中老年人群牙颈部非龋性缺损与（牙合）面磨损的临床分析

目的：调查中老年人群牙颈部非龋性缺损（NCCL）与（牙合）面磨损发生情况,并对两者的发病因素和相互关系进行探讨。方法：对568名45岁及以上机关干部,使用Smith和Knight牙齿磨损指数（TWI）进行牙颈部非龋性缺损与（牙合）面磨损的患病情况调查。结果：该研究人群NCCL的患病率为73．24％,（牙合）面磨损患病率为87．50％。NCCL和（牙合）面磨损的患病率和严重程度与性别和年龄相关,发生（牙合）面磨损的患牙更易发生NCCL,反之亦然（P〈0．05）。该人群的磨牙症史、饮食习惯及刷牙方法与NCCL和（牙合）面磨损的发生没有明显相关性。结论：牙颈部非龋性缺损与（牙合）面磨损在中老年人中较常见,两者的发生有一定的联系,（牙合）力、机械摩擦和时间为其发生的共同因素,但加重原因不尽相同。     

Epidemiological evaluation of the multifactorial aetiology of abfractions

The purpose of this study was to determine risk indicators for the aetiology of abfractions (cervical wedge-shaped defects) on teeth using dental and medical variables obtained in a population-based sample of the cross-sectional epidemiological 'Study of Health in Pomerania' (SHIP). Medical history, dental, and sociodemographic parameters of 2707 representatively selected subjects 20-59 years of age with more than four natural teeth were checked for associations with the occurrence of abfractions using a two-level logistic regression model on a tooth and a subject level. The estimated prevalence of developing abfractions generally increased with age. The following independent variables were associated with the occurrence of abfractions: buccal recession of the gingiva, odds ratio (OR) = 6.7; occlusal wear facets of scores 1, 2 and 3, OR = 1.5, 1.9, 1.9; tilted teeth, OR = 1.4; inlays, OR = 1.6; toothbrushing behaviour, OR = 1.9 to 2.0 (two and three times a day versus once a day). First premolars had the highest estimated risk for developing abfractions, followed by the second premolars. Maxillary and mandibular teeth behaved similarly in terms of abfractions, with the exception of mandibular canines, which had a much lower estimated risk of incurring abfractions than did maxillary canines. The results of this analysis indicated that abfractions are associated with occlusal factors, like occlusal wear, inlay restorations, altered tooth position and tooth brushing behaviour. This study delivers further evidence for a multifactorial aetiology of abfractions.     

Relationship between the prognosis of periodontitis and occlusal force during the maintenance phase – a cohort study

Takeuchi N, Ekuni D, Yamamoto T, Morita M. Relationship between the prognosis of periodontitis and occlusal force during the maintenance phase – a cohort study. J Periodont Res 2010; 45: 612–617. © 2010 John Wiley & Sons A/S Background and Objective: Few studies have longitudinally investigated the relationship between periodontal disease progression and occlusal factors in individual subjects during the maintenance phase of periodontal therapy. The aim of this cohort study was to investigate the relationship between biting ability and the progression of periodontal disease in the maintenance phase. Material and Methods: A total of 194 patients were monitored for 3 years during the maintenance phase of periodontal therapy. The subjects with disease progression (Progress group) were defined based on the presence of ≥ 2 teeth demonstrating a longitudinal loss of proximal attachment of ≥ 3 mm or tooth‐loss experience as a result of periodontal disease during the study period. The subjects with high occlusal force were diagnosed as men who showed an occlusal force of more than 500 N and women who showed an occlusal force of more than 370 N. The association between biting ability and the progression of periodontitis was investigated using logistic regression analysis. Results: There were 83 subjects in the Progress group and 111 subjects in the Non‐progress group. A backward, stepwise logistic regression model showed that the progression of periodontal disease was significantly associated with the presence of one or more teeth with a high clinical attachment level (CAL) of ≥ 7 mm (odds ratio: 2.397; 95% confidence interval: 1.306–4.399) ( p = 0.005) and low occlusal force (odds ratio: 2.352; 95% confidence interval: 1.273–4.346) ( p = 0.006). Conclusion: The presence of one or more teeth with a high CAL of ≥ 7 mm and low occlusal force might be possible risk factors for periodontal progression in the maintenance phase of periodontal therapy.     

Teetester对于楔状缺损危险因素的初步探讨

目的 探讨引起楔状缺损的危险因素.方法 应用Teetester咬合分析系统对30例患者的420颗上颌牙齿进行咬合观测,记录早接触患牙、牙合分离时间及牙合力百分比,通过统计学方法分析楔状缺损的危险因素.结果 上颌各类楔状缺损患牙中,前磨牙占比最高,为46.49％;64颗早接触牙齿中42颗伴有楔状缺损,经卡方检验,Pear...     

A study of the influence of occlusal factors and parafunctional habits on the prevalence of signs and symptoms of TMD

PURPOSE: The purpose of this study was to investigate the prevalence of the clinical signs and symptoms of temporomandibular disorders (TMD) and the relationship between occlusal factors, parafunctional habits, and TMD in a young adult nonpatient population. MATERIALS AND METHODS: A questionnaire including data from a history and clinical functional examination was used in the study. All 230 subjects were male recruits, from 19 to 28 years of age (mean 21.3 years). RESULTS: Thirty-eight percent of the subjects reported at least one symptom, while in 45% of the subjects at least one sign of TMD was recorded. Temporomandibular joint clicking (40%) and pain on palpation (34%) were the most commonly recorded signs. Multivariate logistic regression analysis showed several weak but statistically significant correlations between the occlusal factors, parafunctional habits, and TMD in this nonpatient population. TMD signs were thus weakly correlated with malocclusion traits (angle Classes II/1, II/2, III, and cross bite), interferences in retruded contact position, midline discrepancy > or = 2 mm, < or = 10 contacts during maximal biting pressure, nonworking-side interferences, horizontal overlap > or = 5 mm, and parafunctional habits (teeth clenching and teeth grinding). CONCLUSION: Some association between occlusal factors and TMD signs was found. However, this association cannot be considered unique or dominant in defining subjects with TMD in the population.     

The relationship between missing occlusal units and oral health-related quality of life in SDA patients

The aim of this multi-center study was to explore the relationship between missing occlusal units and oral health-related quality of life (OHRQoL) in subjects with the shortened dental arches (SDAs). Subjects with SDAs were recruited consecutively for one month from six university-based prosthodontic clinics. In total, 115 SDA subjects participated (mean age, 58.5 +/- 10.0 yrs; 71% female). The location and number of missing teeth were examined and the number of missing occlusal units was calculated. To evaluate OHRQoL, the Japanese version of the Oral Health Impact Profile (OHIP-J) was administered and the summary score of OHIP-J was calculated. The SDA subjects were categorized depending upon the anterior-posterior lengths of the missing or remaining occlusal units. Regression analyses were performed to investigate 1) the association between missing OU and OHIP-J summary scores and 2) the OHIP-J differences between groups of subjects with various anterior-posterior SDA lengths. The first analyses revealed that one missing OU was significantly related to an increase of 2.1 OHIP-J units (95% CI: 0.6-3.5, P=0.016). The second analysis revealed that subjects who only lost the second molar contact exhibited significantly better OHRQoL than those who lost more teeth (Coefficient: 11.1, 95% CI: 2.8-19.2, P=0.02). Furthermore a statistically significant group difference was observed between the groups with and without the first molar occlusal contact (Coefficient: 12.8, 95% CI: 1.4 to 24.1, P=0.03). These results suggest that missing occlusal units are related to the OHRQoL impairment in subjects with SDAs. They also suggest that the patterns of missing occlusal units are likely to be related to the OHRQoL impairment in SDA subjects with the presence of first molar contact having an important role.     

Non‐carious cervical lesions (NCCLs) in a random sampling community population and the association of NCCLs with occlusive wear

This study investigated the prevalence, risk factors and association of occlusive wear with non‐carious cervical lesions (NCCLs) in the general Chinese population. A total of 1320 subjects were recruited, and multistage and random sampling methods of survey spots were performed. All age groups comprised similar numbers of participants and equal numbers of males and females. Each subject completed a structured interview, and all teeth of each subject were examined by a practitioner to determine NCCLs and occlusive wear. Binary logistic regression was conducted by analysing the association of risk factors with the occurrence of NCCLs. Bivariate correlation analysis was performed by determining the association of NCCLs dimension or depth with the range of occlusive wear facets. Clinical assessment showed that the overall prevalence of subjects diagnosed with NCCLs was 63%. The proportion of subjects or teeth with NCCLs significantly increased with age. Pre‐molars were the most commonly affected teeth. Single variables and interactive effects of variables associated with the occurrence of NCCLs include the following: age group, intensity of toothbrushing, frequency of fresh fruit consumption and interactive effect between intensity of toothbrushing and frequency of fresh fruit consumption. A weak positive correlation of the grading index was found between NCCLs dimension, size or depth and range of occlusive wear facets. This study reported the higher prevalence of NCCLs in the general Chinese population. Implementation of a combined strategy to reduce risk factors of NCCLs could be more effective than individual techniques; meanwhile, the occurrence of NCCL could be related to the wear degree of occlusive defects in the population studied.     

Dentine hypersensitivity in Jordanian dental attenders. A case control study

BACKGROUND: Dentine hypersensitivity (DH) is a common painful condition which affects a significant proportion of the adult population. AIMS: To investigate the relationship between DH and factors such as gingival recession, oral hygiene practices and smoking in Jordanian adults. METHODS: A case control study was performed on dental attenders in the Irbid region of Jordan. A DH group was composed of 126 subjects with a history of sensitivity who also reported discomfort of least two non-carious teeth after an air blast. Each case quantified their personal perception of the severity of pain associated with sensitivity by making a mark on a visual analogue scale The presence and extent of gingival recession was measured on plaster models. An age- and sex-matched control group of 134 subjects who complained of no discomfort was recruited. RESULTS: Independent predictors of DH in multivariate analysis were whether an individual had noticed their teeth getting longer (P = 0.01), infrequent (less than once per day) toothbrushing (P = 0.001), smoking (P = 0.0006) and the presence of recession >or= 3 mm (P = 0.0005). Within the multivariate analysis, the odds ratio for recession of >or= 3 mm to be associated with sensitivity was 2.80 (confidence interval 1.57-4.99). The number of teeth which responded to an airblast was significantly higher in males (P = 0.0004), smokers (P < 0.0001) and those with recession of >or= 3 mm (P < 0.0001). CONCLUSIONS: It is concluded that DH is associated with gingival recession in Jordanian dental attenders. However, the relationship is complex. Infrequent toothbrushing and smoking, which was almost exclusively a male habit, were also factors associated with DH.     

Correlation between periodontal status and biting ability in Chinese adult population

This study investigated the relation between periodontal condition and biting ability in a Chinese population using the pressure-detecting sheet. A total of 142 subjects residing in Nanchang, Jiangxi province, China, participated in the study. The examination included probing pocket depth (PD), clinical attachment level (CAL), bleeding on probing and coronal caries teeth. Biting abilities per person, biting force, biting pressure and occlusal contact area were measured using the sheet. Number of teeth present showed positive correlation with biting force and occlusal contact area, but were negatively correlated with biting pressure. No significant correlation was observed between the mean PD, percentage of pocket > or = 4 mm, bleeding index and any of biting abilities. The mean CAL showed a significantly negative correlation with biting force and occlusal contact area. Multiple stepwise regression analysis selected the number of teeth present, sex and age as the significant factors affecting the biting ability. However, no periodontal indices were picked up as the significantly contributing factor. There appears to be little effect of periodontal condition on biting ability. Ageing was selected as a contributing factor to reduction in the Chinese adults, but not in the Japanese population.     

三维打印及功能引导路径技术获得诊断性全冠功能性[牙合]面形态初探

目的通过在三维打印诊断性全冠上运用功能引导路径(functional generated path,FGP)技术获得修复体功能性[牙合]面形态,探索减少修复体面调改量以及避免干扰的临床方法。方法选择2018年7月至2018年12月于北京大学口腔医学院·口腔医院修复科就诊、需行下颌第一磨牙全冠修复的患者10例,其中男性4例,女性6例,年龄(29.6±7.4)岁;进行基牙预备体模型扫描并获得数字化模型;分别为每例患者制作两种全冠修复体。试验组:制作三维打印聚乳酸基底冠和蜡面,通过口内FGP法直接获得具有功能接触形态的面,扫描后制作计算机辅助设计与辅助制作氧化锆全冠修复体;对照组:按照数据库及经验常规设计制作氧化锆全冠修复体。临床试戴后用逆向工程软件(Geomagic Sudio&Quality)对修复体[牙合]面调改前后的咬合接触位置及面积、咬合接触程度、面调改高度和体积等指标进行数字化定量分析,并对两组数据进行配对t检验。结果10例患者均顺利通过FGP法获得面形态。试验组修复体[牙合]面调改体积[(7.320±4.238)mm3]显著小于对照组[(20.178±9.650)mm3](P<0.05);调改前试验组咬合高点高度[(0.043±0.019)mm]显著低于对照组[(0.594±0.201)mm](P<0.05),咬合接触面积[(11.430±4.102)mm2]显著大于对照组[(4.808±3.223)mm2](P<0.05)。结论运用三维打印及功能引导路径技术可获得修复体[牙合]面的个性化功能接触形态,可比常规方法显著减少修复体[牙合]调改量并降低咬合高点。     

A study of the incidence of overeruption and occlusal interferences in unopposed posterior teeth

OBJECTIVES: To determine the incidence and extent of overeruption in unopposed posterior teeth; to determine the incidence of occlusal interferences associated with unopposed posterior teeth; and to detect an association between the extent of overeruption and the presence of occlusal interference. DESIGN: The study was a single centre clinical retrospective analysis. Setting The setting was in the Combined Care Clinic of Leeds Dental Institute. The patients were undergoing routine restorative care by final year undergraduate dental students during 2000. SUBJECTS AND METHODS: All patients over18 years of age with one or more unopposed posterior tooth, were invited to participate. A sample group of 120 subjects were recruited. A clinical occlusal examination was carried out and the presence of initial retruded contact position (RCP) contacts and excursive interferences were recorded. Study models were made and digitally scanned. OUTCOME MEASURES: Measurements of overeruption from the curve of Spee were made from the images obtained, by a single observer. Reliability of the measurements was assessed by means of a Bland Altman Plot. The presence and site of RCP contacts and excursive interferences were recorded by a single observer. Reliability of the measurements was assessed by means of Kappa scores. The association between overeruption and the presence of occlusal interference was examined using Spearmans Correlation Coefficient. RESULTS: A total of 120 subjects were recruited, with a total of 155 unopposed sites. Eighty-one of the sites belonged to male subjects, 74 to female subjects. The mean age of the group was 50.9 years, Standard deviation 13.9 Eighty-three per cent of sites displayed overeruption (95% CI 78-90), ranging from under 0.5 mm to 5.4 mm. The reliability of the observations was found to be good. A total of 51.6% (95% CI 44-60) of unopposed teeth were involved in RCP contacts or excursive interferences. Thirty-two sites were involved in more than one contact or interference. The intra-examiner agreement was found to be good, using Kappa. The findings of the Spearman's correlation, show that if an association exists between overeruption and occlusal interference, it is weak, and of no statistical significance. CONCLUSIONS: Eighty-three per cent of unopposed teeth are likely to overerupt, and the extent of the overeruption may be marked. The incidence and extent of overeruption is of clinical significance, not only in terms of treatment planning to prevent undesirable vertical movement, but also in the restoration of the edentulous space. The reliability of observations made in the study was found to be good, justifying the methodology. Fifty-one point six per cent of unopposed teeth are likely to be involved in RCP contacts or excursive interferences. The incidence is of clinical significance when planning the restoration of unopposed teeth, or the associated edentulous space. Only a weak statistical association was demonstrated between the degree of overeruption and the presence of occlusal interferences.     

Relationship between pattern of masticatory path and state of lateral occlusal contact

Summary  The purpose of this study is to clarify whether the state of occlusal contact on lateral excursion is related to the pattern of masticatory movement path. The masticatory movement during mastication of softened chewing gum and the occlusal contact on lateral sliding of the mandible by 1 mm (L1), 2 mm (L2) and 3 mm (L3) were recorded in 50 healthy subjects. The path of masticatory movement was classified into one of seven patterns. The number of teeth involved in the occlusal contact in each pattern was investigated and compared among different lateral occlusal positions. The occlusal contact was then classified into 15 types based on one or a combination of the following four regions; incisal region, canine region, premolar region and molar region. The number of occlusal contact type for each pattern was investigated and compared among patterns. The number of teeth involved in occlusal contact decreased as the degree of lateral excursion increased, and significant differences were observed among the lateral occlusal positions ( P  < 0·001). The occlusal contact tended to decrease in the molar region and increase in the canine or premolar regions as the degree of the lateral excursion increased. When comparing among patterns, significant differences were observed at L2 and L3 (L2; P  < 0·001, L3; P  = 0·030) but not at L1 ( P  = 0·318). The difference was remarkable at L2. It was suggested that the state of occlusal contact at L2 and L3, particularly at L2 was related to the masticatory path pattern.     

Tooth loss and associated risk indicators in an adult urban population from south Brazil

The aim of the present study was to assess the prevalence, extent, and risk indicators of tooth loss in a representative adult, urban population in the Brazilian state of Rio Grande do Sul. A sample of 974 subjects (ages 30 to 103 years, mean 48.7, SD 13.4) representative of the metropolitan area of Porto Alegre, Brazil was selected by a multi-stage probability cluster sampling strategy. In all, 94% of the subjects had experienced tooth loss. The mean tooth loss was 11.2 teeth, and varied between 5.5 and 20.2 teeth in the 30-39 and 60 + years age groups, respectively. The multivariable analysis, adjusted for age, showed that subjects who had lost 7-13 or > or = 14 teeth were more likely to be females (odds ratio (OR) = 1.4, 2.4), of low (OR = 2.8, 5.1) or middle socio-economic status (OR = 2.3, 3.4), and heavy smokers (OR= 2.0, 2.3) than those with 6 or fewer missing teeth. Furthermore, loss of > or = 14 teeth was associated with presence of > 50% teeth with attachment loss > or = 5 mm (OR= 5.7), and loss of 7-13 teeth was associated with presence of > 50% teeth with attachment loss > or = 5 mm (OR = 2.4) and having 15-30% or > 30% decayed-filled teeth (OR = 2.7 and 4.1). In conclusion, tooth loss is highly prevalent in this urban Brazilian population. Gender, socio-economic status, cigarette smoking, caries experience, and attachment loss are important risk indicators. A reduction in the population's tooth loss may be achieved by the implementation of community programs for the prevention and treatment of dental caries and periodontal diseases.     

Relation of dietary preference to bite force and occlusal contact area in Japanese children

Summary  The purpose of this study was to examine the relationship of dietary preference to bite force and occlusal contact area in Japanese elementary school children. A total of 348 children, aged 7–12 years, from two public elementary schools located in Okayama Prefecture, Japan, participated in the study. Clinical examination included decayed, missing and filled teeth (dmft and DMFT), and total numbers of deciduous and permanent teeth. Bite force and occlusal contact area were measured using a pressure-detecting sheet. Dietary preference was assessed using a questionnaire in which the answers were given in like/dislike form. Mann–Whitney U- test and multiple logistic regression analysis were applied to analyse the data. In multiple logistic regression analysis after adjustment for age, gender and total number of teeth present, children who liked cabbage and celery showed significantly higher bite force ( P  =   0·05 and P  <   0·01, respectively) than those who disliked these. Children who liked cabbage and celery also showed higher occlusal contact area ( P  <   0·05 and P  <   0·01, respectively) than those who disliked these. The Japanese elementary school children who liked hard foods such as cabbage and celery showed higher bite force and higher occlusal contact area than those who disliked these foods. A positive attitude towards harder food items might contribute to healthy development of the masticatory apparatus.     

Non‐carious cervical lesions in a Nigerian population: Abrasion or abfraction?

OBJECTIVES: To determine the proportion of non-carious cervical lesions (NCCL) that were either abrasion or abfraction like and to test the validity of the assumption that right-handed patients cause more abrasion on the cervical surfaces of teeth on the left side of the mouth. SETTING: Ile-lfe, Southwestern Nigeria. PARTICIPANTS: 106 first time patients diagnosed as having any form of NCCL. DESIGN: Patients were subjected to intra-oral examination followed by the administration of a questionnaire. The cervical lesions were examined and scored using the tooth wear index designed by Smith & Knight 1984. NCCL was diagnosed as abrasion or abfraction like based on established clinical features plus positive history of possible associated aetiological factors. OUTCOME MEASURES: Abrasion and abfraction like lesions. RESULTS: Abrasion was the diagnosis in 630 (62.3%) of the 1,012 tooth sites with NCCL that had no associated occlusal surface wear facet. This constituted about two-thirds of the NCCL. Three hundred and eighty two (37.7%) of the NCCL occurred in association with an occlusal surface wear facet and presented the typical wedge shaped defects with sharp margins characteristic of abfraction. These abfraction like lesions constituted about one-third of the NCCL. 50.8% of abrasive NCCL in right-handed brushers were located on the left side of the mouth. CONCLUSIONS: About one-third of NCCL in the present study presents an abfraction component, and two-thirds abrasion. Although, right-handed brushers had more severe lesions on the opposite side of the mouth, the difference was not statistically significant.     

Analysis of etiologic factors and periodontal conditions involved with 309 abfractions

OBJECTIVES: Non-carious cervical lesions (NCCL), also termed abfractions, have long been thought to be produced by excessive brushing. Nearly 20 years ago an occlusal etiology was proffered (Lee & Eagle 1984). Controversy still exists concerning these two concepts. The present work was carried out to verify the occurrence of signs of excessive brushing or occlusal disturbances associated with abfractions. MATERIAL AND METHODS: All first consultants were screened for the presence of abfractions during one trimester. NCCL were found in 61 patients who consequently received a thorough examination searching for clinical evidence of excessive brushing or occlusal disturbances. The presence of plaque, calculus, periodontitis, or mobility was also noted. Simple frequency and percentage were used to describe the occurrence of different clinical signs in association with the presence of abfractions. RESULTS: Abfractions often exist in mouths presenting plaque (40.1%), calculus (41.7%), or periodontitis (20.4%). Ulceration of the gingiva is a rare finding (1.6%). However, subgingival apical limits were frequent (32.5%). NCCL coexist almost systematically with occlusal wear facets (94.5%). Lack of canine disclusion (77.2%) was also closely associated with the presence of abfractions. Conversely, mobility was seldom found (1.9%). CONCLUSIONS: Clinical signs of excessive brushing were lacking, whereas signs of occlusal disturbance were very consistent with the presence of abfractions.     

Correlation between periodontal status and biting force in patients with chronic periodontitis during the maintenance phase of therapy

Aim: The association between periodontal status and biting force is unclear. The aim of this study was to investigate the relation between periodontal status and biting force in patients with chronic periodontitis during the maintenance phase of periodontal treatment. Material and Methods: A total of 198 patients, who had entered a periodontal maintenance programme, were examined for the presence of restorations on the occlusal surface, probing pocket depth, clinical attachment loss (CAL), bleeding on probing, and mobility of teeth. Quantitative analysis of total biting force, occlusal contact area and biting pressure (defined by biting force per 1 mm² of occlusal contact area) was performed using microcapsular pressure‐sensitive sheets. Results: A multiple stepwise regression analysis showed that total biting force and occlusal contact area were positively associated with the number of present teeth and negatively associated with female gender, mean CAL and mean probing pocket depth. Biting pressure was positively associated with CAL. Conclusions: Reduced periodontal support was found to be associated with decreased total biting force and with increased biting pressure (defined as force per 1 mm² of occlusal contact area).     

Periodontal tactile sensation and occlusal loading condition of autotransplanted teeth: A retrospective pilot study

Purpose

The objectives of this retrospective pilot study were: (1) to examine the occlusal properties (periodontal tactile sensation, occlusal force support ability, dynamic tooth mobility, occlusal force, contact area, preferred chewing side and main occluding area) of autotransplanted teeth with no clinical complications after transplantation (postoperative periods from 1 to 7 years).

应用T-scan III系统对楔状缺损患者牙合接触的研究

目的 测量楔状缺损患牙的接触,探究因素与楔状缺损形成的关系。方法 从32例受检者中选取32颗口内单象限内单颗楔状缺损患牙和34颗同名未患楔状缺损牙分别作为实验组和对照组。应用直接接触测量法及T-scan Ⅲ系统分析受检牙干扰的分布,并应用T-scan Ⅲ系统对受检牙在正中、侧方及前伸运动中的接触进行动态、定量测量。结果实验组中单侧组与双侧组患牙的工作侧干扰牙数百分比（75.0%、70.0%）均高于各自对照牙（17.7%、18.2%）,差异有统计学意义（P＜0.05）;在侧方工作侧运动中,实验组患牙所分担的力及其咬合高点上接触强度,均高于对照牙,差异有统计学意义（P＜0.05）。结论 口内单象限内单颗牙楔状缺损的发生与干扰及力负担过重有关。