Dilemmas in Treatment of Recurrent Recalcitrant Dental Anterior Open Bite

An anterior open bite is one of the most difficult occlusal abnormalities to treat. Quite often this aberration entails dental component and/or skeletal component. The skeletal open bite will require intrusion of the posterior sextants with the assistance of bite blocks, temporary anchorage devices, high pull headgear, and as a last resort - orthognathic surgery. The orthodontic treatment should be augmented with the orofacial myofunctional therapy. In this article, the author describes 3 different variations of treatment of the dental anterior open bite, first on acrylic models, and then on the actual patients. Consideration should be given to patients with a 'short upper lip," and in this case, surgical correction should be entertained.

Anterior open bite--simplified non surgical technique to correct in adults

Skeletal Anterior open bite abnormality in adults is probably the most difficult to correct in orthodontics just behind Skeletal Class III abnormality. Literature research shows various techniques to correct this problem, often via orthognathic surgery, but it was difficult to find in the literatures a simplified non-surgical technique. This author propose, a simplified, non-surgical technique to correct skeletal anterior open bite in adults using non-ligating, frictionless brackets and vertical elastics. Some indications and contra-indications will be discussed

Relationship between pretreatment case complexity and orthodontic clinical outcomes determined by the American Board of Orthodontics criteria

OBJECTIVE

To evaluate the relationship between pretreatment case complexity and orthodontic treatment outcomes.

MATERIALS AND METHODS

The total sample contained 1693 cases (853 females and 840 males, mean age  =  16.3 years) from the archives of postgraduate orthodontic clinics. The complexity of each case was evaluated using the American Board of Orthodontics (ABO) Discrepancy Index (DI), and orthodontic clinical outcomes were evaluated using the ABO Objective Grading System (OGS). Only one investigator evaluated all cases. Multivariate analysis of variance, correlation analysis, and multiple variable regression analysis were used for statistical evaluation (P < .05 as significant).

RESULTS

The mean total DI score was 16.2, and the mean total OGS score was 18. No significant correlation was found between the total DI and the total OGS scores. However, pretreatment overbite, lateral open bite, crowding, buccal posterior crossbite, and other components affected the total OGS score significantly. The highest percentage of passing OGS values was found for cases of medium-level complexity.

CONCLUSION

This retrospective study of university clinical records showed that the posttreatment clinical outcomes were significantly affected from pretreatment case complexity. Posttreatment alignment was affected significantly from pretreatment buccal posterior crossbite and cephalometric values. Similarly, posttreatment buccolingual inclination was affected from pretreatment anterior open bite, occlusion, and other factors. Occlusal contacts were affected significantly from pretreatment lingual posterior crossbite and other factors. In addition, we determined that posttreatment root angulations were affected significantly from pretreatment crowding values.

Association between breastfeeding duration, non-nutritive sucking habits and dental arch dimensions in deciduous dentition: a cross-sectional study

BACKGROUND

This cross-sectional retrospective study was conducted to determine association between breastfeeding duration, non-nutritive sucking habits, dental arch transverse diameters, posterior crossbite and anterior open bite in deciduous dentition.

METHODS

415 children (228 males and 187 females), 4 to 6 years old, from a mixed Indian population were clinically examined. Based on written questionnaire answered by parents, children were divided into two groups: group 1 (breastfed for <6 months (n = 158)) and group 2 (breastfed for ≥6 months (n = 257)). The associations were analysed using chi-square test (P < 0.05 taken as statistically significant). Odds ratio (OR) was calculated to determine the strength of associations tested. Multivariate logistic regression analysis was done for obtaining independent predictors of posterior crossbite and maxillary and mandibular IMD (Inter-molar distance) and ICD (Inter-canine distance).

RESULTS

Non-nutritive sucking (NNS) was present in 15.18% children (20.3% in group 1 as compared to 12.1% in group 2 (P = 0.024)). The average ICD and IMD in maxilla and average IMD in mandible were significantly higher among group 2 as compared to group 1 (P < 0.01). In mandible, average ICD did not differ significantly between the two groups (P = 0.342). The distribution of anterior open bite did not differ significantly between the two groups (P = 0.865). The distribution of posterior crossbite was significantly different between the two groups (P = 0.001). OR assessment (OR = 1.852) revealed that group 1 had almost twofold higher prevalence of NNS habits than group 2. Multivariate logistic regression analysis revealed that the first group had independently fourfold increased risk of developing crossbite compared to the second group (OR = 4.3). Multivariate linear regression analysis also revealed that age and breastfeeding duration were the most significant determinants of ICD and IMD.

CONCLUSIONS

An increased prevalence of NNS in the first group suggests that NNS is a dominant variable in the association between breastfeeding duration and reduced intra-arch transverse diameters which leads to increased prevalence of posterior crossbites as seen in our study. Mandibular inter-canine width is however unaffected due to a lowered tongue posture seen in these children.

An index of orthognathic functional treatment need (IOFTN)

OBJECTIVE

To design a new index categorizing the functional need for orthognathic treatment.

DESIGN

Laboratory-based study.

SETTING

Records were obtained from two UK hospital-based orthodontic departments.

PARTICIPANTS

A panel of four consultant orthodontists, experienced in providing orthognathic care, devised a new index of Orthognathic Functional Treatment Need (IOFTN) with the aid of the membership of the British Orthodontic Society Consultant Orthodontists Group (COG). Twenty-three consultants and post-CCST level specialists took part in the study as raters to test the validity and reliability of the new index.

METHODS

A total of 163 start study models of patients who had previously undergone orthognathic treatment were assessed by the panel of four consultant orthodontists using the new index (IOFTN) and the agreed category was set as the 'gold standard'. Twenty-one consultants and post-CCST level specialists then scored the models on one occasion and two scored 50 sets of models twice to determine the test-re-test reliability.

RESULTS

Kappa scores for inter-rater agreement with the expert panel for the major categories (1-5) demonstrated good to very good agreement (kappa: 0·64-0·89) for all raters. The percentage agreement ranged from 68·1 to 92% in all cases. Intra-rater agreement for the major categories was moderate to good (kappa: 0·53-0·80).

CONCLUSIONS

A new index, the IOFTN, has been developed to help in the prioritization of severe malocclusions not amenable to orthodontic treatment alone. It demonstrates good content validity and good inter-rater and moderate to good intra-rater reliability. As a result of being an evolution of the IOTN, the familiar format should make it easy to determine functional treatment need within daily orthognathic practice.

Application of the dental aesthetic index in the prioritisation of orthodontic service needs

OBJECTIVE

The provision of orthodontic treatment to patients in government funded training institutions is a major challenge due to constrained budget and resource allocation. The Dental Aesthetic Index (DAI) has been used to estimate orthodontic treatment need and as a screening tool to determine treatment priority. The DAI focuses on aesthetics and therefore omits other malocclusion traits that might require orthodontic treatment. The aim of the study was to compare the application of the DAI with the influence other malocclusion traits not included in the DAI might have on the determination of the prioritisation of orthodontic service need.

METHODS

Hundred-and-twenty pretreatment study models of orthodontic patients in the permanent dentition stage were selected from the archived records of the Department of Orthodontics, University of Limpopo, using a systematic sampling method. The study casts were assessed using the DAI. Other malocclusion traits not included in the DAI were also recorded. Descriptive statistics, the Pearson correlation coefficient, Chi-square values and t-tests were employed to analyse the data. P values less than or equal to 0,05 were considered statistically significant.

RESULTS

The mean DAI score was 35.2. Normal or minor malocclusion was found in 19.1% of the sample, whilst 17.5% had definitive malocclusion, 21.7% severe malocclusion, and 41.7% showed handicapping malocclusion. Other malocclusion traits not included in the DAI were identified and these traits accounted for 21.6% of all traits recorded in the study (DAI malocclusion traits accounted for 78.4%). Two thirds of other malocclusion traits were accounted for in categories which the DAI had already prioritised for treatment.

CONCLUSIONS

The study showed that the DAI can be used to prioritise orthodontic service needs and could be applied in government funded institutions.

[Open bite and and therapeutic strategy]

Anterior open bites can be divided into two categories: skeletal and dento-alveolar. The etiology, basically affecting dento-alveolar structures, is functional or mechanical such as the rotation of the first higher molars, the exaggerated curve of Spee and the incisor supraclusion and the simple orthodontic treatment can bring a therapeutic success but functional rehabilitation remains the guaranty of such a stability of our treatment. The purpose of this work is to make a teaching article which puts the point on the interest of the elements of the diagnosis and the orthodontic treatment indicated in certain clinical situations of anterior open-bite; this by detailing biomechanics of correction of this anomaly requiring various therapeutic strategies. Functional rehabilitation remains always the guaranty of such a therapeutic stability. For the teaching aspect, we want to attach stereotypic forms and also to present clinical cases treated in the service of consultation and dental treatment in order to answer such a request.

Non-surgical treatment of anterior open bite and its assessment using the Dawjee analysis: a case report

Anterior open bite (AOB) is a dentofacial problem occurring more commonly in race groups of African origin. Although multi-factorial, the aetiology exerts its influence in tandem with craniofacial development. Diagnosis is confirmed by a cephalometric assessment and points either to a skeletal origin, a dental source, or both. Depending on the time of diagnosis and severity of the condition, treatment can vary from interceptive procedures, orthodontics only, or a combination of orthodontic treatment and orthognathic surgery. A case study is presented of an adult female with AOB who was treated nonsurgically. The diagnosis, treatment technique and outcome are described, as well as a pre- and post-treatment evaluation of the cephalograms using the Dawjee analysis. Comparison of pre- and post-treatment cephalometric values show a definite dentofacial improvement, and identifies specific morphologic areas that have changed as a result of treatment. Transformations in anteroposterior maxillary and mandibular positions and orientation are readily detectable, as well as a repositioning of the alveolar processes. While pre and post treatment cephalometric values presented for this patient compare well, these values are case specific and cannot be implemented widely unless the analysis is applied to a larger and more representative population sample and standardised measurements have been established.

Assessment of orthodontic treatment needs in Brazilian schoolchildren according to the Dental Aesthetic Index (DAI)

OBJECTIVE

To assess the distribution, prevalence and severity of malocclusion and orthodontic treatment needs in schoolchildren from the northeast of Brazil aged between 13 and 15 years.

RESEARCH DESIGN

Cross-sectional study.

PARTICIPANTS

A sample of 600 adolescents (264 males and 336 females) randomly selected and representative of schoolchildren living in Recife (Brazil) was obtained from 12 public schools.

METHOD

The need for orthodontic treatment was measured using the Dental Aesthetic Index (DAI).

RESULTS

Most of the subjects (77%) were deemed to require orthodontic treatment. Only about 5.8% had a handicapping malocclusion that needed mandatory treatment. A severe malocclusion for which treatment was highly desirable was recorded in 47.5% of the adolescents and 23.7% had a definite malocclusion for which treatment was elective. Three main occlusal features were responsible for allocating subjects into the group of "orthodontic treatment required": crowding (47.3%), tooth loss (22.3%) and maxillary overjet of more than 3 mm (21.8%). There were no significant differences (p > 0.05) in mean DAI scores between males and females.

CONCLUSIONS

77% of adolescents from northeast Brazil were in need of orthodontic treatment for dental health reasons. The distribution of DAI scores among Brazilian adolescents is different from that reported in other populations. This study provides baseline data on the need and demand for orthodontic treatment among Brazilian students.

A vertical cephalometric analysis

Correctly assessing open-bite malocclusions has remained problematic because clinicians have not had entirely reliable methods of determining the exact amount of skeletal and dental contributions to the problem. A new cephalometric technique, the vertical cephalometric analysis, offers orthodontists a system that precisely identifies the percentage of skeletal and dentoalveolar components that open-bite patients have. The vertical cephalometric analysis offers a discriminating diagnostic method for evaluating, diagnosing, and treatment planning for patients with open bite. This technique will allow clinicians to classify patients with accuracy, as well as to establish prognoses and select therapies.

Orthodontic treatment need in Peruvian young adults evaluated through dental aesthetic index

The objectives of this study were to evaluate the frequency and severity of the malocclusion and treatment needs in Peruvian young adults. The second aim was to compare the orthodontic treatment needs according to sex and socio-economic status (SES). This cross-sectional study was conducted at the University Dental Clinic of a private university in Lima, Peru. A total of 267 freshmen (from 16 to 25 years old) were randomly selected from a pool of 780 students. Students wearing an orthodontic appliance or reporting a history of orthodontic treatment were excluded from the study. Clinical examinations were conducted using the Dental Aesthetic Index (DAI). Mann-Whitney and Kruskal-Wallis tests were used to compare the DAI scores according to sex and SES, respectively. The mean DAI score was 28.87 points (IC(95%) 27.77; 29.97, where IC indicates interval of confidence). Around one-third of the sample presented severe or very severe malocclusion, which implies a highly desirable or mandatory orthodontic treatment need. No statistically significant difference was found between the DAI scores according to sex (P = .592) and SES (P = .397). Approximately one-third of the evaluated Peruvian young adults would need orthodontic treatment according to the DAI. In this population, malocclusion was characterized by a relatively high frequency of missing teeth, appreciable dental crowding, and inadequate anteroposterior relationships.

Assessment of open and incomplete bite correction by incisor overlap and optical density of polyvinyl siloxane bite registration

Open bite (OB) is a generalized term, which could incorporate subgroups that react differently to vertical correction. The objectives of the present study were to detect vertical treatment changes in incomplete bite (IB: inter-incisor overlap with no lower incisor contact with teeth or palate) and OB (no inter-incisor overlap) groups compared with a complete bite (CB: inter-incisor overlap with full lower incisor contact with teeth or palate) control group, to evaluate treatment response of the central and lateral incisors, and to study the vertico-sagittal interaction. Dental casts were taken at three time points, pre-treatment, post-treatment, and after one year of retention, from 54 Class II patients (22 males and 32 females with a mean age of 11 years 6 months) divided into three groups: CB (n = 21), IB (n = 18) and OB (n = 15). Measurements included incisor overlap (mm) and optical density (OD/mm2) of occlusal bite registration made of polyvinl siloxane. Both CB and IB groups demonstrated post-retention bite opening. However, bite opening in the CB group was three times greater than that in the IB group (e.g. lower lateral = -1.42 mm, 118 OD/mm2 versus -0.40 mm, 107 OD/mm2). Conversely, the OB group showed a significant (P < 0.001) bite closure (e.g. lower lateral = 1.30 mm, -377 OD/mm2). Overjet changes affected OD measurements, causing diversity in OD and millimetric measurements of the lateral incisors in the IB group. In conclusion, the OB group demonstrated a significant stable vertical correction; a post-treatment non-contact inter-incisor relationship was determined by a vertico-sagittal relapse; and full compensation of an IB was not possible.

A study of occlusion in elderly Japanese over 80 years with at least 20 teeth

OBJECTIVES

The purpose of this study was to identify the occlusal status of elderly Japanese over 80 years with at least 20 teeth.

MATERIALS AND METHODS

The study enrolled 76 elderly Japanese (44 male, 32 female) with a mean age of 82 years and an average of 25.7 remaining teeth. The study consisted of intra-oral examination, intra-oral and facial photographs, radiographs and impressions for study casts.

RESULTS

No gender difference was observed in age or number of remaining teeth. Anteroposterior occlusal relationship was characterised by maxillary protrusion in 67.6%, acceptable overjet in 31.0%, and anterior crossbite in 1.4%. Vertically, deep bite was noted in 33.8%, acceptable overbite in 64.8%, and open bite in 1.4%. Most of the subjects had either Angle class I (68.4%) or class II (25.7%) canine relationship. Only 3.9% of the subjects had upper anterior crowding. Lower anterior crowding was observed in 23.7%, but tended not to be severe.

CONCLUSION

These results indicate that Japanese who attained the goal of '8020' have a relatively good occlusion.

Prolonged feeding practice and its effects on developing dentition

Muscular activity of the lips, cheeks, and the tongue are important factors, which not only guide the occlusal development but also affect the growth of the jaws. Bottle feeding has been known to cause a myriad of changes in the oro-facial development. But the adverse effects of feeding practices with respect to developing dentition has been a subject of controversy. Hence a study was designed with the aim and objectives to check the commonly adopted feeding practices in South Kanara, to compare the occlusion of 3- to 5-year-old children with breast feeding, bottle feeding or combination, and to check whether prolonged feeding has any adverse influence on developing dentition. A total of 250 questionnaires were distributed to parents of 3- to 5-year-old children of which 153 were chosen for recording the impression and for studying the occlusion under various parameters. The results of the study indicated definite potential hazards of prolonged breast and bottle feeding especially with a tendency to develop openbite and posterior crossbite. It also suggested that an early preventive and interceptive approach.

Classification of Anterior Open Bite Using Individualized Cephalometry

OBJECTIVE

The objective of this study was to describe the cephalometric characteristics of the open bite, and to classify the open bite according to individualized norms.

MATERIAL AND METHOD

The lateral cephalograms of 134 patients with an anterior open bite (min -0.5 mm) were analyzed. Patients were classified according to the inclination of the jaws, applying the principles of individualized cephalometry. The harmony box described by Hasund was used to define individualized norms for the inclination of the upper and lower jaws in each patient. The open bite was classified into four sub-types: (1) dental, (2) skeletal with enlarged ML-NSL angle, (3) skeletal with reduced ML-NSL angle, and (4) skeletal with deviations in upper and lower jaws. A skeletal open bite was found in 89 patients (66.4%). A dental open bite was found in 45 patients (33.6%).

RESULTS

A number of significant differences were found between these four groups using single-factor variance analysis and the Bonferroni a posteriori test, (p < or = 0.05, p < or = 0.01, p < or = 0.001). The most prominent variables were index value of anterior facial hight, total facial height ratio, gonial angle, and Y-axis. No significant differences were found for overbite, however.

CONCLUSION

It was possible to use individualized norms to classify the open bite into four sub-types. The demarcation between the four groups was supported statistically. The extent of the anterior open bite does not allow any conclusions as to the craniofacial pattern.

The ABO discrepancy index: a measure of case complexity

A criterion for determining the acceptability of a case presented for the American Board of Orthodontics (ABO) Phase III clinical examination is case difficulty. Case difficulty can often be subjective; however, it is related to case complexity, which can be quantifiable. Over the past 5 years, the ABO has developed and field-tested a discrepancy index, made up of various clinical entities that are measurable and have generally accepted norms. These entities summarize the clinical features of a patient's condition with a quantifiable, objective list of target disorders that represent the common elements of an orthodontic diagnosis: overjet, overbite, anterior open bite, lateral open bite, crowding, occlusion, lingual posterior crossbite, buccal posterior crossbite, ANB angle, IMPA, and SN-GoGn angle. The greater the number of these conditions in a patient, the greater the complexity and the greater the challenge to the orthodontist. The ABO is considering several options for applying the discrepancy index to the Phase III clinical examination.

Evaluation of oral and systemic manifestations in an amelogenesis imperfecta population

OBJECTIVES

The aim of this investigation was to describe the dental and craniofacial characteristics of patients with amelogenesis imperfecta (AI).

METHODS

The study group included 43 patients(33 female and 10 male) with a mean age of 11.4+/-2.6 years. A panoramic and a cephalometric radiograph were obtained from each of these patients. Clinically AI cases were divided into four main groups according to Witkop. All patients were evaluated for chronological, bone and dental age. The patients who had severe retarded bone age were evaluated for plasma growth hormone(GH) concentrations.

RESULTS

Dental and bone ages were retarded with respect to chronological age in five patients. Dental maturity and tooth eruption were not age- appropriate in some of our patients. In type III AI patients a delay in skeletal age was observed. Severe late eruption was seen in 3 patients, severe delay in dental maturity was noted in patients with type IV AI. Dental age was clinically lower in GH-deficient subjects, and skeletal age was consistently more retarded than dental age when compared to chronological age. Anterior open bite was present in both primary and permanent dentitions of 50% of the patients with type I AI, 30.8% of the patients with type II AI, and 60% of type III AI.

CONCLUSION

It is concluded that the primary structure for the classification of AI be based on the mode of inheritance, with the clinical and radiographic appearances (and any other features such as systemic findings) being the secondary discriminators.

The effects of infant feeding patterns on the occlusion of the primary dentition

The purpose of this study was to investigate the effects of different methods of infant feeding on the development of the occlusion in the primary dentition. The study included 126 children. Parents completed questionnaires regarding feeding and health history, and the primary dental occlusion was recorded for each child. The authors found that: (1) predominant bottle-feeding between 0 and 6 months of age was associated with the development of a pacifier habit; (2) children who used a pacifier were more likely to develop a nonmesial step occlusion, an overjet >3 mm, and an open bite; (3) children who sucked their thumb were more likely to develop an overjet >3 mm; and (4) in the absence ofnonnutritive oral habits, children who were predominantly bottle-fed between 0 and 6 months of age were more likely to develop an overbite >75%, although just shy of nominal statistical significance.

Effects of different pacifiers on the primary dentition and oral myofunctional strutures of preschool children

PURPOSE

The aim of this study was to evaluate the characteristics of the dental arches and some oral myofunctional structures in 36- to 60-month-old children who sucked a pacifier or did not have this habit.

METHODS

Sixty-one children were divided into 3 groups: (1) those who never sucked a pacifier, (2) those who exclusively sucked a physiological pacifier, and (3) those who exclusively sucked a conventional one. A clinical examination was performed on the children to observe the relationship between the arches and their width, as well as the following oral myofunctional structures: lips, tongue, cheeks, and hard palate.

RESULTS

Statistical analysis showed that: (1) the use of both ytpes of pacifiers led to anterior open bite (prevalence of 50% in both groups; P = . 001), (2) posterior crossbite was present only on children who had a pacifier-sucking habit, (3) the mean oveqrjt was greater on children who sucked physiological (3.6 mm) or conventional (3.7 mm) pacifiers when compared to those with no sucking habits (1.3 mm; P = .001), (4) intercanine distance of the upper arch was significantly smalelr on children who sucked pacifiers (29.6 mm in the physiological group and 29.2 mm in the conventional pacifier group) than those who did not (31.2 mm), and (5) the children who never sucked on a pacifier showed a higher prevalence of normality of cheek mobility (74%; P = .022) and hard palate shape (78%; P = .042).

CONCLUSIONS

Children who sucked pacifiers, both conventional and physiological ones, showed higher prevalence of alterations in the relationship of the dental arches and orla myofunctional structures, when compared to those who never sucked a pacifier.

Dental characteristics of patients with Duchenne muscular dystrophy

A comprehensive assessment of the dental characteristics of 23 patients with Duchenne muscular dystrophy (DMD) was carried out, based on dental records, oral examinations and dental models. Decreasing muscle function was associated with increased plaque and calculus accumulation, leading to gingival inflammation, but caries experience was low. Disturbances in tooth form, number and eruption of the second premolars were observed in 39% of patients. Anterior and posterior open bites were common, associated with lip incompetence, mouth breathing, macroglossia and tongue thrusting. Maxillary and mandibular arch breadths were significantly larger, on average, in the DMD group than in controls. Rather than a normal parabolic arch form, the dental arches in DMD patients tended to be hyperbolic, with the posterior teeth being displaced buccally, consistent with an imbalance between the lingual and facial musculature.

Floating norms and post-treatment overbite in open bite patients

In this study, the clinical significance of three floating norm systems, the Bergen Box (BB), the Segner-Hasund Harmonybox 1 and 2 (SHH1 and SHH2), as well as the influence of treatment modalities for predicting results of an open bite treatment were investigated. In the BB and SHH1, patients with a steep mandibular plane angle or a skeletal open bite configuration (O1mand, O1mandmax, O1max, or N1mand) were considered 'high risk', while in the SHH2, only the configurations O1mand and O1mandmax were considered high risk. All other configurations were designated 'low risk'. It was postulated that in high risk patients, the overbite was likely to relapse into an open bite after retention. Cephalograms of 83 open bite patients taken before treatment (T1) and at the end of retention (T2) were studied. Patients designated as low risk generally had a normal overbite at T2 after treatment, regardless of which box was used. The risk configurations of the SHH1 and SHH2 at T1 were significant predictors of the overbite at T2, the first being slightly better compared with the SHH2. The main clinical values of the SHH1 and SHH2 are strongly supported by the relatively good success rate in distinguishing a low-risk configuration. Reliable prediction of the treatment results of high-risk patients with risk configurations according to the SHH is improved by evaluating treatment modalities. The posterior bite splint seemed to have a bite opening effect, while a bite closing effect was associated with the use of a removable retention appliance.

Readiness for orthognathic surgery: a survey of practitioner opinion

The purpose of this study was to determine if a general consensus exists among orthodontists regarding the features of an adequate presurgical setup. A questionnaire was developed to assess the importance of 12 criteria for surgical readiness. Each criterion was rated on a 5-point scale (1 = Unimportant, 5 = Critical). This questionnaire was sent to 104 randomly selected, board-certified orthodontists in the United States and Puerto Rico. Usable questionnaires were returned by 57 respondents (55% response rate). The highest and most consistent ratings were given for Arch Compatibility in the transverse dimension (mean = 4.66, SD = 0.55), Crossbite (mean = 4.57, SD = 0.63), and Torque of the Anterior Teeth (mean = 4.38, SD = 0.73). Further analysis showed a correlation between surgical experience of the orthodontist and a higher rating of importance for Torque of the Mandibular Teeth (Spearman r = 0.38), Torque of the Maxillary Teeth (Spearman r = 0.37), and Torque of the Anterior Teeth (Spearman r = 0.28). These results suggest that as orthodontists gain surgical experience, they attribute more importance to correcting the torque of the teeth. Also, the relatively large differences in opinion regarding presurgery orthodontic setup support a need for further research and/or educational effort regarding what criteria are important before surgery.

Selection of criteria for assessment of occlusal acceptability

There is no general agreement on criteria that could be applied to distinguish between orthodontically acceptable and non-acceptable occlusions after the completion of dental development. The aim of the present study was to analyse morphological and functional features that could be used as an index to define an acceptable occlusion in young adults. Three expert panels representing specialists in orthodontics and stomatognathic physiology participated in a modified Delphi method. Each panel responded to a questionnaire concerning the usefulness of various occlusal features, and a set of characteristics was selected on the basis of the responses; thereafter, applicability of the chosen characteristics and their cut-offs for an acceptable non-acceptable dichotomy was tested clinically. To obtain a consensus level of 100%, the last panel session was completed with a group discussion. Assessments made using the morphological criteria were compared with those made with the dental health component of the Index of Orthodontic Treatment Need. The selected morphological characteristics consisted of overjet, overbite, canine relationship, crossbite, scissors bite and midline deviation. The functional evaluation comprised assessments of discrepancy between the centric relation and the intercuspal position, working- and non-working-side contacts and protrusion contacts. The dental health component and our morphological criteria showed different sensitivity to contact point displacements, interdigitation in buccal segments and increased overbite. This study provides a set of morphological and functional indicators reflecting the current consensus opinion of Finnish professionals. Further studies are needed to analyse the reproducibility of assessment of the characteristics included.

Duration of nutritive and nonnutritive sucking behaviors and their effects on the dental arches in the primary dentition

The purpose of this study was to determine the association between the duration of nutritive and nonnutritive sucking behaviors and various occlusal characteristics in the primary dentition. Sucking behavior data were collected on 372 children followed longitudinally from birth by using periodic questionnaires completed by parents. Study models were obtained from the children at 4 to 5 years of age and assessed for posterior crossbite, anterior open bite, and overjet. Dental arch parameters including arch widths, arch lengths, and arch depths were measured directly from the models. The subjects were grouped according to type of habit (pacifier or digit) and duration of nonnutritive sucking behaviors (less than 12, 12 to 24, 24 to 36, 36 to 48, and more than 48 months). Children with nonnutritive sucking of less than 12 months were further grouped according to the duration of breast-feeding. The dental arch and the occlusal characteristics were then compared among these groups. The results indicated no relationship between duration of breast-feeding during the first year of life and any dental arch or occlusal parameters. The study found that prolonged pacifier habits resulted in changes to the dental arches and the occlusal parameters that were different from the effects of digit sucking. In addition, some changes in the dental arch parameters and occlusal characteristics (eg, prevalence of posterior crossbite and increased amount of overjet) persisted well beyond the cessation of the pacifier or digit habit. Although further study is needed to determine the effects of nonnutritive sucking behavior in the mixed dentition, the results suggest that current recommendations for discontinuing these habits may not be optimal in preventing habit-related malocclusions.

[A classification of anterior open bite]

OBJECTIVE

It intended to investigate different craniofacial types of anterior open bite.

METHODS

116 patients with anterior open bite were selected randomly. The craniofacial morphology and airway structures were measured and analyzed with multivariate analyses.

RESULTS

4 factors (mandible rotation factor, facial height factor, dental and skeletal saggittal factor and maxillary rotation factor) were extracted from 156 items including age, gender and craniofacial characteristics by data reduction and factor analysis procedure. Anterior open-bite patients were classified into 5 types, which are dental-alveolar type, mandibular clockwise rotation type, long face type, maxillary counter-clockwise rotation type and skeletal Class III type with K-means cluster analysis procedure. A simple cluster method was summarized to facilitate clinical practice.

CONCLUSION

It suggested that classification play an important role in diagnosis and decision making procedure.

The Don Spring Memorial Oration--Part II: early management of the developing Class III malocclusion

It was apparent from Dr Turley's presentation that many cases, previously thought to be untreatable by conventional orthodontic means, can be managed with a high degree of success using the techniques described. It is hoped that this overview of management of the developing Class III malocclusion will provide a rationale, a means and a reason for all of us to feel comfortable in treating these interesting and sometimes difficult cases.