Combined orthodontic and surgical open bite correction

OBJECTIVES

To examine the stability of combined surgical and orthodontic bite correction with emphasis on open-bite closure. All study patients were treated with strict and consistent orthodontic and surgical protocols.

MATERIALS AND METHODS

Study inclusion required all patients to have anterior open bites, maxillary accentuated curve of Spee, 36-month minimum follow-up, and no temporomandibular joint pathology. Thirty patients met the inclusion/exclusion criteria. Importantly, segmental upper arch orthodontic preparation (performed by EG) was used. Surgery consisted of a multisegment Le Fort I (MSLFI) combined with a bilateral sagittal osteotomies (BSSO). Surgery was performed (by ADA and LT) at the Department of Dentistry and Maxillofacial Surgery of the University of Verona, Italy.

RESULTS

The long-term open bite and overjet relapse were not statistically significant. The mean transverse relapse of the upper and lower molars was statistically significant. Of great importance, the upper and lower arch widths narrowed together, maintaining intercuspation of the posterior dentition which prevented anterior open bites from developing.

CONCLUSIONS

This study revealed stability of three-dimensional occlusal correction including anterior open bite. Stable open bite closure was achieved by using rigid protocols for orthodontic preparation, surgical techniques, surgical follow-up, and orthodontic finishing.

Effect of Trimetazidine Dihydrochloride Therapy on Exercise Capacity in Patients With Nonobstructive Hypertrophic Cardiomyopathy: A Randomized Clinical Trial

Importance

Hypertrophic cardiomyopathy causes limiting symptoms in patients, mediated partly through inefficient myocardial energy use. There is conflicting evidence for therapy with inhibitors of myocardial fatty acid metabolism in patients with nonobstructive hypertrophic cardiomyopathy.

Objective

To determine the effect of oral therapy with trimetazidine, a direct inhibitor of fatty acid β-oxidation, on exercise capacity in patients with symptomatic nonobstructive hypertrophic cardiomyopathy.

Design, Setting, and Participants

This randomized, placebo-controlled, double-blind clinical trial at The Heart Hospital, University College London Hospitals, London, United Kingdom was performed between May 31, 2012, and September 8, 2014. The trial included 51 drug-refractory symptomatic (New York Heart Association class ≥2) patients aged 24 to 74 years with a maximum left ventricular outflow tract gradient 50 mm Hg or lower and a peak oxygen consumption during exercise of 80% or less predicted value for age and sex. Statistical analysis was performed from March 1, 2016 through July 4, 2018.

Interventions

Participants were randomly assigned to trimetazidine, 20 mg, 3 times daily (n = 27) or placebo (n = 24) for 3 months.

Main Outcomes and Measures

The primary end point was peak oxygen consumption during upright bicycle ergometry. Secondary end points were 6-minute walk distance, quality of life (Minnesota Living with Heart Failure questionnaire), frequency of ventricular ectopic beats, diastolic function, serum N-terminal pro-brain natriuretic peptide level, and troponin T level.

Results

Of 49 participants who received trimetazidine (n = 26) or placebo (n = 23) and completed the study, 34 (70%) were male; the mean (SD) age was 50 (13) years. Trimetazidine therapy did not improve exercise capacity, with patients in the trimetazidine group walking 38.4 m (95% CI, 5.13 to 71.70 m) less than patients in the placebo group at 3 months after adjustment for their baseline walking distance measurements. After adjustment for baseline values, peak oxygen consumption was 1.35 mL/kg per minute lower (95% CI, -2.58 to -0.11 mL/kg per minute; P = .03) in the intervention group after 3 months.

Conclusions and Relevance

In symptomatic patients with nonobstructive hypertrophic cardiomyopathy, trimetazidine therapy does not improve exercise capacity. Pharmacologic therapy for this disease remains limited.

Trial Registration

ClinicalTrials.gov identifier: NCT01696370.

Radiographic evaluation of dental and cervical vertebral development for age estimation in a young Brazilian population

Age estimation is guided by the evaluation of events that happen during the processes of bone and dental development. The purpose of this study was to validate the method of age estimation proposed by Lajolo et al. (2013) through oro-cervical radiographic indices in Brazilians. The study aimed to verify the effectiveness of age estimation equations through dental and cervical vertebrae examinations, in addition to including dental and cervical vertebrae data in new age estimation equations. The sample consisted of panoramic radiographs and teleradiographs from 510 subjects (8-24.9 years). Age estimation methods were applied by assessing the development of seven mandibular teeth, cervical vertebrae and third molars. Techniques used previously have been combinations of radiographic indices: Oro-Cervical Radiographic Simplified Score (OCRSS) and Oro-Cervical Radiographic Simplified Score without Wisdom Teeth (OCRSSWWT). In the second phase of the study, dental maturation, vertebral measurements, and real age were estimated by regression equations. OCRSS and OCRSSWWT had success rates of 67.4% (R2=0.64) and 70.8% (R2=0.62), respectively. When age estimation equations for tooth evaluations were applied, the average error was 1.3 years, and for cervical vertebrae measurements, the error was 1.9 years. When dental variables and the measurements of cervical vertebrae were included, the average error of equations was 1.0 year. Radiographic indices were easy to perform, and after adequate training, are reliable and can be used in forensic practice. The use of the new equations presented in this study is recommended because including cervical vertebrae and dental data provides greater accuracy for age estimation.

Dentoalveolar effects produced by different appliances on early treatment of anterior open bite: A randomized clinical trial

OBJECTIVES:

To compare different appliances for early anterior open bite (AOB) correction.

MATERIALS AND METHODS:

This was a parallel, randomized clinical trial. A prospective sample of patients with AOB was recruited consecutively. Eligibility criteria included angle class I malocclusion with AOB equal to or greater than 1 mm. Participants were allocated by simple randomization to 4 groups: bonded spurs, chin cup, fixed palatal crib, and removable palatal crib. Dentoalveolar changes among the groups were assessed by blinded observers by comparing lateral cephalograms taken before (T1) and 12 months after treatment (T2; analysis of variance followed by Tukey test). Of the measurements, 30% were reassessed for reliability (intraclass correlation coefficient and Bland-Altman agreement test; α = 5%; 95% confidence interval).

RESULTS:

A total of 99 patients with a mean AOB of 3.7 mm (mean age 8.4 ± 0.8 years, both genders) were recruited. Dropouts occurred in all the groups, yielding a final sample size of 81 analyzed individuals. Intergroup comparisons of differences (T2-T1) showed significant differences for the incisor positioning variables (1.1, 1-PP, 6-PP, IMPA, 1.NB and 1-GoMe). However, there was no significant difference in AOB reduction among the groups, with an average correction of 3.1 mm.

CONCLUSIONS:

All of the tested devices promoted dental changes, especially in the anterior region, and contributed to AOB reduction during the study period. However, fixed palatal crib demonstrated greater impact on the positioning of the incisors.

Long-term evaluation of rapid maxillary expansion and bite-block therapy in open bite growing subjects: A controlled clinical study

OBJECTIVE

To evaluate the long-term effects of rapid maxillary expansion (RME) and posterior bite block (BB) in prepubertal subjects with dentoskeletal open bite.

MATERIALS AND METHODS

The treatment group (TG) comprised 16 subjects (14 girls, 2 boys) with dentoskeletal open bite with a mean age of 8.1 ± 1.1 years treated with RME and BB. Three consecutive lateral cephalograms were available before treatment (T1), at the end of the active treatment with the RME and BB (T2), and at a follow-up observation at least 4 years after the completion of treatment (T3). The TG was compared with a control group (CG) of 16 subjects (14 girls, 2 boys) matched for sex, age, and vertical skeletal pattern. An independent sample t-test was used to compare the T1 to T3, T1 to T2, and T2 to T3 cephalometric changes between the TG and the CG.

RESULTS

In the long term, the TG showed a significantly greater increase in overbite (+1.8 mm), reduced extrusion of maxillary and mandibular molars (-3.3 mm), and, consequently, a significant decrease in facial divergence (-2.8°) when compared with untreated subjects.

CONCLUSIONS

The RME and BB protocol led to successful and stable recovery of positive overbite in 100% of the patients considered. Correction of open bite was associated with reduced extrusion of maxillary and mandibular molars with a significant improvement in vertical skeletal relationships when compared with the CG.

Prediction of mandibular movement and its center of rotation for nonsurgical correction of anterior open bite via maxillary molar intrusion

OBJECTIVES

To evaluate quantitatively the relationship between molar intrusion (change [Δ] maxillary first molar [U6]-palatal plane [PP]) and changes in vertical and sagittal cephalometric parameters and to determine the center of mandibular autorotation.

MATERIALS AND METHODS

Twenty-one patients diagnosed with anterior open bite and successfully treated with molar intrusion (overbite [OB] > 0 mm) were retrospectively enrolled. Lateral cephalograms taken before and after molar intrusion were used to measure changes in vertical and sagittal cephalometric parameters. The center of mandibular autorotation was calculated by measuring displacement of gonion (Go) and pogonion (Pog). Paired t-tests were used to compare variables, and linear regression analysis was used to examine the relationship between ΔU6-PP and other variables.

RESULTS

The mandible exhibited counterclockwise rotation after maxillary molar intrusion, which led to closure of anterior open bite. Strong linear relationships, in descending order, between ΔU6-PP and ΔOB, Δanterior facial height (AFH), Δvertical reference plane (Pog), and Δsella-nasion to Go-menton (SN-GoMe), were observed. When the maxillary molar was intruded 1 mm, OB increased by 2.6 mm, AFH decreased by 1.7 mm, Pog moved forward by 2.3 mm, and SN-GoMe decreased by 2°. The center of mandibular autorotation was located 7.4 mm behind and 16.9 mm below condylion after molar intrusion.

CONCLUSIONS

The mandible exhibited counterclockwise rotation after maxillary molar intrusion; the center of mandibular autorotation was located behind and below condylion with individual variations.

Long-term stability of soft tissue changes in anterior open bite adults treated with zygomatic miniplate-anchored maxillary posterior intrusion

OBJECTIVES

To evaluate soft tissue changes and their long-term stability in skeletal anterior open bite adults treated by maxillary posterior teeth intrusion using zygomatic miniplates and premolar extractions.

MATERIALS AND METHODS

Lateral cephalograms of 26 patients were taken at pretreatment (T1), posttreatment (T2), 1 year posttreatment (T3), and 4 years posttreatment (T4).

RESULTS

At the end of treatment, the soft tissue facial height and profile convexity were reduced. The lips increased in length and thickness, with backward movement of the upper lip and forward movement of the lower lip. The total relapse rate ranged from 20.2% to 31.1%. At 4 years posttreatment, 68.9% to 79.8% of the soft tissue treatment effects were stable. The changes in the first year posttreatment accounted for approximately 70% of the total relapse.

CONCLUSIONS

Soft tissue changes following maxillary posterior teeth intrusion with zygomatic miniplates and premolar extractions appear to be stable 4 years after treatment.

Characteristic of Malocclusion among Saudi Special Need Group Children

INTRODUCTION

The present study analyzed the characteristics of malocclusions, occlusal traits among Special Health care Needs (SHCN) children with Down syndrome (DS) and autism disorder (AD) in Riyadh City, Kingdom of Saudi Arabia.

MATERIALS AND METHODS

A total of 100 DS and 100 AD children from five rehabilitation centers in and around Riyadh, Kingdom of Saudi Arabia, were included in the study. Any children with history of ongoing medical treatment, extraction, or orthodontic treatment were excluded from the study. Out of the 200 patients examined, 131 were males and 69 were females and the age of the children ranged from 6 to 14 years. The children were examined for malocclusion characteristics using the Angle's classification of malocclusion, and also other occlusal traits, such as overjet, overbite, cross bite, and open bite were also determined. The data obtained were analyzed using Statistical Package for the Social Sciences, version 16 to generate descriptive statistics for each variable.

RESULTS

The analyzed data of the right and left permanent molar relation showed higher incidence of class III malocclusion (66%) in DS children as compared with (3-4%) AD children. The AD children presented with higher percentage of class I malocclu-sion (40-41%) as compared with (10-14%) DS children. During examination of the primary molars, the analyzed data showed that left primary molar had more mesial shift in AD children as compared with DS children.

CONCLUSION

Down syndrome children had high incidence of class III malocclusion and autistic children had high incidence of class I malocclusion. Overall, the DS children were more prone to malocclusion.

CLINICAL SIGNIFICANCE

This study provides database for health professionals in Saudi Arabia in regard to malocclusion of autis-tics and DS patients.

Retrospective study of maxillary sinus dimensions and pneumatization in adult patients with an anterior open bite

INTRODUCTION

The aim of this study was to evaluate differences in the maxillary sinus floor levels between adults with an anterior open bite and those without.

METHODS

This retrospective study included 30 subjects: 15 adults with an anterior open bite (mean age, 21.5 ± 4.3 years) and 15 control subjects with normal occlusion (mean age, 21.7 ± 3.1 years). Cone-beam computed tomography and lateral cephalograms were analyzed before treatment.

RESULTS

The open-bite group exhibited a significantly greater maxillary posterior alveolar height (P <0.05). The craniocaudal heights of the maxillary sinus in the region between the first and second molars and between the second premolar and first molar were significantly greater in the open bite group (40.5 and 39.0 mm, respectively) than in the control group (36.7 and 34.7 mm, respectively; P <0.05 for both). The basal bone heights in the regions between the first and second molars, the second premolar and first molar, and the first and second premolars were significantly smaller in the open-bite group than in the control group (P <0.001 for all).

CONCLUSIONS

Vertical pneumatization of the maxillary sinus floor in the region between the first and second molars and between the second premolar and first molar is greater in adults with an anterior open bite than in those without, whereas basal bone height in the maxillary posterior region is lower in the open-bite patients.

Posterior tooth angulations in patients with anterior open bite and normal occlusion

INTRODUCTION

The aim of this study was to compare the posterior tooth angulations in patients with open-bite malocclusion and normal occlusion.

METHODS

Lateral cephalometric headfilms of 45 untreated open-bite subjects were compared with the lateral headfilms of 45 subjects with normal occlusion in the permanent dentition. The groups were matched for age and sex distribution and compared with t tests.

RESULTS

The maxillary and mandibular premolars were more mesially angulated in relation to the bisected occlusal plane, and the first and second molars were significantly more distally angulated in the open-bite group in relation to the palatal and mandibular planes.

CONCLUSIONS

The maxillary and mandibular premolars were more mesially angulated in relation to the bisected occlusal plane and therefore do not compensate for the divergence of the palatal and mandibular planes as the molars do.

[Frequency of signs and symptoms of temporomandibular joint disorders, vertical orthodontic anomalies and their relationships based on screening of a large population]

Altogether 4606 volunteers (2923 vomen, 1683 men) participated in the representative national epidemiological study to screen the alterations of temporomandibular joint (TMJ). The characteristic clinical signs and subjective complaints according to TMJ were evaluated by medical history taking and physical examination. Regarding the orthodontic anomalies, the vertical abnormalities (deep bite and open bite) were specifically noted. Clinical signs showing functional problems of TMJ were found in 45.19% of the screened population, mainly in the group of 35-44 year olds. The frequency of clicking and crepitation of TMJ was significantly higher in women compared to men (p < 0.05). The highest rate of clinical signs of TMJ disorders was found in the South-Transdanubian region, the lowest rate in the Middle-Transdanubian region, between these regions it was a significant difference regarding the frequency of deviation/deflexion (p < 0.05). Of the vertical abnormalities, deep bite occured most frequently in the 35-44 ys old age group. The prevalence of deep bite was higher among males than females in the whole screened population, but the difference was not statistically significant. Significant relationship was detected between deep bite and TMJ pain, deep bite and noises in the joint in the majority of the population. The most frequent anomaly in the South-Transdanubian region was deep bite, while the open bite occured most frequently in south middle part of Hungary. Conclusion: the Hungarian population needs well organized specific programs to improve the oral health including TMJ and orthodontic aspects.

Anterior maxillary dentoalveolar and skeletal cephalometric factors involved in upper incisor crown exposure in subjects with Class II and III skeletal open bite

OBJECTIVE

To compare the anterior dentoalveolar and skeletal maxillary cephalometric factors involved in excessive upper incisor crown exposure (UICE) in subjects with skeletal open bite Class II (SOBCIIG) and Class III (SOBCIIIG) against an untreated control group (CG).

MATERIALS AND METHODS

Seventy pretreatment lateral cephalograms of orthodontic young adult patients (34 men, 36 women) were examined. The sample was divided into three groups according to both sagittal and vertical growth pattern and occlusion. The CG group (n  =  25) included Class I, normodivergent cases with adequate overbite, and the SOBCIIG group (n  =  25) and SOBCIIIG group (n  =  20) included skeletal Class II or III malocclusions, respectively, with hyperdivergent pattern and negative overbite. Several cephalometric measurements were considered (skeletal and dental). Analysis of variance, multivariate analysis of covariance, and Tukey HSD post hoc tests were used. Principal component analysis (PCA) was used for reducing the number of cephalometric variables related to UICE. Finally, a multiple linear regression was calculated.

RESULTS

Significant differences in UICE were found between the groups (P < .05). UICE was 3.9 mm in SOBCIIG, 2.5 mm in SOBCIIIG, and 0.4 mm in CG. PCA showed that a nondental component-including vertical maxillary height (VMH) and upper lip height (ULH)-was the only component significantly associated with UICE. The regression model had a moderate prediction capability.

CONCLUSIONS

Although the UICE was statistically different in SOBCIIG, the values were within the esthetic standards. The UICE was mainly influenced by VMH and ULH.

Dental and skeletal components of Class II open bite treatment with a modified Thurow appliance

INTRODUCTION

Due to the lack of studies that distinguish between dentoalveolar and basal changes caused by the Thurow appliance, this clinical study, carried out by the School of Dentistry--State University of São Paulo/Araraquara, aimed at assessing the dental and skeletal changes induced by modified Thurow appliance.

METHODS

The sample included an experimental group comprising 13 subjects aged between 7 and 10 years old, with Class II malocclusion and anterior open bite, and a control group comprising 22 subjects similar in age, sex and mandibular plane angle. Maxillary/mandibular, horizontal/vertical, dental/skeletal movements (ANS, PNS, U1, U6, Co, Go, Pog, L1, L6) were assessed, based on 14 landmarks, 8 angles (S-N-ANS, SNA, PPA, S-N-Pog, SNB, MPA, PP/MPA, ANB) and 3 linear measures (N-Me, ANS-Me, S-Go).

RESULTS

Treatment caused significantly greater angle decrease between the palatal and the mandibular plane on the experimental group, primarily due to an increase in the palatal plane angle. ANB, SNA and S-N-ANS angles significantly decreased more in patients from the experimental group. PNS was superiorly remodeled. Lower face height (ANS-Me) decreased in the experimental group and increased in the control group.

CONCLUSIONS

The modified Thurow appliance controlled vertical and horizontal displacements of the maxilla, rotated the maxilla and improved open bite malocclusion, decreasing lower facial height.

Cross sectional: normal maximal incisal opening and associations with physical variables in children

PURPOSE

The purpose of this investigation was to establish a normal range of maximal incisal opening (MIO) in children, and the correlation between MIO with age, height, weight, gender, race, and molar relationship.

METHODS

Calibrated examiners used the TheraBite Range of Motion (ROM) scale to obtain two MIO readings from 500 enrolled subjects, accounting for overbite or open bite. The subject's height, weight, molar relationship, age, gender, and race were recorded. Subjects were stratified according to age, and mean MIO ± standard deviation for each age group was determined.

RESULTS

Mean MIO was positively correlated with age (P<.001), height (P<.001), weight (P<.001), and race (P<.001). However, height became insignificant in the multivariable regression model. On average, MIO of African-Americans was 3.66 mm larger than Whites (P<.001), and MIO of Hispanics/Latinos was 2.52mm greater than Whites (P<.001). There was no statistically significant association with left or right molar relationships (P=.07, P=.26 respectively) or gender (P=.58).

CONCLUSIONS

TheraBite ROM scale is a practical tool to clinically measure MIO. MIO mimics somatic growth, peaking at age 12-13 years for females and 14-15 years for males. African-Americans and Hispanics/Latinos have a greater mean MIO than Whites. The established norms will be useful in diagnosis and treatment.

Basic dental information needed for the OFM initial occlusal evaluation

It is incumbent upon the orofacial myologist to evaluate the presenting client's occlusion and detect any behaviors which may be influencing the alignment of the dentition or interfering with the treatment plan of the referral source. In order to accomplish these tasks, it is necessary to share some common terminology and to effectively communicate between all the participants involved in the treatment plan. The purpose of this article is to assist in accomplishing these goals.

Etiology and pathogenesis of anterior open bite: a review

OBJECTIVE

To review the etiology and pathogenesis of anterior open bite malocclusion.

DATA SOURCE

Review of literature was affected through Pubmed, Google scholar and Science direct. References identified from articles found from the primary search were also reviewed.

STUDY SELECTION

Published data on etiology and pathogenesis of anterior open bite over the last five decades (1960-2009) were utilised.

DATA EXTRACTION

Full articles, abstracts and relevant book chapters were read and analysed to determine the relevant material for this article.

DATA ANALYSIS

All relevant articles were reviewed in full and necessary information eextracted as necessary.

CONCLUSION

A clear understanding of the etiology and pathogenesis of anterior open bite is essential in the diagnosis, prevention and management of this malocclusion.

A comparison of dental changes produced by mandibular advancement splints in the management of obstructive sleep apnoea

BACKGROUND

Mandibular advancement splints (MAS) are a recognised and popular treatment option for obstructive sleep apnoea (OSA) due to their simplicity, tolerance and non-invasiveness.

OBJECTIVES

To investigate and compare the dental changes associated with the use of monoblock and duoblock appliances.

METHODS

Fifty-two pretreatment and follow-up study models of patients from a public hospital and private dental clinic were assessed. Seventeen subjects used a soft elastomeric monoblock appliance (MB), 29 subjects used a hard acrylic duoblock (DB) and six subjects wore a monoblock followed by a duoblock appliance (MB-DB). Measurements of dental and arch changes were obtained and analysed on study models and standardised bitewing radiographs.

RESULTS

A statistically significant reduction was observed in the maxillary intercanine distance in all splint categories, with DB users showing the greatest decrease (p < 0.05). The change in the mandibular intercanine distances differed according to splint categories (p < 0.05). MB and MB-DB patients demonstrated a decrease in this measurement variable, whereas an increase was seen in DB users. A statistically significant increase in the mandibular intermolar distance was also observed in all splint categories (p < 0.05), with DB users showing the greatest increase.

CONCLUSIONS

Both MB and DB appliance systems produced similar, but mild dental effects. No particular appliance can be recommended and the choice of appliance should be considered on a case-by-case basis.

Influence of the cephalometric characteristics on the occlusal success rate of Class II malocclusions treated with nonextraction or with two maxillary premolar extraction protocols

AIM

To compare the initial cephalometric characteristics of complete Class II malocclusions treated with nonextraction or with two maxillary premolar extractions and to verify their degree of influence on the occlusal success rate.

METHODS

A sample of 84 records from patients with complete Class II malocclusions was divided into two groups. Group 1 consisted of 31 patients treated with nonextraction at an initial mean age of 12.95 years, while group 2 included 53 patients treated with two maxillary premolar extractions at an initial mean age of 13.3 years. Initial and final occlusal statuses were evaluated on dental casts with Grainger's Treatment Priority Index (TPI); the initial cephalometric characteristics were obtained on the pretreatment cephalograms. The initial cephalometric characteristics of the groups were compared by t test. A multiple linear regression analysis was used to evaluate the influence of all variables in the percentage of TPI reduction.

RESULTS

The pretreatment cephalometric characteristics of the two maxillary premolar extraction cases were a greater vertical growth pattern, greater max illary and mandibular incisor protrusion, greater maxillary incisor and molar dentoalveolar heights, and greater upper and lower lip protrusion than the nonextraction group. However, the regression analysis demonstrated that only the extraction protocol was significantly associated with the occlusal success rate in the groups.

CONCLUSIONS

It was concluded that the initial cephalometric characteristics of the groups did not influence the occlusal success rate of the two treatment protocols investigated.

Transverse dentoskeletal features of anterior open bite in the mixed dentition

OBJECTIVE

To apply both conventional cephalometric analysis and morphometric analysis (thin-plate spline analysis) to posteroanterior (PA) cephalograms to test the hypothesis that the dentoskeletal features of subjects with anterior open bite in the mixed dentition are no different from those of normal controls.

MATERIALS AND METHODS

A group of 22 white subjects (6 males, 16 females; mean age, 8.7 +/- 0.7 years) with anterior open bite (AOBG) was compared with a control group (CG) of 22 white subjects (11 males, 11 females; mean age, 9.2 +/- 0.8 years) with Class I occlusal relationships, and without anterior open bite and sucking habits. Subjects of both groups were in the mixed dentition and had no history of orthodontic treatment. Between-group statistical comparisons were performed with independent sample t-tests and permutation tests.

RESULTS

AOBG exhibited statistically significant shape differences with respect to CG that consisted of a transverse contraction of the zygomatic region, of the maxilla (at both skeletal and dentoalveolar levels), and of the mandible (in both condylar and gonial regions), with a downward dislocation of point menton. With conventional cephalometrics, AOBG showed a statistically significant transverse deficiency in the zygomatic region (-4.8 mm), in the maxilla at both skeletal and dentoalveolar levels (-2.0 mm and -3.0 mm, respectively), and in the mandible in both condylar and gonial regions (-3.6 mm and -4.0 mm, respectively).

CONCLUSION

Subjects with anterior open bite showed transverse deficiencies in the zygomatic region, in the maxilla, and in the mandible when compared with normal subjects.

Myotonic dystrophy and craniofacial morphology: clinical and instrumental study

AIM

The aim of this study is to assess if, and to what extent, myotonic dystrophy can affect the craniofacial growth pattern.

MATERIALS AND METHODS

The research was conducted on a sample of 27 patients with Steinert's myotonic dystrophy (study group). Each subject underwent a clinical examination with impression-taking and intra- and extraoral photographs. A latero-lateral projection teleradiography in the mirror position was also taken and a cephalometric examination was performed. The assessed values were compared with those obtained from a group of healthy subjects (control group).

RESULTS

Statistical analysis of the data obtained from the myotonic patients who developed the disease during the growth phase revealed alterations in the transversal plane and, to an even greater extent, the vertical one, with a high frequency of anterior open bite. Discussion and conclusions Regarding the pathogenesis of these types of skeletal dysplasias, the authors hypothesise a posterior rotation growth pattern, resulting from gravitational force prevailing over the deficit of the elevator muscles.

Cornelia de Lange syndrome: description of the orofacial features and case report

Cornelia de Lange Syndrome (CdLS) is a very rare syndrome characterised by multiple congenital anomaly affecting various organs and severe mental retardation. Incidence has been reported to be 1: 10.000-20.000 among the general population, with no racial predilection. The aetiology is still unknown but researchers, in 2004, discovered a mutation of the NIPBL gene located on chromosome 5 which is considered to be responsible of the disease. The main clinical features of the syndrome regard distinctive facial features, severe growth retardation, developmental and mental delay, hirsutism, structural limb abnormalities. The authors describe the main features of the syndrome focusing on oral and facial malformations and report a case of a three years old patient with CdLS.

Three-year stability of open-bite correction by 1-piece maxillary osteotomy

INTRODUCTION

The purpose of this retrospective cephalometric study was to evaluate the long-term vertical stability of anterior open-bite correction by 1-piece Le Fort I osteotomy and rigid fixation.

METHODS

The sample comprised 40 consecutively treated patients from the files of the Department of Orthodontics, University of Oslo, Norway. All subjects had received a 1-piece Le Fort I osteotomy as the only surgical procedure from 1990 through 1998 and were followed for 3 years according to a protocol for data collection. Lateral cephalograms were obtained before surgery and at 5 occasions after surgery.

RESULTS

The mean open bite before surgery was 2.6 mm; at the 3-year follow-up, 35 patients had a positive overbite, and the remaining 5 patients had an open bite between 0.2 and 0.9 mm. Impaction of the posterior maxilla >or=2 mm relapsed on average by 31%, and inferior repositioning of the anterior maxilla >or=2 mm relapsed by 62%. Maxillary vertical skeletal changes during the postsurgery period were compensated for by orthodontic dentoalveolar adaptation. Most of the skeletal relapse occurred during the first 6 months after surgery and always in the direction opposite to the surgical movement. The relative contribution of mandibular and maxillary changes in anterior open-bite closure was approximately 3:1.

CONCLUSIONS

Surgical correction of anterior open bite was generally stable over a 3-year period, and skeletal relapse was counteracted by dentoalveolar compensation.

Morphological characteristics of the symphyseal region in adult skeletal Class III crossbite and openbite malocclusions

OBJECTIVE

To evaluate the relationship of the morphological characteristics of the symphyseal region of adult Class III malocclusion to the differences in overjet and overbite.

MATERIALS AND METHODS

The basal and symphyseal widths along with the alveolar and symphyseal heights were evaluated using data from the lateral cephalograms of Korean adult male skeletal Class III, divided into crossbite (n = 28) and openbite (n = 41) groups. Korean male normal occlusion samples (n = 32) were used as controls.

RESULTS

The width of the symphyseal region including the basal width, point B width, Id width, symphyseal thickness, and pogonion width were similar in adult Class III crossbite and normal occlusion groups, but significantly less in the adult Class III openbite group (P < .001). The alveolar height was similar in the adult Class III crossbite and control groups, but significantly less in the adult Class III openbite group (P < .05). However, the symphyseal height was similar in all three groups.

CONCLUSIONS

An openbite, rather than a negative overjet, is the major factor influencing the symphyseal morphology in an adult Class III malocclusion.

Use of the centroid method of occlusion for studying the vertical and horizontal relationship of the mandible and maxilla

The aim of the present study was to verify whether the centroid method of occlusion for studying mandibular and maxillary growth enables accurate determination of vertical occlusal patterns (open and deep bite). Lateral cephalograms were obtained of Japanese adult females aged over 18 years of age with a Class II malocclusion (61 open bite and 47 deep bite), or a Class III type open bite (70 subjects) or deep bite (21 subjects) malocclusion. One-way analysis of variance followed by a Bonferroni's t-test was used to compare the results among these four groups. The Deltaabc area, which comprised the palatal, Ar-Gn, and A-B planes, was shown to be significantly larger in the open bite than in the deep bite group for both Class II and Class III malocclusion types (P < 0.01). There was no difference in the Deltaabc area between the Class II and Class III open bite groups or between the Class II and Class III deep bite groups. These findings suggest that the centroid method of occlusion is a versatile diagnostic technique that can accurately differentiate between vertical occlusal patterns of Class II and III types of malocclusion limited to Japanese adult females. The analytical method is also unaffected by gnathostatic differences according to Angle classification.

[Etiological aspects of anterior open bite]

INTRODUCTION

Open bite is a multifactorial phenomenon and no single factor can account for open-bite. Etiology plays an important role in diagnosis. Heredity, unfavorable growth patterns, incorrect jaw postoure, are the characteristics of skeletal open bite.

DIGIT SUCKING

Depending on where the thumb is placed, a number of different types of dental problems can develop. Malocclusions of the late mixed or permanent dentitions, caused by thumb sucking are not self corrected and orthodontic treatment is necessary for their correction.

LYMPHATIC TISSUE

In order to produce oral respiration, the mandible is postured inferiorly with the tongue protruded and resting against the oral floor. This postural alteration induces dental and skeletal modifications similar to those caused by thumb sucking. This may cause excessive eruption of the posterior teeth, leading to an increase in the vertical dimension of the face and result in development of anterior open bite.

TONGUE THRUST

Tongue habits cause an anterior open bite or they develop secondarily to thumb sucking. In skeletal open bite the tongue habit acts as a secondary factor which helps to maintain or exacerbate the condition. Many orthodontists have had a discouraging experience of completing dental treatment, with what appeared to be good results, only to discover that the case had relapsed because the patient had a tongue thrust swallowing pattern.

CONCLUSION

Dentoalveolar or habitual open bite is caused by habits, which influence the growth and development of dentoalveolar processes and contribute to occlusal disharmonies. Prior to eruption of adult dentition, open bite related to oral habits is usually not a concern as when the habits stop, because the erupting dentition tends to improve spontaneously. Treatment is usually not necessary until permanent teeth erupt (approximately 6 years old).

Complete entrapment of the maxilla. Two different case therapies

Treatment and management of complete entrapment of the maxilla by the mandible can be one of the most difficult orthodontic cases. This affects normal growth and development of the patient. Two entirely different treatment modalities will be demonstrated for correction.

Cephalometric features of anterior open bite

AIMS

To evaluate and characterize the skeletodental morphology of anterior open-bite cases in the Saudi Arabian population and the differences between males and females.

SUBJECTS AND METHODS

Cephalometric characteristics of 111 (58 females, 53 males) subjects with anterior open bite were compared with 60 (30 females and 30 males) control subjects. Both open-bite and control subjects were patients in the orthodontic department at King Abdulaziz University, Saudi Arabia. The inclusion criterion for open-bite subjects was the presence of at least 1-mm anterior open bite. For control subjects, the criteria were orthognathic profile with a Class I molar and canine relationship. All cephalometric radiographs were digitized.

RESULTS

Both female and male open-bite subjects showed a significant increase in the lower anterior facial height, mandibular plane angle, gonial angle, Y-axis, mandibular occlusal plane to SN angle, and a significant decrease in maxillary length. Both the maxilla and the mandible were in a retruded position in relation to the SN plane. In addition, the interincisal angle was significantly increased. However, all dental heights showed no significant differences between open-bite and control subjects. Gender differences were found only in the significantly decreased linear skeletal measurements and in mandibular anterior and posterior dental heights. Comparison between the results of this study and reported studies of other populations revealed insignificant differences in most of the measurements.

CONCLUSION

This study confirms previous studies that showed the openbite malocclusion is largely due to changes in the skeletal pattern.

Bite Force and Maxillofacial Morphology in Patients With Duchenne-Type Muscular Dystrophy

PURPOSE

The purpose of this study is to evaluate maxillofacial morphology and bite force in patients with severe Duchenne-type myodystrophy.

PATIENTS AND METHODS

The subjects included 24 men (average age, 21.5 years; range, 17 to 30 years) with Duchenne-type muscular dystrophy receiving treatment in National Ioh Hospital. Lateral and axial cephalograms were used to assess the morphology in this study. The maximum bite force on the first molar and the maximum mouth opening distance were measured.

RESULTS

The anterior open bite was visualized in most patients on the lateral cephalogram. The upper and lower arch lengths in the patients were significantly smaller than those in the controls (P < .05). In contrast, the upper and lower arch widths in the patients were significantly larger than those in the controls (P < .05). The maximum bite force and maximum mouth opening distance in the patients were significantly lower than those in the controls (P < .05).

CONCLUSION

These results appear to be very useful for improving the care and treatment of patients with Duchenne-type muscular dystrophy.

Severe anterior open-bite malocclusion

This case report describes the treatment of a severe anterior open bite, Class II malocclusion with a history of dummy sucking. The 9-year-old girl presented with a significant anteroposterior and vertical discrepancy. Her face was convex with procumbent lips. She had an anterior open bite of 9 mm, an overjet of 8 mm, and a transverse maxillary deficiency. In consultation with the parents and patient, a nonsurgical therapy was elected, with the goals of reducing protrusion and closing the anterior open bite.

Enamel dysplasia with odontogenic fibroma-like hamartomas: review of the literature and report of a case

This article reports on a case presenting with a rare syndrome characterized by enamel dysplasia and multiple unerupted teeth with large solid fibrous pericoronal lesions manifesting with odontogenic fibroma-like features. Our case shows in addition to these findings an anterior open bite malocclusion and gingival overgrowths. These overgrowths exhibit the microscopic features of the multiple pericoronal odontogenic fibroma-like lesions that appear to be the hallmark of this syndrome. This unusual case brings the total number documented in the literature to 5, all of which were reported from South Africa.

Anterior open bite: cephalometric evaluation of the dental pattern

The purpose of this study was to compare the dental pattern of patients with anterior open bite malocclusion to that of individuals with normal overbite by utilization of lateral cephalograms, panoramic radiographs and study casts. The findings showed that there was no significant difference in the inclination of the occlusal plane (SN.PlO) and position of the maxillary and mandibular incisors (1-NA, 1-NB) between both groups of individuals; but the angles of inclination of the maxillary and mandibular incisors (1.1, 1.NA and 1.NB) differed statistically between patients with anterior open bite of the individuals that presented normal overbite, which suggests that the anterior open bite may be of dental origin.

[Peculiarities of face structure in adults and teenagers with deep bite and deep incisor overbite according to rhoentgenocephalometric studies]

Based on rhoentgenocephalometric study of 207 patients (82 men and 135 women) aged from 16 to 43 years (average age 24,5 years) with deep bite (119 patients) and deep incisor overbite (88 patients) some peculiarities of face structure were determined in case of such abnormalities as well as pathogenetic mechanism of their formation was specified.

Relationship between internal derangement of the temporomandibular joint and dentofacial morphology in women with anterior open bite

INTRODUCTION

Anterior open bite is known to be associated with internal derangement of the temporomandibular joint (TMJ). This study examined the relationships between internal derangement and dentofacial morphology in women with anterior open bite.

METHODS

Fifty-one women with anterior open bite were enrolled in this study. The sample was divided into 3 groups based on magnetic resonance imaging of bilateral TMJs: normal disk position, disk displacement with reduction, and disk displacement without reduction. One-way analysis of variance was used to compare the 3 groups with respect to the cephalometric variables, and Duncan's multiple comparisons were performed at the 95% confidence level to identify the differences among the 3 groups.

RESULTS

Internal derangement of the TMJ was much more prevalent in subjects with a more posteriorly rotated mandibular ramus, a smaller mandible, and a greater tendency for a skeletal Class II pattern, although all subjects had an anterior open bite. These patterns were more severe as the internal derangement progressed to disk displacement without reduction.

CONCLUSIONS

Some cephalometric characteristics, such as a decrease in posterior facial height, decrease in ramus height, and backward rotation and retruded position of the mandible, are associated with TMJ internal derangement in women with anterior open bite.

An accurate system of serially recording anterior open bite using a modified technique for impression taking and study model construction

A simple impression technique is described that enables the clinician to record an anterior open bite, to provide accurate study model construction, and to monitor the anterior open bite. A case is presented that illustrates this technique with subsequent monitoring over an 8-year period

Non-surgical risk factors for condylar resorption after orthognathic surgery

BACKGROUND

Condylar resorption following orthognathic surgery is an important cause of late skeletal relapse. However, its pathogenesis is not well understood. The purpose of this study was to find non-surgical risk factors for condylar resorption after orthognathic surgery.

PATIENTS

In this retrospective study, 17 patients (Group I) who developed postoperative condylar resorption were selected. These patients were compared with 22 patients (Group II) without postoperative condylar resorption, but who showed mandibular hypoplasia with a preoperative high mandibular plane angle of more than 40 degrees.

METHODS

Possible non-surgical risk factors were sought by analysing clinical and radiological data collected preoperatively and immediately, 6 weeks, and 1 and 2 years postoperatively.

RESULTS

There was no significant difference of gender distribution between the two groups. Patients in Group I were significantly younger (p=0.02) than those in Group II. The incidence of temporomandibular joint dysfunction in both groups was similar preoperatively, but was significantly higher (p=0.001) postoperatively in Group I. The posterior inclination of the condylar neck in Group I was also significantly greater (p<0.001). The preoperative mandibular plane angle in Group I (mean value: 49.4 degrees ) was significantly greater (p=0.005) than in Group II (mean value: 44.9 degrees ). The preoperative SNB angle, overbite, and posterior facial height and ratio (posterior/anterior facial heights) in Group I were significantly smaller (p<0.05).

CONCLUSION

The present study suggests that the posteriorly inclined condylar neck should be considered as a relevant non-surgical risk factor.

A cephalometric comparison of black open-bite subjects and black normals

Orthodontic surveys of the adolescent and adult population of the United States have shown that the incidence of anterior open bite is three to four times higher in blacks than in whites. A cephalometric comparison of black subjects with and without an open bite was used to identify skeletal and dental differences between the two groups. Statistically significant differences were found in the vertical skeletal dimensions and incisor proclination. The open-bite group had a significantly longer anterior lower facial height and total facial height. The mandibular plane was rotated down relative to the cranial base and Frankfort plane and gonial angle was increased in the open-bite sample. There were small differences between the open bite and non-open-bite groups in the cranial base angle and the overbite depth indicator of Kim. No significant differences were found in the skeletal anteroposterior dimensions or dental vertical development. The vertical skeletal pattern and the greater degree of dental proclination differentiated black patients with an anterior open bite from those without.

Stability after rigid fixation of simultaneous maxillary impaction and mandibular advancement osteotomies

The purpose of this study was to investigate the short- and long-term stability of bimaxillary surgery following LeFort I (LF-1) impaction with simultaneous bilateral sagittal split ramus osteotomy (BSSO) and mandibular advancement using the technique of rigid internal fixation (RIF). In order to assess the postoperative maxillary and mandibular movement pattern in 26 patients with vertical maxillary excess and mandibular deficiency, cephalograms were taken immediately preoperatively, and 1 week, 2 months, and 1 year after surgery. With paired t-test showing no statistically significant postoperative change for the point A of the maxilla from immediate postsurgery to longest follow-up (P> 0.05), the used technique of "RIF LF-I impaction and RIF BSSO advancement" tended to render excellent postsurgical stability in the horizontal (0.1+/-0.8mm mean posterior movement) and vertical (0.1+/-0.5mm mean inferior movement) direction. There was no instance of maxillary relapse of >2mm. Regarding mandibular BSSO advancement, the point B showed a significant vertical upward movement (1.6+/-1.2mm) (P< 0.001) and a slight horizontal forward movement (0.3+/-2.0mm) (P> 0.05) at 1-year follow-up. The incidence of posterior relapse of >2mm accounted for 11.5%. The data confirm the concept that the bimaxillary approach of "LF-I impaction and BSSO advancement" using the described technique of RIF is a stable procedure in the treatment of open bite patients classified as vertical maxillary excess in combination with mandibular deficiency.

Occlusal interferences in orthodontic patients before and after treatment, and in subjects with minor orthodontic treatment need

Different opinions have been expressed concerning the effect of orthodontic treatment on mandibular function. One factor discussed is occlusal interferences. The aim of this study was to establish the prevalence of occlusal interferences in 210 orthodontic patients before (mean age 12 years 8 months) and after (mean age 16 years 10 months) treatment and to compare them with subjects with minor orthodontic treatment need. The results showed a decrease in retruded contact position/intercuspal position (RCP/ICP) interferences in all morphological deviations, age, and gender groups. The prevalence of mediotrusion interferences decreased in some types of malocclusions whilst in others there was no change. One reason for this is that treatment was started when the majority of the patients had no second or third molars erupted. At the final registration, the second molars were erupted in all patients, and the third molars were erupted in approximately 25 per cent. Mediotrusion interferences were more consistent with basal morphological deviations, for example, Class III relationships and anterior open bite were more consistent in the same person, and more difficult to eliminate than RCP/ICP interferences. RCP/ICP interferences, often caused by dental deviation in position, size, and shape, were easier to correct. Optimal orthodontic treatment, if necessary, including selective grinding, will decrease the prevalence of occlusal interferences.

Study on the correlation between tongue size and openbite

OBJECTIVE

To investigate the correlation between tongue size and openbite.

METHODS

The tongue size of the openbite patients and the subjects with normal occlusion was measured by B-type ultrasonic imaging respectively. The tongue size of the openbite patients and the subjects with normal occlusion was compared.

RESULTS

The tongue size in openbite group was larger than in normal occlusion group. The difference was statistically significant.

CONCLUSIONS

Tongue size was related to the openbite.

Seckel syndrome: report of a case

An interesting case of a seven years old boy with a combination of clinical, genetic, radiological, pathologic and dental findings is presented in view of Seckel syndrome literature. General appearance of the patient was characterized by small forehead, posteriorly slanted ears, slightly beaked nose, midfacial hypoplasia very stunted stature with microcephaly. He had borderline mental retardation with normal motor development. Class II dentoskeletal pattern with mild overjet and open bite, congenitally missing permanent teeth, microdontia, enamel hypoplasia, taurodontism and dentinal dysplasia was observed according to the clinical and radiographic examination. In conclusion, Seckel syndrome is not encountered routinely in dental clinics, this case illustrates the importance of dental care in such a rare condition.

Reproducibility of characteristics assessing the occlusion of young adults

The aim of the present investigation was to analyze the reproducibility in the assessment of six morphological and three functional characteristics included in a new method evaluating the occlusion in young adults. These characteristics comprised coincidence of midlines, overjet, overbite, canine relationship, crossbite, scissors bite, recurrent deviation on opening, guided lateral excursions, and discrepancy between the centric relation and the intercuspal position. The study was conducted in three stages: (1) five observers assessed the occlusions of five volunteers, (2) seven observers assessed nine volunteers, and (3) five observers assessed nine volunteers. Two calibrated orthodontists were used as references. For numerical variables, the nonparametric method for repeated measurements (Friedman's test) was used to test the significance of differences, while the proportion of agreement was calculated for categorical assessments. The results were analyzed using two precision levels: within a measurement unit/the same category and an acceptable/nonacceptable dichotomy. The magnitude of systematic differences was small and of minor clinical importance except in measurements of recurrent deviation on opening. The proportional agreement for acceptance was good in the assessment of overjet, coincidence of midlines, crossbite, scissors bite, open bite, and discrepancy between the centric relation and the intercuspal position. Moderate agreement was achieved in the assessment of overbite, canine relationship, recurrent deviation on opening, and guided lateral excursions. Among the nonacceptable cases, the agreement ranged from poor to good. The results indicated that noncalibrated observers assess categorical characteristics inconsistently.

The Garcia Distraction Appliance: treatment of the TMD patient with an anterior open bite

A temporomandibular joint case with an anterior open bite and a high mandibular plane angle was treated by erupting the posterior teeth after creating a posterior open bite using a Garcia Distraction Appliance and a Garcia Pivot Splint.

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.

Schinzel-Giedion syndrome: interesting facial and orodental features, and dental management

Schinzel-Giedion syndrome comprises multiple congenital anomalies. The orofacial features include coarse facies, frontal bossing, ocular hypertelorism, anterior open bite and macrodontia. Two cases are presented in which the presence of specific craniofacial anomalies with bilateral hydronephrosis confirmed the diagnosis. In one patient, bottle-feeding was associated with caries in maxillary central and lateral incisors, but the second patient was permanently tube fed and did not experience any dental caries. Clinical management of these patients requires a coordinated approach from a team of medical and dental specialists.

Skeletal and dento-alveolar stability after surgical-orthodontic treatment of anterior open bite: a retrospective study

The aim of this investigation was to assess skeletal and dento-alveolar stability after surgical-orthodontic correction of skeletal anterior open bite treated by maxillary intrusion (group A) versus extrusion (group B). The cephalometric records of 49 adult anterior open bite patients (group A: n = 38, group B: n = 11), treated by the same maxillofacial surgeon, were examined at different timepoints, i.e. at the start of the orthodontic treatment (T1), before surgery (T2), immediately after surgery (T3), early post-operatively (+/- 20 weeks, T4) and one year post-operatively (T5). A bimaxillary operation was performed in 31 of the patients in group A and in six in group B. Rigid internal fixation was standard. If maxillary expansion was necessary, surgically assisted rapid palatal expansion (SRPE) was performed at least 9 months before the Le Fort I osteotomy. Forty-five patients received combined surgical and orthodontic treatment. The surgical open bite reduction (A, mean 3.9 mm; B, mean 7.7 mm) and the increase of overbite (A, mean 2.4 mm; B, mean 2.7 mm), remained stable one year post-operatively. SNA (T2-T3), showed a high tendency for relapse. The clockwise rotation of the palatal plane (1.7 degrees; T2-T3), relapsed completely within the first post-operative year. Anterior facial height reduction (A, mean -5.5 mm; B, mean -0.8 mm) occurred at the time of surgery. It can be concluded that open bite patients, treated by posterior Le Fort I impaction as well as with anterior extrusion, with or without an additional bilateral sagittal split osteotomy (BSSO), one year post-surgery, exhibit relatively good clinical dental and skeletal stability.