Search Results (7)

Background: Condylar hyperplasia (CH) leads to mandibular overgrowth with anatomical, aesthetic, and functional consequences, particularly affecting facial harmony. It is characterized by severe mandibular prognathism (MP) in bilateral cases. This study aims to propose a therapeutic algorithm for diagnosing and treating bilateral condylar hyperplasia (BCH) based on demographic, clinical, craniofacial growth, and clivus ratio uptake conditions. Methods: Ten patients with severe skeletal Class III by MP, whose alteration was clinically associated with BCH, were consecutively evaluated in a specialized dentofacial deformity center between the period of 2019 and 2024. A detailed protocol was followed to gather clinical history, assess anatomical features, evaluate malocclusion, and identify potential BCH. When suspicion arose, a nuclear medicine test measured condylar scintigraphy uptake. If the result was positive, patients underwent bilateral condylectomy, following one of three treatment protocols. Results: Severe PM, pronounced Class III with excessive negative overjet, elongated condyles of normal anatomy, absence of family history, and accelerated growth since preadolescence and adolescence were common characteristics in these patients. Regarding the treatment protocol chosen according to the characteristics of the patients, five cases followed treatment protocol A: condylectomy and surgical correction of the alteration in two surgical stages. Two cases followed protocol B: bilateral condylectomy and orthognathic surgery in the same surgical time, and three cases followed protocol C: condylectomy and later post-surgical orthopedics and/or orthodontics without a second surgical intervention. Histopathological results confirmed bilateral hyperplastic growth and stability in mandibular size, and occlusion was observed during follow-up. Conclusions: Specialists need to recognize the clinical signs of BCH and use scintigraphy tests to measure condylar metabolic activity when suspected. Early detection of BCH is crucial, as it influences treatment decisions and helps prevent relapses in orthodontic or surgical interventions aimed solely at correcting or compensating for Class III malocclusion caused by MP. Full article

The lateral pterygoid muscle (LPM), a critical component of the masticatory muscles, typically comprises upper (SLPM) and lower (ILPM) heads. However, it is essential to note that the LPM’s structure is not a constant feature, as the number of bundles and their topography can vary. Moreover, additional heads, such as medial and middle heads, and unique-headed configurations of the LPM have been reported. Several studies have demonstrated the penniform structure of the LPM, which is further supported by its diverse pattern of innervation. Anatomically, the LPM originates from the greater wing and lateral pterygoid plate of the sphenoid bone, with variations in these origins being common. For instance, the presence of a broad lateral pterygoid plate or extensions from it can enlarge the origin area of the LPM. Equally variable are the insertions of the LPM, which can include attachments to the mandibular condyle and the temporomandibular joint disc. In some cases, aberrant LPM bundles may attach to the mandibular condyle outside the mandibular notch. Rarely encountered muscles like the pterygoideus proprius, pterygospinosus, and pterygofacialis further add to the diversity of this muscle. The anatomy of the LPM is subject to modification due to factors like atrophy or hypertrophy. Therefore, it is imperative to recognize that a one-size-fits-all anatomical pattern for the LPM does not exist. Instead, a personalized therapeutic approach should be based on a case-by-case determination of the LPM’s specific anatomical configuration. This nuanced understanding challenges the simplistic view of the LPM and underscores the need for individualized clinical considerations. Full article

Objective: The aim of this study was to describe the prevalence of anatomical variants in the bifid mandibular condyle (BMC) and report its association with temporomandibular joint (TMJ) pathology. Methods: We searched the Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception up to September 2023. Two authors independently performed the search, study selection, and data extraction, and they also assessed the methodological quality with an assurance tool for anatomical studies (AQUA). Finally, the pooled prevalence was estimated using a random effects model. Results: A total of 50 studies met the eligibility criteria. Twenty studies, with a total of 88,625 subjects, were included in the meta-analysis. The overall prevalence of the bifid mandibular condyle (BMC) variant was 1% (95% CI = 1% to 2%). Conclusions: The correlation between the BMC and TMJ pathologies has a relatively low prevalence in studies that present a considerable number of subjects. From a clinical point of view, a direct association cannot be made between the presence of the BMC and TMJ pathologies or symptoms. Full article

Background: the position of the mandibular lingula (Li) affects the success rate of the inferior alveolar nerve block (IANB) and ramus osteotomies. This study evaluated the position of the Li, to investigate the anatomical relationship between the Li and some anatomical measurements using cone beam computed tomography (CBCT). Methods: 201 hemimandibular CBCTs of 111 patients (43 males and 68 females; 18 to 88 years old) were retrospectively evaluated. The Li location was determined from the lingula tip to: the occlusal plane, the anterior and posterior borders of the mandibular ramus, the lower border of the mandible, the distal surface of the mandibular second molar, and the mandibular notch. We evaluated the correlations between the Li and the anteroposterior diameter of the mandibular ramus; the vertical distance between condyle and mandibular angle; the mesial–distal diameter of the first, second, and third mandibular molar, the intercanine distance, the intermolar distances among the first, second, and third mandibular molars; the distance between the intermolar line of the first molar and midline, and the length of the mandibular body. Results: the vertical distance of the Li from the occlusal plane was 11.22 ± 4.27 mm. Some parameters significantly correlated with the anatomical measurements taken into consideration. Conclusions: the present study provides new information concerning the Li and mandibular anatomy in the Italian population. Moreover, by correlating some anatomic measurements to the Li position, the localization of the Li is made possible, indirectly through the measurement of some distances between anatomical landmarks. Full article

Open reduction and internal fixation (ORIF) is becoming increasingly common in treatment of the condylar process, including mandible head fractures. This approach significantly improves the results in terms of anatomical reduction of bone fragments, and shortens the treatment time, allowing for early functional recovery. The success of ORIF is largely determined by the stability of the osteosynthesis. The stabilization effect depends on the screw type and length of the plate used, in addition to the diameter and length of the screws used. The aim of this study was to determine the largest possible screw length that can be used in ORIF of the mandibular condyle considering the variable bone thickness. A total of 500 condyles were examined using computer tomography (CT)-based 3D models in Caucasians. For all models, three measurements were made in the frontal projection in places typical for the stabilization of osteosynthesis plates in the fractures of the condylar process: the base, the top, and the sigmoid notch. In addition, one measurement of the mandible head was made in the place of the greatest width. The results showed that 8 mm screws should be used in the region of the condylar base as the longest anatomically justified screw, whereas in the area of a sigmoid notch only 1.5–2 mm screws should be used. Measurements in the area of the neck top revealed statistically significant differences in the measurements between the sex of patients, with average differences below 1 mm (p < 0.05). In this area, the maximal length of the screw was found to be 10 mm. In mandibular head fractures, the use of long screws is extremely important due to the desired effect of fragment compression. Statistically significant differences were found in the measurement results between women and men. The maximal screw length for bicortical fixation was found to be 22 mm in men and 20 mm in women. In post-traumatic patients, the ability to obtain a clear measurement is often limited by a deformed anatomy. Taking into account the fact that the fracture stability is influenced by both the plate length and the length of the fixation screws, an assessment of the standard measurement values in a cohort group will improve the quality of the surgical fixations of the fractures. Full article

The accuracy of 3D reconstructions of the craniomaxillofacial region using cone beam computed tomography (CBCT) is important for the morphological evaluation of specific anatomical structures. Moreover, an accurate segmentation process is fundamental for the physical reconstruction of the anatomy (3D printing) when a preliminary simulation of the therapy is required. In this regard, the objective of this study is to evaluate the accuracy of four different types of software for the semiautomatic segmentation of the mandibular jaw compared to manual segmentation, used as a gold standard. Twenty cone beam computed tomography (CBCT) with a manual approach (Mimics) and a semi-automatic approach (Invesalius, ITK-Snap, Dolphin 3D, Slicer 3D) were selected for the segmentation of the mandible in the present study. The accuracy of semi-automatic segmentation was evaluated: (1) by comparing the mandibular volumes obtained with semi-automatic 3D rendering and manual segmentation and (2) by deviation analysis between the two mandibular models. An analysis of variance (ANOVA) was used to evaluate differences in mandibular volumetric recordings and for a deviation analysis among the different software types used. Linear regression was also performed between manual and semi-automatic methods. No significant differences were found in the total volumes among the obtained 3D mandibular models (Mimics = 40.85 cm³, ITK-Snap = 40.81 cm³, Invesalius = 40.04 cm³, Dolphin 3D = 42.03 cm³, Slicer 3D = 40.58 cm³). High correlations were found between the semi-automatic segmentation and manual segmentation approach, with R coefficients ranging from 0,960 to 0,992. According to the deviation analysis, the mandibular models obtained with ITK-Snap showed the highest matching percentage (Tolerance A = 88.44%, Tolerance B = 97.30%), while those obtained with Dolphin 3D showed the lowest matching percentage (Tolerance A = 60.01%, Tolerance B = 87.76%) (p < 0.05). Colour-coded maps showed that the area of greatest mismatch between semi-automatic and manual segmentation was the condylar region and the region proximate to the dental roots. Despite the fact that the semi-automatic segmentation of the mandible showed, in general, high reliability and high correlation with the manual segmentation, caution should be taken when evaluating the morphological and dimensional characteristics of the condyles either on CBCT-derived digital models or physical models (3D printing). Full article

Dislocation of the mandibular condyle is the clinical condition of the condyle head being displaced out of the glenoid fossa but still remaining within the joint capsule. However, the anatomy of the mandibular condyle, glenoid fossa, and zygomatic arch usually prevent the dislocation of intact condyles out of the glenoid fossa whenever the mandible is subjected to high impact. Complete dislocation of the mandibular condyle from the glenoid fossa can be classified into four groups: anterior, posterior, lateral, and superior dislocation. All the groups except anterior dislocation are rare. Superolateral dislocation of the intact mandibular condyle occurs very rarely. We report a case of lateral dislocation of bilateral intact condyles associated with left parasymphysis fracture. The purpose of this report is to review all of the available English literature on this dislocation and discuss the possible causative mechanism and diagnostic features, as well as clinical management. Full article