Facial Height Research Articles

Imaging study on the relationship between anterior and posterior occlusal planes and temporomandibular osteoarthrosis.

The aim of this study was to compare the anterior and posterior occlusal plane characteristics of patients with different temporomandibular joint osseous statuses. A total of 306 patients with initial cone beam CT (CBCT) and cephalograms were included. They were divided into three groups on the basis of their temporomandibular joint osseous status: bilateral normal (BN) group, indeterminate for osteoarthrosis (I) group, and osteoarthrosis (OA) group. The anterior and posterior occlusal planes (AOP and POP) of the different groups were compared. Then, the regression equation was established after adjusting for confounding factors, and a correlation analysis between the occlusion planes and other parameters was performed. SNA, SNB, FMA, SN-MP, Ar-Go, and S-Go were correlated with the occlusal planes. Relative to the BN and I groups, the FH-OP of the OA group increased by 1.67° on the average, FH-POP increased by 1.42° on the average, and FH-AOP increased by 2.05° on the average. The occlusal planes were steeper in the patients with temporomandibular osteoarthrosis than in the patients without it, and the mandible rotated downward and backward. The height of the mandibular ramus, the mandibular body length, and the posterior face height were small. In clinical practice, attention should be given to the potential risk of temporomandibular joint osteoarthrosis in such patients. In addition, SNB, FMA, SN-MP, Ar-Go, S-Go, and occlusal planes had moderate correlations.

FACIAL MORPHOMETRIC STUDY OF ADULT HAUSA MALE TAXI AND TRICYCLE DRIVERS IN KANO, NIGERIA

Human faces contain several cues, for example, identity, emotional expression, age, gender, ethnicity, attractiveness, personality traits, and many more. The aim of this study was to determine the facial parameters in the population of Hausa Male taxi and tricycle drivers in Kano, Nigeria and to compare them with those determined in earlier studies in different populations. Four hundred (402) subjects were selected from the two association in Kano state, Tsaya da Kafarka Taxi Drivers Association and Tricycle Operators Association Kano (TOAKAN), using random sampling methods, with the age range of the participants between 18-50 years and Those with facial deformities or craniofacial trauma, surgery, and congenital facial abnormalities were excluded from the study. Photographic methods were used to capture the face. The data were expressed as mean ± SD, frequency, and percentages. It was observed that facial height (tr_gn) was higher in the facial vertical dimensions than the rest with the mean value of 190.59 ±17.60mm, while the lower face width (go1_go2) was higher in the horizontal facial dimensions than the rest, with the mean value of 115.92±11.86mm. The right eye length (ex1_en1) was slightly lower (30.07±3.80mm) than the left (30.27±3.81mm). In conclusion, the present study has established the baseline data of facial dimensions of Hausa Male taxi and tricycle drivers in Kano, Nigeria.

How Do the Faces of Kyrgyz Beauties Look? A Photogrammetric Analysis of Beauty Pageant Winners.

The aim of this study was to assess how the eyes of Kyrgyz beauties look through an anthropometric analysis of beauty pageant winners. Eleven winners of the Miss Kyrgyzstan contest (2011-2021) were included. Ten other beauty contest winners were added, resulting in a total of 21 beauties who were included. The horizontal corneal diameter, which is 11.75mm, was used as a standard distance. Other distances were calculated in millimeters based on the proportions of the pixels measured. Twenty-six distances (face: 10, eyebrows: 2, eyes: 4, nose: 4, lips: 4, and chin: 2) and 9 angles (forehead-brow, cantal tilt, 5 face angles, the mandible angle, and the chin angle) were measured. Thereafter, 16 indices (forehead: 1, eyes: 5, nose: 4, lips and chin: 3, and contours 3) were calculated. The forehead-brow angle was 82.2±7.2 degrees. The canthal tilt was 9.0±2.0 degrees. The overall face angles 1 and 2 were 108.6±4.1 degrees and 69.6±2.3 degrees, respectively. The midface angles 1 and 2 were 129.9±3.8 degrees and 125.1±3.9 degrees, respectively. The lower face angle was 139.6±4.1 degrees. The mandible angle and chin angle were 136.9±4.0 degrees and 106.0±4.0 degrees, respectively. The ratio of forehead height to total face height was 0.33±0.03. The ratio of nose height to total face height was 0.25±0.02. The lower face width/face width ratio was 0.82±0.05. The ratio of face width to total face height was 0.72±0.03. The ratio of midface height to total face height was 0.34±0.02. The data from this study might serve as the recommended esthetic proportions for performing plastic surgical procedures.

Effects of vertical control on anatomic and aerodynamic characteristics of the oropharyngeal airway during premolar extraction treatment of Class II hyperdivergent nonsevere crowding malocclusion

This study aimed to analyze the effects of premolar extraction treatment with vertical control on changes in the anatomy and aerodynamics of the oropharynx in Class II hyperdivergent malocclusion with nonsevere crowding. Thirty-nine patients with Class II hyperdivergent malocclusion were enrolled consecutively. All the participants underwent 4 premolar extractions. The high-pull J-hook and mini-implants were used to provide vertical control. Cone-beam computed tomography was performed before and after treatment. The participants were divided into a decreased lower vertical facial height group (n= 23) and an increased lower vertical facial height group (n= 16) on the basis of superimposition. The aerodynamic characteristics, including airway resistance (inspiration, Rin; expiration, Rex) and maximum velocity (inspiration, Vmaxin; expiration, Vmaxex) at inspiration and expiration, were calculated using computational fluid dynamics. Anatomic characteristics, including volume and cross-sectional area (CSAmin), were measured using the Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif). After treatment, the median volume and CSAmin increased by 2357 mm3 and 43 mm2, respectively, and median Rin and Vmaxex decreased by 0.15 Pa/L/min and 0.24 m×s-1, respectively, in decreased lower vertical facial height group. In contrast, the median CSAmin decreased by 9.5 mm2 in the increased lower vertical facial height group. All the changes were statistically significant (all P<0.05). Significant differences in volume, CSAmin, Rin, and Vmaxex were observed between the 2 groups. Vertical control might improve the anatomic and aerodynamic characteristics of the oropharyngeal airway during premolar extraction treatment of Class II hyperdivergent malocclusion with nonsevere crowding.

Morphometric cranial standards for sex estimation of a population in two ethnic groups in Southwest Iran

BackgroundThis study aimed to evaluate the cephalometric landmarks, cranial measurements, and cephalic index based on geographical and ethnic characteristics to make a database for the southwest Iranian population. MethodIn this analytical cross-sectional study, different anatomic criteria were collected from head MRI images. The anthropometric measures taken included the maximum cranial length, maximum cranial height, maximum cranial breadth, cranial base length, foramen magnum length, upper facial height, lower facial height, foramen magnum breadth, bizygomatic breadth, orbital breadth, nasion-opisthion. The categorization of the head shape was based on the cephalic index. The cranial index was calculated using the equation ([maximum cranial breadth/maximum cranial length] × 100). These assessments were compared to define sexual dimorphism and inter-population variation in size and shape. ResultsSexual dimorphism existed in all cephalometric data except the cephalic index. The measurements comparisonin ethnicities showed that only (eu–eu) differs significantly between the two groups, which is 2,253 mm less in the Arab population compared to the Lur population (P value = 0.022). The cephalic index in males and females was found to be 73.66 and 75.08, respectively. Accordingly, 53.99% were dolichocephalic, 30.06% were mesocephalic, 14.11% were brachycephalic, and 1.84% were hyperbrachycephalic. The shape of the head had no relation to ethnicity but was related to sex (P value = 0.045). Conclusion: It is shown that cephalometric data can be used as diagnostic criteria to determine sex and ethnicity in the southwest Iranian population. It should be further verified on a greater sample size that evaluates more study age distribution.

Association Between Growth Hormone Receptor Gene Polymorphisms rs6180, rs6182, and rs6184 and Craniofacial Parameters in Indian Population

Objective/Background Craniofacial growth and development is influenced by growth hormone, which is in turn facilitated by the growth hormone receptor (GHR). GHR gene polymorphisms have been found to be associated with mandibular morphology and skeletal facial profiles in various populations. The aim of this study was to determine the association of single nucleotide polymorphisms (SNP) of GHR gene rs6180, rs6182, and rs6184 with maxillomandibular parameters in the Indian population. Setting and Sample Population A cross sectional study was conducted on 174 male and female Indian subjects in the age range of 20 to 32 years who reported for orthodontic treatment. Material and Methods Venous blood and lateral cephalogram were collected from each participant for genetic and cephalometric analysis. Genotypes of each SNP were identified by polymerase chain reaction—restriction fragment length polymorphism. Independent t test and Analysis of Variance (ANOVA) were done for intra and inter group comparisons with SPSS software. Results SNPs rs6180, and rs6182 were found to be associated with sagittal position and length of maxilla and mandible, anterior facial height, and growth pattern. SNP rs6184 did not have any significant association with the craniofacial parameters. Conclusion The results suggest that the GHR gene might be a candidate gene for maxillomandibular morphology in the Indian population.

Cephalometric evaluation of deep overbite correction using anterior bite turbos.

To evaluate the outcome of treating deep overbite (OB) using anterior bite elevators concurrently with a pre-adjusted edgewise appliance. The Case Western Reserve University (CWRU) cephalometric analysis was used to isolate tipping movement of upper (TUI) and lower incisors (TLI), bodily tooth movement of upper (BUI), and lower incisors (BLI), as well as vertical skeletal changes in the anterior region of the maxilla (MXSK) and mandible (MNSK). Thirty treated subjects were examined at pretreatment (T1) and posttreatment (T2) and compared to an untreated control group matched on age, sex, and Angle malocclusion from the Bolton Brush Growth Study Collection (CWRU, Cleveland, Ohio). Overbite (OB) in the treated group was decreased significantly (P < .001) (-5.6 mm) compared to controls. Statistically significant (P < .001) changes were found for BUI (-0.7 mm), TUI (0.9 mm), TLI (-1.4 mm), BLI (-1.1 mm), and MNSK (-1.6 mm). Most of the overbite correction was in the lower arch and included tipping and intrusion of the lower incisors along with an increase in lower vertical facial height. Deep OB correction was achieved efficiently using anterior bite elevators with pre-adjusted edgewise appliance. Correction using bite turbos would be a treatment option for individuals presenting with decreased lower facial height and deep bite.

Vertical effects of distalization protocol with Clear aligners in Class II patients: a prospective study.

The aim of the present prospective study was to detect the effects on vertical dentoskeletal dimension produced by molar distalization with Clear Aligners in a group of subjects with Class II malocclusion. The Clear Aligners Group (CAG) comprised 20 patients (13 females, seven males) with a mean age of 17.2±3.2 years. The same standardized protocol of sequential distalization was applied in all subjects. For each patient lateral cephalograms have been analyzed before treatment (T1) and at the end of the therapy (T2). At the end of treatment, clear aligners were effective in the correction of Class II dental relationship with the correction of the overjet (-1.3 mm). The treated group showed statistically significant reduction in FMA angle (-1.3°) associated with a counterclockwise rotation of the occlusal plane (POccl^PF -3.1°; SN^POccl -4.2°) and a slight intrusion of maxillary first molars to palatal plane (-0.9 mm). Finally, statistically significant differences were detected in anterior facial height (N-Me) and in the ArGo^GoMe angle (-1.2 mm and -3.4°, respectively). Upper molar distalization with clear aligners represents a valid alternative to non-extraction treatment of Class II malocclusion, reducing the extrusion of maxillary first molars and improving the control of the occlusal plane and of the vertical dimension.

Outcome of Vertical Skeletal Pattern in the Buccal Corridor Area Show during Posed Smile

Aim: To determine link between a patient's buccal relationship and vertical skeletal corridor region display during a posed grin. Study design: Descriptive study. Place and duration of study: Department of Orthodontic, Ayub Dental College from 1st July 2022 to 31st December 2022. Methodology: One hundred and seventy patients with normal, additional and insignificant buccal corridors were enrolled. The patient's Frankfort Horizontal plane parallel to the floor, their lips relaxed, and their teeth in centric occlusion, lateral cephalograms were obtained. Results: The measurement of the buccal corridor area visible during a frontal grin varies from 0 mm to 4.50mm. The average size of the buccal corridor was 1.799±0.9904 mm. The ratio of lower anterior facial height towards total anterior facial height ranged from 48° to 67° with mean anterior facial height was 45.246±2.48. Conclusion: Lower anterior facial height has a substantial impact on how much of the buccal corridor region shows during posed smiles, and a rise in ratio causes less buccal corridor area to display. Keywords: Inter-commissure width, Inter-pre-molar width, Inter-pupillary distance

Covariance patterns between ramus morphology and the rest of the face: A geometric morphometric study

The growth and development of the mandible strongly depend on modeling changes occurring at its ramus. Here, we investigated covariance patterns between the morphology of the ramus and the rest of the face. Lateral cephalograms of 159 adults (55 males and 104 females) with no history of orthodontic treatment were collected. Geometric morphometrics with sliding semi-landmarks was used. The covariance between the ramus and face was investigated using a two-block partial least squares analysis (PLS). Sexual dimorphism and allometry were also assessed. Differences in the divergence of the face and anteroposterior relationship of the jaws accounted for 24.1% and 21.6% of shape variation in the sample, respectively. Shape variation was greater in the sagittal plane for males than for females (30.7% vs. 17.4%), whereas variation in the vertical plane was similar for both sexes (23.7% for males and 25.4% for females). Size-related allometric differences between the sexes accounted for the shape variation to a maximum of 6% regarding the face. Regarding the covariation between the shapes of the ramus and the rest of the face, wider and shorter rami were associated with a decreased lower anterior facial height as well as a prognathic mandible and maxilla (PLS 1, 45.5% of the covariance). Additionally, a more posteriorly inclined ramus in the lower region was correlated with a Class II pattern and flat mandibular plane. The width, height, and inclination of the ramus were correlated with facial shape changes in the vertical and sagittal planes.

Prediction of the Post-Pubertal Mandibular Length and Y Axis of Growth by Using Various Machine Learning Techniques: A Retrospective Longitudinal Study.

The aim was to predict the post-pubertal mandibular length and Y axis of growth in males by using various machine learning (ML) techniques. Cephalometric data obtained from 163 males with Class I Angle malocclusion, were used to train various ML algorithms. Analysis of variances (ANOVA) was used to compare the differences between predicted and actual measurements among methods and between time points. All the algorithms revealed an accuracy range from 95.80% to 97.64% while predicting post-pubertal mandibular length. When predicting the Y axis of growth, accuracies ranged from 96.60% to 98.34%. There was no significant interaction between methods and time points used for predicting the mandibular length (p = 0.235) and Y axis of growth (p = 0.549). All tested ML algorithms accurately predicted the post-pubertal mandibular length and Y axis of growth. The best predictors for the mandibular length were mandibular and maxillary lengths, and lower face height, while they were Y axis of growth, lower face height, and mandibular plane angle for the post-pubertal Y axis of growth. No significant difference was found among the accuracies of the techniques, except the least squares method had a significantly larger error than all others in predicting the Y axis of growth.

Prediction of root canal lengths and pulp volume of the maxillary permanent first molar based on stature, crown diameters, and facial morphometry.

This study purposed to develop statistical models to predict palatal (PRL), mesial (MRL), and distal (DRL) root canal length and pulp volume (PV) of the maxillary first permanent molar using stature, gender, mesiodistal (MD), and buccopalatal (BP) crown diameters and some facial morphometries. 57 individuals were included in the study. Cone beam computed tomography was used to measure root canal lengths and PV. The PV calculation was carried out using the software ITK-SNAP 3.4.0. PRL was positively correlated with BP, stature, middle facial height, interalar distance, and bicommissural distance (BCD) (p < 0.05). DRL was positively correlated with BP, MD, and stature (p < 0.05). MRL was positively correlated with BP, MD, stature, lower face height, bizygomatic distance, and BCD (p < 0.05). PV was negatively correlated with age and BCD (p < 0.05). Although all models have significant predictive power for the root lengths and PV, no model could explain variances greater than 30%. The highest and lowest predictive ability was obtained for PRL and DRL, respectively. While the most significant predictor was BP for PRL and DRL, it was the age for PV.

Skeletal and dental effects of serial extractions performed with or without maxillary expansion-A retrospective controlled study.

The study aimed to compare severe crowding treatment's skeletal and dental effects by serial extractions or maxillary expansion and serial extractions in the mixed dentition phase. The retrospective controlled study included lateral cephalograms of 78 subjects aged 8.5 ± 1.4 years, 52 consecutively treated because of severe crowding, and 26 untreated controls matched for baseline age and observational period. Subjects were clustered according to the treatment modality, either serial extraction (EX) or expansion and extraction (EXP-EX) group. Sagittal and vertical skeletal as well as dental cephalometric parameters were assessed at baseline and after the eruption of all permanent posterior teeth, and group comparisons were performed. Both treatment modalities significantly affected the vertical skeletal parameters in terms of decreasing the mandibular and occlusal plane inclination and increasing the facial height index. A distinct treatment effect on the gonial angle was observed, with a significant decrease in its superior part observed in both extraction groups. The annualized changes in the superior part of the gonial angle significantly differ (P = .036) between the Control (-0.04 ± 0.6), EX (-0.44 ± 0.6) and EXP-EX (-0.34 ± 0.5) groups. Upper and lower incisor inclination did not change significantly in any of the groups; however, the interincisal angle at follow-up was significantly smaller in the Control compared with both treated groups. Serial extractions and a combination of maxillary expansion and serial extractions have similar significant skeletal effects, mainly affecting vertical cephalometric parameters if performed during the pre-pubertal growth phase.

Challenges and Opportunities of Secondary Use of health Data in Developing Countries

Human faces contain several cues, for example, identity, emotional expression, age, gender, ethnicity, attractiveness, personality traits and many more. The aim of this study was to determine the facial parameters in the population of Hausa Male taxi and tricycle drivers in Kano, Nigeria and to compare them with those determined in earlier studies in different populations. Four hundred (402) subjects were selected from the two association in Kano state, Tsaya da Kafarka Taxi Drivers Association and Tricycle Operators Association Kano (TOAKAN), using random sampling methods, with the age range of the participants between 18-50 years and Those with facial deformities or craniofacial trauma, surgery, and congenital facial abnormalities were excluded from the study. Photographic methods were used to capture the face. The data were expressed as mean ± SD, frequency, and percentages. It was observed that facial height (tr_gn) was higher in the facial vertical dimensions than the rest with the mean value of 190.59 ±17.60mm, while the lower face width (go1_go2) was higher in the horizontal facial dimensions than the rest, with the mean value of 115.92±11.86mm. The right eye length (ex1_en1) was slightly lower (30.07±3.80mm) than the left (30.27±3.81mm). In conclusion the present study has established the baseline data of facial dimension of Hausa Male taxi and tricycle drivers in Kano, Nigeria.

Facial Anthropometric Norms of the Young Black South African Woman.

In total, 156 Black female students from Sefako Makgatho University between 18 and 25 years of age, with a normal dental occlusion and a normal body mass index were included in the study. Computer-based photographic analysis of participants' faces in anterior, lateral, and basal views was undertaken under strict studio conditions and compared with international studies. Facial height proportions tended toward a smaller upper facial third in comparison with mid and lower facial thirds. Nasal width was greater than other populations, and exceeded the neoclassical canon of one-fifth of facial width. Nasal tip projection was greater than Congolese and African American counterparts. Vermilion height ratios approximated a ratio of 1:1 with lip protrusion beyond the classical Rickets E-line. The "classical" anthropometric measurements most often quoted in academic literature, although important in their own right, do not consider the distinct differences in facial anthropometric norms between population and racial groups. These differences must be taken into consideration to preserve ethnic traits and optimize aesthetic outcomes.

Quantitative analysis of the morphology of the lips according to different anteroposterior and vertical skeletal patterns

Objectives: The aim of this study was to compare the differences in the morphology of the lips according to anteroposte-rior dentoskeletal patterns and facial divergence.Materials and Methods: The samples were composed of the frontal facial photographs of 117 adult patients who satisfied all the cephalometric measurements for six groups (Class I or II or III and normodivergent or hyperdivergent). The morphol-ogy of the lips was evaluated on the frontal facial photographs and the measurements were compared between the groups.Results: In the normodivergent groups, the height-to-width ratio of the lip vermilion was significantly greater in the Class II group than in the Class I group, and the labrale superius angle and upper lip convexity of the Class II group was smaller than that of the Class I group. In the hyperdivergent groups, the stomion inferius angle of the Class III group was smaller than that of the Class II group. Lower facial height and the interlabial gap in the hyperdivergent groups tended to be larger than those in the normodivergent groups. The height-to-width ratio of the lip vermilion and the commissure height were larger in the hyperdivergent groups than in the normodivergent groups. However, the upper lip height and philtrum height did not differ between the hyperdivergent and normodivergent groups.Conclusion: The morphological characteristics of the lip vermilions on the frontal view differed according to the sagittal dentoskeletal relationship and facial divergence.

Comparation between golden rectangle and ideal facial height proposed by the Silva Cephalometric Method (MCS) through digital analysis (NemoStudio 2022) in a university population

Objective: The purpose of this work was to establish a statistical relationship of the results obtained with two different techniques. The comparison was made between the ideal facial height proposed in the Silva cephalometric method (SCM) and the facial height obtained using Euclid's rectangle or golden rectangle. Materials and Methods: 38 cephalometric radiographs of dentistry students of Universidad de Cuenca, of both sexes, were used. All of these radiographs had suitable characteristics for cephalometric tracing in the NemoStudio 2022 software. Once the cephalometric tracing was made using these software tools, SCM was performed on each one of them to collect the data, and then we proceeded to overlap Euclid’s rectangle on all the images. The correlation of these two methods was established with Pearson’s correlation coefficient. Results: It was concluded that the Pearson correlation coefficient was [r]: 0.9271 Conclusions: 5% of the patients presented compatibility with the logarithmic spiral of the golden ratio.

Stability of vertical dimension following total arch intrusion

BackgroundThe purpose of this study is to evaluate stability of vertical dimension following total arch intrusion using miniscrews by measuring the change during treatment and relapse amount after more than one year of retention.MethodsThirty patients (6 men, 24 women) were included in this study. Lateral cephalographs were taken with conventional radiography at the start of treatment (T0), after treatment (T1), and at least one year after treatment (T2). The evaluation was performed by measuring changes of selected parameters during treatment and the extent of relapse after more than one year.ResultsDuring total arch intrusion treatment (T1-T0), anterior and posterior teeth intruded significantly. The mean vertical distance between the maxillary posterior teeth and palatal plane was reduced by 2.30 mm (P < 0.001). The mean vertical distance between the maxillary anterior teeth and palatal plane was reduced by 2.04 mm (P < 0.001). The anterior facial height was also reduced by 2.70 mm (P < 0.001). During retention period (T2-T1), the vertical distance between the maxillary anterior teeth and the palatal plane significantly increased by 0.92 mm (P < 0.001). The anterior facial height increased by 0.81 mm (P < 0.01).ConclusionsAnterior facial height significantly decreases after treatment. During retention period, relapse of AFH and maxillary anterior teeth observed. There was no correlation between initial amount of AFH, mandibular plane angle, or SNPog and posttreatment AFH relapse. However, there was a significant correlation between the amount of intrusion of anterior and posterior teeth achieved by the treatment and the extent of relapse.

Upper airway dimensions and the skeletal parameters in orthodontic patients who developed moderate-severe COVID-19 symptoms during the pandemic.

Large airway dimensions are associated with a rapid decline in the lung function and a higher risk of hospitalization. Therefore, the airway dimensions of healthy subjects who tested positive for coronavirus disease 2019 (COVID-19) may be associated with the severity of COVID-19 symptoms. The objectives of this study were to measure the upper airway dimensions and the craniofacial skeletal parameters in patients who tested positive for COVID-19, to compare the upper airway dimensions and the craniofacial skeletal parameters between patients who developed no/mild symptoms and those with moderate-severe COVID-19 symptoms, and to assess any association of the skeletal relationships (anteroposterior (AP) and vertical) and the upper airway dimensions with the severity of COVID-19 symptoms in adult subjects. A total of 204 orthodontic patients who tested positive for COVID-19 were evaluated. Of these, only 137 met the inclusion criteria. The sample was further subdivided into 2 groups based on the severity of symptoms: cases (moderate-severe symptoms; n = 56); and controls (asymptomatic/ mild symptoms; n = 81). The upper airway dimensions and the skeletal parameters were measured on lateral cephalograms. The nonparametric Mann-Whitney U test was used to detect differences between the cases and the controls. Binary logistic regression analysis was used to evaluate the association between the studied variables and the severity of symptoms. The cases had a reduced lower face height (LFH) and a reduced perpendicular distance from the hyoid bone to the line connecting the anteroinferior limit of the 3rd cervical vertebra (C3) and the retrognathion point (RGN) (HH1) as compared to the controls. Regression analysis revealed a significant association of LFH (p = 0.013), the vertical airway length (VAL) (p = 0.002) and HH1 (p = 0.021) with the severity of COVID-19 symptoms. The types of malocclusion were similar in the cases and the controls. Patients with reduced LFH and VAL, and a superiorly positioned hyoid bone in relation to the mandible developed more severe COVID-19 symptoms.

Association between the severity of hypodontia and the characteristics of craniofacial morphology in a Chinese population: A cross-sectional study.

To investigate craniofacial differences in individuals with hypodontia and explore the relationship between craniofacial features and the number of congenitally missing teeth. A cross-sectional study was conducted among 261 Chinese patients (males, 124; females, 137; age, 7-24 years), divided into four groups (without hypodontia: no teeth missing, mild: one or two missing teeth, moderate: three to five missing teeth, severe: six or more missing teeth) according to the number of congenitally missing teeth. Differences in cephalometric measurements among the groups were analyzed. Further, multivariate linear regression and smooth curve fitting were performed to evaluate the relationship between the number of congenitally missing teeth and the cephalometric measurements. In patients with hypodontia, SNA, NA-AP, FH-NA, ANB, Wits, ANS-Me/N-Me, GoGn-SN, UL-EP, and LL-EP significantly decreased, while Pog-NB, AB-NP, N-ANS, and S-Go/N-Me significantly increased. In multivariate linear regression analysis, SNB, Pog-NB, and S-Go/N-Me were positively related to the number of congenitally missing teeth. In contrast, NA-AP, FH-NA, ANB, Wits, N-Me, ANS-Me, ANS-Me/N-Me, GoGn-SN, SGn-FH (Y-axis), UL-EP, and LL-EP were negatively related, with absolute values of regression coefficients ranging from 0.147 to 0.357. Further, NA-AP, Pog-NB, S-Go/N-Me, and GoGn-SN showed the same tendency in both sexes, whereas UL-EP and LL-EP were different. Compared with controls, patients with hypodontia tend toward a Class III skeletal relationship, reduced lower anterior face height, flatter mandibular plane, and more retrusive lips. The number of congenitally missing teeth had a greater effect on certain characteristics of craniofacial morphology in males than in females.