Origin of the torus mandibularis: An embryological hypothesis

Three-dimensional evaluation of a giant torus in the maxilla and mandible that affected pronunciation: a case report

Introduction and importance

Tori in the maxilla and mandible are often clinically asymptomatic, but can often lead to issues such as obstruction of denture attachment and dysarthria. The authors describe a case involving a substantial torus in the maxilla and mandible that significantly affected speech articulation.

Case presentation

A 72-year-old woman presented with a pronounced torus in the maxilla and mandible. Surgical resection of the lesion resulted in improved tongue movement. Through both pre and postoperative assessments, the authors evaluated pronunciation, generated a three-dimensional (3D) computed tomography (CT)-based image, and quantified the extent of bone removal. A 6-month follow-up demonstrated no recurrence of the condition.

Clinical discussion

Surgical intervention leads to improvements in soft palate sounds. The surgical intervention proved effective in ameliorating speech articulation difficulties, and the application of 3D-CT image construction was valuable.

Conclusion

To summarize, the authors successfully managed and treated a giant torus in the maxilla and mandible, a condition scarcely been reported in the literature. This report is the first to detail the application of 3D analysis for the evaluation a torus.

The ciliary protein C2cd3 is required for mandibular musculoskeletal tissue patterning

The mandible is composed of several musculoskeletal tissues including bone, cartilage, and tendon that require precise patterning to ensure structural and functional integrity. Interestingly, most of these tissues are derived from one multipotent cell population called cranial neural crest cells (CNCCs). How CNCCs are properly instructed to differentiate into various tissue types remains nebulous. To better understand the mechanisms necessary for the patterning of mandibular musculoskeletal tissues we utilized the avian mutant talpid2 (ta2) which presents with several malformations of the facial skeleton including dysplastic tendons, mispatterned musculature, and bilateral ectopic cartilaginous processes extending off Meckel's cartilage. We found an ectopic epithelial BMP signaling domain in the ta2 mandibular prominence (MNP) that correlated with the subsequent expansion of SOX9+ cartilage precursors. These findings were validated with conditional murine models suggesting an evolutionarily conserved mechanism for CNCC-derived musculoskeletal patterning. Collectively, these data support a model in which cilia are required to define epithelial signal centers essential for proper musculoskeletal patterning of CNCC-derived mesenchyme.

Early recurrence of mandibular torus following surgical resection: A case report

INTRODUCTION AND IMPORTANCE

Tori are benign bony outgrowths that occur in different locations along the mandible and maxilla. Their origin is still uncertain; however, various hypotheses have been put forward, including male gender or mechanical overload. Recurrence of a torus after surgical resection is rarely described, and even less rapidly after a procedure.

CASE PRESENTATION

We present here the case of a 52-year-old patient who presented voluminous mandibular tori on the lingual side. The tori recurred very rapidly after the first resection surgery and with the same initial volume. Pathological examinations confirmed the histological type. The identified risk factors were excessive fish consumption, occlusal overload factors, and male gender. The patient then underwent a second surgery associated with a mouth guard in order to treat bruxism. There was no recurrence after one year of follow-up.

CLINICAL DISCUSSION

This case report highlights the fact that there is still a lack of understanding of the risk factors associated with torus. However, several studies have been able to understand certain genetic or dietary mechanisms in the genesis of these exostoses.

CONCLUSION

This case emphasizes the importance of mechanical overload in the recurrence of exostoses, which, coupled with dietary, gender, and ethnic factors, may be responsible for recurrence in this patient. The detection of factors associated with the risk of recurrence is a major challenge.

Fetal Development of Human Oral Epithelial Pearls with Special Reference to Their Stage-Dependent Changes in Distribution

Objective

To access detailed distribution and age-dependent changes of oral epithelial pearls.

Design

Investigation and analysis with human fetal serial sections.

Setting

Institute of Embryology.

Methods

This study examined serial frontal sections of the upper and lower jaws of 19 human fetuses at 12 to 18 weeks and of the lower jaws of four late-stage fetuses.

Results

The upper jaw contained more than 20 midline and more than 60 lateral pearls greater than 20 μm in diameter, whereas the lower jaw contained fewer than 30 pearls of the same size. Midline pearls in the upper jaw were often cylindrical or rugby-ball shaped, whereas all pearls in the lower jaw were small and spherical. Epithelial pearls in the upper jaw started developing along the upper midline until 12 weeks; lateral pearls and additional midline pearls (or strictly, paramedian pearls) developed until 15 weeks. In the lower jaw, however, pearl development started at 18 weeks and was almost always from the dental lamina. Some of the fetuses assessed had an open nasopalatine canal without a duct, but there was no fibrous connection between this canal and pearls. Similarly, the lip frenulum or incisive suture was not connected with these pearls.

Conclusion

The timing and sequence of development suggest that postfusion rupture of the palate by midline pearls was unlikely.

[Physical examination of oral cavity and physiological variations]

Clinical examination from front to rear of oral cavity, mouth closed then open. Inspection and bimanuel exam. Face examination but also cervical lymph nodes, skin and mucous. Early diagnosis of oral cancer. To reduce diagnostic wavering and patient's stress, physiological varants are important to know. In most cases, clinical examination is enough for diagnosis.

Asymmetric bone remodeling in mandibular and maxillary tori

OBJECTIVES

Tori are frequent paucisymptomatic bony outgrowths of the oral cavity in three locations: torus palatinus (TP), mandibularis (TM), and maxillaris (TMax). Their usually described histological characteristics are unspecific: normal cortical bone with more or less trabecular bone. The aim of this study was to describe tori's specific morphological and histomorphometric characteristics.

MATERIALS AND METHODS

Histological characteristics in a series of 18 tori collected after surgical removal were analyzed. Microcomputed tomography provided a 3D analysis. Mineral apposition rate (MAR) was measured after double tetracycline labeling. Osteoid tissue was identified by Goldner's trichrome and osteoclasts by the tartrate resistant acid phosphatase identification in undecalcified sections. Iron and aluminum were detected by histochemical staining methods. Osteoid thickness and MAR were determined at the outer surface of the torus and in the Haversian canals.

RESULTS

Tori appeared made of lamellar Haversian bone in 16/18 cases. Osteoid thickness did not differ between the outer surface and within the canals. An asymmetric bone remodeling was observed in the Haversian canals of 15 tori: osteoid seams were deposited on the side close to the free torus surface, and Howship's lacunae with numerous osteoclasts were observed on the opposite side. A high MAR was found at the surface of the tori and within the canals. There was no iron or aluminum deposit.

CONCLUSIONS

Tori may be characterized by a specific asymmetric bone remodeling which seems to determine their shape.

CLINICAL RELEVANCE

This finding could constitute a specific histological feature allowing to differentiate tori from exostoses. Graphical abstract.

The prevalence of antral exostoses in the maxillary sinuses, evaluated by cone-beam computed tomography

Background/purpose

Exostoses are outgrowths of normal compact and cancellous bone and may occur in different locations of the jaw. Exostoses are a rare anatomic variation in the maxillary sinuses. The purpose of this study was to investigate retrospectively the prevalence of location, size, shape, and symmetry of exostoses in the maxillary sinus, and to assess the relationship between demographic variables (i.e., age and sex) via cone-beam computed tomography images.

Materials and methods

Cone-beam computed tomography images of 1000 patients [521 (52.1%) females and 479 (47.9%) males], aged 10–85 years (mean age, 44 years), were examined. Two investigators examined the exostoses for location (i.e., inferior wall, medial wall, lateral wall, or posterior wall of the maxillary sinuses), size, shape (i.e., broad-based or mushroom-like), and symmetry (i.e., unilateral or bilateral). The age of the patients was categorized into three groups: 10–30 years, 31–50 years, and 51+ years. The data were statistically analyzed by using chi-square test, Fisher's exact test, and the t test.

Results

In total, 52 exostoses from 48 patients (4.8%) were identified. Exostoses were more common in females (n = 28, 58.3%) than in males (n = 20, 41.7%); however, there was no statistically significant difference between the sexes (P > 0.05). The presence of exostoses was very similar for all age groups with no statistically significant differences (P > 0.05).

Conclusion

Most exostoses were unilateral and on the inferior wall of the maxillary sinus. No statistically significant difference existed between the frequency and location of exostoses for sex or age groups (P > 0.05).

A Rare Case of Mandibular Exostoses and its Review

Mandibular exostosis is a type of bony prominence caused due to hyperostosis in the mandibular bone. They are benign, broad-based surface masses on the outer or facial aspect of the jaw bones; slowly enlarge over the years to form the bulky masses. During the period between the 10th to 13th week of intrauterine life, changes in the structure of the Meckel's cartilage and the protrusion of the medial lamina of the mandible onto the cartilage can result in the formation of such exostosis. We discuss here a very rare case of a 49-year-old male, in which the buccal exostoses formed underwent changes in size and shape due to certain factors, resulting in a bony bar formation in the mandibular anterior region.

The Origin of the Variations of the Hyoid Apparatus in Human

Currently, theories based on acquired calcification of the stylohyoid ligament are believed to be a pathogenesis of syndromes associated with the hyoid apparatus (HA) and its variations. We studied the development of the HA from Reichert´s cartilage using serial sections of 25 human embryos and 45 fetuses. We ensured a fact that, at the initial stage, the HA appeared as two independent cartilage segments, that is, the cranial or styloid segment and the caudal or hyoid segment of Reichert's cartilage, those are connected by a mesenchymal structure. However, between 8 and 10 weeks of development, the mesenchymal connection was lost. We hypothesize that this disconnection is likely to be one of the major factors to make a descent of the hyoid bone in evolution. The stylohyoid ligament was not observed. The variations of the HA, should be considered variations of the development of Reicherts cartilage. If these variations are maintained in the adult, are likely to explain a major symptom associated with Eagle's syndrome.