前方牵引治疗单侧完全性唇腭裂患者术后前牙反(牙合)畸形的研究

Objective To investigate the effects of maxillary protraction on anterior crossbite in repaired pre-pubertal patients with complete unilateral cleft lip and palate(UCLP).Methods Prospective controlled clinical trial was carried out.Eighteen UCLP patients with anterior crossbite,aged 9.63±1.24 years,were the experimental subjects.Fourteen UCLP patients with similar malocclusion,aged 8.71±1.92 years,were selected as controls.All patients were before puberty according to the evaluation of the hand wrist radiograms.A Hyrax appliance and reverse headgear were applied.Lateral cephalometric radiographs were taken before and after the treatment.Computerized cephalometric analysis was carried out.Results After treatment in experimental group.the maxilla moved forward more significantly.The mandible rotated downward and backward.The intermaxillary relationship and soft tissue profile improved significantly.The rate of maxillary and mandibular Contribution was 1:1.7. ConelusionsMaxillary protraction could improve the imermaxillary relationship and soft tissue profile in UCLP patients with mild or moderate skeletal deformity before puberty.     

OSAHS患者戴用口腔矫治器后颅面、上气道改变的追踪研究

Objective To investigate dental and skeletal changes of oral appliance treating of obstructive sleep apnea and hypopnea syndrome in long-term treatment. Methods A total of 25 patients were included in the study.The cephalometric study was used to investigate the dental,skeletal and airway changes.Results 25 patients were treated with an oral appliance for a mean duration of 5 years.Significant retroclination of the maxillary incisors(3.34±3.36°,P＜0.001)and proclination of the mandibular incisors(1.78±3.06°,P=0.008)were accompanied by reductions in overbite(1.46±1.12 mm,P＜0.001)and oveoet(1.12±0.99 mm,P＜0.001).The MP-FH,MPSN angles increased 1.3°,the face height and the distance between the hyoid and FH plane increased.Conclusions The orthodontic side-effects on the dental,skeletal and airway are sinail during the treatment of patients with OSAHS.     

长春市某小学7～12岁儿童福赛斯坦氏菌和中间普氏菌分布状态调查

Objective To detect the presence of Tannerella forsythus(Tf)and Prevotella intermedia (Pi) using polymerase chain reaction(PCR) in the oral plaque samples from children and investigate the relationship between bacteria and clinical parameters. Methods A total of 151 children aged 7 to 12 years were selected from Changchun primary school. The supragingival plaque sample was collected from the mesiobuccal and labial surfaces of the right maxillary central incisor ( FDI 1 ) and the right maxillary first molar ( FDI 6 ). Extracted DNA from plaque samples was used for PCR analysis. Intraoral examination,probing depth (PD) and bleeding on probing (BOP) were performed and recorded. Results The detection rate for Tf was 40. 3% ( 118/293 ) and Pi was 46. 4% ( 136/293 ) in supragingival plaque. The detection rates for Tf and Pi in molars were much higher than those in incisors( P ＜0. 01 ). The detection rate of Tf and Pi was positively related to BOP + and PD. The detection rate for Pi decreased gradually with age, and the detection rate for Tf was highest in the group aged 7 to 8 and the detection rates for Tf and Pi were higher in the gingiva with BOP + than that with BOP - ( P ＞ 0. 05 ). The detection rates for Tf increased remarkably with BOP + and especially when PD was greater than 4 mm. Conclusions Detection rates of putative periodontal pathogens from healthy children of 7 to 12 years of age were high. The detection rates for Tf and Pi in molars were much higher than those in incisors, and the presence of Tf and Pi in supragingival plaque was related to periodontal parameters.     

唇腭裂患者上颌前部牙槽骨厚度及骨开窗、骨开裂的三维评价研究

目的　利用锥形束CT（cone-beam CT,CBCT）评价不同类型唇腭裂患者上颌前部牙槽骨厚度和形态,以及上前牙骨开窗、骨开裂情况。方法　选择016年8月至019年10月间在南京医科大学附属口腔医院就诊拟行口腔正畸治疗的唇腭裂患者85例（男51例,女34例,平均年龄（14.65±4.95）岁）,其中单侧唇裂伴牙槽突裂（unilateral cleft lip and alveolus,UCLA）患者19例,单侧完全性唇腭裂（unilateral complete cleft lip and palate,UCLP）患者5例,双侧完全性唇腭裂（bilateral complete cleft lip and palate,BCLP）患者14例。在正畸治疗开始前均予以拍摄颌面部CBCT,应用Image J软件测量其上前牙唇腭侧牙槽骨厚度（alveolar bone thickness,ABT）,计算骨开窗、骨开裂发生率,并比较不同唇腭裂类型患者上颌前部ABT及上前牙骨开窗、骨开裂发生率的差异。结果　UCLP、UCLA患侧上前牙骨开裂发生率（34.9%、4.9%）显著高于其健侧（10.7%、11.1%）,但骨开窗发生率无统计学差异。UCLP健侧上中切牙（5.9%）、侧切牙（9.7%）骨开裂发生率低于UCLA。UCLA、UCLP、BCLP三组间患侧上前牙骨开裂及骨开窗发生率均无统计学差异。UCLP、UCLA患侧上前牙ABT在多部位小于其健侧。除UCLP/UCLA患侧侧切牙外,UCLA、UCLP、BCLP各类型上前牙唇侧平均ABT均小于腭侧。UCLA、UCLP、BCLP三组间患侧上前牙唇腭侧平均ABT无统计学差异。UCLP患侧上侧切牙、尖牙分别在唇侧和腭侧根颈处ABT大于UCLA。结论　单侧唇腭裂患者患侧上前牙骨开裂发生率高于健侧,ABT则在多部位小于其健侧;而三种类型患者上前牙唇侧ABT均小于其腭侧。单侧唇裂伴牙槽突裂与单侧完全性唇腭裂患者健侧上中切牙、侧切牙骨开裂发生率及患侧侧切牙、尖牙根颈处牙槽骨厚度存在差异;单侧与双侧完全性唇腭裂间上前牙骨开窗、骨开裂发生率及牙槽骨厚度则无差异。     

Clinical study of correction of ClassⅡdivision 1 malocclusion with improved mandibular lip bumper in mixed dentition

Objective To evaluate the early treatment effects of improved mandibular lip bumper on patients with Angle Class Ⅱ,Division 1 malocclusion in mixed dentition.Methods According to inclusion criteria of the study,six patients with Angle Class Ⅱ,Division 1 malocclusion in mixed dentition were selected and treated with improved mandibular lip bumper and maxillary removable appliance.Cephalometric analysis was performed before and after treatment.Resuits The improved appliance could stimulate the growth of mandible.After treatment,overjet and molar relationship improved.Conclusions The improved mandibular lip bumper can interrupt lip-biting and is helpful to achieve growth modification in treating Class Ⅱ,Division 1 malocclusion.     

拔除下颌第三磨牙矫治14～23岁骨性Ⅲ类错(牙合)的临床效果观察

目的 分析拔除下颌第三磨牙矫治骨性Ⅲ类错(牙合)畸形后患者牙(牙合)面的变化,探讨该矫治模式的适应证、疗效和临床意义.方法 选择处于生长发育减速期和结束期的骨性Ⅲ类错(牙合)畸形患者19例(女性16例,男性3例),拔除下颌第三磨牙,配合摇椅形弓和短Ⅲ类牵引技术矫治骨性Ⅲ类错(牙合)畸形.通过头影测量对患者治疗前后的骨骼和牙齿变化进行评估,并进行配对t检验.结果 治疗后下颌切牙和磨牙发生明显的舌向移动,下切牙至Y轴的距离由治疗前的65.96 mm减至治疗后的63.98 mm,向远中移动(1.98±1.36)mm.下颌第一磨牙至Y轴的距离由治疗前的43.00 mm减至治疗后的39.84 mm,向远中移动(3.16±1.23)mm.矫治后下颌第一磨牙向远中倾斜(12.37±6.81)°,前牙覆盖增加(2.75±1.65)mm,矫治前后差异有统计学意义(P<0.05).结论 拔除下颌第三磨牙配合摇椅形弓和短Ⅲ类牵引技术可明显远中移动下颌磨牙和切牙.

Abstract：

Objective To assess the skeletodental changes after extracting mandibular third molars in skeletal Class Ⅲ patients in both post-puberty and adult.Methods Nineteen skeletal Class Ⅲ patients in post-puberty or adult(16 female,3 male)successfully treated with extracting mandibular third molars were included in the study.Cephalograms were analyzed to assess the skeletal and dental changes before and after treatment.Paired t-test was performed for statistical analysis of the data.Results The results revealed that the main changes were upright[(12.37±6.81)°]and distal movement[(3.16±1.23)mm]of the mandibular molars,and retraction[(1.98 ±1.36)mm]of the mandibular incisors.There was a significant improvement in overjet[(2.75±1.65)mm].Conclusions The lower molars and incisors could be distalized significantly with extraction of the lower third molars.     

台阶式垂直闭合曲内收上颌切牙的三维有限元分析

目的 研究台阶式垂直闭合曲在三维空间内对上颌切牙位置的控制作用.方法 选择一名正常 志愿者,对其上颌牙列和牙槽骨进行三维螺旋CT扫描,只对上颌右侧中、侧切牙及牙槽骨进行建模和数据计算,利用Ansys软件生成右侧弓丝-托槽-上颌切牙段及牙周支持组织的三维有限元模型,最后根据镜像对称原理建立弓丝-托槽-上颌切牙段及牙周支持组织的三维有限元模型.模拟台阶式垂直闭合曲在临床上的使用情况加力,分析上颌切牙的位移趋势以及牙周支持组织中的应力分布规律.结果 台阶式垂直闭合曲作用下,上颌中切牙舌向、唇向最大位移分别为5.29×10-2和0.71×10-2 mm;龈向、向最大位移分别为10.47×10-3和10.20×10-3 mm;近中、远中最大位移分别为10.26×10-3和1.63×10-3 mm;侧切牙舌向、唇向最大位移分别为3.31×10-2和0.41×10-2 mm;龈向、向最大位移分别为10.52×10-3 和5.10×10-3 mm;近中、远中最大位移分别为6.29×10-3 和4.64×10-3 mm;二者均表现为舌向、龈向的近似整体移动趋势.中切牙牙齿、牙周膜、牙槽骨的最大应力值分别为31.35、2.52、4.64 MPa;侧切牙牙齿、牙周膜、牙槽骨的最大应力值分别为19.59、1.28、4.12 MPa;二者的应力分布规律相似,牙周膜对应力起缓冲作用.结论 台阶式垂直闭合曲在上颌切牙内收阶段可控制其在三维方向上的位置,对抗"钟摆效应",对临床实践具有一定参考意义.

Abstract：

Objective To investigate the displacement and stress distribution of upper incisors in three-dimensional(3D) space controlled by step-shaped vertical closing loop. Methods The maxillary teeth and alveolar bone of a volunteer with normal occlusion were scanned with 3D spiral CT. Modeling and calculation were only carried out on right upper central incisor, lateral incisor and their alveolar bone in order to simplify the procedures. A 3D finite element model of archwire-brackets-upper incisors and periodontal tissues was developed using Ansys finite element package. Finally, a 3D finite element model of archwire-brackets-upper incisors and periodontal tissues was established based on mirror symmetry principle. The displacement of maxillary incisors and stress distribution in periodontal tissues were analyzed. ResultsWhen step-shaped vertical closing loop was simply drew back 1 mm, the maximum displacement of upper central incisor in labial and lingual direction were 5.29×10-2 and 0.71×10-2 mm; 10.47×10-3 and 10.20×10-3 mm in gingival and occlusal direction, 10.26×10-3 and 1.63×10-3 mm in medial and distal direction; the maximum displacement of upper lateral incisor in labial and lingual direction were 3.31×10-2 and 0.41×10-2 mm, 10.52×10-3 and 5.10×10-3 mm in gingival and occlusal direction, 6.29×10-3 and 4.64×10-3 mm in medial and distal direction, the displacement trend of them were moving lingually and gingivally similar to bodily movement. The stress peach of upper central incisor, periodontal ligament and alveolar bone were 31.35, 2.52 and 4.64 MPa, the stress peach of upper lateral incisor, periodontal ligament and alveolar bone were 19.59, 1.28 and 4.12 Mpa, the stress distribution of them were similar and the periodontal ligament buffered the stress imposed on the tooth. Conclusions The position of upper incisors in 3D space could be controlled by step-shaped vertical closing loop and the pendulum effect could be confronted.     

替牙期骨性Ⅲ类单侧完全性唇腭裂患者修复术后口周力的分布特征

目的:通过与同龄非唇腭裂正常 儿童比较,研究替牙期骨性Ⅲ类单侧完全性唇腭裂(unilateral cleft lip and palate,UCLP)患者上下颌不同位点口周力的特征。 方法:选取替牙期6～12岁UCLP患者20例(男14例,女6例)为UCLP组;同龄正常 儿童21例(男14例,女7例)为对照组。采用口周肌压力采集系统测量每个研究对象息止 位时双侧上下颌中切牙、尖牙或乳尖牙、第一前磨牙或乳磨牙、第一恒磨牙的唇颊、舌腭侧龈缘的口周力。使用SPSS 25.0统计软件对数据进行统计分析。 结果:1．UCLP组上颌口周力裂侧大于非裂侧( P<0.05),下颌口周力两侧无差异( P>0.05)。2. UCLP组上颌口周力大于对照组( P<0.05),两组上颌唇颊侧的口周力均在第一前磨牙/乳磨牙区最大,在中切牙区最小。3. UCLP组下颌唇颊侧口周力小于对照组( P<0.01),下颌中切牙舌侧区UCLP组大于对照组( P<0.05)。4. UCLP组上颌牙弓内外口周力差值大于对照组( P<0.05),下颌差值小于对照组( P<0.01)。 结论:替牙期骨性Ⅲ类UCLP患者口周力较同龄非唇腭裂正常 儿童存在异常。     

*"All-on-4"种植即刻修复技术的临床应用研究

Objective To evaluate the preliminary clinical results of application of All-on-4 immediate junction in edentulous patients. Methods Twenty nine edentulous patients with 140 immediately loaded implants supporting fixed complete-arch all-acrylic prostheses from April 2008 to October 2009 in Peking University School of Stomatology were included. The implant-supported fixed complete-arch all-acrylic prostheses were delivery on the operation day. At time of abutments connection, a panoramic radiograph was taken. And radiographic assessment of the marginal bone level was performed in every 2 months. Clinical observe items included marginal bone level, integrity of the restoration,survival of the implants and degree of satisfaction of the patients. Results A total of 140 implants were immediate loading. Eight implants were lost during 6-8 weeks after immediate loading, giving survival rate of 94. 3% . The marginal bone level was (0. 8 ± 0.4) mm . The All patients were satisfied with the clinical results. Conclusions The data and the experience described in this study indicate that All-on-four immediate function technique can be a predictable technique for edentulous patients. Further study is needed to determine the long-term result of the technology.     

*"All-on-4"种植即刻修复技术的临床应用研究

Objective To evaluate the preliminary clinical results of application of All-on-4 immediate junction in edentulous patients. Methods Twenty nine edentulous patients with 140 immediately loaded implants supporting fixed complete-arch all-acrylic prostheses from April 2008 to October 2009 in Peking University School of Stomatology were included. The implant-supported fixed complete-arch all-acrylic prostheses were delivery on the operation day. At time of abutments connection, a panoramic radiograph was taken. And radiographic assessment of the marginal bone level was performed in every 2 months. Clinical observe items included marginal bone level, integrity of the restoration,survival of the implants and degree of satisfaction of the patients. Results A total of 140 implants were immediate loading. Eight implants were lost during 6-8 weeks after immediate loading, giving survival rate of 94. 3% . The marginal bone level was (0. 8 ± 0.4) mm . The All patients were satisfied with the clinical results. Conclusions The data and the experience described in this study indicate that All-on-four immediate function technique can be a predictable technique for edentulous patients. Further study is needed to determine the long-term result of the technology.     

Hypodontia in children with various types of clefts

The prevalence of hypodontia in children with clefts, both inside and outside the cleft region, and the possible association between the side of the cleft and the side of the missing teeth were studied using radiographs of 278 patients with cleft lip, cleft palate, or both (158 boys and 120 girls), age 5 to 18 years (mean age 10.4 years). A hypodontia prevalence of 77% (excluding third molars) was found for the total cleft sample. This was significantly higher, both statistically and clinically, than the incidence of hypodontia reported for noncleft populations, and considerably higher than the prevalence reported in other studies of children with clefts. The maxillary permanent lateral incisors were the teeth most frequently missing on the cleft side (259 teeth) followed by the maxillary (47 teeth) and mandibular (23 teeth) second premolars, in both boys and girls. The teeth that were most often missing on the noncleft side were the maxillary second premolars (12 teeth), followed by the maxillary lateral incisors (10 teeth) and mandibular second premolars (6 teeth). Hypodontia of both the maxillary lateral incisors and second premolars was found more frequently on the left side, which also has a higher frequency of clefting.     

An audit of concomitant dental anomalies with maxillary talon cusps in a group of children from Hong Kong

AIM: To investigate the prevalence of various concomitant dental anomalies in Hong Kong children with true talon cusps on the permanent maxillary incisors. METHODS: Dental records and radiographs of a group of Hong Kong Chinese primary schoolchildren with true talon cusps (half crown height or more) on one or more permanent maxillary incisors were selected and studied retrospectively. The prevalence of various dental anomalies in this group of children was compared with that of the general population of Hong Kong Chinese children of similar age. RESULTS: A total of 11,537 records were reviewed and 58 children with true talon cusps on one or more permanent maxillary incisors were identified. A total of 69 permanent maxillary incisors were affected, of which all except one were lateral incisors. Dens evaginatus on premolars, supernumerary teeth in the anterior maxilla, and hypodontia were found in 5 (8.6%), 5 (8.6%), and 5 (8.6%) cases respectively. The prevalence of supernumerary teeth was significantly higher in children with true talon cusps as compared with the results of two previous general studies of Chinese children of similar age (P<0.05, Fisher's exact test). CONCLUSION: Children with true talon cusps on the permanent maxillary incisors were more frequently affected by supernumerary teeth in the anterior maxilla. Further studies with a larger sample are needed to confirm a true association.     

Prevalence of abnormalities in dental structure, position, and eruption pattern in a population of unilateral and bilateral cleft lip and palate patients.

OBJECTIVE: To evaluate the dental characteristics of patients subjected to a protocol that included early secondary gingivoalveoloplasty (ESGAP). DESIGN: Panoramic radiographs of 87 patients with unilateral cleft lip and palate (UCLP) and 29 with bilateral cleft lip and palate (BCLP) were evaluated. Missing and supernumerary teeth were also quantified on the cleft and noncleft side and in the maxilla and mandible. Crown and root malformations and tooth rotations were quantified. A subsample in permanent dentition was extrapolated to analyze canine eruption patterns. RESULTS: A total of 48.8% of the UCLP patients presented with missing permanent lateral incisors in the cleft area and 6.1% contralaterally. A total of 4.9% presented with missing second maxillary premolars on the cleft site and 1.2% contralaterally. A total of 7.3% presented with supernumerary lateral incisors, and 45% of the BCLP cleft sites presented with missing lateral incisors, while 25% of the cleft sites presented second maxillary premolars agenesis. Five percent of the cleft sites presented with supernumerary lateral incisors. Evaluation of the subsample in permanent dentition showed that 15.5% had a canine retention and 4.4% of the canines had to be surgically exposed. A significant association was observed between canine inclination and retention but not with absence of the lateral incisor. CONCLUSIONS: The frequency of dental anomalies in this sample was similar to other cleft populations. As surgical trauma has been suggested to damage forming teeth, the results of this study indicated that ESGAP has no detrimental influence on subsequent dental development.     

Evaluation of dehiscence and fenestration in adolescent patients affected by unilateral cleft lip and palate: A retrospective cone beam computed tomography study

Objective:To evaluate the presence of dehiscence and fenestration defects around anterior teeth in the cleft region and to compare these findings with the noncleft side in the same patients using cone beam computed tomography (CBCT).Materials and Methods:CBCT scans of 44 patients (26 males, 18 females; mean age, 14.04 ± 3.81 years) with unilateral cleft lip and palate (UCLP) were assessed to define dehiscences and fenestrations of the anterior teeth in both cleft and noncleft sides of the UCLP patients and a control group of noncleft patients (51 patients; 21 males, 30 females; mean age, 14.52 ± 1.16 years). Data were analyzed using Pearson’s χ² and Student’s t-test.Results:The prevalence of dehiscences at the maxillary central incisors, lateral incisors, and canines teeth were 43.2%, 70.6%, and 34.1% on the cleft side and 22.7%, 53.1%, and 27.3% on the noncleft side of UCLP patients, and 13.7%, 7.8%, and 13.7% in controls, respectively (statistically no difference between the sides of cleft patients). The cleft patients had a statistically significantly higher prevalence of dehiscences than did the controls on both the cleft and noncleft sides (P < .05), except for the maxillary central incisors. Fenestrations for these teeth were significantly more common on the cleft side in UCLP patients compared with controls (P < .05), whereas the difference for maxillary lateral incisors was not statistically significant.Conclusions:Patients with UCLP showed a higher prevalence of dehiscence and fenestration defects around the maxillary anterior teeth.     

Dental abnormalities, bone graft quality, and periodontal conditions in patients with unilateral cleft lip and palate at different phases of orthodontic treatment.

OBJECTIVES: To evaluate the dental and periodontal condition of patients with unilateral cleft lip and palate (UCLP) before orthodontic treatment and evaluate whether the dental and periodontal condition of these patients during and after orthodontic treatment was jeopardized by the duration of the orthodontic and surgical treatment. DESIGN: Seventy-five individuals with UCLP (52 males, 23 females), between ages 8 and 20 years, participated in a retrospective study during their final follow-up visit with regard to dental abnormalities, such as hypodontia, external root resorption, crown and root malformation, and supernumerary teeth. Alveolar bone height and periodontal attachment loss on the cleft side were also screened before or after bone grafting and at different stages of orthodontic treatment. RESULTS: Hypodontia of the lateral incisor was found in more than 50% of the patients on the cleft side. Second premolars and/or lateral incisors outside the cleft area were missing in 27.2% of the patients. In 32%, malformations of the teeth near the cleft were noticed. In general, the teeth around and in the cleft of the patients showed normal septal bone heights and a healthy periodontium. Sixty of the 75 patients received a bone graft to restore the interrupted alveolar process. In 93.3% of these patients, the cleft was grafted before the eruption of the canine. CONCLUSION: The periodontium of the teeth in and around the cleft in patients with UCLP observed during and after orthodontic treatment can cope relatively well with the long orthodontic treatment and combined surgical interventions. The children, who had not yet started treatment, also showed enough bone support and no periodontal problems of the teeth besides the cleft. Early secondary bone grafting seems to give optimal periodontal results.     

Maxillary lateral incisors of subjects with cleft lip and/or palate: Part 2.

Maxillary lateral incisors on the alveolar cleft were investigated in 431 cleft children registered in the Department of Orthodontics, Kyushu University Dental Hospital. The majority of primary maxillary lateral incisors were located on the distal side of the alveolar cleft in both unilateral cleft lip and alveolus (UCLA) and unilateral cleft lip and palate (UCLP) subjects. Permanent teeth in UCLA tend to be located distally, but in UCLP they tend to be congenitally absent (p less than .01). The majority of primary teeth had normal shapes; the majority of permanent teeth were of intermediate type or were missing congenitally. One third of the UCLA and one half of the UCLP subjects who had primary maxillary lateral incisors were not followed by permanent replacements. The location of the majority of permanent maxillary lateral incisors tallied with that of the primary ones except in four UCLA, ten UCLP, and two bilateral cleft lip and palate (BCLP) subjects. Four UCLA and ten UCLP subjects who had primary lateral incisors on the distal side were followed by their permanent successors on the mesial side. Three UCLP and one BCLP subjects had permanent maxillary lateral incisors even though they had no temporary predecessors.     

Left-sided predominance of hypodontia irrespective of cleft sidedness in a French population

Objective : Individuals with oral clefts exhibit considerably more dental anomalies than do individuals without clefts. Our aim was to evaluate the prevalence of tooth agenesis in a sample composed of 124 children (81 boys and 43 girls, mean age 12.5?years) with clefts registered with the Cleft Palate Center in Strasbourg (France). Design : Cleft types and dental agenesis were assessed by clinical and radiographic examination. Cleft types were divided into four groups according to the clinical extent of the cleft (cleft lip only [CL, 12.9%], cleft lip and alveolus [CLA, 4%], cleft lip and palate [CLP, 49.2%], and cleft palate only [CP, 33.9%]). Results : Of the subjects 63% had evidence of hypodontia: maxillary lateral incisors (54%) and upper and lower premolars (32%) were the most common missing teeth. The number of dental ageneses associated with CP (54%) and CLP (79%) was significantly higher than that with CL (33%). All these anomalies were found in proportionately higher frequencies as the severity of the cleft increased, and we found left side predominance for hypodontia (p < .01) irrespective of cleft sidedness. Conclusions : Both right-sided and left-sided clefts were more frequently correlated with left-sided dental agenesis. This left-sided prevalence suggests that common signaling malfunctions might be involved, both in dental development anomalies and cleft genesis.     

乌鲁木齐地区青少年恒牙形态及数目异常的分析

目的探讨乌鲁木齐地区青少年先天缺失牙、多生牙、过小牙的发生率及好发部位。方法本文观察和分析了620例患者的全颌曲面体层X线片．均无恒牙拔牙史或牙齿损伤史。结果先天缺失牙（包括第三磨牙）的发生率为45．48％,第三磨牙的缺失发生率为32．58％,缺失牙的好发部位依次为上颌第三磨牙、下颌第三磨牙、下颌侧切牙、下颌中切牙、上颌第二双尖牙等;多生牙发生率为2．58％,好发部位是上颌切牙区。过小牙的发生率为6．30％．其主要为上颌侧切牙。结论牙齿先天缺失在人群中的发生率明显高于多生牙．缺失牙主要发生在功能相对弱的牙位上：缺失牙与过小牙之间存在一定联系．     

Dental abnormalities in permanent dentition in children with submucous cleft palate

Seventy-three children with submucous cleft palate (38 girls and 35 boys), mean age 8.2 years (range 7.7-9.5), were studied retrospectively from orthopantomograms. Dental abnormalities in permanent dentition were found in 26 patients (36%). Missing teeth, mainly lower 2nd premolars, upper lateral incisors, and upper 2nd premolars, were found in 12 patients (16%). Most of the patients had 1 or 2 missing teeth, 2 had 3 missing teeth. In 5 patients hypodontia was associated with another dental abnormality. Other dental abnormalities included peg-shaped lateral incisors in 7 patients (10%), ectopic eruption of upper 1st molars in 6 patients (8%), transposition of upper canines and 1st premolars in 3 patients (4%), supernumerary teeth in 2 patients (3%), and palatally displaced upper canines in 1 patient (1%). As children with submucous cleft palate have a tendency towards increased frequency of missing teeth and other dental abnormalities, the need for thorough clinical and radiological dental examination is emphasized.