Age-related variations in position and morphology of the temporomandibular joint in individuals with anterior openbite and crossbite: a multi-cross-sectional comparative study.

BACKGROUND: This study aimed to compare the age-related positional and morphological characteristics of the temporomandibular joint (TMJ) between individuals with anterior openbite or crossbite and controls. METHODS: This multi-cross-sectional comparative study analysed cone-beam computed tomography images of 750 participants, equally divided into the openbite, crossbite, and control groups (OBG, CBG, and CG, respectively). Each group was further divided into five subgroups (8-11 years, 12-15 years, 16-19 years, 20-24 years, and 25-30 years). Measurements of the TMJ included the position of the condyles in their respective fossae and morphology of the condyles and fossae. Data were submitted to statistical analysis. The study adhered to the STROBE Statement checklist for reporting of cross-sectional studies. RESULTS: Condyles were positioned more posteriorly with increasing age in all groups, and the condylar position was more posterior in the OBG than in the CBG. The articular eminence inclination increased with age in all the groups. There were significant differences in the articular eminence inclination among the three major groups at the age of > 15 years, and the condylar path was flatter in the CBG than in the OBG. CONCLUSIONS: Age-related morphological and positional characteristics of the TMJ differed considerably among OBG, CBG and CG. Contrary to CBG, OBG was found to have relatively posterior condylar position and steeper condylar path.

Anterior openbite malocclusion in adults.

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.

Evaluation of temporomandibular joint space and condylar morphology in patients with anterior open-bite based on cone-beam CT / 口腔疾病防治

Objective@#To investigate the difference of the temporomandibular joint between patients with anterior open-bite and normal overbite with cone beam CT (CBCT).@*Methods @# Fifty-four patients with anterior open bites and 54 patients with normal overbites were selected from the Department of Orthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University from June 2014 to August 2020. Sagittal and coronal images of the temporomandibular joint were reconstructed with multiplanar reconstruction techique. The Kamelchuk method was used to measure the superior, posterior and anterior space of the temporomandibular joint, and the condylar morphology was divided into two types: normal and abnormal. The joint space and condylar morphology of the anterior open-bite group and the normal overbite group were statistically analyzed. The anterior open-bite group was divided into 3 subgroups: ① Ⅰ° open-bite (open bite distance < 3 mm), ② Ⅱ° open-bite (open bite distance ≥ 3 mm and ≤ 5 mm) and ③ Ⅲ° open-bite (open bite distance > 5 mm). The difference of overbite spaces of the temporomandibular joint was compared among these three subgroups.@*Results@#Compared to the normal group, no significant differences were found for the anterior and superior space of the temporomandibular joint in the anterior open-bite group (P > 0.05), but the posterior space increased significantly (P < 0.01). A total of 52.8% of patients in the anterior open-bite group had abnormal condyles, whereas 21.3% of patients in the normal group, overbite significant differences was found between the two groups (P < 0.01). Compared with patients with Ⅰ° and Ⅱ° openbite, the condyle of patients with III° open bites was more forward in the fossa (P < 0.05).@*Conclusion @#The position of the condyle in the fossa of patients with anterior open bites is more forward, and abnormal condylar bone is more common found.

Association of Dysplastic Coronoid Process with Long-Face Morphology.

Vertical malocclusion is a developmental condition, resulting from complex interactions among multiple etiological factors during the growth period. As a tricky dentofacial deformity clinically, long-face (LF) morphology is characterized by excessive vertical facial growth with severe disarrangement of jaws and teeth. Since the improvement of LF patients on facial profile and occlusion is often difficult and lacks long-term stability, it becomes important to unravel the etiology of LF pattern formation for early prevention and treatment. In the current studies, we identified a transgenic mouse model that exhibited a dysplastic coronoid process and LF morphology. Although the mutant mice exhibited jaw structures and occlusion comparable to controls at birth, they all acquired typical LF morphology with anterior open bite during postnatal growth, resembling clinical features of the selected skeletal class III patients. Since the coronoid process provides an insertion site for the temporalis attachment, we examined the initial development and differentiation of the temporalis and found identical results in both control and mutant mice before E17.5 when the temporal muscle makes attachment to the coronoid process. However, thereafter, we observed altered orientation and reduced size of the cross-sectional area of the temporalis in mutant mice, which persisted to the weaning stage. Biomechanical analysis and simulation modeling further support the idea that altered morphology of the coronoid process may impair the efficiency of the vertical temporalis contraction and appears to correlate with LF formation. Consistently, we present evidence that a dysplastic mandibular coronoid process was also seen in some human patients with skeletal III LF morphology. Taken together, the results presented in this study establish an association of the craniofacial bony structures with vertical patterning, which will have implications in earlier prediction for clinical precaution and intervention.

Modified Haas Expander for the Treatment of Anterior Openbite and Posterior Crossbite Associated with Thumb Sucking-A Case Report: 3-Years Follow-Up.

Thumb sucking is an abnormal habit that occurs in childhood and can cause several malocclusions if it persists for a long time. Malocclusions caused by oral habits require proper treatment timing to maintain a normal growth and should be treated at an early age. This case report shows the management of thumb sucking and early correction of anterior open bite and posterior crossbite by a modified Haas expander. Three-year follow-up results showed the effectiveness of this special designed appliance.

Anterior open-bite treatment by means of zygomatic miniplates: a case report.

This case report presents the treatment of a patient with skeletal Cl II malocclusion and anterior open-bite who was treated with zygomatic miniplates through the intrusion of maxillary posterior teeth. A 16-year-old female patient with a chief complaint of anterior open-bite had a symmetric face, incompetent lips, convex profile, retrusive lower lip and chin. Intraoral examination showed that the buccal segments were in Class II relationship, and there was anterior open-bite (overbite -6.5 mm). The cephalometric analysis showed Class II skeletal relationship with increased lower facial height. The treatment plan included intrusion of the maxillary posterior teeth using zygomatic miniplates followed by fixed orthodontic treatment. At the end of treatment Class I canine and molar relationships were achieved, anterior open-bite was corrected and normal smile line was obtained. Skeletal anchorage using zygomatic miniplates is an effective method for open-bite treatment through the intrusion of maxillary posterior teeth.

The Factors Affecting Long-Term Stability in Anterior Open-Bite Correction - A Systematic Review.

OBJECTIVE: The present systemic review was conducted with the main purpose to evaluate the quantitative effects of orthognathic surgeries, extraction versus non-extraction treatment, and the type of malocclusion in the stability of anterior open-bite (AOB) correction over the long-term. METHODS: The systematic search for studies was conducted through MEDLINE, CINAHL, EMBASE, Scopus, PsychINFO, various key journals, and review articles; November 30, 2016, was the last date for the search. The Quality Assessment Tool for Quantitative Studies was used to grade the methodological quality of the studies. RESULTS: The present review included 14 studies. Stability of the corrected AOB ranged from 61.9% to 100%. The studies with orthognathic surgeries showed a stability of 70-100%. The studies without orthognathic surgeries showed the stability of 61.9-96.7%. All of the studies were retrospective. The mean change in AOB before (T1) and after treatment (T2-T1) was 0.1 mm to 6.93 mm and the mean change in overbite from T2 to T3 (T3-T2) was -0.06 mm to 2.5 mm. CONCLUSION: Studies with orthognathic surgeries presented with high amount of long-term stability in corrected AOB. No significant difference was noticed in relation to the type of malocclusion and extraction or non-extraction cases.

Anterior open-bite orthodontic treatment in an adult patient: A clinical case report.

A 45-year-old woman presented with an anterior open-bite complaining chiefly of her unpleasant smile esthetics and masticatory and speech problems. Treatment included speech therapy initiated immediately after bonding. Lingual spurs were positioned on the mandibular incisors in order to help tongue rehabilitation. During the working phase, temporary anchorage devices (TADs) were used at the mandibular anterior segment to intrude the lower left premolars. A splint was used to ensure retention in the upper and lower arches; an enveloppe linguale nocturne (ELN) was provided. Non-surgical open-bite treatment could offer a valid alternative to orthognanthic surgery when cephalometric evaluation shows no vertical growth pattern; patient compliance is essential to prevent relapse.

Molar intrusion in the management of anterior openbite and 'high angle' Class II malocclusions.

Orthodontic correction of anterior openbite has conventionally involved extraction therapy or an adjunctive maxillary impaction osteotomy. However, bone anchored molar intrusion treatments have been reported in recent years as a less invasive alternative for such patients. This paper describes the concepts and treatment processes involved with mini-implant molar intrusion to correct anterior openbite and reduce patients' excessive vertical facial proportions.

Correction of the occlusal and functional sequelae of mandibular condyle fractures using orthodontic mini-implant molar intrusion.

We report on the non-surgical management of an adult female whose bilateral mandibular condylar fractures had resulted in a clockwise (posterior) mandibular rotation, limitation of mandibular movements and increased occlusal loading on the molar teeth. She refused maxillary surgery and was treated with a minimally-invasive approach, involving orthodontic fixed appliances and mini-implant intrusion of the maxillary molar teeth. This provided both occlusal and functional improvements, including a significant increase in the inter-incisal distance, which were stable after one year of retention.

Post-operative Stability of Counter Clockwise Rotation of the Mandibular Plane in Skeletal CIII with Anterior Openbite Patients

3degrees).CONCLUSION: This study evaluated the amount of horizontal relapse, and the degree of relapse. Stable results were obtained. Although there was no statistical significance between the degree of openbite and the amount of horizontal relapse, the group with a greater amount of openbite had a greater amount of relapse.

Central tongue reduction for macroglossia

Macroglossia can cause dentomusculoskeletal deformities, instability of orthodontic and orthognathic surgical treatment, and create masticatory, speech and airway management problems. To determine whether a reduction glossectomy is necessary, it will important to identify the signs and symptoms of macroglossia. Development of dentoskeletal changes directly related with tongue size, such as an anterior open bite or a Angle Class III malocclusion tendency, would indicate that reduction glossectomy may be beneficial. For reduction glossectomy, several techniques have been reported. However, in most techniques the tip of tongue is removed. So its excision causes the loss of most mobile and sensitive portion of the tongue, and creates ankylosed, globular tongue. To avoid such problems, central tongue reduction technique have been proposed. This article will introduce central tongue reduction for anterior openbite case associated with macroglossia.

Evaluation of skeletal stability after BSSRO in skeletal class III with anterior open bite

OR = 1mm). Serial lateral cephalometric radiographs were taken within 2 weeks preoperatively, within 1 week postoperatively and at a follow up period that ranged from 7 to 24 months postoperatively. All cephalometric radiographs were traced and digitized using the Quick ceph image Pro for analysis. And then, horizontal and vertical changes of reference points(B point, Pogonion, L1) were assessed by the linear measurements in millimeters on both axes. The results were as follows: 1. Mean horizontal relapses were 0.67+/-0.93mm (11%) at B point (P0.05). 3. The mean angular change of occlusal plane to SN was 0.24+/-1.19 (P>0.05) and that of mandibular plane to SN was 1.03+/-1.85 (P<0.05). 4. There was correlation between the extent of preoperative overbite and the postsurgical relapse at B point and Pogonion. 5. There was no correlation between the amount of surgically produced horizontal movement and the postoperative horizontal relapse at B point.

Postoperative stability and occlusal plane alternation by orthgnathic surgery of skeletal Class III malocclusion with anterior open bite / 대한치과교정학회지

The purpose of this study is to investigate the stability of counterclockwise rotation of mandible by sagittal split ramus osteotomy to correct the skeletal Class III malocclusion with anterior open bite. Twenty five skeletal Class III open bite patients(mean age 20.6 years) who were treated by the sagittal split ramus osteotomies with rigid fixation were examined in this study. Cephalometric radiographs were taken for ach patients preoperative(T1), early postoperative(T2), and late postoperative period(T3). Mean postoperative period(T3).Mean postoperative period was 8.0 months. Cephalomerric analysis was done and data from T1, T2, and T3 were analyzed statistically by paired t-test and pearson correlation analysis. The following results were obtained. 1. Mandibular plane angle decreased 2.9degrees and mandibular occlusal plane angle related to SN plane decreased 2.7degrees after orthognathic surgery(T2). At 6 months after orthgnathic surgery(T3), mandibular plane angle increased 1.0degrees, but mandibular occlusal plane angle did not changed. 2. The amount of horizontal relapse long time after orthornathic surgery(T3) was 1.6mm at B point and it was 22% of the total posterior movements. There was no vertical relapse in the anterior facial height. 3. The related factor with horizontal relapse at late postoperative period was mandibular plane angle(p<0.01). The related factors with decreasing posterior facial height were amount of mandibular setback(p<0.01), increasing of mandibular ramus height(p<0.01), and decrease of the mandibular plane angle during operation(p<.01). 4. There was no relationship between the amount of changes in mandibular occlusal plan angle during operation and the amount of relaspe after surgery.

Change of condylar position after orthodontic treatment of anterior open bite / 대한치과교정학회지

This study was aimed to evaluate the changes in condylar position when severe anterior open bite patients were treated with MEAW. The subjects consisted of 11 patients(21 TMJs) who visited the department of orthodontics in SNUH, having severe anterior open bite as a chief complain. They were supposed to wear the up and down elastics and MEAW after finishing the leveling. The condylar position was evaluated with individualized corrected tomography in centric occlusion taken before and after treatment. The results were as follows; 1. In the change of condylar position after treatment, there were no statistically significant differences in right and left TMJs. 2. In the change of condylar position after treatment, there were no statistically significant differences in each malocclusion groups. 3. There were no statistically significant differences in percent displacement of condyle between before and after treatment. 4. There were no statistically significant differences in the amount of change in condylar change.

An electromyograghic study of muscular activities of tongue and lip muscles in anterior open-bite / 대한치과교정학회지

The purpose of the present study was to investigate the difference of muscular activities of the tongue and lip muscles between anterior open-bite and normal occlusion during various function. Thirty eight subjects of 12.1-39.6 years were employed in this study: Eighteen subjects were anterior open-bites and twenty subjects were normal occlusions. During rest position, maximum effort of lip sealing, command swallow of saliva and sucking & swallowing of juice, the electromyographic datas of the genioglossus, superior longitudinal muscle of tongue, upper and lower orbicularis oris were recorded and integrated with Medelec MS 25 electromyographic machine. Lateral cephalometric radiographs were taken on all subjects for the analysis of tongue posture and size. All data were recorded and statistically processed. The findings of this study can be summerized as follows: 1. During the rest position, muscular activity of tongue was higher than that of lip muscle in open-bite, but no difference in normal occlusion group. 2. During the swallowing of juice, the activity of orbicularis oris was higher than that of genioglossus in open-bite. But the normal occusion was showed higher activity of tongue during the swallowing of juice. 3. The open-bite, compared to the normal occlusion, had higher value of tongue muscle activity during the rest position. 4. Compared to normal occlusion group, the open-bite had higher value of lip muscle activity during the sucking and swallowing of juice. 5. During the command swallow of saliva, the normal occlusion was showed harmonious swallowing pattern, but the open-bite showed much variation and disharmony in muscular contraction sequence, tended to absent of lip muscle activity. 6. At the lateral cephalometric radiographs, compared to the normal occlusion, the open-bite was showed lower tongue posture. But no difference was found in intermaxillary space. It is suggested that the open-bite, compared to the normal occlusion, had higher muscular activity of tongue during the rest position and various functions, showed lower tongue posture on the lateral cephalogram. In the development of anterior open-bite malocclusion, these factors may be an etiologic factor.

A cephalometric evalauation of anterior openbite malocclusions treated by multiloop edgewise archwire technique / 대한치과교정학회지

The purpose of this study was to evaluate the change of before and after treatment of anterior openbite malocclusions treated by Multiloop Edgewise Archwire technique. The openbite sample consisted of 4 male and 12 female adults, treated with nonextraction or third molar extraction. The normal sample consisted of 58 subjects, which have pleasing facial profile and normal occlusion and no experience of orthodontic or prosthodontic treatment. The 58 subjects of normal sample were subdivided by cephalometric vertical relationship of face. The 40 subjects, cephalometric vertical relationship of face was in normal range, classified as Normal Sample group 1. The 18 subjects, increased cephalometric vertical relationship of face, classified as Normal Sample group 2. The computerized cephalometric analysis was accomplished with 50 reference points for 22 skeletal measurements, 46 dentoalveolar measurements, 8 soft tissue measurements. Statistical analysis of the data was carried out with paired t-test, Student's t-test, and DUNCAN test using SAS(PC version). The results were as follows: 1. There were no statistically significant differences in skeletal measurement between before and after treatment. The major changes were in dentoalveolar region. 2. After treatment, the long axis of maxillary and mandibular posterior teeth were distally tipped-back, and uprighted to bisected occlusal plane. The interincisal angle was increased. 3. There were no statistically significant increase in the upper posterior dental height and statistically significant decrease in the lower posterior dental height. The upper anterior dental height was increased, but there was no statistically significant increase in the absolute upper anterior dental hight. The lower anterior dental height was increased. 4. After treatment, the maxillary occlusal plane to palatal plane angle and the mandibular occlusal plane to mandibular plane angle were statistically significant increased. Then, there were no statistically significant difference between after treatment group and normal sample group 2. 5. After treatment, the percentage of upper lip length to upper anterior dental height was decreased. Then, There were no statistically significant difference between after treatment group and normal sample group 2.