The prevalence of Molar Incisor Hypomineralisation (MIH) in a group of Italian school children.

AIM: This epidemiological study in a group of Italian children was undertaken in order to increase our knowledge of the prevalence of Molar Incisor Hypomineralisation (MIH) in different European countries. METHOD: A population of school children aged 7.3 - 8.3 years, living in Lissone, Northern Italy, was examined for the presence and severity of MIH. RESULTS: Of a total of 227 children (113 females), 31 (13.7%) had MIH, the tooth prevalence in the permanent first molars being 5.8%. Fifteen children (6.6%) had demarcated opacities in the incisors with a tooth prevalence of 2.1%. The defects in the molars were mild with the exception of one child who had severe defects. CONCLUSION: MIH was quite common in this Italian town, and the prevalence figures were near those reported in Scandinavian countries but clearly higher than those from Dresden, Germany.     

Mineral content in teeth with Deciduous Molar Hypomineralisation (DMH)

Objectives

We report the mineral (hydroxyapatite) density of sound and opaque areas in DMH molars with sound parts of (carious) deciduous teeth serving as controls.

Methods

Twenty-nine extracted second primary molars obtained from 15 children were studied. Thirteen of these molars were DMH molars with yellow opacities, seven were DMH molars with white opacities, three DMH molars with brown opacities and eleven were molars without DMH. Prior to microCT scanning, the teeth were mounted in impression material (Impregum^®) and stored in water with a thymol crystal. Spot analysis and line scans were performed in areas with opacities and in sound areas.An ANOVA test and t-tests were used to test if there were significant differences between the groups.

Results

The average densities of the hydroxyapatite in yellow and brown opacities (1368 mg HA/cm² and 1407 mg HA/cm², respectively) were significantly lower than in clinically unaffected enamel (1747 mg HA/cm²) of DMH molars or of sound molars (1758 mg HA/cm²). The mineral density in white opacities (1737 mg HA/cm²) was not different from that in the enamel of sound molars. The mineral density values in yellow and brown enamel opacities were in between those of dentine (1018 mg HA/cm²) and enamel.

Conclusions

DMH molars with yellow or brown opacities had a 20–22% lower mineral density in the hypomineralised enamel compared with sound molars. White opacities do not show a lower mineral content. The reduction in enamel mineral content in DMH molars stressed the need for a preventive approach in DMH.     

Dental management strategies for Molar Incisor Hypomineralization

BackgroundMolar Incisor Hypomineralization (MIH) is defined as a hypomineralization of systemic origin that can affect all permanent first molars and, in most cases it can also affect the permanent incisors.ObjectiveThe aim of this review was to describe the various options available to treat and restore MIH-affected molars.ResultsMIH is a developmental, qualitative enamel defect caused by reduced mineralization of the inorganic enamel components, leading to enamel discoloration and defects in the affected teeth. MIH in permanent molars is usually associated with caries and intense pain, and children often become disruptive during MIH treatment due to the challenges associated in achieving proper anesthesia of the affected teeth.ConclusionEarly detection and appropriate therapy can prevent severe complications and improve both masticatory function and esthetics. The treatment of MIH varies from a simple procedure, such as a controlled clinical eruption, to extensive and recurrent treatments in more severe cases.     

Esthetic rehabilitation of first permanent molars affected with severe form of Molar Incisor Hypomineralization using indirect composite onlays-A case series

Restorative management of MIH affected young permanent first molars is often challenging for pediatric dentists. Poor patient compliance, extreme sensitivity, rarity of the condition and increased treatment costs are some of the factors compounding its management. Traditionally, Stainless Steel and Cast Metal crowns have been the mainstay for management of these molars. However, young age of patients and demand for esthetics necessitates the search for an esthetic and conservative alternative. Present case series aims to highlight the use of minimally invasive Indirect Composite Onlays for rehabilitation of ten permanent molars affected with severe form of MIH in children, aged 8–14 years. At 30–36 months (x? 34.8 mths) follow-up, all the onlays were found to be in place with complete elimination of pre-treatment sensitivity. Marginal integrity and anatomic form remained unaltered over time. Depreciation in colour stability and evidence of cavosurface marginal discolouration at 30 months was evident in only one of the restored onlays. Thus, Indirect Resin onlays may serve as esthetic conservative restorative alternative for MIH affected molars with favourable outcomes.     

Current Products and Practice

Abstract

Virtual learning environments (VLEs) are attractive solutions for the delivery of education on-line. Orthodontic education online has the potential to alleviate some of the problems caused by increasing demands on academic staff, the impact of the European work time directives and changes in junior doctors’ hours. All act to constrain the effective training of orthodontic postgraduates. The design of a VLE is driven by modern concepts in learning and teaching, the structure, content and assessment methods will help determine the range of behaviours any programme hopes to encourage. This paper aims to provide information on how a modular specialist-training programme in the United Kingdom has been developed and enhanced by a VLE.     

Current Products and Practice

Abstract

Due to an increasing demand for superior aesthetics during fixed appliance treatment, the use of aesthetic brackets has grown in popularity over recent years. Although often requested by patients, aesthetic brackets are not without their disadvantages. This article presents the currently available plastic and ceramic brackets and discusses the potential problems associated with each. Recent advances, introduced by manufacturers in an attempt to overcome their clinical disadvantages, are described.     

Current Products and Practice

Abstract

Objective: To collect information on the current consent practices of consultant orthodontists for orthodontic and joint orthognathic treatment.

Design: Postal questionnaire.

Subjects and Methods: The questionnaire was sent to all 222 consultant orthodontists held on the database of the British Orthodontic Society. The questionnaire consisted of five multi-part questions requiring tick-box responses.

Outcome: A total of 199 questionnaires were returned.

Results: Written information on orthodontic treatment was provided by 56 per cent of respondents whilst 41 per cent obtained written consent. Written information on joint orthognathic treatment was provided by 47.5 per cent of respondents, whilst 20 per cent obtained joint written consent. Most who obtained written consent for orthodontics and joint orthognathic treatment used 16 years as an appropriate age for patients to provide their own consent.

Conclusions: Consent practice amongst consultant orthodontists varies, with 35 per cent providing neither written information nor seeking written consent prior to orthodontic or joint orthognathic treatment.     

Incisor and mandibular movement during retrusion

Human mastication, respiration, speech, swallowing and suckling are directed by the jaw muscle activites, the temporo-mandibular joints, the ligaments and by the occlusal dental contacts. Mastication is usually assessed by border movements of the mandibular incisors. While the border movements of opening, protrusion and lateratrusion are often used to determine the mandibular functions, the movement of retrusion is rarely considered in the study of the human oro-facial functions. Our purpose was to evaluate the mandibular movement of retrusion in a population that did not present any symptoms nor clinical signs of temporo-mandibular disorders. The study was performed on 117 males and 121 females (age range: 17.7-65.2 years; mean age: 31.1 years) using electrognathographic registrations (Sirognatograph(*), Siemens, Benshein, Germany). Every patient was instructed and trained before recording. The measurements were calculated on the sagittal plane registrations. The results showed that the mandibular movement of retrusion was present in 233 out of the 238 studied subjects (97.9%) whatever was the dental class, the age or the sex. The width range was between 0.3 and 5.4 mm and the mean value was 1.75+/-0.91 mm. The inferential analysis performed by a 3-way ANOVA model demonstrated no significant difference in retrusion value by dental class, gender or age. The most frequent numerical value was 1.5 mm, observed in 16 subjects (6.7% of the studied population). These results suggest that, in order to respect the physiological characteristics, more attention is needed in performing dental treatments.     

Incisor edge-centroid relationships and overbite depth

Interincisor angulation is commonly held to be a critical factor in determining overbite depth, where there is incisor contact. In this study significant correlations between these variables were found in Class II, division 2 malocclusions although interincisor angle explained less than a third of the variance in overbite depth. It was found that the anteroposterior relationship of the lower incisor edge to the upper incisor root centroid is more strongly related to overbite depth and it is suggested that this is a useful factor to take into account in planning treatment in Class II cases.     

Incisor crown shape and crowding.

The aim of this study was to investigate correlations between the shape of mandibular incisor crowns and crowding. Study models of 50 untreated white subjects (25 men and 25 women) with varying degrees of crowding were studied. The lower incisors were sectioned and imaged at the contact point and midpoint levels, and the mesiodistal width was measured. Crowding was quantified by using both Little's irregularity index and anterior tooth size-arch length discrepancy. The ratio of the 2 mesiodistal widths was correlated with Little's irregularity index and anterior tooth size-arch length discrepancy. In the women, the ratio showed correlations of 0.52 (P =.008) and 0.55 (P =.005) for central and lateral incisors, respectively, with anterior tooth size-arch length discrepancy. No predictors of lower incisor crowding could be established from mandibular incisor crown shape in this study.     

Current Products and Practice Section

Abstract

There are potential religious, cultural and ethical dilemmas facing patients who are undergoing orthodontic treatment. Opinions were collected from religious and cultural leaders, as well as from non-religious groups who take an ethical standpoint on certain medical or dental treatment. Factors relating to ingredients in orthodontic products, timing of orthodontic appointments, and the effects of religious fasting are all discussed. It is important to recognize all patients’ opinions and beliefs when planning and undertaking orthodontic treatment.     

Incisor display during speech and smile: Age and gender correlations

Objectives:To evaluate age- and gender-related changes in the soft tissues, incisors, and gingival display during rest, speech, and posed smile.Materials and Methods:A total of 265 participants (122 men, 143 women) ranging in age from 19 years to 60 years were recruited for this study. Participants were divided into one of the following four age groups: 19 to 24 years, 25 to 34 years, 35 to 44 years, and 45 to 60 years. Image capture was performed using standardized videographic methods. Each video produced pictures where measurements were performed: rest, speech, and smile positions.Results:A statistically significant gender dimorphism was apparent in most of the variables. There was a significant increase in the upper lip length and lip commissures height with aging and more markedly in men. A greater exposure of mandibular incisor with increasing age was a feature in both genders. With increasing age there was a significant decrease in maxillary incisor display, especially for men.Conclusions:After 25 years of age there is significant difference in the aging process between men and women. Gingival and maxillary incisor display during speech and smile is a youthful and feminine characteristic.     

The Lower Lip Position and Incisor Overjet

Abstract

1147 children aged 11–12 years were examined to determine the mean overjet values relative to five defined postural lower lip/maxillary central incisor relationships.

A mean overjet of 3·025 mm was found in those children having a postural lower lip position related to the middle third of the maxillary central incisor; and those having no lower lip cover had a mean overjet of 4·26 mm. In contrast, the mean overjet value was 9·18 mm for those children having a “negative” lip position.

The observed differences between the mean overjet values relative to each lower lip position are statistically significant, but the only lower lip/maxillary central incisor relationship which appears to have any marked clinical significance is the one defined as—1 (i.e. the trapped lower lip).     

下颌有阻生倾向智牙胚与阻生智牙拔除术的比较研究

目的:比较下颌有阻生倾向的智牙胚拔除术与下颌阻生智牙拔除术的手术难度及术后并发症。方法:研究组选取有阻生倾向的下颌智牙胚拔除术病例41例,并随机收集成年下颌埋伏阻生智牙拔除病例40例作对照。收集两组拔牙手术操作时间、术后疼痛、局部肿胀、张口度改变情况的数据,并进行对比分析。结果:下颌有阻生倾向的智牙胚拔除术操作时间短,术后的肿胀、疼痛及开口改变情况,均较对照组轻。结论:下颌有阻生倾向的智牙胚拔除术,操作简单,术后不良反应较轻,恢复快。     

Molar root furcation: morphometric and morphologic analysis

The objective of the present study was a morphometric and morphologic analysis of maxillary and mandibular first and second molars using three different techniques. Measurements of 207 maxillary molars (105 first and 102 second molars) and 207 mandibular molars (110 first and 97 second molars) were measured; root length, radicular trunk length (RTL), mesiodistal and buccolingual diameters (BLD) at the cementoenamel junction, inter-radicular angle (IRA) width, and furcal roof area (FRA) were recorded. No significant statistical correlations were found for most of these measurements, the only exception being the relationship between IRA/FRA, IRA/BLD in maxillary molars, and IRA/RTL in the maxillary first molar. Morphologic examination was carried out by stereo microscopy, light microscopy of undecalcified sections, and scanning electron microscopy. All of these techniques showed the complexity of the furcation area with a large number of anatomic irregularities and plaque-retentive structures that could hamper adequate cleaning during periodontal treatment.