Quantitative description of overjet and overbite and their relationship with the craniofacial morphology

This study was designed to explore whether overjet and overbite relationships might be correlated with the anteroposterior and vertical craniofacial dimensions. The material used to test this hypothesis was lateral cephalometric radiographs from 92 adults (49 women and 43 men) with Angle Class I molar and canine relationships and a harmonious profile. Data were analyzed using the t-test, Kendall's tau-b correlation and cluster analysis. The results revealed that a) women exhibit an increased overjet compared to men, and smaller vertical facial dimensions; b) there is a significant correlation between overjet and overbite, overbite and posterior facial height, and overbite and mandibular angle; c) in the two groups of individuals that were separated on the basis of overjet and overbite, only the mandibular plane exhibited a statistical difference between the two groups: groups with small values for overjet and overbite possess high mandibular angles and a decreased mandibular plane angle accompanies large values for overjet and overbite; d) groups separated on the basis of mandibular plane angle were not independent from the groups separated on the basis of overjet and overbite. In summary, occlusal characteristics are not found to be associated with any particular skeletal pattern.     

Prevalence of Defined Symptoms of Malocclusion among Probands Enrolled in the Study of Health in Pomerania (SHIP) in the Age Group from 20 to 49 Years

SUBJECTS AND METHODS: SHIP is a complexly structured, population-based cross-sectional study of adults in the German region of Pomerania (age group covered: 20-79 years). Findings in a population subgroup (age group 20-49 years; n = 1777; 53.1% women; 46.9% men) were subjected to orthodontic evaluation. Graduated registration of anterior crowding, overjet, frontal overbite and sagittal intermaxillary relationship of the posterior teeth; registration of ectopic canines, posterior crowding, anterior and posterior crossbite, negative overjet, retroclination of the upper incisors, buccal nonocclusion, and lateral open bite. The prevalence of almost regular dentition and of symptoms of malocclusion as well as the frequency of orthodontic treatment (subjective patient data) undergone by men and women were recorded. The correlation between the registered symptoms of malocclusion was calculated. RESULTS: 92.2% of the subjects had symptoms of malocclusion varying in number and severity. An anatomically correct dentition was found in only 7.8% of cases, and an "almost regular dentition" (inclusion criteria defined) in 14.2%. 32.8% of the subjects had severe malocclusion (inclusion criteria defined). The most frequent symptoms were anterior crowding, increased overjet, and distoclusion. These symptoms were significantly more frequent in women, while spacing and edge-to-edge bite, excessive overbite and mesioclusion were more frequent in men. 26.7% of the probands (28.0% women, 25.3% men) reported having received orthodontic treatment. The prevalence of craniofacial malformations (cleft lip and palate, syndromes) was 0.09% in women and 0.2% in men. Increased overjet was most frequently correlated with other symptoms of malocclusion.     

Effect of Incisor Angulation on Overjet and Overbite in Class II Camouflage Treatment. A typodont study

OBJECTIVES: To determine the amount of variation in overjet and overbite that may result from changes in upper and lower incisor angulations following upper first premolar extraction treatment in Class II malocclusions. MATERIALS AND METHODS: Typodonts were set up to simulate a skeletal Class II occlusion treated with upper first premolar extractions. The upper incisor angulation was altered through a range from 100 degrees to 120 degrees to the palatal plane by 2 degrees increments. The overjet and overbite were measured with every 2 degrees of upper incisor angulation change. A regression analysis was performed on the experimental data, and the regression coefficients, slope, and intercept were estimated. RESULTS: Excessive proclination of the lower incisors will result in an abnormal overjet and overbite relationship for any magnitude of upper incisor angulation. A normal lower incisor angulation facilitates the attainment of an optimal occlusion. Excessive palatal root torque of the upper incisors will result in an increase in overjet and a consequent decrease in overbite. If the upper incisors are excessively retroclined, an edge-to-edge incisor relationship will result. CONCLUSION: Class II camouflage treatment with upper first premolar extractions requires correctly angulated incisors to achieve optimal buccal segment interdigitation and incisor relationship. Labial root torque and interproximal reduction of the lower anterior teeth should be considered when the lower incisors are excessively proclined.     

Clinical crown length and reduction in overjet, overbite, and dental height with orthodontic treatment

To evaluate the clinical crown length relative to fixed-appliance orthodontic treatment of excessive overjet and deep overbite and to correlate such changes to the vertical dental height, the following measurements were undertaken for 12 females and 8 males, between the ages of 16 and 20 years, on three separate occasions--2 days before banding, 2 days after debanding, and 12 months after debanding: (1) overjet, overbite and dental height measured from right lateral cephalometric x-ray films; (2) clinical crown length, measured from study models, of 400 teeth divided into four groups--maxillary incisors and canines (120 teeth), maxillary second premolars and first molars (80 teeth), mandibular incisors and canines (120 teeth) and mandibular second premolars and first molars (80 teeth); and (3) gingival condition by means of the gingival index of L?e and Silness. Fixed edgewise orthodontic appliances were used and the four first premolars were extracted. From the results of the investigation, the following conclusions were evident: after a 12-month follow-up observation period, the achieved reduction in overjet, overbite, and dental height showed relapses of 9%, 11%, and 29%, successively; only 7% of the 400 teeth examined showed reductions in clinical crown length. This change was probably the result of gingival hyperplasia. The gingival condition greatly improved by approximately 64% after 12 months of debanding, accompanied by 25% to 50% relapse in the amount of change in clinical crown length (noted 2 days after debanding); and the intrusive tooth movement during orthodontic correction of deep overbite was the result of vertical movement of the tooth, with its investing tissues and soft-tissue attachment, into the jaws.(ABSTRACT TRUNCATED AT 250 WORDS)     

Retrospective Analysis of Casts to Assess Cervical Headgear Treatment in the Presence of Vertical Growth Pattern

Abstract Objective: Does molar distalization as effected by cervical headgear increase the vertical dimension of occlusion in patients with vertical growth pattern? Materials and Methods: A sample of 86 patients with neutral and vertical growth pattern in the late mixed dentition stage underwent headgear treatment. Their initial and intermediary casts were retrospectively analyzed for occlusal relationships at the maxillary first molars and degrees of overjet and overbite. The only cases included were those in which headgear treatment was carried on for at least 6 months, achieving a minimum distalization of 4 mm. The intermediary casts were fabricated after headgear treatment had been completed and prior to the initiation of multiband treatment.Patients were divided into three groups (N, V1 and V2) according to the degrees of vertical growth pattern, which were determined based on y-axis angle values. Results: Grouped by degrees of vertical growth, the data revealed occlusal relationship changes of 6–8 mm and overjet reductions of 0.6–1.2 mm. The overbite changes were unexpectedly small (0–0.04 mm).Grouped by degrees of overbite, the data revealed that headgear treatment increased the vertical dimension of occlusion in deep-bite patients (> 4 mm), while giving rise to decreases in patients with overbites of < 3 mm.     

An analysis of complete and incomplete overbite in class II division 1 malocclusions (an analysis of overbite incompleteness)

A retrospective cephalometric study of Class II Division 1 malocclusions was carried out. Sixty patients with complete overbites were compared with another group of 60 matched in every respect, with the exception of having incomplete overbites. All patients were in the permanent dentition stage and aged between 10 and 14 years. An incomplete overbite was related to vertical variation in the skeletal pattern. This was demonstrated by greater anterior lower facial height, greater gonial angle, and steeper mandibular plane inclination. Incisor alveolar heights and molar heights did not vary between the groups. No differences between groups were noted for the degree of overjet reduction achieved during treatment, or in post retention relapse of overbite and overjet.     

Relationships between the upper central incisor crown forms and degree of labial inclination,overbite, and overjet in Japanese young adults

PURPOSEThe present study aimed to investigate the relationships between the crown form of the upper central incisor and their labial inclination, overbite, and overjet.MATERIALS AND METHODSMaxillary and mandibular casts of 169 healthy dentitions were subjected to 3D dental scanning, and analyzed using CAD software. The crown forms were divided into tapered, square, and ovoid based on the mesiodistal dimensions at 20% of the crown height to that at 40%. The degree of labial inclination of the upper central incisor was defined as the angle between the occlusal plane and the line connecting the incisal edge and tooth cervix. The incisal edges of the right upper and lower central incisor that in contact with lines parallel to the occlusal plane were used to determine the overbite and overjet. One-way ANOVA was performed to compare the labial inclination, overbite, and overjet among the crown forms.RESULTSThe crown forms were classified into three types; crown forms with a 20%/40% dimension ratio of 1.00±0.01 were defined as square, >1.01 as tapered, and <0.99 as ovoid. The labial inclination degree was the greatest in tapered and the least in square. Both overbite and overjet in tapered and ovoid were higher than those in square.CONCLUSIONUpper central incisor crown forms were related to their labial inclination, overbite, and overjet. It was suggested that the labial inclination, overbite, and overjet should be taken into consideration for the prosthetic treatment or restoring the front teeth crowns.     

Dental compensation for moderate Class?III with vertical growth pattern by extraction of the lower second molars

Objectives

Analysis of the effects and side effects of treatment of patients with moderate skeletal Class?III and vertical growth pattern by means of extraction of the second molars in the lower jaw.

Patients and methods

A total of 20 patients with a mean age of 12.9 years were examined retrospectively. Inclusion criteria consisted of a Wits value of 0 to ?5, a posterior growth pattern of the mandible (Hasund analysis), an overjet of ?2 to 1?mm, and an overbite of 0 to ?3?mm. Treatment was performed using a straight-wire appliance. As part of the treatment, the lower second molars were extracted and Class?III elastics attached. Cephalograms and orthopantomograms taken before and after treatment were used for evaluation.

Results

Treatment resulted in a significant change in the mean overjet from 0.5?mm to 2.1?mm and the attainment of a positive mean overbite of ?1.0?mm to 0.9?mm. The occlusal plane rotated anteriorly from 18.8° to 13.7°. The skeletal parameters showed a change in the Wits value from ?3.3?mm to ?1.4?mm and an anterior mandibular rotation (ML-NSL 35.5° vs. 32.0°). The soft tissues revealed an increase in the distance between the lower lip and the ??esthetic line?? to the posterior (?2.0?mm vs. ?3.9?mm).

Conclusion

Dental compensation of moderate skeletal Class?III with a tendency to an anterior open bite with vertical growth pattern by extracting the lower second molars, combined with Class III elastics, resulted in an anterior rotation of the occlusal plane and mandible. Eighteen of 20 patients achieved a physiological overjet and positive overbite. A prerequisite for this therapy is the presence of lower wisdom teeth; a potential side effect is elongation of the upper second molars.     

Comparison of Japanese and European overbite depth indicator and antero-posterior dysplasia indicator values

This study evaluated cephalometric differences between 113 Japanese (43 males and 70 females, aged 14.1 ± 5 years) and 106 European subjects (36 males and 70 females, aged 13.5 ± 7.3 years) using two compound angular measurements and their single components: the overbite depth indicator (ODI) for the assessment of vertical skeletal relationships and the antero-posterior dysplasia indicator (APDI) for an evaluation of sagittal dysgnathia. Both populations were assigned to groups representing Angle Classes I, II, and III, and an anterior open bite (AOB) group. Two sample t- and Wilcoxon signed-ranks tests were performed (P < 0.05). The ODI values showed no statistically significant differences between the Japanese and European samples. The Japanese sample showed a significantly smaller APDI but only in the Class II group. In the Japanese Class II and III subjects, the malocclusion patterns were more pronounced than those in the Caucasian sample (overbite, overjet, and APDI).     

Assessment of the relationships among posture, maxillomandibular denture complex, and soft-tissue profile of aesthetic adult Korean women

The objective of this study was to assess the relationships among the posture, the maxillomandibular denture complex, and the soft-tissue profile of aesthetic adult Korean women. From an initial group of 346 women, the authors examined 28 beautiful adult Korean women who had normal vertical and sagittal skeletal relationships and normal occlusion. There were no differences in the inclinations of the incisors to the occlusal planes in the maxilla and the mandible in the data for Korean women vs. Arnett's data for white women. However, the overbite and overjet in Korean women were slightly smaller than in white women. AB to maxillary occlusal plane angle (MxOP) represented the anteroposterior denture base discrepancy to the occlusal plane. Angulation of the maxillary occlusal plane to the Frankfurt (FH) plane and the true vertical line at submasale (TVL) (Sn) was a little steeper in Korean women than in white women. The FH plane was almost parallel to the true horizontal line in Korean women who had normal vertical and sagittal skeletal relationships and normal occlusion. With regard to soft-tissue variables, the upper lip length (Sn-Stms), interlabial gap, upper incisor exposure, nasolabial angle, lip and nose tip projection value, and TVL (Sn)-to-upper lip line (UL) angle showed interracial differences. The results of this study can assist in the diagnosis and treatment planning of orthognathic surgery.     

Long-term stability of skeletal Class III patients treated with splints, Class III elastics, and chincup.

Long-term results from orthopedic management of skeletal Class III malocclusions are sparse. The purpose of this study was to evaluate the stability of results after facial growth and treatment with splints, Class III elastics, and chincup (SEC III) and to investigate the main determinants of relapse. Data from pretreatment, posttreatment, and long-term (at least 3 years after retention) serial cephalograms of 52 patients who received SEC III treatment were studied: only those with long-term data when growth had ceased (women over 18 and men over 21 years of age) were selected. At the end of the follow-up period (an average of 9 years), only 6 of the 52 patients had clinical relapse (overjet 相似文献   

Correction of a severe Class III malocclusion.

The success of early orthopedic treatment in patients with Class III anomalies depends on facial skeletal development and type of treatment. This case report describes the treatment of a 12.6-year-old girl who had a severe Class III malocclusion with a 6-mm anterior crossbite, a deep overbite, a narrow maxilla, and unerupted maxillary canines. The treatment plan included rapid palatal expansion to expand the maxilla, reverse headgear to correct the maxillary retrognathia, a removable anterior inclined bite plane to correct the anterior crossbite and the deep overbite, and fixed edgewise appliances to align the teeth. One canine was brought into alignment, but the other was placed in occlusion in its transposed position. Ideal overjet and overbite relationships were established, and the final esthetic result was pleasing.     

The effect of retention on the relapse of Class II Division 1 cases

Sixty cases of Class II Division 1 malocclusion were studied; 30 of them had been retained after the completion of orthodontic treatment, the other 30 had not and acted as a control group. Using measurements from lateral skull radiographs and statistical analysis, the two groups were compared in respect of skeletal pattern, soft tissue, overjet, overbite and interincisal angle. Both the retained and the non-retained group showed a tendency to relapse after the completion of active treatment; a tendency to relapse even while in retention was observed. The relapse in overjet was found to be more significant than the relapse in overbite. In both groups the relapse in overjet was found to be associated with the size of the original overjet, the overbite at the end of active treatment and the interincisal angle at the end of active treatment. In both groups the relapse in overbite was found to be associated with the size of the original overbite, the change in maxillary-mandibular planes angle and the interincisal angle at the end of active treatment.     

Relationship between overbite/overjet and clicking or crepitus of the temporomandibular joint

AIMS: Since occlusal variables such as overbite and overjet have been thought to be associated with temporomandibular disorders (TMD), and joint sounds are some of the most prevalent signs of TMD, the aim of this study was to determine whether overbite and overjet are risk factors for temporomandibular joint (TMJ) sounds. METHODS: A population-based cross-sectional study of 3,033 subjects (age range, 10 to 75 years; 53% female) was conducted in Germany. Overbite/overjet, reproducible reciprocal clicking (RRC) during open-close jaw movements that did not occur in the protrusive jaw position, and joint crepitus were assessed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). RESULTS: When age and gender were controlled for, high or low values of overbite and overjet were not associated with a greater risk of RRC and crepitus as compared to a reference category of a normal overbite and overjet of 2 to 3 mm (multiple logistic regression; odds ratios 0.7 to 1.3; P > .05 for all). CONCLUSION: This study showed that higher or lower overbite or overjet jaw relationships, even extreme values, are not risk factors for TMJ sounds as assessed by clinical examination.     

The Effect of Retention on the Relapse of Class II Division I Cases

Abstract

Sixty cases of Class II Division 1 malocclusion were studied; 30 of them had been retained after the completion of orthodontic treatment, the other 30 had not and acted as a control group. Using measurements from lateral skull radiographs and statistical analysis, the two groups were compared in respect of skeletal pattern, soft tissue, overjet, overbite and interincisal angle. Both the retained and the non-retained group showed a tendency to relapse after the completion of active treatment; a tendency to relapse even while in retention was observed. The relapse in overjet was found to be more significant than the relapse in overbite. In both groups the relapse in overjet was found to be associated with the size of the original overjet, the overbite at the end of active treatment and the interincisal angle at the end of active treatment. In both groups the relapse in overbite was found to be associated with the size of the original overbite, the change in maxillary-mandibular planes angle and the interincisal angle at the end of active treatment.     

The effect of anterior inclined plane treatment on the dentoskeletal of Class II division 1 patients

Most of Class II malocclusions are due to underdeveloped mandible with increased overjet and overbite. Lack of incisal contact results in the extrusion of the upper and lower anterior dentoalveolar complex, which helps to lock the mandible and prevent its normal growth and development, and this abnormality is exaggerated by soft tissue imbalance. The purpose of this study was to evaluate the skeletal and dental changes in patients treated with anterior inclined plane appliance in growing patients with moderate Class II Division 1 having deep overbite. In this study, 25 patients, including 15 girls and 10 boys, with a mean age of 9 +/-1.2 years were selected; all of them presented with moderate Class II deep bite with increased overjet and normal or horizontal growth pattern. Pre- and post-treatment X-rays and photos for an average of 8 months were taken. The statistical assessment of the data suggested that there were no significant changes in the vertical skeletal parameters. The mandibular incisors were protruded, whereas the maxillary incisors were retruded. Overbite and overjet were also reduced. There was significant increase in the mandibular length. The results revealed that in mixed dentition patients, the inclined plane corrected Class II discrepancies mostly through dentoskeletal changes.     

前牙覆(牙合)相关因素的研究

目的 :探讨不同类型错牙合畸形中与前牙覆牙合相关的多种因素。方法 :恒牙期错牙合 14 4例 ,其中 ,I类骨骼型 74例 ,II类 70例。在自然头位下摄取头颅定位侧位片。以覆牙合值为因变量 ,分析前牙覆牙合与其他头影测量参数的相关关系 ,并建立以覆牙合值为因变量的多元回归方程。结果 :I类骨骼型组多元回归分析显示 ,前牙覆盖、后面高及上切牙高度值越大 ,或下面高及下磨牙高度距离值越小 ,前牙覆牙合越深 ;在II类骨骼型组 ,前牙覆盖、上下切牙角及下切牙倾斜度值越大 ,或下颌角及上磨牙高度值越小 ,前牙覆牙合越深。 2个方程分别能解释 75 .8%和 62 .3 %的前牙覆牙合值的变化。其中 ,前牙覆盖值对前牙覆牙合最具影响。结论 :与前牙覆牙合相关的X头影测量参数包括牙性的和骨性的 ,这些参数相互补偿 ,其中 ,前牙覆盖值对维持正常且稳定的前牙覆牙合起着最重要的作用。     

下颌尖牙高[牙合]型[牙合]板配合直丝弓矫治器治疗前牙深覆[牙合]深覆盖临床观察

目的：总结下颌尖牙高[牙合]型[牙合]板配合直丝弓矫治器治疗前牙深覆[牙合]深覆盖的临床疗效。方法：选择Angle Ⅰ类错[牙合]上颌前牙有散在间隙伴深覆[牙合]深覆盖病例15例,男7例,女8例。年龄18～22岁。均采用国产直丝弓托槽,先行上颌牙固定矫治。同时下颌配戴尖牙高[牙合]型[牙合]板打开咬合,矫治前拍摄头颅侧位定位片,待咬合打开,后牙有接触时再拍摄头颅侧位定位片,选择头影测量指标22项,对测量结果进行T检验。结果：MP—SN,S-Ar—Go,Y—axis在戴尖牙高[牙合]型[牙合]板治疗前后均有显著性差异,N—Me,ANS—Me也有显著性差异,下颌平面角增大,下颌有后旋趋势,有利于改善低角型面形。U6-PP,L6-PP增大,有显著性差异,上下后牙均有升高,有利于打开咬合,解除深覆[牙合]。U1-PP增大有显著性差异,提示上前牙伸长,L1-Mp有减小的趋势,没有显著性差异,下前牙有压低的可能。U1-SN,UI—NA,U1-PP有非常显著差异,上颌前牙明显内收,深覆盖明显改善。结论：下颌尖牙高[牙合]型[牙合]板配合直丝弓矫治器是-种治疗前牙深覆[牙合]深覆盖的有效方法。     

正畸治疗中磨牙的拔除和保留(三十九)——牙槽外区域骨骼支抗钉牵引牙列向远中在减数磨牙矫治中的应用

目的:总结在减数磨牙矫治中应用牙槽外区域骨骼支抗钉牵引牙列向远中的矫治设计方法.方法:选择应用骨骼支抗钉的减数磨牙矫治病例35例,男12例,女23例.骨骼支抗钉均植入牙槽骨以外,上颌多在颧牙槽嵴,下颌多在颊棚区.常规排齐整平牙弓后更换特澳丝,应用镍钛拉簧牵引全牙弓向远中以解除牙弓拥挤或前突.结果:矫治结束时均达到前牙覆耠覆盖正常,后牙尖窝交错咬合,侧貌明显改善的矫治效果.结论:牙槽外区域骨骼支抗钉的应用丰富了减数磨牙矫治设计的内容,是今后减数磨牙矫治的重要发展方向.     

Maxillary incisor angulation and its effect on molar relationships

OBJECTIVES: To determine the variation in molar relationships when upper incisor angulations are altered in a Class I occlusion with normal overjet and overbite. MATERIALS AND METHODS: Typodonts were set up to simulate a Class I occlusion on a normal skeletal base. The lower incisors were positioned normally at 92 degrees to the mandibular plane and the upper incisor angulations were altered from 90 degrees to 130 degrees by 2 degrees increments to the palatal plane. The changes in molar relationships were measured with every 2 degrees of upper incisor angulation change. A regression analysis was performed on the experimental data, and the regression coefficients, slope, and intercept were estimated. RESULTS: A negative linear relationship between upper incisor angulations and change in molar relationship was observed. On average, a change of 20 degrees in upper incisor angulation will alter the molar relationship by 1.8 mm. CONCLUSIONS: Changes in upper incisor angulations are significantly related to change in the molar relationship. Upper incisor angulations that deviate significantly from normal values are likely to result in less than ideal buccal segment relationships.