Investigation of Craniofacial Morphology in Patients with Hypo- and Oligodontia

Aim:   

This cephalometric study was performed with the intention to qualify and quantify differences between the craniofacial morphology in persons with congenitally missing teeth (hypo- and oligodontia) in comparison with the craniofacial morphology in persons without missing teeth.     

少牙畸形患者牙弓长度和宽度的临床研究

目的研究少牙畸形患者牙弓的长度和宽度,为临床诊治提供参考。方法选取少牙畸形与正常的牙模型各50副,用游标卡尺测量并计算牙弓长度和宽度的各项参数,采用ANOVA法进行统计分析。结果少牙畸形患者较正常的上、下牙弓长度分别少4.40mm和2.80mm,上、下颌尖牙宽度分别少2.82mm和2.70mm,上、下颌磨牙宽度分别少3.40mm和1.80mm。两组测量项目的差异均有统计学意义(P<0.01)。结论正畸治疗时,应当考虑到少牙畸形患者的牙弓长度和宽度均较正常小。     

下颌偏斜患者颌面结构及其颈椎姿势生长变化的研究

目的：研究下颌偏斜患者颌面结构及颈椎姿势的生长变化趋势。方法：对20例儿童下颌偏斜患者，20例成人下颌偏斜患者及20例儿童正常咬合者，20例成人正常咬合者拍摄头颅定位侧位片，进行头影测量分析及统计学分析。结果：下颌偏斜患者成人组的咬合平面、下颌平面倾斜度及颈椎弯曲度大于儿童组而颈椎的倾斜度小于儿童组，患者头颈呈前倾，前伸位。结论：随着年龄的增大，偏颌畸形可能逐渐影响颌面形态及颈椎姿势。下颌偏斜患者应尽早矫治，在矫治颌面畸形的同时还应矫正异常的颈椎姿势。     

Effect of Cleft Lip and Palate Repair on Craniofacial Morphology in Patients with Unilateral Complete Cleft Lip and Palate

目的通过对替牙期正常儿童及单侧完全唇腭裂(UCLP)患者X线头影测量侧位片进行比较研究,了解唇腭裂及其手术对颌骨发育的影响,探索继发畸形的发病机制.方法将替牙期的正常儿童及UCLP患者分为四组①正常对照组(Normal),本组包括48名替牙期正常湖北地区儿童;②未手术组(NO),本组10名UCLP患者未经任何手术治疗;③唇裂修复组(OL),34名UCLP患者已行唇裂修复,腭裂暂未手术;④唇腭裂修复组(OLP),16名UCLP患者已行唇、腭裂修复.各受试对象拍摄X线头影测量侧位片,测量描述颌骨的形态特征及生长方向,对各组之间测量结果进行统计学分析.结果未行手术治疗的UCLP患者颌骨形态除腭部先天性发育不足外,颌骨侧位头影测量与正常无显著性差异;OL和OLP组较正常存在严重的颌骨畸形,主要表现为上颌后缩、位置后移,同时下颌骨向后下旋转移位;OL和OLP组上颌后缩的程度无显著性差异.结论UCLP患者颌骨具有趋于发育正常的生长能力;手术是导致颌骨继发畸形的主要因素;对于单侧完全唇腭裂患者,唇裂修复术对颌骨发育的影响较腭裂修复术更严重.     

蒙古族正常中小学生硬组织颅面结构的研究

为建立蒙古族硬组织Ｘ线头影测量正常值，揭示蒙古族颅面结构生长发育的规律及特征，以１８０例蒙古族中小学生为对象、运用计算机辅助Ｘ线头影测量系统，对其颅面、牙２３项硬组织指标进行了测量．首次建立了蒙古族硬组织颅面结构的Ｘ线头影正常值标准．研究发现，蒙古族颅面结构的深度及高度男性大于女性，骨侧貌面形男性较女性为凸，颅面深度及高度随生长发育增大，侧貌凸度则逐渐减小．与汉族相比，蒙古族具有颅面深度及高度较大、下切牙直立、男性侧貌较凸的特征．上述结果为本民族错畸形的诊断、治疗及审美标准的建立提供了客观依据     

青年女性咬肌B超形态与面颌形态关系的研究

目的：了解肌肉功能与颅颌面形态之间相互作用关系及作用模式，探讨错He畸形的形成机理。方法：本研究采用超声成像技术测量31例正常He青年女性其浅层咬肌横截面的周长、面积、横径、平均厚度及纵截面的长度，并将其与头影测量指标进行统计相关分析。结果：紧咬位浅层咬肌厚度与上颌骨长度、后面高成正相关关系；长度与下颌升枝与SN平面的前下交角、下颌体长度、下颌综合长度、前下面高、全前面高、磨牙区牙槽高成正相关关系。结论：浅层咬肌的厚度、长度对颅颌面垂直向形态有显著影响，同时厚度影响面中份深度。     

Craniofacial features of subjects with adenoid, tonsillar, or adenotonsillar hypertrophy

Objective

To analyze the craniofacial features in children with adenoid hypertrophy, tonsillar hypertrophy, and adenotonsillar hypertrophy.

Materials and methods

20 patients with adenoid hypertrophy (AG), 20 subjects with tonsillar hypertrophy (TG) and 20 patients with adenotonsillar hypertrophy (ATG) were selected. A control group (CG) of 20 children with non-obstructive adenoids or tonsils was also obtained. Kruskal-Wallis test and Tukey's post hoc tests were used to compare the angular and linear measurements obtained from the lateral cephalograms.

Results

No significant differences were observed between AG and CG. Conversely TG exhibited smaller ANB and OVJ values and a larger SNB value when compared to both CG and AG, larger Go-Me, Ar-Gn and Ar-Go measures and a smaller NSGn angle with respect to AG. ATG showed a smaller ANB angle in comparison with CG and AG, larger Ar-Gn and Go-Me values when compared to AG, a smaller SNB angle and a larger NSGn angle with respect to TG.

Conclusions

Subjects with tonsillar hypertrophy showed an increased length of the mandibular ramus, a more horizontal growth direction, an increased length of the mandibular body, a more anterior mandibular position and a smaller sagittal discrepancy between the maxilla and the mandible than subjects with adenoid hypertrophy.     

青少年牙发育不全患者颅面结构的初步研究

目的探讨牙发育不全患者的颅面结构,为临床诊治提供参考。方法选择英国牙发育不全患者病历59份纳入研究组,根据缺牙类型和缺牙数将研究组分为轻度、中度、重度、极重度共4个亚组,其中男27例,女32例,平均年龄（13.1±3.1）岁。以Woodworth等报道的正常资料为对照组。对所有研究对象进行X线头影测量对比分析。结果研究组与对照组的SNA、SNB、MMA差异无统计学意义,且均在正常值范围内。同T3组相比,T4组的SNB增大（t=-2.76,P=0.015）、MMA减小（t=-3.03,P=0.007）、ANB减小（t=-2.26,P=0.034）,三者差异均有统计学意义;59例牙发育不全患者中Ⅲ类颅面结构患者居多。结论牙发育不全患者的平均头影测量值在正常值范围内,59例牙发育不全患者中Ⅲ类颅面结构患者居多、上下颌平面角减小。     

Prosthodontic Rehabilitation with a Telescopic Prosthesis of a Nonsyndromic Oligodontia Patient

Oligodontia is the congenital absence of six or more permanent teeth, excluding the third molars. Oligodontia of permanent dentition is a rare occurrence. Preservation of the remaining deciduous dentition in such situations is important for both functional and esthetic rehabilitation of the patient. This clinical report describes the rehabilitation of a 16‐year‐old male with oligodontia of permanent teeth treated by an interdisciplinary team of prosthodontist, pedodontist, and orthodontist. The remaining deciduous dentition was endodontically treated. Occlusal vertical dimension (OVD) of the deciduous dentition was assessed. A full‐mouth single piece porcelain‐fused‐to‐metal telescopic prosthesis for the maxillary and mandibular arches was planned with a minimal increase in OVD. The telescopic prosthesis provided excellent retention, stability, esthetics, and stress equalization on the remaining deciduous dentition. Maintenance of oral hygiene procedures was simplified for the adolescent with the telescopic prosthesis. Preservation of remaining deciduous dentition and fabrication of a telescopic prosthesis in this patient provided an effective esthetic and functional rehabilitation.     

Craniofacial growth in the ferret (Mustela putorius furo)--a cephalometric study

OBJECTIVE: When suggesting the ferret as a valid laboratory model in craniofacial research, it is essential to know about its normal craniofacial growth. DESIGN: Sixteen ferret kits (eight male and eight female) were selected for the present investigation. Serial lateral and dorsoventral cephalograms were taken on each animal at a mean age of 25, 35, 55, 80 and 300 days. The cephalograms were then digitised and the coordinates of 33 landmarks were derived on each set of cephalograms. Thirty-four variables were then calculated on each set of cephalograms by computer image programs with the coordinate data. Results were analysed statistically, and the craniofacial growth pattern and related sexual dimorphism were described in three perspectives: lateral and dorsoventral viscero- and neurocranium, and lateral mandible. FINDINGS: In both sexes, the viscero- and neurocranium follow an orderly pattern of expansive growth in three dimensions. The growth of the mandible is mainly characterised by an anteroposterior elongation of the mandibular body, an enlargement of the coronoid process, and an increase in height of the alveolar process. The growth rate varies with site. Craniofacial growth in ferrets starts to slow down and finally ceases earlier in female than in male animals.     

Effects of severity and location of nonsyndromic hypodontia on craniofacial morphology

Objective:To evaluate the effects of severity and location of nonsyndromic hypodontia on craniofacial morphology.Materials and Methods:A total of 154 patients with at least two or more congenitally missing teeth were selected and divided into two groups (group I [mild]: patients with two to five missing teeth; group II [severe]: patients with six or more missing teeth). The patients with hypodontia were divided into three groups according to the location of missing teeth in the dental arches (anterior, posterior, and both anterior and posterior) and location of missing teeth between the jaws (maxilla, mandible, and both maxilla and mandible). Fifty Class I patients without any missing teeth served as the control group. Twenty-one measurements were performed on lateral cephalograms. Intergroup differences for the severity and location of hypodontia were analyzed using analysis of variance (ANOVA) and post-hoc Tukey tests.Results:Significant decreases were found in mandibular plane angles (P < .05), upper and lower incisor measurements (P < .05), anterior (P < .001) and posterior (P < .05) face heights, and ramus height (P < .01), as well as a significant increase in the soft tissue convexity angle (P < .05) among the hypodontia groups and control group. These differences were more excessive in the severe hypodontia group. Upper lip-E plane measurements were significantly longer in the mandible group than in the maxilla group (P < .01).Conclusions:Patients with congenitally missing teeth have different craniofacial morphologies. The severity and location of missing teeth have a significant effect.     

Absolute and relative growth of the rat craniofacial skeleton

Growth of the craniofacial region involves a mosaic of intramembranous and endochondral growth sites that grow at varying rates and mature at different times. OBJECTIVE: The goal of this study was to compare absolute and relative growth of the craniofacial skeleton in wild-type Lewis rats to measures of somatic growth. DESIGN: Lateral and dorsoventral X-rays of the head as well as the hindlimb were obtained weekly from 4 to 9 weeks of age. The X-rays were scanned, digitized, and selected linear distances were measured between points. Multilevel statistical models were used to generate absolute growth curves. RESULTS: Although most growth curves were linear, several were quadratic (exhibiting a deceleration with age), and one displayed a third-order curve. Considerable variation in relative maturity was evident at the first time interval, ranging from 42% of mature (9 week) size (weight) to 97% of mature size (cranial width). Tibial length and body weight were less mature than most, but not all, craniofacial measures. With one exception (bizygomatic width), width measures were relatively more mature than vertical or depth measures. Vertical measures tended to be among the least mature of the craniofacial dimensions. Among the depth (length) measurements, there was a trend of higher maturity for cranial vault/cranial base measures and lower maturity for facial measures. Conclusions: The wide spectrum of relative and absolute growth potentials demonstrated in this study indicate that the rodent craniofacial complex is amenable to testing the hypothesis that a component's response potential is related to its growth potential.     

恒牙初期安氏Ⅱ~1错不同骨面型颅底形态变化的头影测量分析

目的:探讨安氏Ⅱ1错牙合不同骨面型的颅底形态特征。方法:选取恒牙初期的正常牙合和Ⅱ1错牙合均角型、高角型、低角型的X线头颅侧位片各30张,男女各半,通过X线头影测量分析,比较Ⅱ1错牙合3种骨面型和正常牙合的颅底形态变化。结果:Ⅱ1错牙合3种骨面型均表现为颅基底角(Ba-SE-FMS)增大,高角组尤其表现在颅前基底角(FMS-SE-PM)增大,均角组、低角组颅中基底角(Ba-SE-PM)增加更为明显。Ⅱ1错牙合颅底的有效垂直高度从低角组、均角组、高角组依次减小。结论:颅基底角可能更准确反映颅底的曲度,体现Ⅱ1错牙合不同骨面型形成的机制。     

Prevalence and genetic basis of tooth agenesis

Tooth agenesis or hypodontia is one of the most common anomalies of the human dentition, characterized by the developmental absence of one or more teeth. Many studies have reported that the prevalence of congenital absence of permanent teeth varies from 3% to 11% among European and Asian populations. Recent advances in the fields of molecular biology and human genetics have improved our understanding of the cause of tooth agenesis. In this review, we assess the previous literature on prevalence of tooth agenesis comparing the Japanese with other racial populations, and describe the recent genetic studies associated with hypodontia in human and mouse models.     

The influence of the extend of isolated palatal cleft on craniofacial morphology

PurposeThe aim of this study was to determine what influence that extent of cleft may have on craniofacial morphology in children with a cleft palate by retrospectively comparing craniofacial morphologies in age-matched prepubertal children.Materials and methodsUsing a retrospective study design, we compared the craniofacial morphology cephalometrically, of 14 Japanese girls at age 9 years with a cleft soft palate (Group_CSP), with 13 age-matched Japanese girls with cleft soft and hard palate, not extending as far as the incisive foramen (Group_CPNIF), and 12 age-matched Japanese girls with cleft soft and hard palate, extending as far as the incisive foramen (Group_CPIF), living in the same region (Hokkaido, Japan). None of them had received dentofacial orthopaedic treatment. P < .05 was considered statistically significant.ResultsIn Group_CPNIF, the maxilla was significantly short (P < .05), the anterior parts of the maxilla being retruded (P < .05), compared with Group_CSP and, compared with Group_CPNIF, in Group_CPIF, anterior part of the maxilla was positioned posteriorly (P < .05), the maxillary body was significantly smaller (P < .01).ConclusionsThis study suggests that in prepubertal children, as the congenital defect in the tissue of the palate extended, the shortness in the anteroposterior maxillary length, accompanying anterior part of the maxilla in posterior position, was more marked.     

Cephalometric craniofacial features in Saudi parents and their offspring

Objective:To estimate the correlation and heritability values of craniofacial variables between parents and their offspring.Materials and Methods:The sample comprised 24 Saudi families; each family consisted of father, mother, son, and daughter. Lateral cephalometric radiographs were taken for each family member. Twenty-eight angular, linear, and proportional cephalometric variables were measured. Interfamilial correlations and heritability (h²) values were estimated among father-son, father-daughter, mother-son, and mother-daughter pairings.Results:The most similar angular measurements between parents and offspring were related to mandibular variables, which were as follows: MP-SN°, MP-FH°, SNB°, and SNPog°; facial height dimensions and mandibular body length were among the highest similar linear variables. Lower facial height percentage had greater resemblance to parents with regard to proportional measurements. Both the correlation coefficients and the heritable values of these characteristics were stronger in the father-offspring than the mother-offspring pairings. The daughters'' cephalometric craniofacial characteristics were more affected by the parents than were those of the sons.Conclusions:The overall correlation and h² mean values for the three types of measurements showed stronger values in the father-offspring than the mother-offspring groups, with the father-daughter pairings more significant than the father-son groups.     

Head Posture and Cervicovertebral and Craniofacial Morphology in Patients with Craniomandibular Dysfunction

A relationship between particular characteristics of dental occlusion and craniomandibular disorders (CMD) has been reported, while less attention has been focused on the possible effect of dysfunction of the masticatory system on head posture or cervicovertebral and craniofacial morphology. Natural head position roentgen-cephalograms of 16 young adults with complete dentition taken before and after stomatognathic treatment displayed an extended head posture, smaller size of the uppermost cervical vertebrae, decreased posterior to anterior face height ratio, and a flattened cranial base as compared with age-and sex-matched healthy controls. The lordosis of the cervical spine straightened after stomatognathic treatment. The results are an indication of the close interrelationship between the masticatory muscle system and the muscles supporting the head, and lead to speculation on the principles of treating craniomandibular disorders.     

西安地区恒牙早期Ⅲ类错颅面类型构成分析

目的：分析西安地区恒牙早期Ⅲ类错颅面类型的构成。方法：以本院正畸科2003～2008年恒牙早期Ⅲ类错患者为研究对象,采用计算机辅助X线头影测量技术,分析恒牙早期Ⅲ类患者在矢状向与垂直向的构成。结果：恒牙早期Ⅲ类错矢状向主要表现形式为双颌发育基本正常或上颌正常,下颌发育过度。垂直向主要表现为均角型。低角型、高角型差异不显著。交叉分析显示：上下颌均发育正常的均角型患者和上颌正常,下颌发育过度的均角型患者最多见;其次是上颌发育不足,下颌正常的均角型患者。结论：恒牙早期Ⅲ类错在矢状向与垂直向均表现出一定的趋势,分析与研究这类错的构成加深了对西安地区Ⅲ类错患者颅面类型的认识,并对临床上合理矫治提供一定的参考。     

Maturational and functional related differences in rat craniofacial growth

BACKGROUND: Whilst decreases in masticatory muscle function have been linked with increased prevalences of craniofacial dysmorphology and malocclusion in humans, the relative susceptibility of the different craniofacial components remains poorly understood. METHODS: Thirty-two wild-type male Sprague-Dawley rats were randomly assigned to two groups (n=16 each), one raised on a soft diet (SD) and the other on a hard diet (HD). Body weights and three radiographs (lateral, dorso-ventral, and tibial X-rays) were taken at baseline (T1=23 days old) and every 2 weeks thereafter for 8 weeks (T5=79 days old). The X-ray images were scanned, standardised points were digitised, and linear measurements were calculated. Multilevel statistical models were used to describe longitudinal absolute growth changes and statistically evaluate group differences. Relative maturity curves were generated for each measurement based on the animals' T5 status. The experimental effect was calculated as the absolute and relative growth differences between the HD and SD groups. RESULTS: The HD group was significantly heavier than the SD group at T5, but no differences in tibial length were observed. Eight of the 20 craniofacial measurements (40%) showed significant size differences at the end of the experiment, with the SD group showing deficiencies in each instance. All of the vertical measurements, as well as most of the mandibular (67%) and transverse (67%) measures, showed absolute growth deficits in the SD group. Relative maturity curves demonstrated considerable variation among craniofacial structures (ranging from 42 to 98%). The neurocranial measures were the most mature; the mandibular measures were the least mature; the viscerocranial measures, which were most variable, tended to be intermediate. Whilst unrelated to the absolute experimental effect, the structures' relative maturity explained almost 70% (r=-0.82) of the relative experimental effect. CONCLUSION: The results of this study support the notion that masticatory function is a key determinant of the craniofacial growth pattern and that its effects are modulated by the relative growth potential of the different craniofacial components.     

不完全性腭裂修复术后患者替牙期的颅面特征初探

目的比较不完全性腭裂患者修复术后与健康儿童替牙期颅面形态的差别，进一步了解不完全性腭裂患者的颅面特征。方法选择20例不完全性腭裂修复术后，处于替牙期的患者作为腭裂组，年龄7～11岁；选择年龄、性别匹配的非腭裂健康儿童35名作为对照组。对两组研究对象的头颅侧位X线片进行X线头影测量对比分析。结果腭裂组全颅底长、上颌长、下颌有效长度分别为86．48mm、44．79mm、65．45mm，对照组分别为91．27mm、48．84mm、70．49mm，差异均有统计学意义（P〈0．001）。结论不完全性腭裂患者颅面部发育不足，呈Ⅲ类骨面型。