Craniofacial Measurements Research Articles

Assessment of the Relationship between Craniofacial Measurements and Maxillary Central Incisor Width using Cone Beam Computed Tomography

ABSTRACT Aim: This study aimed to explore the relationships between bizygomatic width, inter-orbital distance, and the central incisor width (CIW). Materials and Methods: A total of 80 cone beam computed tomography (CBCT) scans were analyzed. The measurements taken included bizygomatic width and inter-orbital distance. A bivariate correlation was performed to evaluate the relationships between CIW and craniofacial measurements. Independent samples t-tests were used to compare these measurements between genders. Results: Mean values for CIW and bizygomatic width were significantly higher in males than females (P < 0.05). The bivariate analysis revealed significant, positive, moderate correlations between CIW and bizygomatic width (r = 0.401, P < 0.01), but not inter-orbital distance (P > 0.05). Conclusion: This study found that while bizygomatic width is moderately correlated with CIW, inter-orbital distance is not. Additionally, significant gender differences exist regarding bizygomatic width and CIW, with males exhibiting larger dimensions.

Comparison of Craniofacial Anthropometric Measurement Accuracy of Manual Technique vs. Cone-Beam CT Scanning.

This study aimed to compare the accuracy of linear measurements obtained using the classical (manual) method versus cone-beam computed tomography (CBCT) in craniofacial anthropometry, specifically targeting the infraorbital foramen (IOF). This study involved two sample groups: one of 40 dry skulls measured manually using digital calipers, and the other of 40 CBCT 3D images digitally measured. Measurements included IOF height, distances between the IOF and nasion (N), IOF and frontomalar orbital (FMO), and between the two IOFs. Statistical analysis was performed using an ANOVA, t-test, and Fisher's test with a significance level of 0.05. The manual method recorded a mean IOF height of 2.1 mm, while CBCT showed a mean of 3.52 mm. Significant differences were recorded between the two methods when measuring IOF height, with a p < 0.001. However, CBCT measurements generally yielded higher accuracy and lower variance due to the absence of significant differences (p > 0.05). The distance between the two IOFs measured by both methods differed significantly (p = 0.03157), with CBCT measurements showing higher values. In conclusion, although no significant differences were found in the overall accuracy of the two methods, CBCT proved to be a more reliable tool for detailed craniofacial measurements due to its higher accuracy and reproducibility. CBCT demonstrated superior consistency in measurements, offering enhanced precision in assessing craniofacial structures. These findings support the growing preference for CBCT in maxillofacial surgery, where precision is critical for successful outcomes. Nonetheless, manual techniques remain valuable in settings where advanced imaging is not accessible.

Reliability assessment of craniofacial and airway measurements: a comparative study between multidetector computed tomography and cone-beam computed tomography.

To compare the intra- and inter-examiner reliability of multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) using Amira and Dolphin software analyses for craniofacial/airway measurements by six examiners. Five adults and one dry skull with CBCT and MDCT scan files were duplicated and randomly numbered. Six orthodontic residents imported these files into two software programs, oriented the images, set thresholds, and performed 26 measurements. Intra- and inter-examiner reliabilities were determined by using intraclass correlation coefficient (ICC) and presented with scatterplots. Variables including anterior nasal width, posterior nasal width, frontomaxillary suture right-to-left, inner nasal contour point right-to-left, and minimum cross-sectional area in the oropharynx showed "moderate" to "substantial" intra- or inter-examiner agreement. Amira provided relatively reliable airway assessment, while Dolphin showed standard deviations 10 to 30 times larger for volumetric airway measurements. MDCT scans significantly reduced airway volume/area measurements compared to CBCT, except for intraoral airway volume. Unreliable skeletal measurements and low reliability of Dolphin for airway analysis discourage using CT to quantitatively correlate changes in craniofacial structures with airway dimensions.

Craniofacial Measurements and Indices Trends in Latvian Children Aged 1-15.

This study aimed to assess the trends in craniofacial measurements and indices in Latvian children aged 1-15. The anthropometrical measurements (head circumference, length, width, facial length, and width) were conducted on 375 children according to the guidelines by R. Martin, K. Saller, and J. Prīmanis at the Anthropology laboratory at the Institute of Anatomy and Anthropology, Rīga Stradiņš University. The cephalic index (CI) and the facial or prosopic index (PI) were calculated, allowing for a detailed examination of cranial and facial proportions. The data were analyzed using descriptive and inferential statistics, including the Pearson Chi-square test and the Spearman correlation coefficient. The findings revealed a consistent increase in head circumference with age, with boys generally having slightly larger heads than girls. The boys and girls exhibited growth in head length and width, particularly noticeable between 1 and 2 years of age. Facial length and width increased with age, with boys typically having longer facial lengths and broader faces than girls. The most common cephalic index category is mesocephaly, which accounts for 52.85% of the population, followed by dolichocephaly at 32.94%. Brachycephaly and hyperbrachycephaly are less prevalent, representing 11.36% and 2.86% of the population. Regarding the facial index categories, hypereuryprosopic is the most prevalent, representing 45.54% of the population, closely followed by euryprosopic at 43.74%. Mesoprosopic is significantly less common, representing only 9.95%. The least common categories are leptoprosopic and hyperleptoprosopic, with prevalences of 0.64% and 0.12%, respectively. The indices analysis showed variations across age groups, with dolichocephaly being more common at younger ages and decreasing over time. Brachycephaly and hyperbrachycephaly remained relatively stable or decreased slightly with age, while mesocephaly displayed less variation. The relationship between the FI and CI in younger age groups was typically weak to moderate and inverse, with a significance level of p < 0.001 or p < 0.01. However, no meaningful correlation was observed in older children aged 14-15. This study provides valuable insights into the craniofacial development of Latvian children, highlighting the measurements, cranial and facial types, and their variations across age groups.

Two-step cluster analysis based on three-dimensional CT measurements of craniofacial structures in severe craniofacial microsomia

BackgroundThe Pruzansky-Kaban and OMENS classifications do not provide additional details on temporomandibular joint deformities. The aim of this study was to classify and quantitatively delineate severe forms of craniofacial microsomia based on three-dimensional maxillofacial measurements, focusing on deformities in the zygomatic, temporal, and mandibular bones. MethodsMaxillofacial computed tomography(CT) scans of children with severe types of CFM from 2010 to 2020 were collected. Three-dimensional measurements of zygomatic arch length, height of mandibular ramus, height of maxilla, and occlusal cant were performed. Two-step cluster analysis was conducted based on zygomatic arch continuity, occlusal cant, the ratio of affected side to unaffected side(A/U ratio) for zygomatic arch length, mandibular ramus height, and maxillary height. ResultsFifty patients (32 male, 18 female) were included in the study. They were classified into 2 clusters through cluster analysis. Cluster 1 comprised subjects (44% of patients) with continuous zygomatic arches. Cluster 2 comprised subjects (39%) with discontinuous zygomatic arches. The zygomatic arch A/U ratio in Cluster 1 was greater than that in Cluster 2, with statistical significance observed. Additionally, the maxilla height A/U ratio in Cluster 1 was lower than in Cluster 2, also with statistical significance. There was no statistically significant difference observed in the ramus height A/U ratio and occlusal cant between Cluster 1 and Cluster 2. ConclusionsBased on craniofacial measurements, severe CFM can be categorized into two types: continuous zygomatic arch and discontinuous zygomatic arch. This cluster analysis complemented the OMENS classification and could assist in the selection and design of prosthetic joints for patients with CFM.

Association between maxillary incisor width and craniofacial measurements: A cone beam computed tomography study

Accurate prediction of maxillary central incisor width (CIW) is essential in prosthodontics for selecting appropriately sized denture teeth. While traditional methods exist, the digital era may offer more reliable techniques for anterior tooth selection. The purpose of this study was to investigate the correlation between CIW and craniofacial measurements derived from cone beam computed tomography (CBCT) scans to identify predictors for CIW and examine possible sexual dimorphism. A retrospective analysis was conducted on 80 three-dimensional skull models (40 men, 40 women; age range: 20 to 48 years) generated from segmented CBCT scans. Measurements included CIW, interpterygoid hamulus distance, bi-orbital width, interorbital distance, and piriform aperture width. Statistical analyses comprised independent t tests, bivariate correlations, and multiple linear regression (α=.05). Significant sexual dimorphism was observed in CIW, interpterygoid hamulus distance, and bi-orbital width (P<.05). CIW positively correlated with bi-orbital width (r=.75, P<.001) and piriform aperture width (r=.49, P<.001). Multiple regression analysis revealed bi-orbital width, and interorbital distance, along with sex, as significant predictors of CIW (R²=.59, P<.001). Bony bi-orbital width, interorbital distance, and sex can be used to estimate the maxillary CIW.

Comparison of craniofacial anthropometric measurements with the golden ratio in young adults

Comparison of craniofacial anthropometric measurements with the golden ratio in young adults

Differences in linear and angular measurement of the lower facial third in lateral cephalometry and lateral photometry: A comparative study

BackgroundIn clinical orthodontic practice, to evaluate aesthetics in dentistry, lateral cephalometry and lateral photometry are used to measure and assess craniofacial morphology. In contrast to cephalometry, photometry has no radiation hazard and is less expensive. There has been a paradigm shift in contemporary orthodontics that now emphasizes soft tissue aesthetics, rather than depending entirely on hard tissue evaluation from lateral cephalometry. Therefore, the key question is whether lateral photometry can be a substitute for conventional cephalometry for diagnostics, prognostic analysis, and treatment planning. ObjectiveTo differentiate between lateral cephalometry and lateral photometry measurement in children with stage 2 and 3 vertebrae maturation in the Deutero Malay population. Materials and MethodsA standardized protocol was followed for all lateral cephalograms and photographs from 38 subjects who met the inclusion criteria. Three parameters focusing on the lower third craniofacial measurement were investigated: two linear parameters (mandibular ramus length and mandibular length) and one angular parameter (gonial angle). These parameters were measured using Webceph software. All parameters were digitized on both cephalograms and photographs and were compared using an independent sample t-test. ResultsWhen comparing the angular cephalometric and photometric variables, we found that the mandible length (Go-Me) and gonial angle (∠Go) in the cephalometry measurements had an insignificant difference compared to the photometric measurements, while the ramus length (Co-Go) in the cephalometry measurement had a significant difference compared to the photometric measurements. ConclusionAlthough we cannot rule out cephalometry as the primary record in orthodontics, lateral photometry assessment can be used as an alternative candidate for measuring mandibular body measurements and gonial angle in stage 2 and 3 cervical maturation in the Deutero Malay race.

Evaluation of a Structured Light Scanner for 3D Facial Imaging: A Comparative Study with Direct Anthropometry.

This study evaluates the accuracy and repeatability of craniofacial measurements with a 3D light scanner, specifically the EINSTAR scanner, in comparison to traditional caliper measurements for facial anthropometry. Eleven volunteers were assessed by two examiners, one experienced and one inexperienced, who performed direct caliper measurements and indirect measurements using the scanner. Results indicated minimal differences between caliper and scanner results, with overall high accuracy and reliability demonstrated by correlation coefficients. Despite the slightly longer scanning time, the benefits of 3D imaging, including detailed surface mapping and virtual modeling, justify its integration into clinical practice, particularly in maxillofacial surgery and craniofacial assessment. Craniofacial measurements obtained with the EINSTAR scanner showed excellent reliability and accuracy, which qualifies this method for clinical and scientific use.

Automated Craniofacial Biometry with 3D T2w Fetal MRI.

Evaluating craniofacial phenotype-genotype correlations prenatally is increasingly important; however, it is subjective and challenging with 3D ultrasound. We developed an automated landmark propagation pipeline using 3D motion-corrected, slice-to-volume reconstructed (SVR) fetal MRI for craniofacial measurements. A literature review and expert consensus identified 31 craniofacial biometrics for fetal MRI. An MRI atlas with defined anatomical landmarks served as a template for subject registration, auto-labelling, and biometric calculation. We assessed 108 healthy controls and 24 fetuses with Down syndrome (T21) in the third trimester (29-36 weeks gestational age, GA) to identify meaningful biometrics in T21. Reliability and reproducibility were evaluated in 10 random datasets by four observers. Automated labels were produced for all 132 subjects with a 0.03% placement error rate. Seven measurements, including anterior base of skull length and maxillary length, showed significant differences with large effect sizes between T21 and control groups (ANOVA, p<0.001). Manual measurements took 25-35 minutes per case, while automated extraction took approximately 5 minutes. Bland-Altman plots showed agreement within manual observer ranges except for mandibular width, which had higher variability. Extended GA growth charts (19-39 weeks), based on 280 control fetuses, were produced for future research. This is the first automated atlas-based protocol using 3D SVR MRI for fetal craniofacial biometrics, accurately revealing morphological craniofacial differences in a T21 cohort. Future work should focus on improving measurement reliability, larger clinical cohorts, and technical advancements, to enhance prenatal care and phenotypic characterisation.

Two-dimensional facial photography for assessment of craniofacial morphology in sleep breathing disorders: a systematic review.

Craniofacial morphology is integral to Sleep Breathing Disorders (SBD), particularly Obstructive Sleep Apnea (OSA), informing treatment strategies. This review assesses the utility of two-dimensional (2D) photogrammetry in evaluating these metrics among OSA patients. Following PRISMA guidelines, a systematic review was conducted. PubMed, Embase, and Lilacs databases were systematically searched for studies utilizing 2D photography in SBD. Findings were narratively synthesized. Thirteen studies involving 2,328 patients were included. Significant correlations were found between craniofacial measurements-specifically neck parameters and facial width-and OSA severity, even after BMI adjustment. Ethnic disparities in craniofacial morphology were observed, with photogrammetry effective in predicting OSA in Caucasians and Asians, though data for other ethnicities were limited. Pediatric studies suggest the potential of craniofacial measurements as predictors of childhood OSA, with certain caveats. 2D photogrammetry emerges as a practical and non-invasive tool correlating with OSA severity across diverse populations. However, further validation in various ethnic cohorts is essential to enhance the generalizability of these findings.

Anthropometric Study of Correlation between the Selected Craniofacial Measurements with the Stature in Adult Bangladeshi Manipuri Males

Cephalofacial anthropometry can be useful for racial identification, forensic scientist, physical anthropologist, genetic counsellors as well as reconstructive surgery for the purposes of identification of an individuals and understanding human physical variation, gender and ethnicity especially with facial recognition as a tool in recent advances in biometrics. Stature is one of the important criteria for personal identification which has a proportional biological relationship with every parts of the human body like head, face, trunk, extremities and vertebral column. In this study, our main goal is find out the correlation between the selected craniofacial measurements with the stature in Adult Bangladeshi Manipuri males. This cross-sectional study was carried out in 100 healthy adult males from March 2017 to February 2018 in the Department of Anatomy, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. Descriptive statistics and testing of hypotheses were used for the analysis using SPSS software (version 22.0). Here non- significant positive correlations of the stature with the mandible height and significant positive correlations of the stature with mandible breadth was found. The Mean (±SD) of Mandible height (sto-gn) was 4.44 (±0.69), Mandible breadth (go-go) was 11.45 (±0.57). This study will be anticipated to provide baseline quantitative data on the linear craniofacial measurements and the stature of adult Bangladeshi Manipuri males. And using larger samples with non-contact measurement technique will help in defining craniofacial anthropometric profiling of the adult Bangladeshi Manipuri males. Mugda Med Coll J. 2024; 7(1): 19-25

Classification of Malaysian individuals using Fordisc 3 based on four craniofacial measurements

ABSTRACT Fordisc is a discriminant function computer program used to study ancestry, although it lacks representation from a Malaysian sample. Our aim was to evaluate ancestry estimates of Fordisc 3 with Malaysian crania of known sex and ethnicity. A dataset from Hisham and Ibrahim of 300 individuals was included in this study. They had undergone full-body computed tomographic scanning prior to post-mortem examination with scan resolutions of 1.0 mm. Maximum cranial length, maximum cranial breadth, nasal height, nasal breadth, and midorbital width were obtained from these images. Measurements were fed into the Fordisc 3 program and were analysed using the Forensic Anthropology Data Bank (FDB) and Howells’ reference populations according to sex, however midorbital width was excluded in all analyses. Ancestry assessment was evaluated on the basis of percentage of correctly classified individuals. Based on Howells database, 50.67% of the sample are correctly classified into Asian, in contrast to only 32.33% according to FDB. These classification trends are limited by the number of measurements, reference populations available in Fordisc and population history of the sample itself. We need to collect standard anthropological measurements in future research and potentially contribute to the database in Fordisc to improve its performance.

Craniofacial anthropometric measurements of the cohort of Egyptian male school children and their utility in detection of abnormalities

BackgroundAnthropology is a scientific discipline which applies scientific methods to identify and quantitate inter-individual variations in body structure and function. Anthropometry assesses craniofacial dysmorphology in genetic disorders and helps to detect phenotypic differences in diseases with common underlying cause. This study is part of a comprehensive cross-sectional study of craniofacial and oral findings in Egyptian school children. This paper focused on establishing the norms of Egyptian male school children and its utility in determining the differences in facial measurements of a child with Prader–Willi syndrome (PWS). Thirty craniofacial measurements were taken from 55 healthy Egyptian school children aged 12–14 years with mean age 13±0.64\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$13\\pm 0.64$$\\end{document} and a PWS child aged 13.6 years. The PWS measurements were compared with healthy children of the same age using computed Z-score.ResultsMorphological face height of the PWS child was within the normal range. However, upper face height and nose height were significantly lower with Z-scores of -\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-$$\\end{document} 3.18 and -\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$-$$\\end{document} 2.7, respectively; right and left mandibular body length and upper lip height were significantly higher than the mean of healthy children with corresponding Z-scores of 2.95, 2.48, and 2.33.ConclusionsBy establishing the norms of Egyptian male school children and utilizing these data, we can identify the difference in facial measurements among children with abnormalities like PWS. This information can be used during periodic checkups as a simple, non-invasive, and economical method for the detection of these abnormalities.

Three-dimensional Measurement of the Zygomatic-maxillary Complex in the Class III Malocclusion Patients with Maxillary Retrusion.

This study investigated the anatomic features of the zygomatic-maxillary complex in patients with maxillary retrusion without clefts. Individuals were grouped, and craniofacial measurements were performed for 21 individuals with skeletal Class III malocclusion with maxillary retrusion (CIII) and 48 individuals from the control group (CG). We evaluated the predetermined hard-tissue and soft-tissue points of the facial profile in each group. Independent sample t -tests were performed to determine the differences between groups (significance set at P <0.05). Multiple points on the midface, including the most posterior point on the contour of the maxillary alveolar process, lowest point of the zygomaticomaxillary suture, furthest point to the zygomatic self-base plane, superior point in the infraorbital foramen, and lowest point of the inferior margin of the orbit to the coronal plane were smaller in CIII than in CG (all P <0.05). The soft tissue thickness in these regions was significantly increased compared with that in the normal group. In summary, for class III malocclusion patients with maxillary retrusion, the deficiency in the midface gradually decreased going upward, with the deficiency at the maxillary alveolar level being the most serious. To some extent, soft tissues compensate for the deficiencies in the facial skeleton, and standard Le Fort I osteotomy advancement was sufficient to achieve a harmonious appearance.

Parentally Exposed Zebrafish Larvae Have Altered Craniofacial Measurements: Multigeneration Developmental Atrazine Toxicity

Parentally Exposed Zebrafish Larvae Have Altered Craniofacial Measurements: Multigeneration Developmental Atrazine Toxicity

ANALYSIS OF THE RELATIONSHIP BETWEEN THE GOLDEN RATIO AND THE FACIAL PARAMETER THROUGH CBCT IN SEVENTH CYCLE STUDENTS OF THE FACULTY OF DENTISTRY OF THE UNIVERSITY OF CUENCA, PERIOD SEPTEMBER 2023 - FEBRUARY 2024.

The clinical skill necessary to modify dentofacial structure through orthodontic procedures, maxillofacial surgery or plastic surgery involves having a deep understanding of facial harmony. This encompasses the evaluation of facial aesthetics, proportions and symmetry to achieve optimal results.To analyze the relationship between the elements of the golden ratio with the facial parameter using CBCT and lateral cephalic of the seventh cycle “A” students of the Faculty of Dentistry of the University of Cuenca. The group of participants in the study was made up of students of the seventh cycle Orthodontics course at the University of Cuenca, which includes 34 people between the ages of 20 and 30 years, belonging to both sexes, with and without orthodontic treatment. with class I malocclusion complete dentition. The facial type of each patient was analyzed in relation to the presence or absence of the divine proportion (1.618) between head height and width. bizygomatic. Additionally, a data collection matrix was developed to evaluate craniofacial anthropometric measurements. It was observed that 0% are brachyfacial, 0% are mesofacial and 100% are dolichofacial. Furthermore, the vertical relationship and harmonic profile component of the golden ratio was present in a higher percentage (66.66%) in dolichofacial individuals when compared to the other facial types.The morphological facial type that had the most predominance in our study was the dolichofacial with absence of brachyfacials and mesofacials, in the students there was more golden ratio in the vertical relationship and harmonic profile regardless of the sex of the students.

Study of Cephalic Index and its correlation with Sex and Race in Central India

The technique of expressing quantitatively the form of the human body, living or dead and also skeleton is anthropometry. In the world, all human beings belong to the same species, Homo sapiens. Any two individuals are not the same in all their measurable traits, even there are differences in the genetically identical twins in some respects. For estimating sex and race, cephalofacial measurements and indices are useful like the cephalic index or cranial index. 3-4 racial groups are organized by anthropologists based on skull categorization methods. India falls in this craniofacial measurements group's as considered by Thomas Huxley. Asian skulls are brachycephalic with wide faces having flat supranasal regions and facial flatness. Craniofacial type of Australoids fall between Negroids and Caucasoids. The study was conducted on 196 medical students (92 males and 104 females). Hardlika's method was used to measure the cephalic index. The mean cephalic index was 79.71 ± 4.55 in males and in females it was 83.14 ± 7.69. Irrespective of gender the mean cephalic index of overall study was found to be 81.53 ± 6.62. Based on cephalic index, 45.65% males were dolicocephalic, 31.52% mesocephalic, 15.22% brachycephalic and 7.61% hyperbrachycephalic. In females, 46.15% were dolicocephalic, 33.65% mesocephalic, 10.58% brachycephalic and 9.62% hyperbrachycephalic.

Can intraoral and facial photos predict obstructive sleep apnea in the general and clinical population?

This study aimed to evaluate and compare measurements of standardized craniofacial and intraoral photographs between clinical and general population samples, between groups of individuals with an apnea-hypopnea index (AHI) ≥ 15 and AHI < 15, and their interaction, as well as the relationship with the presence and severity of obstructive sleep apnea (OSA). We used data from 929 participants from Sleep Apnea Global Interdisciplinary Consortium, in which 309 patients from a clinical setting and 620 volunteers from a general population. AHI ≥ 15 were observed in 30.3% of the total sample and there were some interactions between facial/intraoral measures with OSA and both samples. Mandibular volume (p < 0.01) and lateral face height (p = 0.04) were higher in the AHI ≥ 15 group in the clinical sample compared to the AHI ≥ 15 group in the general population and AHI < 15 group in the clinical sample. When adjusted for sex and age, greater mandible width (p < 0.01) differed both in the clinical and in the general population samples, reflecting AHI severity and the likelihood of OSA. The measure of smaller tongue curvature (p < 0.01) reflected the severity and probability of OSA in the clinical sample and the higher posterior mandibular height (p = 0.04) showed a relationship with higher AHI and higher risk of OSA in the general population. When adjusted for sex, age, and body mass index, only smaller tongue curvature (p < 0.01) was associated with moderate/severe OSA. Measures of greater tongue and mandible were associated with increased OSA risk in the clinical sample and craniofacial measurement was associated in the general population sample.

Effects of 4-hexylresorcinol on facial skeletal development in growing rats: Considerations for diabetes.

: To investigate the long-term effects of 4-hexylresorcinol (4HR) on facial skeletal growth in growing male rats, with a focus on diabetic animal models. : Forty male rats were used. Of them, type 1 diabetes mellitus was induced in 20 animals by administering 40 mg/kg streptozotocin (STZ), and they were assigned to either the STZ or 4HR-injected group (STZ/4HR group). The remaining 20 healthy rats were divided into control and 4HR groups. We administered 4HR subcutaneously at a weekly dose of 10 mg/kg until the rats were euthanized. At 16 weeks of age, whole blood was collected, and micro-computed tomography of the skull and femur was performed. : All craniofacial linear measurements were smaller in the STZ group than in the control group. The mandibular molar width was significantly smaller in the 4HR group than in the control group (P = 0.031) but larger in the STZ/4HR group than in the STZ group (P = 0.011). Among the diabetic animals, the STZ/4HR group exhibited significantly greater cortical bone thickness, bone mineral density, and bone volume than the STZ group. Serum testosterone levels were also significantly higher in the STZ/4HR group than in the STZ group. : 4HR administration may have divergent effects on mandibular growth and bone mass in healthy and diabetic rats. In the context of diabetes, 4HR appears to have beneficial effects, potentially through the modulation of mitochondrial respiration.