Progressive idiopathic condylar resorption: Three case reports

Changes in occlusal relationships observed using an intraoral scanner in patients with an acquired open bite: A case report

PATIENTS

This case report describes a procedure for assessing changes in occlusal relationships in patients with acquired open bites due to temporomandibular joint disease using an intraoral scanner (IOS). A digital impression was made using the IOS at the initial visit. Subsequent impressions were made every 6 months using the IOS and magnetic resonance imaging (MRI) or computed tomography (CT). Standard triangulated language (STL) image files of two digital impressions at different points in time were superimposed, including the occlusal relationship with reference to the maxillary dentition. Finally, three-dimensional (3D) changes in the occlusal relationship over time were evaluated.

DISCUSSION

In Case 1, the superimposed STL image indicated almost no evident deviation of the mandible. Therefore, an orthodontic treatment was initiated. In contrast, in cases 2 and 3, where changes in the occlusal relationship continued, secondary treatment was postponed and patients continued to be monitored periodically. In case 3, even though left condyle resorption was progressive, the degree of open bite on the right side improved after 6 months. However, the open bite continued to progress for another 6 months despite the stability of the condyle.

CONCLUSIONS

Changes in the condylar shape observed using imaging may not always reflect changes in the occlusal relationship. In addition to changes in the condyles and eminences of the temporomandibular joint (TMJ), changes in the occlusal relationships of patients with acquired open bite should be evaluated using an intraoral scanner.

Current Status of the Management of Idiopathic Condylar Resorption/Progressive Condylar Resorption-A Scoping Review

The temporomandibular joint (TMJ) is a complex synovial joint shrouded in mystery, as the etiology of many TMJ disorders are unsolved. Idiopathic/progressive condylar resorption (ICR/PCR) is one such TMJ disorder characterized by a gradually deteriorating mandibular condylar mass, resulting in severe mandibular retrognathia, which often accompanied by clockwise rotation of mandible and an anterior open bite. Since the etiology of the ICR/PCR remains unclear, no definitive prevention or management options have been established. To date, various symptomatic non-surgical, surgical, and salvage management options have been developed and reported. To understand the current status of the ICR/PCR management options, this article provides an overview of the options presently reported in the literature to reduce its TMJ symptoms and improve mandibular function and form.

Controversial Aspects of Diagnostics and Therapy of Idiopathic Condylar Resorption: An Analysis of Evidence- and Consensus-Based Recommendations Based on an Interdisciplinary Guideline Project

Idiopathic condylar resorption (ICR), though a rare event, is associated with severe detrimental sequelae for the patient. To date, the etiology remains unknown, and treatment strategies are highly controversial. Therefore, the aim of this study is to present an analysis of the consensus- and evidence-based approach to ICR by a German interdisciplinary guideline project of the AWMF (Association of the Scientific Medical Societies in Germany). Following a systematic literature search, including 56 (out of an initial 97) publications, with a predominantly low level of evidence (LoE), two independent working groups (oral and maxillofacial surgery and interdisciplinary, respectively) voted on a draft comprising 25 recommendations in a standardized anonymized and blinded Delphi procedure. While the results of the votes were relatively homogeneous, the interdisciplinary phase required a significantly higher number of rounds (p < 0.001). Most of the controversial recommendations were related to initial imaging (with consensus on CT/CBCT as the current diagnostic standard for imaging), pharmacotherapy (no recommendation due to lack of evidence), discopexy (no recommendation possible due to low LoE) and timing of orthognathic surgery (with consensus on two-staged procedures after invasive TMJ surgery, except for single-stage procedures if combined with total joint reconstruction). Overall, the Delphi procedure resulted in an interdisciplinary guideline offering the best possible evidence- and consensus-based expertise to date in the diagnosis and treatment of ICR.

Treatment of severe open bite and mandibular condyle anterior displacement by mini-screws and four second molars extraction: A case report

BACKGROUND

Temporomandibular joint (TMJ) disorders are closely related to high-angle and skeletal Class II malocclusion. Sometimes pathological changes in the mandibular condyle can cause open bite to occur after growth is complete.

CASE SUMMARY

This article is about the treatment of an adult male patient with a severe hyperdivergent skeletal Class II base, an unusual and gradually occurring open bite and an abnormal mandibular condyle anterior displacement. Because the patient refused surgery, four second molars with cavities and root canal therapy were extracted, and four mini-screws were used for intrusion of the posterior teeth. The treatment duration was 22 mo, and after the treatment, the open bite was corrected and the displaced mandibular condyles were seated back to the articular fossa as shown by cone-beam computed tomography (CBCT). Based on the patient’s open bite history, the result of clinical examinations and CBCT comparisons, we believe it is possible that the occlusion interference was eliminated after the four second molars were extracted and the posterior teeth were intruded, and the patient's condyle spontaneously returned to its physiologic position. Finally, a normal overbite was established, and stable occlusion was achieved.

CONCLUSION

This case report suggested that identifying the cause of open bite is essential, and the TMJ factors for hyperdivergent skeletal Class II cases should be particularly examined. For these cases, intruding posterior teeth may place the condyle in a more appropriate position and provide an environment suitable for TMJ recovery.

Can Botulinum Toxin-A Contribute to Reconstructing the Physiological Homeostasis of the Masticatory Complex in Short-Faced Patients during Occlusal Therapy? A Prospective Pilot Study

The physiological homeostasis of the masticatory complex in short-faced patients is too robust to be disintegrated and reconstructed due to the powerful masseter muscle. This study innovatively introduced the botulinum toxin-A (BTX-A) into the field of dental occlusal treatment, providing a novel and minimally invasive therapy perspective for the two major clinical problems in these patients (low treatment efficiency and high rates of complications). In total, 10 adult patients with skeletal low angle seeking occlusal treatment (age: 27.0 ± 6.1 years; 4 males and 6 females) were administered 30−50 U of BTX-A in each masseter muscle and evaluated before and 3 months after injection based on cone-beam computed tomography (CBCT). We found a significant reduction in the thickness of the masseter muscle (MMT) (p < 0.0001). With regards to occlusion, we found a significant increase in the height of the maxillary second molar (U7-PP) (p < 0.05) with significantly flattened occlusal curves (the curve of Spee [COS] (p < 0.01), and the curve of Wilson [COW] (p < 0.05)). Furthermore, the variations in the temporomandibular joint exhibited a significant reduction in the anterior joint space (AJS) (p < 0.05) and superior joint space (SJS) (p < 0.05). In addition, the correlation analysis of the masticatory complex provided the basis for the following multiple regression equation: MMT = 10.08 − 0.11 COW + 2.73 AJS. The findings from our pilot study indicate that BTX-A, as a new adjuvant treatment attempt of occlusal therapy for short-faced patients, can provide a more favorable muscular environment for subsequent occlusal therapy through the adjustment of the biting force and may contribute to the reconstruction of healthier homeostasis of the masticatory complex. However, further research is required to establish the reliability and validity of these findings.

A novel three-dimensional morphological analysis of idiopathic condylar resorption following stabilisation splint treatment

Bone modelling evaluation is important for monitoring idiopathic condylar resorption (ICR) progress. To compare condylar modelling in ICR patients treated with or without stabilisation splints (SSs). Eighty-four condyles from 84 ICR patients were studied: 42 received SS therapy (SS group); 42 received conventional therapy (control group). Cone-beam computed tomography images at diagnosis (T0) and after at least 6 months (T1) were used for three-dimensional reconstruction. Volume differences between T0 and T1 (δV) were used to evaluate the amount of modelling. Percentage of growth area (PCT) was used to assess the condylar surface growth tendency. No significant change in condylar volume was found in the SS group, whereas that in the control group was significantly decreased at T1 (P <.0001). The amount of modelling differed among condylar subregions within the SS group: among 6 subregions (P =.0137), between anterior and posterior regions (P =.0336) and between lateral, intermediate and medial regions (P =.0275). Control group condylar subregions showed no significant differences in the amount of modelling. The anabolic modelling tendency of the total condylar surface in the SS group was greater than that in the control group (P =.0251); however, there were no statistical differences in PCTs among condylar subregions in either group. SS therapy effectively reduced further bone destruction and promoted condylar modelling. Three-dimensional morphological analysis is a novel method that can accurately evaluate the amount of bone modelling and growth tendency in ICR patients.