Centrographic analysis of 1-phase versus 2-phase treatment for Class II malocclusion

Very early orthodontic treatment: when, why and how?

Introduction:

Several orthodontic problems should already be treated at an early age to prevent the necessity of future complex and expensive procedures. Scientific evidence suggests that posterior crossbites, mild to moderate Class III, as well as certain Class II malocclusions, open bites and arch length discrepancies can benefit from simple, but efficient interceptive therapy.

Objective:

To summarize the existing evidence-based literature on early orthodontic treatment, and to illustrate its application and effectiveness by showcasing multiple clinical examples.

Conclusion:

Early short-term interceptive orthodontic treatment with simple appliances, in the deciduous or early mixed dentition phase, can efficiently correct certain malocclusions and help to either reduce the complexity or even avoid the necessity of complex and expensive procedures during puberty. For certain patients with significant arch length discrepancy the concept of serial extractions should be part of the orthodontic armamentarium.

Perception, knowledge and attitudes of Brazilian orthodontists on the treatment of Class II malocclusions

The present study aimed to assess the perception and knowledge of Brazilian orthodontists on the ideal moment to treat Class II malocclusions. Questionnaires with open, semi-open and close questions were sent by e-mail to 1653 Brazilian orthodontists. These orthodontists were registered in the Brazilian Association of Orthodontics and Dentofacial Orthopedics (ABOR). One-hundred and three (9.86%) Orthodontists replied to the questionnaires. Most of them were males (60.5%) with specialization as the highest level of professional qualification (59.9%). Most of the orthodontists (51%) reported preference for treating Class II malocclusions in late mixed dentition, followed by the early mixed dentition (29%). The age range between 10 and 12 years old figured as the most prevalent in patients searching for treatment (42.7%). Most of the patients searching for treatment were females (69.7%). Preferences for functional orthopedic appliances were reported by 35% of the orthodontists. Brazilian orthodontists revealed a trend for treating patients with Class II malocclusions in the late mixed dentition. Female patients aged from 10 to 12 years old represented the majority of patients that search for orthodontic treatment. Functional orthopedic appliances were preferred by Brazilian orthodontists for treating Class II malocclusions.

Volumetric changes in pharyngeal airway in Class II division 1 patients treated with Forsus-fixed functional appliance: A three-dimensional cone-beam computed tomography study

Objective:

Recent years have witnessed a renewed interest to determine a quantifiable relationship between mandibular advancement performed with an orthodontic appliance and the resulting airway volume. The study was conducted to evaluate the volumetric changes in pharyngeal airway space using cone-beam computed tomography (CBCT) in Class II division 1 patients with retrognathic mandible treated by Forsus-fixed functional appliance and to compare them with their pretreatment findings.

Materials and Methods:

Thirty patients with Class II division 1 malocclusion of age group 10–17 years were selected randomly and evaluated for changes in pharyngeal airway volume with and without Forsus-fixed functional appliance. Patients in each group underwent CBCT scan of head and neck region at pretreatment stage and 6 months after the initial scan. Institutional approval for the project was obtained from the Ethical Committee. Volumetric changes of upper (oropharynx) and lower (hypopharynx) pharyngeal airways were measured on scanogram using computer software and intragroup comparisons were done.

Results:

There was a statistically significant increase in the volume of both hypopharynx and oropharynx and also total airway volume in patients treated with Forsus-fixed functional appliance. Three-dimensional reconstruction of the airway also demonstrates a considerable increase in pharyngeal airway space.

Conclusion:

Forsus-fixed functional appliance can be a promising appliance for improving pharyngeal airway volume in Class II division 1 patients with retrognathic mandible thus preventing obstructive sleep apnea and other respiratory problems in future. However, the long-term implications of this treatment modality need further consideration and a longer period of follow-up.

Do orthodontists recommend Class II treatment according to evidence-based knowledge?

AbstractIntroductionThe adequate indications for the timing of treatment for Class II malocclusion are mandatory for the ethical and efficient practice of orthodontics, but clinicians are reluctant to accept new information that contradicts their preferred method of treatment.ObjectiveThe aim of this investigation was to assess the agreement regarding the indications for Class II malocclusion interceptive therapy between a group of international opinion-makers on early treatment and a group of orthodontists and to compare their treatment indications with the current evidence-based knowledge.Material and methodAn electronic survey containing photographs of mild, moderate and severe Class II malocclusions in children was sent to two panels of experts. Panel 1 (n=28) was composed of international orthodontists who had authored world-class publications on early orthodontic treatment, and Panel 2 (n=261) was composed of clinical orthodontists. Based on a 5-point Likert-type scale, the orthodontists selected their therapy option for each of the 9 Class II malocclusion cases.ResultThe Class II malocclusion treatment recommendations of Panel 2 were significantly different from those offered by Panel 1 with a skew of at least 1 scale point toward earlier treatment. The Class II malocclusion treatment recommendations of the members of Panel 1 members were in accordance with contemporary evidence-based knowledge.ConclusionClass II malocclusion overtreatment appears to be the tendency among clinical orthodontists but not among orthodontists who are academically involved with early treatment. There is a gap between the scientific knowledge and the practices of orthodontists.

The applicability of centrographic analysis in pleasing craniofacial phenotypes

Context

There has always been a need for nonnumeric facial analyses that would not compare an individual’s facial measurements with the preestablished norms, rather evaluate the facial form individually. This would help in diagnosis and treatment planning, unique to that individual.

Aims

The purpose of the study was to determine and establish a relation between skeletal, dental and soft tissue structures using centrographic analysis (CGA) in pleasing faces of Western Uttar Pradesh population.

Materials and Methods

A total of 50 subjects (22 males and 28 females) with “most pleasing faces” were taken up for the study, within the age group of 20-25 years. Frontal facial photographs and lateral cephalograms were taken for all the subjects. Conventional cephalometric analysis and CGA were applied to each lateral cephalogram. Arithmetic mean and standard deviation values were calculated, and an independent t-test was performed for calculating cephalomorphic norms and comparison between the male and female sample.

Results

The results showed that, the adults in the age group of 20-25 years, belonging to the Western Uttar Pradesh population have protrusive maxillary and mandibular skeletal bases and retrusive upper lip on contrary to a protrusive lower lip, though a sexual dimorphism was observed. The upper centroid and lower centroid values were statistically greater in women (P = 0.05 and P = 0.04 respectively) whereas, upper lip linear value was statistically greater in men.

Conclusions

The CGA is valid for Western Uttar Pradesh population. The Western Uttar Pradesh adults have protrusive mandible and a retrusive upper lip though there exists a sexual dimorphism. These practical centrographic norms can be used as an adjunct to the conventional cephalometric evaluation of an individual for diagnosis and treatment planning.

Class II malocclusion occlusal severity description

Objectives

It is well known that the efficacy and the efficiency of a Class II malocclusion treatment are aspects closely related to the severity of the dental anteroposterior discrepancy. Even though, sample selection based on cephalometric variables without considering the severity of the occlusal anteroposterior discrepancy is still common in current papers. In some of them, when occlusal parameters are chosen, the severity is often neglected. The purpose of this study is to verify the importance given to the classification of Class II malocclusion, based on the criteria used for sample selection in a great number of papers published in the orthodontic journal with the highest impact factor.

Material and Methods

A search was performed in PubMed database for full-text research papers referencing Class II malocclusion in the history of the American Journal of Orthodontics and Dentofacial Orthopedics (AJO-DO).

Results

A total of 359 papers were retrieved, among which only 72 (20.06%) papers described the occlusal severity of the Class II malocclusion sample. In the other 287 (79.94%) papers that did not specify the anteroposterior discrepancy severity, description was considered to be crucial in 159 (55.40%) of them.

Conclusions

Omission in describing the occlusal severity demands a cautious interpretation of 44.29% of the papers retrieved in this study.

The applicability of a non-anatomical soft and hard tissue centroid line (S&H centroid) in cephalometrics

The applicability of a newly introduced non-anatomical soft and hard tissue cephalometric centroid line (S&H centroid) was investigated. The "S&H centroid" line established from 12″ × 14″ lateral cephalometric radiographs of 57 selected adults was used as a base to create a new cephalometric reference line "Centroid-Nasion". The reliability and the use of the newly created "Centroid-Nasion" as a reference line was tested against the conventional "Sella-Nasion" cephalometric reference line to evaluate the sagittal and vertical maxillary and mandibular relationship. Pearson's correlation coefficient, one way ANOVA, and Tukey multiple comparison post Hoc statistical tests were used. The digitization technique was reliable. The "Centroid-Nasion" cephalometric reference line created by utilizing the "S&H centroid" line, was found to be as useful as the conventional "Sella-Nasion" cephalometric plane in establishing and differentiating between sagittal and vertical intermaxillary relationships.

Comparison of arch dimension changes in 1-phase vs 2-phase treatment of Class II malocclusion

INTRODUCTION

We compared arch dimension changes in 1-phase and 2-phase treatment of Class II malocclusion. This was a prospective randomized clinical trial conducted in the Department of Orthodontics at the University of Florida between 1990 and 2003.

METHODS

During phase 1 treatment, 86 subjects were treated with a bionator, 93 were treated with headgear/biteplane, and 81 served as the observation group. For phase 2, all subjects were then treated with full orthodontic appliances. Arch dimensions were followed; maxillary and mandibular alginate impressions were taken at baseline, end of early Class II treatment or observation, beginning of fixed appliance treatment, end of orthodontic treatment, and approximately 3 years posttreatment. Alginate impressions were taken of each dental arch at each data collection point. These were poured in orthodontic stone, trimmed, and photocopied from the occlusal aspect. These images were then scanned and measured.

RESULTS

Although differences between the treatment groups were found in both the maxillary and mandibular arches after phase 1, these differences were no longer evident by the end of full orthodontic treatment or after posttreatment retention.

CONCLUSIONS

There were no differences in arch dimensions after 1-phase or 2-phase treatment of Class II malocclusion.