Unilateral hemimandibular hyperactivity: Clinical features of a population of 128 patients

Single photon emission computed tomography (SPECT) diagnostic accuracy in active unilateral condylar hyperplasia: Retrospective study

The aim of this study was to assess the diagnostic accuracy of single photon emission tomography (SPECT) in unilateral condylar hyperplasia (UCH). To this end, 3D morphometric changes of the mandibles in one year were assessed (T0 vs. T1) and compared over SPECT results in T1, in a sample of 40 patients. A contingency table was constructed based on these results for SPECT diagnostic accuracy evaluation, classifying patients as SPECT true-positive, true-negatives, false positives and false-negatives. Additionally, the morphometric analysis was used to describe the presentation of mandibular changes using principal component analysis (PCA) and non-parametric statistics. We obtained diagnostic accuracy results of sensitivity 81%, specificity 63%, positive predictor value (PPV) 59%, negative predictor value (NPV) 83% and accuracy 70%, showing that SPECT yields poor results regarding accuracy diagnostic performance. The morphometric analysis showed that individuals without progress of asymmetry and those with more progress differ particularly in a group of landmarks representing the mental region and the right mandibular body. Based on these landmarks, difference among the four SPECT-accuracy groups was statistically significant (p < 0.001), where the landmark showing the largest change within a year had a mean increase of 1.13 + 0.66 mm. Within the limitations of the study, it seems that SPECT alone is not suitable for making surgical decisions regarding condylectomy in active UCH. Follow up with morphological assessment methods are recommended for confirming an active UCH in combination with SPECT.

Evaluation and management of temporomandibular disorders. Part 1: an orthopedic physical therapy update on examination and clinical reasoning

Temporomandibular (TM) disorders afflict many people globally and, despite the presence of existing peer-reviewed material that assists conservative orthopedic providers, recent advances in knowledge indicate that updated resources are required for students, clinicians, and educators. This two-part series builds off previously published material to present newer supplementary information that can be useful during the evaluation and management processes. Content in Part 1 of this series includes a discussion about the factors that have been shown to contribute to TM disorders, an updated perspective of relevant pain science, a discussion of self-report outcome measures, and various different topics related to the examination of patients with TM disorders. Part 2 addresses information related to the temporomandibular joint disc, joint hypermobility, oral splints, and clinical reasoning. In combination with other available publications, this two-part series provides clinicians an opportunity to improve their delivery of effective and efficient clinical services for people diagnosed with TM disorders.

Is There a Correlation between Gingival Display and Incisal Inclination in a Gummy Smile? Study on Cephalometric Parameters

BACKGROUND

Excessive gingival display or "gummy smile" is a clinical condition where a maxillary gum shows between the inferior line of the superior lip and the gingival line of the incisive superior during a spontaneous smile. The aim of this research was to understand the various skeletal and dentoalveolar components contributing to a gummy smile in a sample of 120 patients.

MATERIAL AND METHODS

This retrospective case-control study had the primary objectives of analyzing the existence of a correlation between the presence of gingival exposure and the alteration of the inclination of the upper incisors with respect to the Frankfurt plane, the Palatine plane (bi-spinal) and to the NA line in a sample of orthodontic patients, and also evaluating the association with skeletal, dental, and aesthetic cephalometric parameters.

RESULT AND CONCLUSIONS

In our study, it's emerged a correlation between the gingival exposure and the presence of alterations to incisal torque in the vestibular direction and the quantity of maxillary gingiva evident during the smile, which is correlated in particular to the Is-Sts distance, overjet and overbite. The major indicative data, therefore, are related to the vertical position of the upper incisors, in particular with respect to the upper lip and to the sagittal position.

Can electrocautery of the mandibular condyle effectively treat condylar hyperplasia?

This study aims to introduce and evaluate a novel technique to treat unilateral condylar hyperplasia (UCH) by electrocauterization of the mandibular condyle via an intraoral approach. Patients suffering from unilateral condylar hyperplasia (UCH) were included in this study. All patients underwent electrocauterization of the affected condyle. An intraoral incision on the anterior border of the mandibular ramus was made to expose the external surface of the ramus and access the anterior border of the condylar head. A hole was then drilled into the condyle and cauterization was performed; six patients also received orthognathic surgery during the procedure. Patients underwent careful clinical assessment and radiological evaluation including panoramic view, lateral and posteroanterior cephalometry, cone-beam computed tomography (CBCT) and scintigraphy to assess condylar growth for a period of 12-24 months. Ten patients (5 male and 5 female) with active UCH type 1B or 2A were included in this study with a mean age of 20.7 years (range, 18-21.7 years). At the 12-month postoperative assessment, clinical evaluation showed stable dental occlusion with no midline shift; scintigraphy showed persistently reduced cellular activity, and computed tomography scans revealed no degeneration in either of the condyles with complete healing of the drilled holes. Within the limitations of this study it seems that the proposed treatment approach might be an alternative to previously established protocols.

Methods of Definitive Correction of Mandibular Deformity in Hemimandibular Hyperplasia Based on Radiological, Anatomical, and Topographical Measurements-Proposition of Author's Own Protocol

In order to fully evaluate and establish the degree of bone overgrowth, various radiological studies are essential in the careful planning of the amount of surgical excision. In the presented paper, the authors use self-designed anatomo-topographical reference points for planning the surgeries. Routine panoramic radiographs and low-dose computed tomography based on anatomical landmarks help in measuring the proportions of mandibular bone overgrowth with the following preoperative anatomical landmarks: (Go-Go), (Go(Right)-Gn), (Go(Left)-Gn), and (Me−Gn). Measurements taken at selected points and landmarks (gonion-gnathion/gnathion-menton) are easy to conduct. In the authors’ proposal, the main key factor is total chin correction, which is necessary in cases of severe overgrowth; when F0 > C and Go-Gn>, there is >7 mm of vertical bone overgrowth, and the mandibular canal is positioned <5 mm from the inferior mandibular border—MIB. Larger overgrowths (>7 mm) have a greater outcome on the final symmetry than smaller overgrowths. As no guidelines are known, the authors present their own proposal.

What Features on Routine Panoramic Radiographs Could Help Orthodontists to Estimate the Occurrence of Condylar Hyperplasia from Other Mandibular Asymmetries—Retrospective Analysis Study

Hemimandibular hyperplasia (HH) and elongation (HE) are the most common pathologies present in the mandible. Presented condylar hyperplasias have their own radiological and clinical features. In most cases, patients suffer from various forms of malocclusion. From a total of 150 asymmetrical jaw radiographs evaluated, 46 were evaluated and included in this study. A retrospective study on the data of 46 selected patients treated, diagnosed, and consulted from various forms of mandibular and skeletal asymmetry based on routine diagnostic panoramic radiographs evaluated typical and atypical radiological and anatomical symptoms of condylar hyperplasia. The presented evaluation focused on mandibular, maxillary, and other bones, in order to distinguish condylar hyperplasia from other forms of mandibular asymmetry. The degree of maxillary downward growth followed by the occurrence of an open bite on the affected side estimate the degree/presence or cessation of growth in the affected condyle. Mandibular asymmetry with incisor teeth inclination remains the most typical characteristic of condylar hyperplasia. Increased height of mandibular ramus differentiates between condylar hyperplasia and elongation, which also influences the position of the inferior alveolar nerve. Mentioned symptoms, described as the acronym “Go Moira!”, are useful in a quick and simple “glimpse of an eye” differential diagnostic approach. It is possible to quickly and accurately establish the first diagnosis simply by a careful evaluation of patients’ panoramic radiographs.

Reference values of mandibular condylar growth activity: a study of SUVmax with quantitative bone SPECT/CT

OBJECTIVE

To assess the condylar growth activity (CGA) with quantitative bone single photon emission computed tomography/computed tomography (SPECT/CT) to establish reference values of maximum standardized uptake value (SUVmax) and cutoff values for identifying active unilateral condylar hyperplasia (UCH) in different ages.

METHODS

We analyzed the CGA of 58 UCH patients and that of 125 volunteers as a control group by SUVmax of quantitative bone SPECT/CT imaging. The SUVmax and the uptake difference between bilateral condyles among different age groups were analyzed. SUVmax cutoff values for detecting active condyle were calculated by receiver operating characteristic curve analysis.

RESULTS

The condylar SUVmax in 10-19, 20-29, 30-39, 40-49 and 50-59 years old groups of volunteers were 6.24 ± 1.39, 4.76 ± 0.98, 3.23 ± 0.64, 3.00 ± 0.61 and 2.90 ± 0.53, respectively. The uptake difference between bilateral condyles in the control group was 3.84% ± 1.71%. The affected condylar SUVmax was significantly higher than that of the contralateral condyle in active UCH patients (6.03 ± 2.85 vs. 3.96 ± 1.07; Z = -5.264; P = 0.000). SUVmax of the affected condyles in active UCH patients was not statistically higher than condylar SUVmax in the corresponding age group (6.03 ± 2.85 vs. 5.50 ± 1.41; Z = -0.173; P = 0.863). SUVmax of the unaffected condyles was significantly lower than condylar SUVmax in the corresponding age group (3.96 ± 1.07 vs. 5.50 ± 1.41; Z = -5.833; P = 0.000). SUVmax cutoff values for identifying active condyle were 6.26 and 4.53 in patients of 13-19 and 20-29 years old, respectively.

CONCLUSIONS

The condylar SUVmax varied with age. Different cutoff values of condylar SUVmax should be employed for diagnosing active UCH for patients in different ages.

The need for secondary orthognathic surgery after high condylectomy in patients with active unilateral condylar hyperplasia

The need for secondary orthognathic surgery (OS) after a high condylectomy (HC) in patients with active unilateral condylar hyperplasia was assessed in 25 patients, reviewing patient characteristics and treatment planning. At 6-12 months after HC, 13 patients (52%) required secondary OS. The amount of mandibular dental midline shift before the HC (P=0.037), and a dental crossbite that was present before the HC (P=0.017) were significantly associated with the need for secondary OS. Overall, the mandibular dental midline coincided with the facial midline in eight patients (32%) at 2 weeks after HC. In 16% of the patients, no additional OS was needed despite this being the initial treatment plan. Additionally, the initially planned type of secondary OS was modified in six other patients. Early HC in skeletally immature patients provided very good results, both aesthetic and functional, with only two of them needing supplementary OS at 6-12 months after HC. The HC remains a valuable treatment in patients with active unilateral condylar hyperplasia, as it can eliminate the need for secondary OS and is very well tolerated by most patients.

Assessment of maxillary canting on cone beam computed tomography and digital models: A retrospective study and proposal of a method

OBJECTIVES

The mounting of the plaster casts on articulator procedure is routinely performed in orthognathic surgery to assess canting of the maxillary occlusal plane, but the currently used protocols and reference plane could be source of errors which affect reliability. Nowadays the assessment of canting of the maxillary occlusal plane could be also performed with an entirely digital protocol. Aim of the study was to propose a method to evaluate canting in patients affected by Unilateral Condylar Hyperplasia, comparing the measurements performed on digital models matched on CBCT with those made on traditional articulator.

MATERIALS AND METHODS

A retrospective cross-sectional study was designed on 20 patients affected by vertical Unilateral Condylar Hyperplasia treated in the Units of Orthodontics and Maxillo-Facial Surgery. The canting of the maxillary occlusal plane was measured on plaster casts mounted on the conventional articulator and the measures were compared with those made on digital models matched on CBCT, according the protocol developed in our Unit. Molar, canine and basal difference were measured. To compare the two protocols and to test the agreement, we performed descriptive statistics, comparison between means and Bland Altman analysis. P value was set at 0.05.

RESULTS

Statistic comparison demonstrated agreement between measurements performed with the digital protocol and conventional physical method.

CONCLUSION

Measurements of canting with digital protocol are comparable to the physical standard method. A total digital protocol allows faster availability and storage of patient's data and better communication between orthodontist and maxillo-facial surgeon, especially in patients affected by three-dimensional malocclusions.

Are There Mandibular Morphological Differences in the Various Facial Asymmetry Etiologies? A Tomographic Three-Dimensional Reconstruction Study

PURPOSE

Facial asymmetries (FAs) have been classified according to the mandibular morphological differences to obtain better diagnostic and treatment decisions. The purpose of the present study was to establish diagnostic differentiation among FAs using computed tomography (CT) and 3-dimensional (3D) reconstruction.

MATERIALS AND METHODS

We performed a cross-sectional study of patients with a diagnosis of FA, who had been evaluated by CT and 3D reconstruction in the same clinical center from 2015 to 2018. The following mandibular anatomic characteristics were compared between the 2 sides (deviated side vs contralateral side) and type of FA: condylar length, mandibular ramus length and width, mandibular body length, and symphysis deviation.

RESULTS

The 53 patients included 23 men and 30 women (age range, 16 to 25 years). Six categories of FA were identified: hemimandibular elongation (n = 25), hemimandibular hyperplasia (n = 2), hybrid hyperplasia (n = 3), asymmetric mandibular prognathism (n = 14), asymmetry of the glenoid fossa (n = 2), and functional laterognathism (n = 7). The condylar length and mandibular ramus width were greater in the displaced side than in the contralateral side, with differences of -2.0 ± 2.8 mm (P < .001) and -0.5 ± 1.7 mm (P = .009), respectively. The mandibular body length was greater on the contralateral side (mean difference, 2.1 ± 3.5 mm; P < .001). The symphysis deviation was 5.0 ± 3.4 mm, and those with a hybrid form presented with a greater deviation, with values greater than 10 mm, followed by those with hemimandibular elongation.

CONCLUSIONS

The evaluation of the CT images and 3D reconstructions in patients with FA provided detailed information of the mandibular structure that is useful to compare the differences between sides and to classify the entities associated with FA.