Cranial Base Length Research Articles

In utero nicotine exposure affects murine palate development.

Despite data linking smoking to increased risk of fetal morbidity and mortality, 11% of pregnant women continue to smoke or use alternative nicotine products. Studies confirm that nicotine exposure during pregnancy increases the incidence of birth defects; however, little research has focused on specific anatomic areas based on timing of exposure. We aim to determine critical in utero and postnatal periods of nicotine exposure that affect craniofacial development, specifically palate growth. Malformation of the palatal structures can result in numerous complications including facial growth disturbance, or impeding airway function. We hypothesized that both in utero and postnatal nicotine exposure will alter palate development. We administered pregnant C57BL6 mice water supplemented with 100 μg/mL nicotine during early pregnancy, throughout pregnancy, during pregnancy and lactation, or lactation only. Postnatal day 15 pups underwent micro-computed tomography (μCT) analyses specific to the palate. Resultant pups revealed significant differences in body weight from lactation-only nicotine exposure, and μCT investigation revealed several dimensions affected by lactation-only nicotine exposure, including palate width, palate and cranial base lengths, and mid-palatal suture width. These results demonstrate the direct effects of nicotine on the developing palate beyond simple tobacco use. Nicotine exposure through tobacco alternatives, cessation methods, and electronic nicotine delivery systems (ENDS) may disrupt normal growth and development of the palate during development and the postnatal periods of breastfeeding. Due to the recent dramatic increase in the use of ENDS, future research will focus specifically on this nicotine delivery method.

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.

The relationship of anterior occlusion and skeletal variables with the frontal sinus index: An analytical cross-sectional study.

To determine the relationship of anterior occlusion and skeletal variables with the frontal sinus index. The retrospective, analytical, cross-sectional, study was conducted from July to November 2020 at Dr Ishratul- Ebad Khan Institute of Oral Health Sciences and Dow Dental College, Dow University of Health Sciences, Karachi, and comprised data from 2015 to 2018 related to pre-treatment lateral cephalograms for determining frontal sinus index and other cephalometric variables. The dental casts were observed for incisor classification. Patients with Class I incisors formed the comparison group, while the rest comprised 5 malocclusion groups. The frontal sinus was traced, and the sinus index was calculated. Data was analysed using STATA 15 and R 3.5.1. Of the 240 subjects, there were 40(16.66%) in each of the 6 groups; 155(64.6%) females and 85(35.4%) males. The mean age of the sample was 21.33±3.52 years (range: 16-29 years). The mean sinus index was higher in all malocclusion groups than the comparison group, but it was significantly higher only in Class II division 2 and anterior open bite groups (p<0.05). The only exception to the trend was Class II division 1 with and without contact in which the value was lower (p>0.05). The anterior cranial base length, sella-nasion mandibular plane angle, and upper incisor palatal plane angle significantly affected the frontal sinus index (p<0.05). The frontal sinus index could be considered an indicator of harmonious anterior occlusion.

Length of cranial base and total face height in cephalograms for sex estimation in Indonesia

Background: Sex estimation is the first step in identifying bodies following disasters or accidents. Craniometric analysis of lateral cephalograms can be used in the process. Among the measurements that can be used are the length of cranial base, determined by Basion–Nasion (Ba-N) length, and the total face height, determined by the Nasion–Menton (N-M) length, which can highlight significant differences between men and women. Purpose: This study aimed to determine the differences in length of cranial base and total face height measurements between men and women and to demonstrate how these two measurements can be used for sex estimation in the Indonesian population. Methods: This cross-sectional study employed a patient database from the dental hospital of Universitas Gadjah Mada. The study sample consisted of 116 cephalograms taken of 58 men and 58 women aged 20–40 years. The linear measurements were taken using EzDent-I Vatech software. Results: The mean cranial base length measurements in the men and women groups were 103.83 ± 4.37 and 96.01 ± 3.80 mm, respectively, whereas the total face height measurements were 121.03 ± 7.26 and 111.23 ± 5.09 mm, respectively. The Mann–Whitney U-Test revealed a significant difference (p &lt; 0.05) between the groups. Logistic regression showed that the two measurements can be used to form an equation for sex estimation with an accuracy of 88.8%. Conclusion: Length of cranial base (Ba-N) and total face height (N-M) measurements from lateral cephalograms can accurately be used for sex estimation. Further research among specific populations is required to develop accurate methods for sex estimation employing morphometric examination on radiographs.

Cranial Base Measurements in Skeletal Malocclusion among Orthodontic Patients.

Facial growth and development is necessary for proper orthodontic diagnosis and treatment planning. Growth of cranial base is linked to the overall growth of facial bones, especially the maxilla and mandible. Any change in the amount and direction of growth of the cranial base can have direct or indirect effects on the developing maxilla and mandible. Thus the aim of this study was to determine the linear and angular cranial base measurements in different skeletal malocclusion in Nepalese population. Pretreatment lateral cephalograms of 225 patients aged between 17-30 years were collected. Linear measurements Sella-Nasion (S-N), Sella-Articulare (S-Ar), Articulare-Gonion (Ar-Go), Gonion-Gnathion (Go-Gn) and angular measurements Saddle angle (N-S-Ar), Articular angle (S-Ar-Go) and Gonial angle (Ar-Go-Gn) were measured. In angular measurements statistically significant differences were found in the saddle and gonial angles between class I, II, and III skeletal pattern. In linear measurements, anterior and posterior cranial base lengths were not significantly different among groups however, ramal height and mandibular body length were significantly different among groups with a P value < 0.05. Skeletal class III has a larger gonial angle, ramal height and mandibular length. Males have larger linear measurements and females have larger angular measurements.

Assessment of Frontal Sinus Volume and Cranial Base Length Based on Different Vertical Skeletal Patterns: A Cone Beam Computed Tomographic Study.

Introduction Evaluating craniofacial growth is an essential component of orthodontic treatment, and it is assessed by examining the cranial base. The anterior cranial base is regarded as a stable structure, and the frontal sinus is also recognised as a contributing component in the formation of the cranial base.The frontal sinus, a cavity present in the frontal bone, displays variation in both size and shape and has an impact on the overall structure of the skull and face. This study aims to evaluate the impact of vertical skeletal patternand gender on the volume of the frontal sinus. Materials and methodology In this study, 90 cone beam computed tomography (CBCT) scans from the record's section were included, comprising 46 males (55.44%) and 44 females (48.88%) aged 20 to 35 undergoing orthodontic treatment. The assessment involved evaluating vertical skeletal patterns using a lateral cephalogram derived from the CBCT scans, and volumetric analysis of the frontal sinus was conducted usingDolphin Imaging software (version 11.9; Dolphin Imaging and Management Solutions, Chatsworth, California). Statistical analysis was performed on the collected data using SPSS software, version 20.0 (IBM Corp., Armonk, NY). Pearson correlation, a one-way ANOVA test to determine any statistically significant differences between the means of both frontal sinus volume and cranial base length groups individuallyand an independent t-test to compare the sample means between the frontal sinus volume and cranial base length groups were performed. Results: A non-significant association was observed between frontal sinus volume and cranial base length in skeletal open bite (p = 0.73) and skeletal deep bite (p = 0.12) between males and females, which implies there is no substantial association between frontal sinus volume (p = 0.08) and cranial base length (p = 0.41) in the different vertical skeletal patterns. Conclusion: Frontal sinus volume was similar in subjects with a skeletal open bite and a deep bite. Males and females did not show a difference in frontal sinus volume. Hence, it was concluded that frontal sinus volume and anterior cranial base cannot be used as parameters to predict vertical malocclusions.

The Correlation Between the Foramen Magnum Dimensions and the Main Craniometric Data of the Skull

The purpose of the study was to study the correlation between the length and width of the foramen magnum and the craniometric data of the skull. Methods. The research material consisted of 200 skulls. There were 20 skulls of adolescence age, I adulthood age 68, II adulthood age 72, and elderly age 40. In total, there were 86 male skulls and 114 female skulls. Foramen magnum length is measured as the mid-sagittal distance from the most anterior point on the foramen magnum to opisthion. Foramen magnum breadth is gauged between the lateral margins of the foramen magnum at the point of greatest lateral curvature. A non-parametric ρ-Spearman's rank correlation was used in the study. Results. A correlation between the foramen magnum length and foramen magnum breadth is identified (r=0.479, P&lt;0.001).The foramen magnum length positively correlates with maximum cranial length, nasio-occipital length, bizygomatic breadth, basion-bregma height, cranial base length, basion-prosthion length, biauricular breadth, upper facial breadth, left and right orbital breadths, left and right orbital height, biorbital breadth, interorbital breadth, frontal chord, biasterionic breadth, bimaxillary breadth, and zygoorbitale breadth. The foramen magnum breadth positively correlates with maximum cranial length, nasio-occipital length, bizygomatic breadth, basion-bregma height, cranial base length, basion-prosthion length, maxilla-alveolar breadth, maxilla-alveolar length, biauricular breadth, upper facial breadth, nasal height, left and right orbital breadths, left and right orbital heights, biorbital breadth, frontal chord, parietal chord, bimaxillary breadth, and zygoorbitale breadth. Conclusion. The fact that the length and breadth of the foramen magnum positively correlate with many basic craniometric indicators allows us to regard the foramen itself, or rather, the structures limiting it, as quite stable.

Role of Growth Hormone Therapy in Craniofacial Development of Children with or without Growth Hormone Deficiency—A Systematic Review

Objective To evaluate effect of growth hormone (GH) therapy in craniofacial development in children with or without growth hormone deficiency. Method The systematic review was conducted by searching the electronic databases—PubMed, Cochrane clinical trials register, Google scholar, and EBSCO host. Randomized controlled trials and observational studies published till January 2022 were included. The risk of bias was assessed by Risk-Of-Bias VISualization (ROBVIS) tool. The risk of bias of the included studies was presented as a “traffic light” plot of individual studies and a summary diagram. Data was studied by two authors and any dispute was resolved by another reviewer. Result A total of 964 articles were obtained through electronic database search. After eliminating the duplicates, 13 articles met inclusion criteria. Of the 13 studies, 8 studies had moderate risk of bias, 2 had serious risk of bias, and 1 had critical risk of bias as per the ROBINS-I assessment. According to the RoB 2, two studies were having high risk of bias. Conclusion The maxillary length, the mandibular length, and the cranial base length increased post-GH therapy, causing an overall increase in the facial height. The limitation of GH therapy was in the transverse direction as maxillary and mandibular arch dimensions remained almost equal to those in the untreated subjects. Dentition had minimal influence of GH therapy. Registration The systematic review was registered in the International Prospective Register of Systematic Reviews database under CRD42021257044.

Novel prediction models for pharyngeal-airway volume based on the cranial-base and midsagittal cross-sectional area of the airway in the pharyngeal region: A cephalometric and magnetic resonance imaging study.

The objective of the study was to elucidate the association between cranial base (Bjork-Jarabak analysis), midsagittal cross-sectional area of the airway in the pharyngeal region (MCSA-PR) data and pharyngeal-airway volume (PAV) and develop a model that could help clinicians predict PAV using two-dimensional (2D) data (Bjork polygon and MCSA-PR). Pre-treatment lateral cephalometric radiographs and magnetic resonance imaging (MRI) scans of 82 women were categorized into three anteroposterior skeletal groups based on ANB angle: Class I (n = 29), 1.5° ≤ ANB≤5.1°; Class II (n = 26), ANB >5.1°; Class III (n = 27), ANB <1.5°. The Bjork polygon, MCSA-PR data from cephalograms and PAV data from MRI scans were examined. Intergroup comparisons were performed using the Kruskal-Wallis test and one-way analysis of variance (ANOVA), with pairwise comparisons conducted using the Bonferroni-corrected Mann-Whitney U-test for the Kruskal-Wallis test and Bonferroni-corrected multiple comparison test for one-way ANOVA. Forward multiple linear regression was used to create model equations for predicting PAV. MCSA-PR and anterior (N-S) and posterior (S-Ar) cranial-base lengths were positively correlated with the PAV. We developed four models; three operated at the group level, and one encompassed the entire sample. Notably, all models could effectively explain the variance in the PAV data. The model for the Class I group was the strongest (adjusted R2 = 0.77). Our findings indicate the remarkable potential of the MCSA-PR, N-S and Bjork sum angles (BSA) as predictors of the PAV and the relevance of 2D cephalometric and cranial-base parameters in predicting the three-dimensional (3D) pharyngeal-airway size.

The Outcomes of Endoscopic Suturectomy in Syndromic Craniosynostosis.

Endoscopic suturectomy is a widely practiced surgical option for infants with craniosynostosis. But the efficacy and safety of the procedure remain unclear in syndromic patients. This study aims to evaluate the efficacy and safety of endoscopic suturectomy for patients with syndromic craniosynostosis. From January 2013 to December 2020, 242 patients underwent endoscopic suturectomy at our institution. The surgical outcome was determined to be favorable or unfavorable based upon the necessity of an additional cranial surgery upon the last follow-up. First, we analyzed the outcomes of 26 syndromic craniosynostosis patients who have followed up for over a year. Second, we compared the outcomes between the syndromic (N=12) and nonsyndromic (N=11) patients with bilateral coronal synostosis who have followed up for over a year. Twenty-three out of 26 syndromic craniosynostosis patients (88%) showed favorable outcomes without significant complications. In the analysis for bilateral coronal synostosis patients, 11 of 12 syndromic patients (92%) presented favorable outcomes, and all nonsyndromic patients showed favorable outcomes. No significant differences were observed in various anthropometric indices (cranial index, intracranial volume, anterior cranial height, anterior cranial base length, and cranial height-length index) and surgical outcomes between syndromic and nonsyndromic groups. Endoscopic suturectomy has the potential to be a surgical option for syndromic craniosynostosis. Even for patients with unfavorable outcomes, endoscopic suturectomy could serve as a bridge treatment for infants to counter cranial deformation before additional extensive surgery.

Effects of thalassaemia major on components of the craniofacial complex- a cephalometric study in Andhra Pradesh population

Introduction: The cephalometric study was conducted to evaluate the craniofacial effects of thalassaemia major on the Andhra Pradesh population. Methods: A total of 32 thalassaemic patients (23 male, 9 female) were selected from the Thalassaemia and Sickle Cell Society and 32 controls (19 male, 13 female) from schools of Hyderabad city to eliminate any bias on the ethnic background. All 64 lateral cephalograms were taken under standard conditions with teeth in occlusion and lips in a relaxed position. Forty - two linear and angular cephalometric parameters defining craniofacial morphology (22 skeletal, 13 dentoalveolarand 7 softtissue) were selected. Results: Everypatient with thalassaemia exhibited a skeletal base relationship of class II, accompanied by an average ANB angle of 4°. There was a significant increase in the length of the anterior cranial base. The length of the maxillary and mandibular base was significantly reduced, and the mandible appeared to be retruded in the face. Pronounced vertical growth was evident from linear and angular measurements. The dental deviations seen in thalassaemic patients were proclination, significant over-eruption of the maxillary anterior teeth and increased overjet. A marked increase in the convexity of the lower face, prominent upper lip, reduced nasolabial angle and increased inter-labial angle were evident from soft tissue measurements. Conclusions: The reduced length of the maxillary and mandibular base could be due to chronic anaemia which causes retardation of growth in thalassaemic patients. An increase in the anterior cranial base length resulted in the posterior positioning of the mandible and an increase in anterior facial height led to a skeletal class II pattern.Keywords: Anaemia; craniofacial growth; cephalometry; thalassaemia major.

Cephalometric Assessment of Condylar Position among Individuals with Different Skeletal Malocclusion Patterns

Introduction: There are variations in growth and orientation of cranial base region where the maxilla and mandible articulate. This leads to differential movement of the maxilla and mandible causing changes in glenoid fossa and condylar position. Therefore, this study was conducted to determine the condylar position in patients with different skeletal sagittal malocclusion patterns. Methods: An analytical cross-sectional study was conducted among 165 individuals, having skeletal Class I, Class II and Class III relationship (55 in each group) selected by convenience sampling method after receiving ethical approval and informed consent. Lateral cephalograms were taken and measurements for determining condylar position were done and compared among three groups. Data were analyzed in SPSS version 16. Kruskal-Wallis H test was used to determine the mean difference in between condylar positions of three skeletal malocclusion patterns and Mann-Whitney U test was done for their pairwise comparison. Results: There was no significant difference in posterior cranial base length (P=0.200) and saddle angle (P=0.517) in three skeletal malocclusion class groups. However, the three malocclusion patterns showed significant differences in gonian angle (P=0.001) and articular angle (P=0.013). Significant moderate negative correlation in saddle angle and articular angle (P&lt;0.001) was observed. Conclusion: The findings of this study concluded that condylar position based on posterior cranial base length was not associated with different skeletal malocclusion patterns. However, articular angle was significantly lower in skeletal class III than in class II.

Association between the occurrence of buccally displaced canine and palatal and craniofacial morphology in adolescents.

The main objective of the present research study is to evaluate the association between the occurrence of buccally displaced canine (BDC) and the palatal as well as the craniofacial morphology in adolescents in accordance at the early permanent dentition. As the experimental group, 100 adolescents of Chinese ethnicity (mean age 13.05 years) with crowding and buccally displaced canine (BDC-c) were selected in comparison with the same number of candidates (mean age 12.59 years) without BDC and crowding as control group. Digital dental casts and cephalograms were collected for three dimensional (3D) and cephalometric measurements. An independent sample T-test was used to compare the cephalometric values between the two groups. Logistic regression as commonly statistical methods used in empirical study including categorical dependent variables was used to identify the joint effects of the dental variables' 3D measurements. When comparing the groups with above analysis, patients with BDC showed a statistically significant narrower and higher palatal vault. For the cephalometric variables, the anterior cranial base length, sagittal position of the maxilla (SNA), sagittal position of the mandible (SNB), and skeletal relationship between maxilla and mandible (ANB) appeared to be smaller, whilst palatal plane angle (SN-PP), Frankfort-mandibular plane angle (FMA), anterior facial height, and lower facial height were larger in BDC-c control group (p < 0.05). A smaller inter-first premolar width was significant in the prediction model (p = 0.002). This study highlights that BDC-c participants in early permanent dentition exhibited a narrower dental arch and higher palatal vault, of which a smaller inter-first premolar width would significantly increase the occurrence of BDC.

Evaluation Of Sphenoid Sinus Volume And Cranial Base Length In Subjects With Different Sagittal Skeletal Malocclusions

Introduction: The most hidden and inaccessible of all the paranasal air sinuses is the sphenoid sinus, a cavity with an irregular shape that is situated in the middle of the cranial base. Since the anterior cranial base shows little growth after the age of 7, it is regarded as a stable reference for cephalometric analysis. Objective: The aim of this study was to predict skeletal malocclusion by correlating the length of the cranial base and the volume of the sphenoid sinus in different sagittal skeletal patterns.Materials and methodology: In this study, a total of 30 cone beam computed tomography (CBCT) scans of patients, aged between 18 and 35 years who underwent orthodontic and orthognathic treatment were evaluated. DICOM files from the CBCT scans were imported and viewed using Dolphin imaging software. Skeletal malocclusion was evaluated using a lateral cephalogram obtained from the CBCT. Volumetric analysis of the sphenoid sinus and length of the cranial base was evaluated with the help of the Dolphin imaging software. A normality test was done to decide the statistical method for data analysis. A one-way ANOVA with Tukey’s post hoc test was done to compare the three groups. Results: There was a correlation noted between the volume of the sphenoid sinus in skeletal class II malocclusion but no correlation was noted in the length of the cranial base. The mean value of the volume of the sphenoid sinus in subjects with class II skeletal malocclusion was 12613.50± 2023.409 which was greater compared to the other skeletal malocclusions.Conclusion: Sphenoid sinus volume was reported to be increased in subjects with skeletal class II malocclusion but there was no correlation between the cranial base length and sphenoid sinus volume in any group.

Cranio-facial bones evaluation based on clinical CT data for sex determination in Northwest Indian population

The skull and pelvis have been the first choice of bones for determination of unknown human remains. The goal of the present study was to derive discriminant function equations by using clinical CT scan data of cranio-facial bones for sex determination in Northwest Indian population. This study was conducted at Department of Radiology, by collecting the retrospective data of CT scan of 217 samples. In the data, 106 were males and 111 were females in the age group between 20 and 80 years. The total number of parameters under investigation were 10. All the selected variables were sexually dimorphic and showed significant values. 91.7% of original grouped cases were correctly classified to their sex category. The TEM, rTEM and R were under the acceptable limits. The univariate, multivariate and stepwise discriminant function analysis recorded an accuracy of 88.9%, 91.7% and 93.6% respectively. Multivariate direct discriminant function analysis stepwise method yielded the highest level of accuracy in differentiating males and females. All the variables reflected statistically significant difference between males and females (p less than 0.001). The best single parameter with highest level of sexual dimorphic trait was length of cranial base. This study aims to provide sex assessment using clinical data of CT scan in Northwest Indian population by incorporating the BIOFB cranio-facial parameter. The morphometric measurements taken on CT scan images can be utilized by forensic experts in identification process.

Enlarged occipital spur and craniofacial morphology: a cephalometric analysis.

This cross-sectional study aimed to investigate the association between the occipital spur length and craniofacial morphology in individuals with occipital spur (OS). The study included cephalometric images from 451 individuals (196 females, 255 males, age range was 9-84years). The spur length and craniofacial characteristics were evaluated using cephalograms. Based on spur length, subjects were divided into two groups: the OS group (N = 209) and the enlarged occipital spur (EOS) group (N = 242). Descriptive statistics, Independent T-test, Mann-Whitney U test, chi-square test, Kruskal-Wallis test, and age- and sex-based stratified analyses were performed. The level of significance was set at p < 0.05. Males had significantly larger spur length than females. Spur length was shorter in individuals under 18 than the groups over 18. After adjusting for gender and age, ramus height, mandibular body length, effective length of maxilla, effective length of mandible, anterior cranial base length, posterior cranial base length, anterior facial height, posterior facial height, facial height index, and lower anterior facial height had statistically significant differences between OS group and EOS group. Males exhibit greater spur length than females. Patients under 18 had a shorter spur length than adults. Linear craniofacial measurements were found to be greater in subjects with EOS than the individuals with OS. The craniofacial growth and development of an individual might be associated with EOS. The causal relationship between EOS and craniofacial development requires further longitudinal studies.

Comparative Evaluation of Cranial Base Length and Flexure on Facial Parameters in Hypodivergent, Normodivergent and Hyperdivergent Patients: A Retrospective Cephalometric Study.

The aim of the study was to assess the influence of cranial base length (CBL) and Flexure on facial parameters in Hypodivergent, Normodivergent, and Hyperdivergent patients. Around 60 standardized cephalograms were divided into Hypodivergent, Normodivergent, and Hyperdivergent groups (20 each) based on the FMA angle. The CBL, cranial flexure (CF), and various facial parameters were measured for each case. The results were analyzed for the correlation between Cranial and facial parameters in each of the three study groups. Comparison and Pairwise Comparison of variables between study groups were done using ANOVA and Tukey's post hoc Test. Cranial base length, mandibular body length, LAFH, N-Me-Go angle (p-value <0.001), and Jarabak's ratio were found to be significantly different between the groups. Pearson's Correlation showed that most of the facial parameters had a significant correlation with CBL in Hypodivergent groups. The CBL is more closely related to facial parameters in vertical dysplasia individuals than CF. The CBL is positively correlated to facial variables, especially in Hypodivergent individuals. The N-Me-Go Angle introduced in the study was significantly different in all three vertical facial types studied; hence, it cannot be used as a valuable diagnostic tool. Changes in the length and flexure of the cranial base influence the anteroposterior position of jaw bases. The influence of the cranial base on the development of vertical dysplasias is not studied much, hence the present study aims at resolving this lacuna in literature.

Commensal Microbiota Effects on Craniofacial Skeletal Growth and Morphology.

Microbes colonize anatomical sites in health to form commensal microbial communities (e.g., commensal gut microbiota, commensal skin microbiota, commensal oral microbiota). Commensal microbiota has indirect effects on host growth and maturation through interactions with the host immune system. The commensal microbiota was recently introduced as a novel regulator of skeletal growth and morphology at noncraniofacial sites. Further, we and others have shown that commensal gut microbes, such as segmented filamentous bacteria (SFB), contribute to noncraniofacial skeletal growth and maturation. However, commensal microbiota effects on craniofacial skeletal growth and morphology are unclear. To determine the commensal microbiota's role in craniofacial skeletal growth and morphology, we performed craniometric and bone mineral density analyses on skulls from 9-week-old female C57BL/6T germ-free (GF) mice (no microbes), excluded-flora (EF) specific-pathogen-free mice (commensal microbiota), and murine-pathogen-free (MPF) specific-pathogen-free mice (commensal microbiota with SFB). Investigations comparing EF and GF mice revealed that commensal microbiota impacted the size and shape of the craniofacial skeleton. EF versus GF mice exhibited an elongated gross skull length. Cranial bone length analyses normalized to skull length showed that EF versus GF mice had enhanced frontal bone length and reduced cranial base length. The shortened cranial base in EF mice was attributed to decreased presphenoid, basisphenoid, and basioccipital bone lengths. Investigations comparing MPF mice and EF mice demonstrated that commensal gut microbes played a role in craniofacial skeletal morphology. Cranial bone length analyses normalized to skull length showed that MPF versus EF mice had reduced frontal bone length and increased cranial base length. The elongated cranial base in MPF mice was due to enhanced presphenoid bone length. This work, which introduces the commensal microbiota as a contributor to craniofacial skeletal growth, underscores that noninvasive interventions in the gut microbiome could potentially be employed to modify craniofacial skeletal morphology. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

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.

Craniofacial Morphology of Temporomandibular Disorder Patients with Different Disc Positions: Stratifying Features Based on Sex and Sagittal Skeletal Pattern.

Disc displacement (DD) appears in the majority of temporomandibular disorder (TMD) patients. The correlation between craniofacial morphology and different disc positions has been underlined, while the craniofacial morphological differences based on sex and sagittal skeletal pattern stratification have been insufficiently studied. In this study, 304 patients with TMD complaints were included and classified into normal position, disc displacement with reduction (DDwR) and disc displacement without reduction (DDwoR) groups according to magnetic resonance imaging. A total of 24 cephalometric measurements, covering the cranial base, vertical relationship, sagittal relationship, mandible position and morphology, and dental relationship, were assessed using lateral cephalograms. A stratified analysis was performed based on the sex and sagittal skeletal pattern. Overall, DD patients had distinctive craniofacial morphological features. The posterior cranial base length and mandibular arc angle were statistically different only in females, while the Y-axis angle, occlusal plane angle and sella nasion point A angle (SNA) might be unique features in males. Skeletal class II had the most statistically different measurements compared to the others. Differences in the Frankfort mandibular incisor angle (FMIA) and saddle angle were especially displayed in skeletal class III patients. The sex and skeletal sagittal pattern could affect the morphological differences in TMD patients with different disc positions.