Cephalometric Characteristics in Chilean Latino Population with Normal Occlusion and Harmonic Profiles in Permanent Dentition. A Retrospective Study / Características Cefalométricas en Población Latina Chilena con Oclusión Normal y Perfiles Armónicos en Dentición Permanente. Un Estudio Retrospectivo

SUMMARY: Malocclusion is usually treated based on clinical decisions complemented with a cephalometric analysis, allowing the comparison of an individual with standard reference norms. Cephalometric standards have mostly been obtained from Caucasian population, but may not be appropriate for other ethnic groups, becoming a clinically relevant problem in multicultural and multiracial societies. The present study aimed to establish cephalometric norms for Chilean-Latino population, using a representative sample of class I individuals in permanent dentition. A sample of 72 cephalometric x-rays of class I growing individuals (47 women and 25 men) between 10 and 20 years of age with class I occlusion and harmonic profile was obtained from the records of the Universidad de los Andes taken between 2012 and 2019, including 1164 individuals. The radiographs were classified according to their cervical vertebral maturation status, and cephalometrically analyzed, obtaining vertical and sagittal parameters in soft and hard tissues, which were compared with Caucasian cephalometric norms. The statistical analysis was performed using descriptive and inferential statistics (T-test, ANOVA and Bonferroni tests). Cephalometric norms were obtained for hard and soft tissues. Upon comparison with Caucasian norms, the subjects included in the sample present a tendency towards a convex profile, significant incisal proclination, dental protrusion, labial biprotrusion and an acute nasolabial angle. There are cephalometric differences between the Caucasian cephalometric norms and those observed Chilean Latino population, displaying differences at a hard and soft tissue level that should be taken into account for clinical decision making in Orthodontics.

La maloclusión generalmente se trata con base en decisiones clínicas complementadas con un análisis cefalométrico, lo que permite la comparación de un individuo con normas de referencia estándar. Los estándares cefalométricos se han obtenido en su mayoría de población caucásica, pero pueden no ser apropiados para otros grupos étnicos, convirtiéndose en un problema clínicamente relevante en sociedades multiculturales y multirraciales. El presente estudio tuvo como objetivo establecer normas cefalométricas para población chileno-latina, utilizando una muestra representativa de individuos clase I en dentición permanente. Se obtuvo una muestra de 72 radiografías cefalométricas de individuos en crecimiento clase I (47 mujeres y 25 hombres) entre 10 y 20 años de edad con oclusión clase I y perfil armónico de los registros de la Universidad de los Andes tomados entre 2012 y 2019, incluidas 1164 personas. Las radiografías se clasificaron según su estado de maduración vertebral cervical, y se analizaron cefalométricamente, obteniendo parámetros verticales y sagitales en tejidos blandos y duros, que se compararon con normas cefalométricas caucásicas. El análisis estadístico se realizó mediante estadística descriptiva e inferencial (T-test, ANOVA y pruebas de Bonferroni). Se obtuvieron normas cefalométricas para tejidos duros y blandos. En comparación con las normas caucásicas, los sujetos incluidos en la muestra presentan una tendencia hacia un perfil convexo, proinclinación incisal significativa, protrusión dental, biprotrusión labial y un ángulo nasolabial agudo. Existen diferencias entre las normas cefalométricas caucásicas y las observadas en población latina chilena, mostrando diferencias a nivel de tejidos duros y blandos que se deben considerar para la toma de decisiones clínicas en Ortodoncia.

Three dimensional measurement of craniofacial hard tissues for the Han nationality with normal occlusion in Changsha area / 中南大学学报(医学版)

Objective:To explore the influence of gender and age on the measurement of cone beam CT (CBCT) in normal and occluded craniofacial hard tissues for Han nationality in Changsha area.Methods:A total of 80 CBCT data of normal and occluded craniofacial hard tissues for Han nationality in Changsha area were collected,including 40 adults [16 males and 24 females,aged (17.57±1.83) years] and 40 children[16 males and 24 females,age (11.50±1.26) years].Threedimensional cephalometric measurements were carried out by Dolphion Imaging software,and the influence of gender and age was compared.Results:The symmetry of craniofacial hard tissues in male and female in the adults was good (the maximum asymmetric rate R was 6.39％ and the minimum asymmetric rate R was 0.08％).There was no significant differencein the anterior palatal width,palatal width,the upper incisor protrusion distance,the lower incisor protrusion distance,hyoid-mandibular plane,basal epiglottis width,and palatal plane airway width between the males and females (all P＞0.05);while the remaining indicators were significantly higher in males than those in females (all P＜0.05).There was no significant gender difference in angle indicators (all P＞0.05).There were significant differences in the posterior height,the maxillary length,the lower incisor protrusion,and the mandibular plane angle between the adults and the children(all P＜0.05);but the rest of indicators were not significant difference (all P＞0.05).Conclusion:The symmetry of craniofacial hard tissues for Han nationality in Changsha area is good.The gender and age affect the line space measurements but not affect the most of the angle measurements.

The long term stability of skeletal class III malocclusion after orthodontic-surgery:A meta-analysis / 实用口腔医学杂志

Objective:To analyze the long term stability of the hard and soft tissues of the skeletal class III malocclusion after ortho-dontic-surgery by Meta-analysis.Methods:The randomized controlled trials(RCT),quasi-randomized controlled trials and clinical case-control trials(CCT)about the long-term stability of skeletal class III malocclusion after orthodontic-surgery was collected from Co-chrane Library,PubMed,Medline,CNKI,VIP and Wanfang databases from inception to December 31,2013 by literature search.Two professionally trained reviewers evaluated the quality of the screened literatures,scored literatures with the NOS evaluation tool,and collectd data and information of the literatures with medium and higher quality.Revman5.2 was used for the Meta-analysis.Results:4 CCTs articles and 178 cases were included.The results of Meta-analysis showed that:1.The stability of the hard tissue:the differ-ence of SNA(WMD =-0.58,95%CI[-1.18,0.02]),SNB (WMD =0.25,95%CI[-0.42,0.91]),ANB(WMD =-0.70, 95%CI[-1.44,0.04])and MP-SN(WMD =0.39,95%CI[-0.25,1.04])at post-operation and 3 years after operation had no statistical significance.Point A remained relatively stable position and point B had some replace 3 years after surgery compared with that at post-operative.2.The stability analysis of soft tissue:the healing effect of the soft tissue was stable,except the LowerlipeNperp had some recurrence 3 years after surgery.Conclusion:In the long term,after orthodontic and surgical treatment for skeletal class III malocclusion the hard and soft tissues kept stabile except a little replapse of the mandibular and the LowerlipeNperp.

Role of buccal corridor in smile esthetics and its correlation with underlying skeletal and dental structures.

Purpose: This study was designed to evaluate the buccal corridor in smile esthetics and to correlate it with underlying hard tissues. Materials and Methods: Posed smiling frontal photographs, digital posterior-anterior (PA) cephalograms, and study models of 25 males and 25 females in age range of 18-25 years were taken. Photographs were evaluated for smile esthetics by eight orthodontists, eight plastic surgeons, eight beauticians and eight lay people to group them into three groups with least attractive, average and attractive smile and buccal corridor width was measured. Digital PA cephalograms were transferred on Nemo-tech software for frontal facial analysis. Intercanine and intermolar widths were measured on upper study model with the help of a digital calliper. Results: The buccal corridor width was least in attractive smile group and maximum in least attractive smile group. The buccal corridor width had a negligible correlation with hard tissues and a mild to moderate inverse correlation with intercanine and intermolar widths within the groups. Conclusion: As the amount of buccal corridor display was increased, smiling images were scored less attractive by the evaluators. The buccal corridor is not influenced by underlying skeletal hard tissues but have mild to moderate inverse correlation with the intercanine and intermolar width.

A color contrast aided density imaging technique to differentiate between dental hard tissues and its relevance.

Aim: Radiographic interpretation of a disease requires knowledge about normal structures. The calcifying jaw diseases can range from radiolucent areas to varying degrees of calcification. Therefore, it is vital to differentiate radiographically between various hard tissues. Materials and Methods: We have illustrated the use of computed tomography scan to quantify the calcified structures as dentin and enamel in a case of ameloblastic fibro-odontoma. Results: The enamel, dentin and cementum showed different values. Conclusion: The "Dentascan" can be used to distinguish the hard tissues in a variety of calcifying diseases of jaws.

Soft- and hard-tissue changes after extraction space closure with micro-screw implant / 复旦学报（医学版）

Objective To investigate the changes of soft and hard tissues after extraction space closure with micro-screw implant as orthodontic anchorage. Methods Twenty cases were selected randomly with the first premolars extraction. Micro-screw implant was used as orthodontic anchorage. Sliding technique was used to close the extraction space. The lateral cephalograms before and after the treatment were evaluated.Results The upper incisors moved 7. 15 mm palatelly, 1. 63 mm intruded. The upper first molar moved 0. 80 mm distally, 1. 80 mm intruded. The lower incisors moved 4. 65 mm distally, 0.48 mm extruded. The lower first molar moved 0. 18 mm mesially, 1.18 mm extruded. A point, B point, upper lip, lower lip showed distal movement. Conclusions Micro-screw implant can provide acceptable and reliable anchorage in the process of extraction space closure, and improve the profile. Besides, it produces skeletal change on the maxilla.