Combined Treatment of Open Bite – Long-term Evaluation and Relapse Factors

Short-term stability of anterior open bite treatment with clear aligners in adults

INTRODUCTION

This study aimed to examine the stability of anterior open bite (AOB) treatment with clear aligners.

METHODS

This retrospective cohort study included 52 adult AOB patients (aged >18 years; 15 males, 37 females) who underwent nonextraction clear aligner treatment and were at least 1 year posttreatment. Eleven cephalometric measurements were evaluated at pretreatment, end of active treatment, and at least 1-year posttreatment. Overbite change, the primary outcome variable, and other cephalometric changes during treatment and retention were calculated, and repeated measures analysis of variance were performed. Stepwise multiple regression was used to make a prediction equation for open bite relapse.

RESULTS

The mean retention period was 2.1 ± 1.1 years. The mean change in overbite during treatment was 3.3 ± 1.5 mm; 6% of patients presented relapse at least 1 year after treatment completion. The mean change of overbite (0.2 ± 0.5 mm) during the retention period was not statistically significant (P = 0.59). None of the 11 cephalometric measurements showed significant change during the retention period. The prediction model showed that only the coefficient for a tongue posture issue at the initial examination was statistically significant.

CONCLUSIONS

AOB was successfully corrected in all 52 patients using only clear aligners with no additional adjunctive aids such as microimplants. When retained with maxillary and mandibular fixed retainers and maxillary and mandibular vacuum-formed retainers, there was no significant change in cephalometric measurements during the short-term retention period.

Postoperative complications in asthmatic patients following orthognathic surgery: A two-year follow-up study

BACKGROUND

Lack of evidence exists related to the incidence of postoperative complications in asthmatic patients following orthognathic surgery. The present study aimed to assess the incidence and risk factors of postoperative complications in asthmatic patients following orthognathic surgery.

MATERIAL AND METHODS

A retrospective cohort study was conducted which consisted of two groups of patients i.e., asthmatic and systemically healthy patients, who underwent conventional orthognathic surgical procedures (Le Fort I osteotomy, bilateral sagittal split osteotomy, and genioplasty). The recorded postoperative complications in both groups of patients included infection, relapse, altered facial sensation, temporomandibular joint disorder, respiratory complications, and hemorrhage-related events. The association between baseline variables and complications for identifying the possible risk factors was assessed using bivariate analysis and a logistic regression model.

RESULTS

A total of 886 patients underwent orthognathic surgery over a period of 6-years. Following the eligibility criteria, 16 patients were recruited in the asthmatic group and 278 patients were systemically healthy. The most common complications in the asthmatic patients were altered sensation (37.5%) followed by TMJ disorder (25.0%) and relapse (18.8%). These patients were associated with an increased risk of relapse (P = 0.048) compared to healthy patients. Following adjustment of baseline variables, increased risk of relapse was still associated with asthma (odds ratio [OR]. = 4.704, P = 0.027).

CONCLUSION

Asthmatic patients suffer from a significantly higher risk of relapse and need to be closely monitored following orthognathic surgery to ensure a stable outcome. Asthma does not seem to have a significant impact on other postoperative complications.

Mandibular morphometric analysis in open bite early treatment relapse subjects: a retrospective observational pilot study

BACKGROUND

The purpose of this retrospective study was to evaluate the mandibular shape differences between a group of success and a group of failure Anterior Open Bite (AOB) malocclusion early orthodontic treatment in growing subjects, in order to identify mandibular features of relapse.

METHODS

Twenty three patients (7 males, 16 females, 9.3 years ±1,5 years) were enrolled from the Department of Orthodontics at the University of Rome Tor Vergata. Inclusion criteria were: white ancestry, overbite < 0 mm, mixed dentition phase, end-to-end or Class I molar relationship, first skeletal class assessed on lateral cephalograms (0° < ANB < 4°), cervical skeletal maturation CS1-CS2, no previous orthodontic treatment, no congenital diseases. Pre-treatment (T1) lateral cephalograms were acquired. Each patient underwent early orthodontic treatment with Rapid Maxillary Expander (RME) and Bite Block (BB) or Quad-Helix Crib (QHC) until open bite correction. Radiographic records were recollected at T2 (permanent dentition, skeletal cervical maturation CS3-CS4). Mean interval time T2-T1 was 4.2 years ±6 months. According to treatment stability, a Relapse Group (RG 11 patients, 3 M, 8F; 13.7 years ±8 months, 7 subjects treated with RME/BB, 4 with QH/C) and a Success Group (SG, 12 patients, 4 M, 8F; 13.4 ± 10 months, 7 subjects treated with QH/C, 5 with RME/BB) were identified. On the lateral radiographs the mandibular length (Co-Gn), the inferior gonial angle (NGo^GoMe) and the antegonial notch depth (AND) were analyzed. Then the mandibular Geometric Morphometric analysis (GMM) was applied. Intergroup statistically significant differences were found using student's t-tests. Procrustes analysis and principal component analysis (PCA) were performed for the GMM.

RESULTS

At T1 no statistically significant differences were found between RG and SG, however higher values of antegonial notch depth were found in RG. T2-T1 comparison showed in RG statistically significant increases in Co-Gn (p = 0.04), NGo^GoMe angle (p = 0.01) and antegonial notch depth (p = 0,04). PC1 confirmed the increase in the antegonial notch depth in RG when compared to SG at T2.

CONCLUSIONS

The increased antegonial notch depth associated with the increased mandibular length and the increased gonial angle could be responsible of relapse of early orthodontic treatment in open bite growing subjects.

Anterior openbite malocclusion in adults: Treatment stability and patient satisfaction in National Dental Practice-Based Research Network patients

OBJECTIVES

To investigate stability and satisfaction in adult anterior open bite (AOB) patients at least 9 months post-treatment, as well as patient and practitioner factors that may be associated with stability and satisfaction.

MATERIALS AND METHODS

Practitioners and their adult AOB patients were recruited through the National Dental Practice-Based Research Network. Data on patient and practitioner characteristics, treatment recommendations and factors were previously collected. Treatment stability was determined by assessing post-treatment intraoral photographs. Patient satisfaction was determined from post-treatment questionnaires. Treatment was categorized into aligners, fixed appliances, temporary anchorage devices, and orthognathic surgery. Extractions were also investigated. Retention type was categorized into vacuum-formed, Hawley-style, or bonded retainers, and regimens were classified as full-time or part-time wear.

RESULTS

Retention data collected from 112 patients had a mean post-treatment time of 1.21 years. There were no statistically significant differences in stability between treatment groups. Depending on whether a qualitative index or a millimetric measure was employed, stability ranged from 65% to 89%. Extractions and less initial lower incisor proclination were associated with higher stability in patients treated with fixed appliances only. High satisfaction was reported by patients at retention. There were no clear differences in stability or satisfaction among retention types or regimens.

CONCLUSIONS

The stability of adult AOB orthodontic treatment was high, regardless of treatment or retainer modality. Satisfaction in adult AOB patients was high, regardless of retention type or regimen.

Vertical stability of different orthognathic treatments for correcting skeletal anterior open bite: a systematic review and meta-analysis

BACKGROUND

Several orthognathic procedures have been applied to correct skeletal anterior open bites (SAOB). Which method is most stable has been debated and no consensus has been reached and there is no conclusive evidence for clinicians to use.

OBJECTIVE

To analyse whether maxillary, mandibular, or bimaxillary surgery provides a better stability.

MATERIALS AND METHODS

A systematic search was conducted up to December 2020 using PubMed, EMBASE, Medline, Scopus, Web of Science, Cochrane CENTRAL, and Google Scholar. We made direct comparisons among the controlled trials and also made indirect comparisons via subgroup analysis on the aspects of occlusional, skeletal, and dento-alveolar stability to assess the overall stability of each method.

RESULTS

Finally 16 cohort studies were identified. At the occlusional level, pooled change in overbite was 0.21 mm in maxillary surgery, 0.37 mm in bimaxillary surgery, and -0.32 mm in mandibular surgery. At the skeletal level, pooled sella-nasion-Point A angle (SNA) was -0.12 degrees in bimaxillary surgery, -0.37 degrees in maxillary surgery and -0.20 degrees in mandibular surgery. The sella-nasion to palatal plane angle (SNPP) relapsed to a statistically significant degree in all samples received single maxillary surgery. Relapse of the sella-nasion-Point B angle (SNB) was 0.47 degrees in mandibular setback, -1.8 degrees in mandibular advancement, and -0.48 degrees in maxillary surgery. The Sella-Nasion to mandibular plane angle (SNMP) relapsed more in procedures involving bilateral sagittal split osteotomy than in other procedures. As for dento-alveolar changes, intrusion of molars and extrusion of incisors took place in most patients.

CONCLUSIONS

Bimaxillary surgery produced the most beneficial post-operative increase in overbite, maxillary surgery led to a lesser but still positive overbite change, and mandibular surgery correlated with some extent of relapse. Skeletally, bimaxillary surgery was more stable than maxillary surgery at both SNA and SNPP; SNB was more stable in mandibular setback than advancement; and SNMP was unstable in both mandibular and bimaxillary surgeries versus maxillary surgery with comparable surgical changes. Dento-alveolar compensation helped maintain a positive overbite.

REGISTRATION NUMBER

CRD42020198088.

[Evaluation for vertical stability after various orthognathic surgical treatment plans for skeletal class Ⅲ malocclusion with anterior open-bite]

OBJECTIVE

To evaluate vertical stability after various orthognathic surgical treatment plans for skeletal class Ⅲ malocclusion with anterior openbite.

METHODS

A retrospective multicenter cohort study was conducted to investigate vertical stability after various orthognathic surgical treatment plans for skeletal class Ⅲ malocclusion with anterior openbite. From 2010-2016, 122 patients from two domestic stomatological hospitals were included in our study. Patients were divided into four groups according to their treatment plans, namely, bilateral sagittal split ramus osteotomy (BSSRO), intraoral vertical ramus osteotomy (IVRO), BSSRO+Le Fort Ⅰ, and IVRO+Le Fort Ⅰ. All patients followed a standardized examination procedure at 6 and 24 months post-treatment. The observation indexes include overbite, mandibular plane angle, and intermaxillary angle.

RESULTS

1) The significantly reduced ratio of the overbite in the BSSRO+Le Fort Ⅰ and IVRO+Le Fort Ⅰ groups were less than the BSSRO and IVRO groups at 6 and 24 months post-treatment. 2) The significantly increased ratio of the mandibular plane in BSSRO+Le Fort Ⅰ and IVRO+Le Fort Ⅰ groups were less than BSSRO and IVRO groups at 6 and 24 months post-treatment. 3) The significantly increased ratio of the intermaxillary angles in BSSRO+Le Fort Ⅰ and IVRO+Le Fort Ⅰ groups were less than the BSSRO and IVRO groups at 6 months post-treatment, while there was no statistical difference at 24 months post-treatment.

CONCLUSIONS

Bimaxillary surgery (BSSRO+Le Fort Ⅰ and IVRO+Le Fort Ⅰ) is more effective than mandibular surgery to control vertical relapse.

Morphology of open bite

OBJECTIVES

The purpose of this work was to define and illustrate the skeletal morphology of open-bite patients against the background of sagittal jaw relationships on the basis of lateral cephalograms.

MATERIALS AND METHODS

Lateral cephalograms of 197 untreated adults were analyzed in dental imaging software (Onyx Ceph 3™; Image Instruments, Chemnitz, Germany). Four groups were formed based on vertical (Index scores) and sagittal (individualized ANB values) parameters. Ninety-nine patients were defined as the control group due to their neutral sagittal and vertical relationships. The remaining patients were found by their vertical relationships to represent open-bite cases and were divided by their sagittal relationships into three study groups: neutral (Class I, n = 34), distal (Class II, n = 26), and mesial (Class III, n = 38). A geometric morphometric approach was used to analyze the x,y-coordinates of 28 skeletal landmarks on each cephalogram. Relative size was captured based on centroid size (CS). The shape-determining factors in the groups were compared by permutation testing after Procrustes transformation, and intergroup differences were visualized in the form of thin-plate splines.

RESULTS

While size (CS) was significantly increased in the Class III group, the other two groups were not different from the control group. After Procrustes transformation, characteristic and invariably significant (p < 0.001) differences in shape were detected. Neutral (Class I) open bite involved compression in the mandibular ramus and the upper anterior facial third, including vertical expansion in the lower molar and anterior nasal spine areas. Mesial (Class III) open bite was associated with pronounced vertical and sagittal size reductions in the upper posterior segments and reduced lengths of the mandibular ramus. Distal (Class II) open bite involved expansion in the pterygoid area and compression in the mandibular ramus.

CONCLUSION

Open bite is not a homogeneous group. Our geometric techniques of morphometric analysis revealed typical patterns, thus, confirming the differences observed by traditional morphometry. True skeletal overdevelopment appears to be present only in open-bite cases having a mesial jaw relationship. All open-bite groups have in common that the mandibular ramus is compressed, but marked differences are seen in terms of vertical development of the maxilla. This differentiated view of open-bite cases should be taken into consideration during individual etiology assessment and treatment planning.

Multidisciplinary correction of anterior open bite relapse and upper airway obstruction

A 27-year-old man presented an anterior open bite relapse. He had low tongue posture positioned anteriorly at rest and during swallowing and reported chronic difficulty in nose breathing. Head cone-beam computed tomography revealed nasal septum deviation, right turbinate hypertrophy, and left maxillary sinus congestion, which were thought to contribute to the breathing problem, encourage the improper tongue posture, and thereby cause the relapse. Multidisciplinary treatment involving an otorhinolaryngologist, an orthodontist, and a periodontist resolved the upper airway obstruction and corrected the malocclusion. The follow-up examination after 3 years 5 months demonstrated stable results.

Closure of anterior open bites with mandibular surgery: advantages and disadvantages of this approach

INTRODUCTION

While closure of an anterior open bite with a mandibular procedure may predispose a surgical case to instability, there are instances where this type of treatment planning is indicated.

METHODS AND MATERIALS

In this paper, the authors review the advantages and disadvantages of this approach and present three cases with varying degrees of success. Additionally, treatment strategies are presented for managing large advancements of the maxilla and mandible.

RESULTS AND SUMMARY

Counterclockwise rotation of the mandible is a valuable tool that can be used in the treatment of patients with dentofacial deformities.