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)     

The effect of overbite and overjet on clinical parameters of periodontal disease: A case control study

AimTo investigate the association of overjet and overbite with clinical parameters of periodontal disease.Material and methodsThe study was performed in Riyadh, Saudi Arabia, from March 2017 to March 2018. 600 Saudi males aged 20–30 years old were included. Participants were divided into three groups (n: 200) depending on the presence of overjet (OJ) or overbite (OB) and its relationship with periodontal disease. Periodontal parameters were assessed clinically and radiographically. One-way analysis of variance was used to test for any significant differences between groups. Tukey’s post hoc comparison test was used to evaluate correlations among parameters.ResultsOJ exceeding 8 mm was correlated with debris, calculus, and periodontal scores on mandibular anterior teeth, especially on the lingual surfaces.Both OJ and OB groups showed significantly increased PD, compared to that of the control group in measurement at the lingual (P = 0.004, 0.003) and proximal (P = 0.002, 0.002) surfaces of the lower anterior teeth. Finally, the CEJ-AB was statistically significantly higher in the OB group compared to the OJ and control groups (P = 0.091, 0.008).ConclusionThe present study found a correlation between OJ and OB and periodontal disease, as measured using specific parameters. This indicates that periodontal treatment may be insufficient unless the overjet or overbite is corrected.     

成人前牙深覆(牙合)深覆盖的正畸修复联合治疗

目的：探讨正畸联合烤瓷固定修复治疗成人前牙深覆耠深覆盖的临床效果。方法：对前牙深覆[牙合]深覆盖成人患者,采用固定矫治技术整平下颌牙弓,解除深覆[牙合],为上前牙内收获得有效间隙后,行上前牙的改向烤瓷固定修复。结果：治疗后上前牙平均内收5.0mm,下颌spee氏曲线降低1.5mm-2.0mm,患者的面部侧貌得到改善,牙列形态与咬合恢复满意,咀嚼功能良好,随访6～20个月无复发。结论：对前牙深覆[牙合]深覆盖的成人患者采用正畸：联合固定修复进行治疗,既可有效的改善患者的咀嚼功能与美观,又可使下颌牙的牙体组织得以保存,达到更好的口腔修复效果。     

Arrowhead elastic for simultaneous correction of overjet and overbite

Arrowhead elastic may be integrated with fixed appliances to achieve rapid correction of increased overjet and overbite during comprehensive orthodontic treatment. This technique is applicable in routine class II cases involving deep bite, during retention phase in growing children treated with twin block and postsurgically in adult hypodivergent cases.     

Effects of the degree of overbite and overjet on dental health

The purpose of the study was to examine whether any combination of vertical overbite (OB) and horizontal overjet (OJ) may be more favourable than others to dental health in anterior segments. The study group consisted of 74 females and 70 males. The participants were 15-years-old and had 6 anterior teeth in both jaws. The following parameters were assessed: plaque index, gingival index, probing depth, space index, filled surfaces, the number of non-aligned proximal tooth surfaces (NONAS) and the OB/OJ ratio. The results demonstrated that participants with a relatively high OB/OJ ratio (OB/OJ greater than or equal to 1.21) had a more favourable periodontal condition than participants with lower ratios. This was so in both sexes and both jaws. The OB/OJ ratio had little relation to the prevalence of filled surfaces.     

An orthodontic oral appliance: A randomized,controlled pilot study

Objective:This pilot study was performed to test the hypothesis that an orthodontic oral appliance (OA) that is designed to work against the backwardly directed forces on the upper incisors may counteract the reduction in overjet from these devices.Materials and Methods:Thirty patients with normal bites, good oral health, and milder sleep apnea were randomized to treatment with either OAs or orthodontic OAs. Bite changes were evaluated on plaster casts and radiographs and by questionnaires after a mean of 2.4 years in 19 frequent users.Results:Four of nine patients in the orthodontic OA group increased their overjet by ≥0.4 mm, while none of the 10 patients in the OA group experienced that effect.Conclusion:Only the orthodontic OA increases the overjet; this design may therefore be beneficial to patients at risk of negative effects on their bite during OA treatment.     

Longitudinal study of combined orthodontic and surgical treatment of Class II malocclusion with deep overbite

Twenty-one patients who had undergone orthodontic treatment in combination with mandibular advancement surgery to treat Class II malocclusion and deep overbite were followed up. Median vertical relapse at the bony chin (after a mean followup of 16 months) was found to be 2.9 mm (44%). Sagittal advancement was found to have good stability; most of the patients exhibited some additional anterior movement of the chin during the follow-up period. At the same time, the entire mandible rotated counterclockwise and the gonial angle increased. Individual response to treatment varied greatly; two patients exhibited major horizontal relapse. Controlling the position of the mandibular proximal segment seemed to be the most important factor in posttreatment stability of this sample.     

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.     

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.     

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

OBJECTIVES: 1) To define the sagittal and vertical characteristics of anterior teeth in adults with normal occlusions; 2) to explore a relationship between the overbite and overjet; and 3) to relate overbite and overjet to the skeletal pattern. DESIGN: Prospective data collection. SETTING AND SAMPLE POPULATION: Ninety-two adult dental students from the Aristotle University of Thessaloniki (49 females and 43 males) with naturally occurring Class I occlusions. EXPERIMENTAL VARIABLE AND OUTCOME MEASURES: Cephalometric data were collected for overbite, overjet, and skeletal relationships. These were then correlated for potential association between front teeth and vertical and horizontal skeletal relationships. RESULTS: The overjet measures were equally distributed among men and women, but overbite was higher in women. Facial proportions were also bigger in men, but the Mediterranean face was bigger than Northern American Caucasian. The mandibular plane angle could be associated with either increased or decreased overjet and overbite. CONCLUSION: The overbite and overjet features of an occlusion cannot be predictably associated with any particular craniofacial pattern.     

An epidemiologic study of the relationship between overbite and overjet in English children aged 11-12 years

The relationship between overbite and overjet in 1,147 English children aged 11–12 years has been investigated and a statistically significant positive correlation found. It has also been shown that the ratio of the rate of increase of overbite: rate of increase of overjet is approximately 3:1 relative to the defined categories of overbite. The significance of a specific increase in the demand for treatment of deep overbite is also discussed.     

Age dependence of compliance with orthodontic treatment in children with large overjet. An interview study

Large overjet has been associated with an increased risk of trauma of the permanent maxillary incisors, especially before 10 years of age. The prevalence of an overjet of more than 6 mm in 10-year-old Swedish children is about 15%. To prevent trauma by reducing the overjet, this treatment be set in early in life. However, compliance with orthodontic treatment is a significant and well known problem and may be associated with the age of the patient. This study concerns children treated with an open activator with built in headgear (HG activator). The aim of treatment was to reduce the trauma risk in these patients as early as possible, and an objective of the study was to gain better knowledge of young children's (6-13 years of age) motivation for and response to correction of large overjet. In-depth interviews focusing on motivation were held with 18 children. Interviews were transcribed verbatim and analysed according to Grounded Theory, a qualitative method. The results indicate the importance of parental involvement for younger children's compliance. Older children seem to have a higher degree of internal motivation for treatment and less need for parental support for compliance with treatment. If treatment compliance can not be ensured through parents' wholehearted involvement and control it seems to be better to delay treatment until the child is older.     

伴口呼吸习惯安氏Ⅱ1类错患者正畸治疗后牙颌面横向结构的改变

目的探讨正畸治疗对伴口呼吸习惯安氏Ⅱ1类错牙合患者硬组织横向结构的影响.方法对12例伴口呼吸习惯安氏Ⅱ1类错牙合病例用联冠式快速扩弓联合Tip-Edge差动直丝弓技术进行治疗,拍摄治疗前后X线头颅后前位片,进行治疗前后牙颌面横向结构测量分析.结果矫治后上、下磨牙间距分别增加3.73 mm和3.65 mm,与治疗前比较变化有显著性差异(P<0.01);上颌基骨宽度及骨性鼻腔宽度也发生增大;与上磨牙冠根同时被扩宽相比,下磨牙间距的改变主要发生于牙冠部.结论利用联冠式快速扩弓矫治器联合Tip-Edge差动直丝弓技术,可明显增加上颌基骨、上下牙弓及骨性鼻腔的宽度,可有效改善伴口呼吸习惯安氏Ⅱ1类错牙合患者横向发育不足畸形.