surfaces of orthopedic structures. This gap highlights the need for further comprehensive research, which could significantly enhance the diagnostic capabilities for evaluating the condition of prosthetic beds and the surfaces of dental prostheses.

A Soft Tissue-Borne Patient-Specific Guide for Foreign Body Removal in the Facial Region.

Foreign body removal in the facial region poses significant challenges due to the complex anatomy and the proximity to critical structures. This study introduces a soft tissue-borne patient-specific guide (PSG) designed to enhance precision and minimize invasiveness in foreign body removal. Four patients underwent foreign body removal using PSGs, with CT and cone-beam computed tomography (CBCT) imaging employed for segmentation and detailed analysis of both hard and soft tissues. This approach enabled the planning and design of stable and personalized guides. Ultrasound tracing was used for intraoperative verification. All procedures were successful, with minimal scarring, no complications, and reduced operative time. The use of PSGs improved surgical accuracy and efficiency, highlighting their potential for foreign body removal in other regions of the body and for broader clinical applications in maxillofacial surgeries.

Contrast-Enhanced Micro-CT Imaging of Murine Mandibles: A Multi-Method Approach for Simultaneous Hard and Soft Tissue Analysis.

To develop and evaluate a novel multi-method micro-computed tomography (μCT) imaging protocol for enhanced visualization of both hard and soft tissues in murine mandibles, addressing the limitations of traditional imaging techniques in dental research. We employed a contrast-enhanced (CE) μCT imaging technique using Lugol's iodine as a contrast agent to visualize the intricate structures of murine mandibles. The protocol involved the combination of conventional μCT imaging as well as CE-μCT, including decalcification with EDTA, allowing for simultaneous assessment of hard and soft tissues. The method is compared with standard imaging modalities, and the ability to visualize detailed anatomical features is discussed. The CE-μCT imaging technique provided superior visualization of murine mandibular structures, including dental pulp, periodontal ligaments and the surrounding soft tissues, along with conventional μCT imaging of alveolar bone and teeth. This method revealed detailed anatomical features with high specificity and contrast, surpassing traditional imaging approaches. Our findings demonstrate the potential of CE-μCT imaging with Lugol's iodine as a powerful tool for dental research. This technique offers a comprehensive view of the murine mandible, facilitating advanced studies in tissue engineering, dental pathology and the development of dental materials.

Validation of Age Estimation Using the Compositional Variation of Dental Hard Tissue: An X-ray Diffraction Analysis.

Introduction X-rays and X-ray diffraction (XRD) are two non-destructive techniques that determine a material's crystallographic structure, chemical composition, and physical properties. They can also be used to estimate a person's age when it is unknown, assess the need for orthodontic treatment, or predict the likelihood of tooth decay. This research aims to validate the accuracy of age estimation through X-ray diffraction analysis of tooth hard tissue with compositional changes. Methodology Four tooth samples were analyzed using the Pan Analytical XRD (Malvern Panalytical Ltd., UK) unique d8 family platform, which uses Cu Kα radiation (0.154 nm) and a 0.02° scan rate from 0 to 80°. Results The angle of incidence (ω) is established between the sample and the X-ray source. The angle of diffraction, 2θ, is established between the detector and the incident beam. The detector angle 2θ and the incident angle ω always equal half. Inter-atomic distance, or d-spacing (D = 10^-8 cm in Angstrom units), is measured. A greater crystal size or a greater degree of crystallinity may be indicated by a higher peak intensity, which translates to an increased amount of atoms in the crystal. Conclusion The study's findings suggest that XRD is a promising new technique for age determination, as it has an advanced and dynamic approach to finding the crystallographic characteristics of the provided sample.

Establishment of Cephalometric Hard Tissue Profile among Bengali and Caucasian Populations for Orthognathic Surgery

ABSTRACT The study aimed to compare cephalometric hard tissue profile values and analysis between Bengali and Caucasian populations. The study included 100 individuals (50 males, 50 females) aged 18–35. Subjects having class I molar occlusions and well-balanced facial profiles were included in the study. Lateral cephalograms were taken with consent, and a prestructured proforma recorded relevant information and cephalometric measurements. Our study found increased posterior cranial base length in Bengali males and increased anterior cranial base length in both sexes. Bengali males had a less convex profile, while females had a more convex profile compared to Caucasians with similar mandibular features. Increased maxillary and mandibular incisor proclination was observed. Our findings indicate the necessity for separate norms for orthognathic surgery in normal ethnic Bengali adults.

Detection and Imaging of Exposure-Related Metabolites and Xenobiotics in Hard Tissues by Laser Sampling and Mass Spectrometry.

The utility of two novel laser-based methods, laser ablation electrospray ionization (LAESI) and laser desorption ionization (LDI) from silicon nanopost array (NAPA), is explored via local analysis and mass spectrometry imaging (MSI) of hard tissues (tooth and hair) for the detection and mapping of organic components. Complex mass spectra are recorded in local analysis mode from tooth dentin and scalp hair samples. Nicotine and its metabolites (cotinine, hydroxycotinine, norcotinine, and nicotine) are detected by LAESI-MS in the teeth of rats exposed to tobacco smoke. The intensities of the detected metabolite peaks are proportional to the degree of exposure. Incorporating ion mobility separation in the LAESI-MS analysis of scalp hair enables the detection of cotinine in smoker hair along with other common molecular species, including endogenous steroid hormones and some lipids. Single hair strands are imaged by MALDI-MSI and NAPA-LDI-MSI to explore longitudinal variations in the level of small molecules. Comparing spectra integrated from NAPA-LDI-MSI and MALDI-MSI images reveals that the two techniques provide complementary information. There were 105 and 82 sample-related peaks for MALDI and NAPA, respectively, with an overlap of only 16 peaks, indicating a high degree of complementarity. Enhanced molecular coverage and spatial resolution offered by LAESI-MS and NAPA-LDI-MSI can reveal the distributions of known and potential biomarkers in hard tissues, facilitating exposome research.

The Correlation between the Bone Morphotype and Density and Root Apical Resorption of the Anterior Teeth Due to Orthodontic Forces

The potential side effects of modern orthodontic treatment and its unfavorable impact on dentition and hard tissues have been extensively discussed in professional literature for decades. The presence of uncontrolled forces can result in pulp necrosis, radicular reabsorption, and/or loss of alveolar bone. Dehiscence and fenestration are more commonly found in anterior than posterior teeth, where only the periodontal ligament and the mucosa protect the dental root.
 Most studies investigating the effect of periodontal phenotype over gingival recession in orthodontic patients have primarily focused on examining the soft tissues. However, due to the vulnerability of thin alveolar bone, the previous evaluation of orthodontic candidate patients may also include the analysis of hard tissues. Bone density plays an important role in facilitating orthodontic tooth movement, such that reductions in bone density can significantly increase movement velocity. These types of localized density changes can affect the rate of orthodontic tooth movement and may also influence the risk of unwanted outcomes, such as the occurrence of dental external apical root resorption.
 According to the literature, the links of root resorption with the bone morphotype and the density are relevant in clinical dentistry but have not been studied in detail. However, the existing data is not yet conclusive.

In vitro studies on the dependence of drug deposition in dentin on drug concentration, contact time, and the physicochemical properties of the drugs

The chemical analysis of dental hard tissues can provide information on previous drug use due to the deposition of drugs into this tissue. For the interpretation of analytical results in, e.g., postmortem toxicology or regarding archeological samples, the influence of drug dosing, consumption frequency, duration of intake and type of drug on analyte concentrations in teeth has to be characterized. To approximate these correlations, in vitro models were applied to investigate the time dependency of drug deposition via and against pulp pressure (perfusion studies) and the concentration dependency of drug deposition via oral cavity (incubation study) as well as the influence of de- and remineralization (pH cycling) on the incorporation of drugs in bovine dentin pellets. Some of the drugs of abuse most relevant in forensic case work (amphetamines, opiates, cocaine and benzoylecgonine) were applied. Concentrations in dentin samples were analyzed by liquid chromatography–tandem mass spectrometry (LC–MS/MS) after pulverization and extraction via ultrasonication with methanol. The studies showed that drug deposition in dentin likely depends on the physicochemical properties of the drug molecules as well as on the duration of contact with drugs via the blood stream and on drug concentrations present in the oral cavity. Higher drug concentrations in teeth can result from a more frequent or longer drug use. In addition, intake of higher doses or oral/inhalative consumption can also be expected to lead to higher drug concentrations. These findings can be helpful for the interpretation of postmortem cases.

Chromatographic analysis of hard tooth tissue to determine the age of personality

The biochemical approach for age assessment is most appropriate in forensic medicine, as racemization of aspartic acid in bones and teeth is closely related to human biological age. The aim of the study is to assess the biochemical parameters of aspartic acid in human teeth, which can be implemented into forensic practice in Russia. Samples of dentin in amount of 20, taken from the teeth of subjects aged between 16 and 76, were examined. Chromatographic analysis of the samples was performed on a gas chromatograph using chiral column. Statistical data processing showed that the relative squared peak of D-aspartic acid has a strong correlation with human biological age. Data, obtained from the Russian population study, demonstrate the applicability of chromatography for forensic purposes. It should be noted that the approach to the racemization rate estimation in the hard tooth tissue was performed using standard laboratory equipment, which allows to easily implement this method in forensic medical practice.

Multi-atlas segmentation and quantification of muscle, bone and subcutaneous adipose tissue in the lower leg using peripheral quantitative computed tomography.

Accurate and reproducible tissue identification is essential for understanding structural and functional changes that may occur naturally with aging, or because of a chronic disease, or in response to intervention therapies. Peripheral quantitative computed tomography (pQCT) is regularly employed for body composition studies, especially for the structural and material properties of the bone. Furthermore, pQCT acquisition requires low radiation dose and the scanner is compact and portable. However, pQCT scans have limited spatial resolution and moderate SNR. pQCT image quality is frequently degraded by involuntary subject movement during image acquisition. These limitations may often compromise the accuracy of tissue quantification, and emphasize the need for automated and robust quantification methods. We propose a tissue identification and quantification methodology that addresses image quality limitations and artifacts, with increased interest in subject movement. We introduce a multi-atlas image segmentation (MAIS) framework for semantic segmentation of hard and soft tissues in pQCT scans at multiple levels of the lower leg. We describe the stages of statistical atlas generation, deformable registration and multi-tissue classifier fusion. We evaluated the performance of our methodology using multiple deformable registration approaches against reference tissue masks. We also evaluated the performance of conventional model-based segmentation against the same reference data to facilitate comparisons. We studied the effect of subject movement on tissue segmentation quality. We also applied the top performing method to a larger out-of-sample dataset and report the quantification results. The results show that multi-atlas image segmentation with diffeomorphic deformation and probabilistic label fusion produces very good quality over all tissues, even for scans with significant quality degradation. The application of our technique to the larger dataset reveals trends of age-related body composition changes that are consistent with the literature. Because of its robustness to subject motion artifacts, our MAIS methodology enables analysis of larger number of scans than conventional state-of-the-art methods. Automated analysis of both soft and hard tissues in pQCT is another contribution of this work.

IR-Spectroscopic Analysis of Hard Tissues of Lower “Wisdom” Teeth at the Eruption Stage of Connective Tissue Dysplasia

IR-Spectroscopic Analysis of Hard Tissues of Lower “Wisdom” Teeth at the Eruption Stage of Connective Tissue Dysplasia

Histological and Immunohistochemical Analysis of Peri-Implant Soft and Hard Tissues in Patients with Peri-Implantitis.

Currently, researchers are focused on the study of cytokines as predictive biomarkers of peri-implantitis (PI) in order to obtain an early diagnosis and prognosis, and for treatment of the disease. The aim of the study was to characterize the peri-implant soft and hard tissues in patients with a peri-implantitis diagnosis. A descriptive observational study was conducted. Fifteen soft tissue (ST) samples and six peri-implant bone tissue (BT) samples were obtained from 13 patients who were diagnosed with peri-implantitis. All the samples were processed and embedded in paraffin for histological and immunohistochemical analyses. A descriptive and quantitative analysis of mast cells and osteocytes, A proliferation-inducing ligand (APRIL), B-cell activating factor (BAFF), osteonectin (ON), and ∝-smooth muscle actin (∝-SMA) was performed. We observed the presence of mast cells in peri-implant soft tissue in all samples (mean 9.21 number of mast cells) and osteocytes in peri-implant hard tissue in all samples (mean 37.17 number of osteocytes). The expression of APRIL-ST was 32.17% ± 6.39%, and that of APRIL-BT was 7.09% ± 5.94%. The BAFF-ST expression was 17.26 ± 12.90%, and the BAFF-BT was 12.16% ± 6.30%. The mean percentage of ON was 7.93% ± 3.79%, and ∝-SMA was 1.78% ± 3.79%. It was concluded that the expression of APRIL and BAFF suggests their involvement in the bone resorption observed in peri-implantitis. The lower expression of osteonectin in the peri-implant bone tissue can also be associated with a deficiency in the regulation of bone remodeling and the consequent peri-implant bone loss.

Cephalometric analysis of upper lip thickness as a critical aid in formulating a treatment plan in skeletal Class I malocclusion in adults

It is very crucial to understand that both soft tissue drape and the underlying skeletal malocclusion, are sometimes overlooked and this could be misleading for diagnosis and treatment planning .Therefore a sound knowledge of underlying malocclusion and CTP (cephalometric treatment planning) along with accurate clinical examination can aid in better diagnosis and treatment planning. The objective of this study is to understand that soft tissue drape and underlying skeletal malocclusion in Angle’s class I malocclusion could be misleading in treatment planning and therefore to perform necessary cephalometric hard and soft tissue analysis. Lateral cephalograms were obtained in NHP (Natural head position) position of size (20×25cm) FUJIFILM and lateral cephalograms were obtained on radiographic films. Evaluation of lateral cephalograms and the above mentioned parameters were traced and assessed by manual tracing of 150 lateral cephalogram was done using tracing papers with the help of tracing backlight box .Tracing was done with lead pencil point (0.3 mm HB). 150 patient of central Indian population with Angle’s class I malocclusion full permanent dentition between ages 18-45 years were included. Out of these 150 patients 75 males and 75 females patients are included in the study. Upper lip anterior and lip angle shows moderate positive correlation with W angle. The key ridge shows a strong positive correlation with W angle. The upper lip thickness can be used as a treatment plan predictor in Angle’s class I malocclusion as it is strong correlated with W angle. Soft tissue drape especially the upper lip thickness is an essential parameter along with identification of underlying skeletal malocclusion with cephalometric treatment planning measurement like W angle, for treatment planning of even a simple Angle’s class I malocclusion case.

OMENS+ Classification Correlations Analysis of Craniofacial Microsomia in China: The Relationship Between Macrostomia and Mandibular Hypoplasia.

Macrostomia is arare congenital craniofacial deformity that influences the appearance and function of patients. In most cases, it coexists with craniomaxillofacial deformities such as craniofacial microsomia (CFM). This study aimed to analyze the relationship between macrostomia and mandibular hypoplasia so as to facilitate the early detection and diagnosis of children with CFM. It included 236 patients diagnosed with CFM. All underwent facial expression analysis, multi-angle photography, computed tomography, and three-dimensional reconstruction of soft and hard tissues. The clinical classification was performed according to OMENS+. Spearman (rank) correlation analysis was used to analyze the relationship between the severity of macrostomia (C1 and C2) and the degree of mandibular involvement (M1, M2a, M2b, and M3), and the correlation among the components of OMENS+. Of the 80 cases of macrostomia (34%) reported, 72 cases (90%) were C1 and 8 (10%) were C2. The analysis of OMENS+ revealed significant correlations among OMENS+ components. Also, a high correlation was observed between macrostomia (C) and hypoplasia of the mandible (M) ( P = 0.002). Macrostomia was closely related to mandibular hypoplasia among children diagnosed with CFM. These results suggested that patients with macrostomia, who might also have craniofacial malformations caused by other first branchial arch anomalies, should be comprehensively physically examined for other syndromes.

Comparison of anteroposterior lip positions of the most preferred facial profiles of the Nepalese people

Introduction: Though cephalometric analysis of both hard and soft tissue has been done extensively for the treatment planning in orthodontics and orthognathic surgery in Nepalese people for years, they are all based on the norms for the Caucasians. No research has been done to establish the most favored profile amongst the Nepalese. The purpose of this study was to find out the most preferred well balanced or most favored facial profile from a series of 13 silhouettes with varying position of anteroposterior lip position by a group of Nepalese lay persons and general dental surgeons. Materials and Methods: Average profile for male and female were constructed from the profile of 50 Nepalese males and females with normal occlusions and without history of orthodontic and prosthetic replacement. The lips were then protruded or retruded in 1-mm increments and a series of 13 silhouettes were constructed for each male and female with the average profile in the center. The silhouettes were then given to 500 dental surgeons and lay persons each and were asked to rank the 3 most preferred facial profiles in order of preferences. Result: Both the general dental surgeons and the lay persons tend to prefer flatter profile than average for both the sexes. Both the groups preferred more flat profile for women compared to males. The least favored profile was the most protrusive one for both the groups. Conclusion: This research shows that lay persons and the general dental surgeons preferred retruded profile than the average profile though prior research show that Nepalese people have an average profile convex

Novel resin tissue array system reduces sample preparation time, labour and reagent costs in bone tissue histology.

Resin histology plays an essential role in the analysis of hard tissues, such as bone and teeth, as well as in the context of metallic implant analysis. However, the techniques of resin embedding, followed by ground sectioning, are very costly due to significantly increased reagent cost and labour time when compared to the conventional paraffin histology approach. In the present study, a novel resin array system was developed to increase the affordability of a project analysing rat femur tissues containing metallic or polymeric implants. The resin array system enabled the simultaneous embedding of the femur samples in groups of eight samples compared to the conventional resin method where samples are processed individually. The ground sections produced with the resin array system allowed uniform ROI selection, ground section thickness, staining consistency, and histological analysis with Goldner's trichrome stain, offering a substantial opportunity for reproducible immunohistochemistry which is unable to be achieved when processing samples embedded individually. The application of this novel resin array system significantly reduced resource usage when compared to doing the same analysis on individual samples. A reduction of approximately 40% was achieved for both total labour time and total reagent cost through the use of the array system compared with individual embedding. This novel resin array system has widespread applicability to many bone, hard tissue, and metallic implant studies, offering substantial conservation of research funds and increased accessibility to advanced techniques for commercial partners due to more cost-effective sample preparation and more accurate, reproducible data.

Experimental study the anti-inflammatory and osteo-regenerative qualities of the paste based on symphytum officinale tincture and calcium hydroxide

Replacement of the damaged bone remains actual and is far from being completely solved nowadays, despite its centuries-old history. The purpose of study was to investigate the anti-inflammatory and osteo-regenerative qualities of the paste based on Symphytum officinale tincture and calcium hydroxide in treatment on teeth with chronic granulating apical periodontitis in children and in an experiment on animals. Performed morphological and densitometric studies showed that remodeling of bone injury of the lower jaw in rats occurs almost equally in both experimental and control groups, and a paste based on Symphytum officinale tincture and calcium hydroxide also promotes bone regeneration at the defect site and stimulates osteosynthesis. Analysis of liver tissue, soft and hard tissues of the lower jaw in animals suggest that the proposed paste does not produce any toxic effect and provides significant anti-inflammatory properties. The gained result provide grounds to recommend the developed paste for therapeutic use in children as a temporary root canal sealing material in permanent teeth with granulating apical periodontitis.

Expression of DLX6 Gene in Mandibular Deficiency (Retrognathic Mandible): A Randomized Clinical and Genetic Study.

IntroductionThere are various genes that affect craniofacial development and among the important genes that affect jaw development is distal-less homeobox (DLX) 6 genes. The present study was carried out to determine the role of DLX6 gene variations in mandibular deficiency.MethodsThirty subjects having retrognathic mandible were evaluated by clinical examination and assessed using lateral cephalometric radiographs based on cephalometrics for orthognathic surgery (COGS) analysis of hard tissue with N-Pog parameters being less than -13 mm. For the same subjects, saliva samples were taken and sent to biotechnology labs for genetic evaluation. DNA was isolated from salivary samples using a DNA extraction kit and was subjected to polymerase chain reaction (PCR) amplification and sequencing. Single nucleotide polymorphisms (SNP) analysis was done to assess the role of DLX6 gene in these study subjects. Results All 30 subjects showed N-POG parameters of COGS analysis for hard tissue to be less than -13mm, confirming retrognathic mandible. SNP analysis of subjects showed no SNPs in any EXON of the DLX6 gene for all 30 study samples.Conclusion No variations in DLX6 gene were found in the present study. Further studies are required to investigate other genes that could be involved in the cause of retrognathic mandible with a larger sample size and to include subjects in the sample having features other than mandibular retrognathia like hearing loss, abnormal pinnae, ectrodactyly, cleft palate, developmental delay and abnormal teeth to determine the contribution of DLX6 gene variations in mandibular deficiency.

Coordinated labio-lingual asymmetries in dental and bone development create a symmetrical acrodont dentition

Organs throughout the body develop both asymmetrically and symmetrically. Here, we assess how symmetrical teeth in reptiles can be created from asymmetrical tooth germs. Teeth of lepidosaurian reptiles are mostly anchored to the jaw bones by pleurodont ankylosis, where the tooth is held in place on the labial side only. Pleurodont teeth are characterized by significantly asymmetrical development of the labial and lingual sides of the cervical loop, which later leads to uneven deposition of hard tissue. On the other hand, acrodont teeth found in lizards of the Acrodonta clade (i.e. agamas, chameleons) are symmetrically ankylosed to the jaw bone. Here, we have focused on the formation of the symmetrical acrodont dentition of the veiled chameleon (Chamaeleo calyptratus). Intriguingly, our results revealed distinct asymmetries in morphology of the labial and lingual sides of the cervical loop during early developmental stages, both at the gross and ultrastructural level, with specific patterns of cell proliferation and stem cell marker expression. Asymmetrical expression of ST14 was also observed, with a positive domain on the lingual side of the cervical loop overlapping with the SOX2 domain. In contrast, micro-CT analysis of hard tissues revealed that deposition of dentin and enamel was largely symmetrical at the mineralization stage, highlighting the difference between cervical loop morphology during early development and differentiation of odontoblasts throughout later odontogenesis. In conclusion, the early asymmetrical development of the enamel organ seems to be a plesiomorphic character for all squamate reptiles, while symmetrical and precisely orchestrated deposition of hard tissue during tooth formation in acrodont dentitions probably represents a novelty in the Acrodonta clade.

Arnett Facial Soft-tissue Cephalometric Analysis Norms for Mongolian Children

Objectives: This study aimed to determine norms cephalometric norms of Mongolian children and compare their development in boys and girls between 6 and 15 years of age. Methods: Lateral cephalograms were performed on 541 subjects (225 male and 316 females) having normal occlusion between the ages of 6 to 15 years.All radiographs were digitized on a computer using a cephalometric software program. A total of 6 angular, 38 linear measurements were measured by a radiologist for skeletal hard and soft tissue analysis. Results: Mx-ocdusal plane angle, Md1 to Md occlusal plane angle. Nasolabial angle decreased with age. Mx1, Mx occlusal plane angle, and overbite were stable with age. In contrast, the other measurements typically increased with age. No statistically significant gender differences were observed. Some distinct ethnic differences were found between Caucasians and Mongolian children with Mongolian children having thinner and shorter lips compared to Caucasians. Conclusions: No significant differences were observed in any of the dentoskeletal factors representing hard tissue to hard tissue measurements. Results were similar to those found in Caucasian males and females.