Premature gray hair development in the interbrow region owing to the loss of maxillary first molars in young mice.

The exact sites of premature hair graying and whether tooth loss causes this condition remain unknown. In this study, we aimed to explore the effect of reduced mastication on premature hair graying. Maxillary first molars were extracted from young mice, and the mice were observed for 3 months, along with non-extraction control group mice. After 3 months, gray hair emerged in the interbrow region of mice in the tooth extraction group but not in the control group. The expression of tyrosinase-related protein-2 (TRP-2) mRNA was lower in the interbrow tissues of young mice without maxillary molars than in those with maxillary molars. Tooth loss leads to interbrow gray hair growth, possibly because of weakened trigeminal nerve input, suggesting that reduced mastication causes premature graying. Thus, prompt prosthetic treatment after molar loss is highly recommended.

Feasibility of spheno-occipital synchondrosis fusion stages as an indicator for the assessment of maxillomandibular growth: A mixed longitudinal study.

OBJECTIVES: This study aimed to assess the relative growth rates (RGRs) of the maxilla and mandible at varying fusion stages of the spheno-occipital synchondrosis (SOS), thereby elucidating the potential of SOS stages in predicting maxillomandibular growth. MATERIALS AND METHODS: A total of 320 subjects (171 boys and 149 girls), aged 6 to 18 years, were retrospectively included. Each subject had a minimum of two longitudinal cone-beam computed tomography (CBCT) images, with no more than one interval of SOS fusion stage change between the two scans. Subjects were categorized based on their SOS fusion stages and genders. The RGRs of the maxilla and mandible at various SOS fusion stages were measured and compared using longitudinal CBCT images. RESULTS: Significant statistical differences were observed in maxillomandibular RGRs across various SOS fusion stages. In girls, the sagittal growth of the maxilla remained stable and active until SOS 3, subsequently exhibited deceleration in SOS 4-5 (compared to SOS 3-4, P < .05) and continued to decrease in SOS 5-6. Whereas in boys, the sagittal growth of the maxilla remained stable until SOS 4, and a deceleration trend emerged starting from SOS 5 to 6 (P < .01 compared to SOS 4-5). Mandibular growth patterns in both genders exhibited a progression of increasing-accelerating-decelerating rates from SOS 2 to 6. The highest RGRs for total mandibular length were observed in SOS 3-4 and SOS 4-5. CONCLUSION: Spheno-occipital synchondrosis fusion stages can serve as a valid indicator of maxillomandibular growth maturation.

Correlação entre os estágios de maturação da sutura palatina mediana e das vértebras cervicais / Correlation between the maturation stages of the median palatal suture and cervical vertebrae

Introdução: Atualmente, a avaliação da maturação da sutura palatina mediana (MSPM) em pacientes que precisam ser submetidos à expansão rápida da maxila é realizada por meio de tomografias computadorizadas de feixe cônico (TCFC). No entanto, doses adicionais de radiação são induzidas ao paciente para a aquisição desse exame. Objetivo: Correlacionar os estágios de MSPM com os estágios de maturação das vértebras cervicais (MVC). Material e métodos: Um total de 268 TCFC da região da cabeça e do pescoço de indivíduos de ambos os sexos e com idades variando entre 5 e 76 anos foram analisadas de forma cega por uma única examinadora. O estágio de MSPM foi avaliado por meio da observação da maxila no corte axial e foi classificado como A, B, C, D ou E. Por outro lado, o estágio de MVC foi avaliado por meio do corte sagital das vértebras cervicais e foi classificado como CS1, CS2, CS3, CS4, CS5 ou CS6. A concordância intraexaminador foi avaliada por meio do Coeficiente Kappa. O teste de Correlação de Spearman foi utilizado para avaliar a correlação entre os estágios de MSPM e os estágios de MVC. Resultados: Uma correlação positiva forte foi encontrada entre os estágios de MSPM e MVC. Os estágios A e B mostraram correlação com os estágios CS1, CS2 e CS3. Diferentemente, o estágio C se correlacionou com maior frequência com os estágios CS4 e CS5. Por fim, os estágios D e E, se mostraram mais frequentes em indivíduos nos estágios CS5 e CS6 de forma similar. Conclusão: A predição da MSPM por meio da MVC em telerradiografias laterais pode ser uma alternativa viável à avaliação sutural na TCFC em pacientes nos estágios CS1, CS2 e CS3. A partir do estágio CS4, uma TCFC é recomendável para avaliar com maior segurança o estágio de MSPM e definir a melhor modalidade de expansão (AU).

Introduction: Currently, the assessment of maturation of the midpalatal suture (MPSM) in patients who need to undergo rapid maxillary expansion is performed using cone-beam computed tomography (CBCT). However, additional doses of radiation are induced to the patient for the acquisition of this exam. Objective: To correlate the stages of MPSM with the stages of maturation of the cervical vertebrae (CVM). Material and methods: A total of 268 CBCT of the head and neck of individuals of both sexes and aged between 5 and 76 years were analyzed blindly by a single examiner. The MPSM stage was assessed by observing the maxilla in the axial view and was classified as A, B, C, D or E. On the other hand, the CVM stage was assessed in the sagittal view of the cervical vertebrae and was classified as CS1, CS2, CS3, CS4, CS5 or CS6. Intraexaminer agreement was analyzed using the Kappa coefficient. Spearman's Correlation test was used to assess the correlation between MPSM and CVM stages Results: A strong positive correlation was found between MPSM and CVM stages. Stages A and B showed correlation with stages CS1, CS2 and CS3. Differently, stage C correlated more frequently with stages CS4 and CS5. Finally, stages D and E were more frequent in individuals in stages CS5 and CS6, similarly. Conclusion: The prediction of MPSM by assessing CVM in lateral cephalograms seems to be a viable alternative to the sutural evaluation in CBCT in patients in stages CS1, CS2 and CS3. From the CS4 stage onwards, a CBCT is recommended to assess the MPSM stage and define the most adequate expansion modality for patients (AU).

Klotho in Osx+-mesenchymal progenitors exerts pro-osteogenic and anti-inflammatory effects during mandibular alveolar bone formation and repair.

Maxillofacial bone defects are commonly seen in clinical practice. A clearer understanding of the regulatory network directing maxillofacial bone formation will promote the development of novel therapeutic approaches for bone regeneration. The fibroblast growth factor (FGF) signalling pathway is critical for the development of maxillofacial bone. Klotho, a type I transmembrane protein, is an important components of FGF receptor complexes. Recent studies have reported the presence of Klotho expression in bone. However, the role of Klotho in cranioskeletal development and repair remains unknown. Here, we use a genetic strategy to report that deletion of Klotho in Osx-positive mesenchymal progenitors leads to a significant reduction in osteogenesis under physiological and pathological conditions. Klotho-deficient mensenchymal progenitors also suppress osteoclastogenesis in vitro and in vivo. Under conditions of inflammation and trauma-induced bone loss, we find that Klotho exerts an inhibitory function on inflammation-induced TNFR signaling by attenuating Rankl expression. More importantly, we show for the first time that Klotho is present in human alveolar bone, with a distinct expression pattern under both normal and pathological conditions. In summary, our results identify the mechanism whereby Klotho expressed in Osx+-mensenchymal progenitors controls osteoblast differentiation and osteoclastogenesis during mandibular alveolar bone formation and repair. Klotho-mediated signaling is an important component of alveolar bone remodeling and regeneration. It may also be a target for future therapeutics.

Crecimiento transversal del maxilar con uso de placa ortopédica prequirúrgica en pacientes con fisura labiopalatina / Transverse growth of the maxilla with the use of a presurgical orthopaedic plate in patients with cleft lip and palate

RESUMEN Introducción: la ortopedia prequirúrgica en el tratamiento de la fisura labiopalatina constituye una pauta terapéutica controversial. Los investigadores que están a favor plantean que favorece el cierre de la fisura lo cual facilita la cirugía, y otros apoyan el criterio de limitar el crecimiento maxilar y provocar su colapso. Objetivo: determinar los efectos morfológicos en el crecimiento transversal del maxilar durante el período de uso de la placa ortopédica prequirúrgica en niños con fisura labiopalatina atendidos en el Hospital Provincial Universitario «José Luis Miranda» de Villa Clara, en el período de marzo de 2015 a junio de 2019. Métodos: se realizó un estudio de intervención longitudinal. La muestra estuvo conformada por 34 niños previo consentimiento de sus padres o tutores. La información se obtuvo a través de: la entrevista, el examen clínico y mediciones; se aplicaron pruebas estadísticas como el test de Wilcoxon y el estadístico exacto de Fisher. Resultados: en la muestra estudiada predominaron los pacientes del sexo masculino y la fisura transforamen. Con el uso de la placa ortopédica prequirúrgica el maxilar mostró un crecimiento uniforme con un incremento de 5,6 mm de la distancia intercanina y de 5,2 mm de la distancia postgingival desde el nacimiento hasta la cirugía del paladar. La media de crecimiento entre el nacimiento y la cirugía del labio fue de 2,7 y 2,6 mm para la distancia intercanina y postgingival, respectivamente. Conclusiones: la ortopedia prequirúrgica favorece el crecimiento transversal del maxilar con un incremento uniforme de su ancho anterior y posterior.

ABSTRACT Introduction: presurgical orthopaedics in the treatment of cleft lip and palate constitutes a controversial therapeutic guideline. Researchers who are in favour state that it favours fissure closure which facilitates surgery, and others support the criterion of limiting maxillary growth and causing its collapse. Objective: to determine morphological effects on the transverse growth of the maxilla during the period of use of the presurgical orthopaedic plate in children with cleft lip and palate treated at "José Luis Miranda" Provincial University Hospital in Villa Clara from March 2015 to June 2019. Methods: a longitudinal intervention study was carried out. The sample consisted of 34 children with the prior consent of their parents or guardians. The information was obtained through interview, clinical examination and measurements; Wilcoxon's test and Fisher's exact test were applied as statistical tests. Results: male patients and transforamen fissure predominated in the studied sample. The maxilla showed, with the use of the presurgical orthopaedic plate, a uniform growth with an increase of 5.6 mm in the intercanine distance and a 5.2 mm increase in the post-gingival distance from birth to palate surgery. The mean growth between birth and lip surgery was 2.7 and 2.6 mm for intercanine and post-gingival distance, respectively. Conclusions: presurgical orthopaedics favours transverse growth of the maxilla with a uniform increase in its anterior and posterior width.

Gingivosupraperiosteoplasty following Presurgical Maxillary Orthopedics Is Associated with Normal Midface Growth in Complete Unilateral and Bilateral Cleft Patients at Mixed Dentition.

BACKGROUND: Passive orthodontic appliances and gingivosupraperiosteoplasty are adjuncts that can be used by surgeons at the time of primary cleft lip repair. These treatments, along with the surgical technique of cleft lip and palate repair, may impact midface growth. The objective of this study was to describe the authors' protocol for unilateral and bilateral cleft lip repair and to evaluate midfacial growth in a cohort of patients at mixed dentition who had undergone presurgical passive orthodontic appliance therapy and gingivosupraperiosteoplasty at the time of unilateral and bilateral cleft lip repair. METHODS: Fifteen complete unilateral and 15 complete bilateral cleft lip and palate patients underwent passive orthodontic appliance treatment and primary lip repair with gingivosupraperiosteoplasty. Lateral cephalograms were analyzed by three blinded reviewers. Mean cephalometric measurements at mixed dentition were compared to cephalometric values for noncleft patients, unilateral cleft lip and palate patients who did not undergo gingivoperiosteoplasty or presurgical treatment, and unilateral cleft lip and palate patients who underwent gingivoperiosteoplasty/nasoalveolar molding with independent samples t tests. RESULTS: Mean cephalometric values were within age-specific normal values for sella-nasion-A point, sella-nasion-B point, A point-nasion-B point, and facial axis. Eighty-seven (13/15) percent of unilateral cleft lip and palate patients and 93 percent (14/15) of bilateral cleft lip and palate patients did not exhibit skeletal class III malocclusion. There was no significant difference between cephalometric values for our patients and patients who did not receive gingivosupraperiosteoplasty or presurgical treatment or who underwent the gingivoperiosteoplasty/nasoalveolar molding protocol. CONCLUSIONS: Presurgical passive orthodontic appliances, combined with gingivosupraperiosteoplasty at the time of lip repair, leads to normal maxillary development in most patients at mixed dentition. Assessment of midface growth at skeletal maturity is required. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Maduración de la Sutura Palatina Media En Adolescentes y Adultos Jóvenes Chilenos: Estudio Transversal / Midpalatal Sutural Maturation in Chilean Adolescents and Young Adults: Cross-sectional Study

RESUMEN: Objetivo: Evaluar la maduración de la sutura palatina media en adolescentes y adultos jóvenes chilenos, mediante valoración morfológica de imágenes de tomografía computarizada de haz cónico del maxilar. Material y método: Se analizó la sutura palatina media de 150 sujetos entre 15 y 30 años, seleccionados desde la base de datos radiológicos de un centro universitario de salud. La maduración sutural fue evaluada en el corte axial, utilizando el método de Angelieri y cols., clasificándola en cinco etapas (A, B, C, D y E). Se utilizaron las pruebas de correlación de Pearson para medir la concordancia intra e interexaminador, y T-Student para las diferencias entre sexos. Resultados: El estado de maduración más frecuente fue C (43,3%), seguido por E (33,3%) y D (22%). En hombres, la etapa C fue más frecuente (49%), mientras que en mujeres fue la etapa E (39%). Sin embargo, no se encontraron diferencias estadísticamente significativas entre ambos sexos. Conclusiones: Aunque la mayoría de la muestra presentó una etapa tardía de maduración sutural, el 45% presentó estados de maduración sutural donde sería posible la expansión de naturaleza no quirúrgica. Debido a la variabilidad observada en adolescentes y adultos jóvenes, se recomienda la evaluación individual con imagenología 3D.

ABSTRACT: Objective: To evaluate midpalatal suture maturation in Chilean adolescents and young adults through morphological assessment of cone-beam computed tomography images of the maxilla. Materials and methods: Analysis of the midpalatal suture of 150 subjects aged between 15 and 30 was performed, selected from a university clinical center radiological database. Sutural maturation was evaluated in the axial cross-section, using the method described by Angelieri et al., classifying it in five stages (A, B, C, D and E). Pearson's correlation tests were used to assess intra- and inter-examiner agreement, and T-Student for assessing differences between genders. Results: The most frequent maturation stage was C (43.3%), followed by E (33.3%) and D (22%). In men, stage C was more frequent (49%), while in women it was stage E (39%). However, no statistically significant differences were found between genders. Conclusions: Although the majority of the sample presented a late stage of sutural maturation, 45% presented states of sutural maturation where the expansion of a non-surgical nature would be possible. Due to the variability observed in adolescents and young adults, individual evaluation with 3D imaging is recommended.

Could Vitamin D3 Deficiency Influence Malocclusion Development?

The abnormal growth of the craniofacial bone leads to skeletal and dental defects, which result in the presence of malocclusions. Not all causes of malocclusion have been explained. In the development of skeletal abnormalities, attention is paid to general deficiencies, including of vitamin D3 (VD3), which causes rickets. Its chronic deficiency may contribute to skeletal malocclusion. The aim of the study was to assess the impact of VD3 deficiency on the development of malocclusions. The examination consisted of a medical interview, oral examination, an alginate impression and radiological imaging, orthodontic assessment, and taking a venous blood sample for VD3 level testing. In about 42.1% of patients, the presence of a skeletal defect was found, and in 46.5% of patients, dentoalveolar malocclusion. The most common defect was transverse constriction of the maxilla with a narrow upper arch (30.7%). The concentration of vitamin 25 (OH) D in the study group was on average 23.6 ± 10.5 (ng/mL). VD3 deficiency was found in 86 subjects (75.4%). Our research showed that VD3 deficiency could be one of an important factor influencing maxillary development. Patients had a greater risk of a narrowed upper arch (OR = 4.94), crowding (OR = 4.94) and crossbite (OR = 6.16). Thus, there was a link between the deficiency of this hormone and the underdevelopment of the maxilla.

Application of cryopreservation to tooth germ transplantation for root development and tooth eruption.

We cryopreserved mouse tooth germs with widely open cervical margins of the enamel organ to overcome difficulties in cryoprotectant permeation and tested their efficacy by transplanting them into recipient mice. The upper right first molar germs of 8-day-old donor mice were extracted and categorized into the following four groups according to cryopreservation time: no cryopreservation, 1 week, 1 month, and 3 months. The donor tooth germs were transplanted into the upper right first molar germ sockets of the 8-day-old recipient mice. The upper left first molars of the recipient mice were used as controls. The outcome of the transplantation was assessed at 1, 2, and 3 weeks after transplantation. Stereomicroscopic evaluation revealed that most of the transplanted teeth erupted by 3 weeks after transplantation. Micro-computed tomography analysis revealed root elongation in the transplanted groups as well as in the controls. There was no significant difference between the cryopreserved and non-cryopreserved transplanted teeth, but the roots of the cryopreserved teeth were significantly shorter than those of the control teeth. Histological examination revealed root and periodontal ligament formations in all the transplanted groups. These results suggest that the transplantation of cryopreserved tooth germs facilitates subsequent root elongation and tooth eruption.

Comparative Evaluation of Soft Tissue Chin Thickness in Adult Patients with Skeletal Class II Malocclusion with Various Vertical Growth Patterns: a Cephalometric Study.

INTRODUCTION: Facial soft tissue thickness is important not only for plastic surgeons but also for orthodontists to plan the treatment procedure. Genioplasty, an orthognathic surgery in combination with orthodontic treatment is indicated to restore adequate shape and projection of the chin in the face. It has been performed to enhance soft tissue contours related to disproportion between soft and hard tissue. These treatments require the critical information regarding the relation between soft and hard tissues for proper treatment plan-ning. However, there is very minimal documentation on comparison of soft tissue characteristics particularly in Class II malocclusion. AIM: To evaluate and compare soft tissue chin thickness in class II subjects with various growth patterns. To evaluate soft tissue chin thickness difference in males and females and compare the results with previous studies. MATERIALS AND METHODS: The study comprised 150 adults aged between 18 and 26 years (mean age 21 years). Based on FH/MP angle the study sample was allocated into three groups: group I - low (hypodivergent), group II - average, and group III - high (hyper-divergent). Radiographs were traced manually. Angular measurements were computed to determine the vertical position of the maxilla and mandible in relation to anterior cranial base, to true horizontal and to each other. Soft tissue chin thickness was measured at three different levels. RESULTS: Hyperdivergent group showed greater soft tissue chin thickness at Pog-Pog' than the hypodivergent and average angle groups. Hypodivergent group showed greater soft tissue chin thickness at Me-Me' and Gn-Gn' as compared to average and hyperdivergent groups. Males showed greater soft tissue chin thickness at hypodivergent, average and hyperdivergent group than females. CONCLUSIONS: Soft tissue thickness measurements were smaller in adult patients of hyperdivergent group compared to adult patients in clinically average and hypodivergent groups. All STC measurements were greater in men than in women. The findings suggested that STC thickness in hyperdivergent pattern should be considered differently at its most anterior point (Pog) relative to its inferior landmarks (Gn and Me).

Size changes in miR­21 knockout mice: Geometric morphometrics on teeth, alveolar bone and mandible.

MicroRNA­21 (miR­21) is a small non­coding RNA that is differentially expressed during tooth development, particularly during amelogenesis. Although orthodontic tooth movement and the innate immune response are impaired, miR­21 knockout mice demonstrate no obvious skeletal phenotype. However, the consequence of miR­21 knockout on tooth phenotype and corresponding alveolar bone is unknown. The current study utilized landmark­based geometric morphometrics to identify anatomical dissimilarities of the three lower and upper molars, and the corresponding alveolar bone, in miR­21 knockout and wild­type control mice. The anatomical structures were visualized by microcomputer tomography. A total of 36 and 38 landmarks were placed on mandibular and maxillary molars, respectively. For the alveolar bone, 16 landmarks were selected on both anatomical sites. General Procrustes analysis revealed significantly smaller molars and dimensions of the alveolar bone in the mandible of the miR­21 knockout mice when compared with wild­type controls (P=0.03 and P=0.04, respectively). The overall dimension of the mandible was reduced by the lack of miR­21 (P=0.02). In the maxilla, the dimension of the alveolar bone was significant (P=0.02); however, this was not observed in the molars (P=0.36). Based on principal component analysis, no changes in shape for any of the anatomical sites were observed. Dental and skeletal jaw length were calculated and no prognathism was identified. However, the fluctuating asymmetry of the molars in the mandible and the maxilla was reduced in the miR­21 knockout mice by 38 and 27%, respectively. Taken together, the results of the present study revealed that the molars in the mandible and the dimension of the respective alveolar bone were smaller in miR­21 mice compared with wild­type littermates, suggesting that miR­21 influences tooth development.

Diámetro transversal del maxilar en pacientes con maloclusión del Policlínico Mario Escalona. 2019 / Maxillary transverse diameter in patients with malocclusion treated at Mario Escalona Polyclinic. 2019

Introducción: Las anomalías de crecimiento y desarrollo transversal del maxilar constituyen un diagnóstico frecuente en pacientes con maloclusiones. Objetivo: Describir el diámetro transversal del maxilar en pacientes con maloclusiones del Policlínico Mario Escalona, 2019. Material y método: Estudio descriptivo transversal. El universo estuvo formado por todos los pacientes (69), de 12 a 25 años con maloclusiones ingresados en el Servicio de Ortodoncia del policlínico Mario Escalona desde abril de 2018 a febrero de 2019. Se determinó el índice de Bogue y de Mayoral. Los resultados se presentaron en tablas. Resultados: Se encontró el diámetro de Bogue disminuido en el 65,0 por ciento de los pacientes donde se determinó. Todas las medidas de Mayoral analizadas presentaron como promedio valores por debajo de la norma en cada etapa de crecimiento y desarrollo; exceptuando las medidas de 4 a 4 en el Prepúber. En ambos sexos el índice de Mayoral en sus tres niveles o referencias se encontró como promedio por debajo de la norma. En el sexo femenino se detectaron las medias menores (33,7mm, 38,3mm, 44,4mm) respecto al masculino. Se diagnosticó Micrognatismo transversal en el 75,36 por ciento de los pacientes; 80,49 por ciento en las hembras y 67,86 por ciento en varones. Conclusiones: Se encontró una alta frecuencia de micrognatismo transversal. Se detectó discrepancias ligeras del índice de Mayoral según la clasificación sindrómica y la etapa de crecimiento y desarrollo, mientras que en cuanto al sexo se identificaron diferencias de consideración(AU)

Introduction: Growth anomalies and maxillary transverse diameter are frequent diagnoses in patients with malocclusions. Objective: To describe the maxillary transverse diameter in patients with malocclusions treated at Mario Escalona Polyclinic in 2019. Material and method: A cross-sectional descriptive study was conducted. The universe consisted of 69 patients aged 12-25 years who presented malocclusions and were admitted to the Orthodontics Service of Mario Escalona polyclinic from April 2018 to February 2019. Bogue´s index and the index of Mayoral were determined. The results were presented in tables. Results: The transverse diameter of Bogue decreased in 65.0 percent of the patients in whom it was determined. All measures established by Mayoral presented ​​lower average values than the norm at each stage of growth and development; except for measures 4/4 in pre-pubertal patients. In both sexes, the index of Mayoral in its three levels or references was found as an average value below the norm. Lower averages (33.7mm, 38.3mm, 44.4mm) were identified in the female sex with respect to the male sex. Transversal micrognathism was diagnosed in 75.36 percent of patients (80.49 percent females and 67.86 percent males). Conclusions: A high frequency of transversal micrognathism was found. Slight discrepancies of the index of Mayoral were identified according to the syndromic classification and the stages of growth and development while in terms of sex, significant differences were identified(AU)

Variability of the maxillary suture maturation and density in the subjects with different sex and growth status.

INTRODUCTION: The objective of this study was to classify median palatine suture (MPS) maturation type in young and adult patients. Additionally, we compared MPS maturity type and density based on sex and growth status. MATERIALS AND METHODS: In this retrospective cone beam computed tomography study, we included a total of 221 subjects, grouped based on sex and growth status. Once scans were aligned and oriented in the sagittal view, we conducted our evaluations on the axial sections. Based on interdigitation and shape, the MPS were categorized into Maturation Types A through E. Additionally, MPS density was measured as Hounsfield unit equivalent pixel intensity value scale for anterior and posterior sutural regions. RESULTS: The majority of male (39%) and female (42%) subjects had MPS Maturation Type C. A maximum number of growing (42%) patients had Type C and nongrowing subjects (39%) had Type E sutures. The sex comparison showed significantly lower (p < .001) MPS density for both anterior and posterior regions in males when compared to females. Additionally, for the posterior region, nongrowing males had significantly lower (p < .001) MPS density when compared to nongrowing females. Subgroup comparisons of the MPS densities between growing and nongrowing males and growing and nongrowing females showed a significant difference (p < .001). CONCLUSION: Classification of the MPS based on the maturation types provides a reliable predictor for orthodontic treatment planning. MPS density is significantly higher in females as compared to males. Similarly, nongrowing individuals have significantly higher MPS density compared to growing individuals for both anterior and posterior locations.

A morphometric analysis of the immature human infraorbital canal.

PURPOSE: The importance of the infraorbital canal in the growth of the maxilla and associated mid-facial region has significance for innervation of this region as well as the associated dentition, yet little is known about the development of the canal. An analysis of its dimensions and morphology during the late prenatal and early postnatal periods was thus undertaken. The aim of this study was to describe changes in the morphology, size and branching pattern of the infraorbital canal during the late prenatal and early postnatal stages of human growth. METHODS: Fifty human fetal and neonatal maxillae were analyzed. The sample included 27 late prenatal individuals (30 gestational weeks and birth) and 23 early postnatal individuals (birth and 1 year). Maxillae were scanned using a Nikon XTH 225 L micro-CT unit and analyzed using VG studiomax v3.2. Measurements included the maximum width, height and surface area of each foramen associated with the infraorbital canal and the total length of the canal, bilaterally. RESULTS: All the measurements of the canal were greater in the early postnatal group than in the late prenatal group, while the walls and branching pattern of the canal were better developed in the postnatal group. Bone development occurred within the walls as development proceeded. Variations in the branching pattern of the canal were found. CONCLUSION: The morphology of the infraorbital canal reflected the developmental stage of associated structures such as the dentition, maxillary sinus and orbit.

Influence of Monobloc/Le Fort III Surgery on the Developing Posterior Maxillary Dentition and Its Resultant Effect on Orthognathic Surgery.

BACKGROUND: Timing of frontofacial surgery for the syndromic craniosynostosis as it relates to various surgical risks has not been adequately studied. The purpose of this study was to investigate posterior dental complications of midface advancement in patients with syndromic craniosynostosis undergoing surgery at different ages and the effects on subsequent orthognathic surgery. METHODS: A retrospective chart review of patients with syndromic craniosynostosis treated with midface advancement (monobloc or Le Fort III) from 1999 to 2018 was carried out. Patient demographics, records, and imaging studies were reviewed. A subanalysis of those patients who were also treated with orthognathic surgery from 2014 to 2018 with imaging studies available for analysis was also performed. RESULTS: Thirty-seven patients met the inclusion criteria. Sixty-four percent of the patients had radiographic evidence of maxillary molar dental abnormality. Older age at the time of surgery was significantly associated with a lower odds of sustaining dental injury (OR, 0.55; p = 0.034). The odds of damaging second or third maxillary molars was significantly higher with a younger age at the time of surgery (p = 0.021 and p = 0.034). The odds of sustaining dental injury increased moving posteriorly, showing the risk of abnormal pattern of M3 greater than M2 greater than M1. Advanced age at the time of surgery was significantly associated with decreased odds of dental injury (OR, 0.55; p = 0.034). CONCLUSIONS: Damage to the developing permanent maxillary molars may affect orthodontic management, mastication, and potentially maxillary development. Delaying frontofacial surgery until development of the permanent maxillary dentition should be considered if other indications do not mandate earlier intervention.

Tratamiento exitoso con activador funcional removible en paciente clase II esqueletal con mordida en tijera, después del peak de crecimiento puberal: caso y revisión de la literatura / Successful treatment with removable functional activator in a skeletal class II patient with scissor bite, after pubertal growth peak: clinical case and literature review

INTRODUCCIÓN: En pacientes con crecimiento esqueletal clase II, el tratamiento ideal es etiológico modificando la cantidad y dirección de crecimiento mandibular. Con estos objetivos, se usan activadores funcionales (AF) que estimulan el crecimiento mandibular, redirigiéndolo posterosuperiormente a nivel condilar por medio del avance mandibular. Después del peak de crecimiento puberal, la corrección etiológica es quirúrgica. El objetivo del presente artículo es reportar un tratamiento exitoso de un paciente después de su peak de crecimiento puberal, tratado con un AF removible. MÉTODOS: Paciente de 13 años, 3 meses, braquifacial y con perfil facial convexo, presentaba clase II esqueletal debido a mandíbula retrognática. El paciente tenía dentición permanente completa, clase II de Angle, resalte incisivo y sobremordida aumentados, proinclinación incisiva bimaxilar y mordida en tijera de dientes #2.4 y #2.5. RESULTADOS: Después de ocho meses de tratamiento, se observó posición mandibular estable en clase I esqueletal, verificada mediante exámenes funcionales y radiográficos. Se logró resolución de la mordida en tijera. Mejoraron resalte incisivo y sobremordida, así como la proinclinación incisiva bimaxilar. CONCLUSIONES: El momento ideal para utilizar AF en tratamiento de clases II esqueletales es durante o ligeramente después del peak de crecimiento puberal. Sin embargo, los resultados clínicos del presente caso, permiten recomendar el avance mandibular con AF en pacientes braquifaciales clase II, a pesar de que se haya producido el peak de crecimiento puberal. En estos casos, el uso de AF está dirigido principalmente a beneficios dentarios, pero, al mismo tiempo, puede favorecer el crecimiento mandibular

INTRODUCTION: In growing skeletal class II patients, the ideal treatment is etiological and is obtained by modifying the amount and direction of mandibular growth. With this objective in mind, functional activators (FA) are used as they stimulate growth, redirecting it at the condylar level through forward mandibular advancement. After pubertal growth peak, etiological correction is surgical. OBJECTIVE: The present article aims to report a successful treatment in a patient after pubertal growth peak treated with a removable FA. METHODS: >A 13 years 3 months male patient, skeletal class II due to retrognathic mandible, brachyfacial and with a convex facial profile. The patient had complete permanent dentition, Angle class II, increased overjet and overbite. Maxillary and mandibular incisive proclination. Scissor bite of teeth #2.4 and #2.5. RESULTS: Treatment started using a FA for one year after first evaluation. Following eight months of treatment, stable mandibular position was observed in skeletal class I, verified by functional and radiographic examinations. Resolution of scissor bite was accomplished. Overjet and overbite, and bimaxillary incisive proclination were improved. CONCLUSIONS: The ideal time to use FAs for skeletal management in skeletal class II is during, or slightly after peak pubertal growth. However, the clinical results of present case, allows recommending the forward mandibular advancement in brachyfacial skeletal class II patients, even though pubertal growth peak had occurred. In these cases, the use of FA is primarily aimed at the dental benefits, but, at the same time, favoring mandibular growth

Intraspecific variability in human maxillary bone modeling patterns during ontogeny.

OBJECTIVES: This study compares the ontogenetic bone modeling patterns of the maxilla to the related morphological changes in three human populations to better understand how morphological variability within a species is established during ontogeny at both micro- and macroscopic levels. MATERIALS AND METHODS: The maxillary bones of an ontogenetic sample of 145 subadult and adult individuals from Greenland (Inuit), Western Europe (France, Germany, and Portugal), and South Africa (Khoekhoe and San) were analyzed. Bone formation and resorption were quantified using histological methods to visualize the bone modeling patterns. In parallel, semilandmark geometric morphometric techniques were used on 3D models of the same individuals to capture the morphological changes. Multivariate statistics were applied and shape differences between age groups were visualized through heat maps. RESULTS: The three populations show differences in the degree of shape change acquired during ontogeny, leading to divergences in the developmental trajectories. Only subtle population differences in the bone modeling patterns were found, which were maintained throughout ontogeny. Bone resorption in adults mirrors the pattern found in subadults, but is expressed at lower intensities. DISCUSSION: Our data demonstrate that maxillary morphological differences observed in three geographically distinct human populations are also reflected at the microscopic scale. However, we suggest that these differences are mostly driven by changes in rates and timings of the cellular activities, as only slight discrepancies in the location of bone resorption could be observed. The shared general bone modeling pattern is likely characteristic of all Homo sapiens, and can be observed throughout ontogeny.

A study on the morphologic change of palatal alveolar bone shape after intrusion and retraction of maxillary incisors.

The purpose of this study is to evaluate the changes in the palatal alveolar bone thickness and find the factors related to the resorption of the palatal alveolar bone caused by tooth movement after the maxillary incisors were retracted and intruded during orthodontic treatment. The study group comprised of 33 skeletal Class II malocclusion patients who underwent extraction for orthodontic treatment. Palatal alveolar bone thickness changes and resorption factors were identified and analyzed. The changes of maxillary central incisors and palatal alveolar bone thickness were measured, and the corresponding sample t test was performed using SPSS (IBM SPSS version 22). The amount of palatal alveolar bone resorption was measured and various parameters were analyzed to determine which factors affected it. Correlation analysis adopting the amount of palatal alveolar bone resorption as a dependent variable demonstrated that the SNB, mandibular plane angle, and the inclination of the maxillary central incisor were significantly correlated with before treatment. On the other hand, mandibular plane angle, angle of convexity, the inclination of the upper incisor, and the occlusal plane (UOP, POP) were significantly correlated with post-treatment. In addition, the variables related to palatal contour (PP to PAS, SN to PAS, palatal surface angle) and occlusal planes (UOP/POP) were significantly correlated with the difference in palatal bone resorption. During initial diagnosis, high angle class II with normal upper incisor inclination can be signs of high-risk factors. In addition, maintaining the occlusal plane during treatment helps to prevent palatal bone loss.

Periostin and matrix stiffness combine to regulate myofibroblast differentiation and fibronectin synthesis during palatal healing.

Although the matricellular protein periostin is prominently upregulated in skin and gingival healing, it plays contrasting roles in myofibroblast differentiation and matrix synthesis respectively. Palatal healing is associated with scarring that can alter or restrict maxilla growth, but the expression pattern and contribution of periostin in palatal healing is unknown. Using periostin-knockout (Postn-/-) and wild-type (WT) mice, the contribution of periostin to palatal healing was investigated through 1.5 mm full-thickness excisional wounds in the hard palate. In WT mice, periostin was upregulated 6 days post-wounding, with mRNA levels peaking at day 12. Genetic deletion of periostin significantly reduced wound closure rates compared to WT mice. Absence of periostin reduced mRNA levels of pivotal genes in wound repair, including α-SMA/acta2, fibronectin and ßigh3. Recruitment of fibroblasts and inflammatory cells, as visualized by immunofluorescent staining for fibroblast specific factor-1, vimentin, and macrophages markers Arginase-1 and iNOS was also impaired in Postn-/-, but not WT mice. Palatal fibroblasts isolated from the hard palate of mice were cultured on collagen gels and prefabricated silicon substrates with varying stiffness. Postn-/- fibroblasts showed a significantly reduced ability to contract a collagen gel, which was rescued by the exogenous addition of recombinant periostin. As the stiffness increased, Postn-/- fibroblasts increasingly differentiated into myofibroblasts, but not to the same degree as the WT. Pharmacological inhibition of Rac rescued the deficient myofibroblastic phenotype of Postn-/- cells. Low stiffness substrates (0.2 kPa) resulted in upregulation of fibronectin in WT cells, an effect which was significantly reduced in Postn-/- cells. Quantification of immunostaining for vinculin and integrinß1 adhesions revealed that Periostin is required for the formation of focal and fibrillar adhesions in mPFBs. Our results suggest that periostin modulates myofibroblast differentiation and contraction via integrinß1/RhoA pathway, and fibronectin synthesis in an ECM stiffness dependent manner in palatal healing.

Long-term effects of the Forsus Device in Class II division I patients treated at pre-peak, peak, and post-peak growth periods: A retrospective study.

OBJECTIVES: To assess the long-term effects of the Forsus Fatigue Resistant Device (FFRD) for the correction of Class II division 1 malocclusion during pre-peak, peak, and post-peak growth periods. MATERIALS AND METHODS: This retrospective study was conducted on 60 patients that received FFRD with concurrent full-fixed orthodontic appliances during pre-peak (n=18), peak (n=21) and post-peak (n=21) maturational stages. The FFRD groups were compared with 60 untreated Class II control subjects obtained from the University of Michigan growth study and matched by skeletal age, sex, and observation periods. Lateral cephalograms were obtained at three time-points: [T1] pre-treatment; [T2] end of comprehensive orthodontic treatment; and [T3] retention (average of 3 years in retention). Nineteen linear and angular measurements were recorded. Short-term (T1- T2) and long-term (T1-T3) treatment changes were analyzed using paired Wilcoxon Signed Rank tests. RESULTS: In the pre-peak group, FFRD caused temporary restraint of maxillary growth and an increase in mandibular length at T1-T2 compared to controls. No significant differences were found at T2-T3 time points. The net changes (T1-T3) included a restraining effect on the maxilla and dentoalveolar compensation. In the peak group, maxillary restraint effect was seen at T1-T2, but this effect relapsed at T2-T3 time points. Similar to the pre-peak group, the net results (T1-T3) included maxillary headgear effect and dentoalveolar compensation. In the post-peak group, the net effects (T1-T3) of treatment included only dentoalveolar compensation. CONCLUSIONS: Overall, Class II malocclusion correction with FFRD is stable at three years post-treatment and is mainly achieved by maxillary restraint and dentoalveolar compensation at the pre-peak and peak stages and dentoalveolar compensation during the post-peak stage.