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BMJ Case Reports Feb 2019Unilateral condylar hyperplasia is characterised by slow progressive growth of the different parts of mandible, the aetiology of which is still unclear. It is a... (Review)
Review
Unilateral condylar hyperplasia is characterised by slow progressive growth of the different parts of mandible, the aetiology of which is still unclear. It is a self-limiting condition mostly seen between the age of 11-30 years causing facial asymmetry and its progression ceases after a certain time. In literature until now very few cases have been reported and every case that is being reported adds to its features or the aetiology. Previously, it has been classified into two types that is, hemimandibular hyperplasia and hemimandibular elongation. Here, we report a similar case with a few features distinct from those reported earlier.
Topics: Adult; Facial Asymmetry; Humans; Hyperplasia; Male; Malocclusion; Mandible; Mandibular Condyle; Oral Surgical Procedures; Osteotomy; Treatment Outcome
PubMed: 30737324
DOI: 10.1136/bcr-2018-227569 -
The mandible and its foramen: anatomy, anthropology, embryology and resulting clinical implications.Folia Morphologica Nov 2013The aim of this paper is to summarise the knowledge about the anatomy, embryology and anthropology of the mandible and the mandibular foramen and also to highlight the... (Review)
Review
The aim of this paper is to summarise the knowledge about the anatomy, embryology and anthropology of the mandible and the mandibular foramen and also to highlight the most important clinical implications of the current studies regarding anaesthesia performed in the region of the mandible. An electronic journal search was undertaken to identify all the relevant studies published in English. The search included MEDLINE and EMBASE databases and years from 1950 to 2012. The subject search used a combination of controlled vocabulary and free text based on the search strategy for MEDLINE using key words: 'mandible', 'mandibular', 'foramen', 'anatomy', 'embryology', 'anthropology', and 'mental'. The reference lists of all the relevant studies and existing reviews were screened for additional relevant publications. Basing on relevant manuscripts, this short review about the anatomy, embryology and anthropology of the mandible and the mandibular foramen was written.
Topics: Aging; Anesthesia; Animals; Anthropology; Humans; Mandible
PubMed: 24402748
DOI: 10.5603/fm.2013.0048 -
Journal of Oral Biosciences Mar 2024In the absence of soft tissue, skeletal remains are analyzed to identify the deceased. This assessment involves establishing the biological profile that aids medicolegal... (Review)
Review
BACKGROUND
In the absence of soft tissue, skeletal remains are analyzed to identify the deceased. This assessment involves establishing the biological profile that aids medicolegal investigations and fulfils the right of the dead to be identified. Since the mandible is the strongest bone in the skull and easily identifiable, even when fragmented, this study aimed to systematically review its value in constructing the biological profile in the published literature. We searched PubMed, ScienceDirect, Scopus, and Latin American and Caribbean Health Sciences Literature and collected cross-sectional studies published in English before 2021. A risk of bias assessment was completed based on Joanna Briggs Institute's critical appraisal tools. The data are presented descriptively and were analyzed using Microsoft Office Excel 365.
HIGHLIGHT
Of the 104 eligible articles, 94 examined the sexual dimorphism of the mandible, while 25 attempted to estimate age. Ancestry and stature were the least explored biological characteristics (five and one articles, respectively). A metric analysis was the most common approach (n = 80), followed by morphological analysis and combined morphologic and metric techniques (n = 18 and n = 6, respectively). The results showed no statistically significant correlation between an individual's mandible and stature. Orthopantomogram radiography continues to be the most common radiographic technique for assessing the mandible.
CONCLUSION
The mandible is reliable when used for sex estimation; however, caution should be exercised in relying solely on it for morphological assessments. This review provides guidance on estimating age, sex, and ancestry directly from mandibular specimens or radiographs.
Topics: Humans; Cross-Sectional Studies; Mandible; Radiography; Head; Sex Characteristics
PubMed: 38036053
DOI: 10.1016/j.job.2023.11.006 -
International Journal of Implant... Nov 2023Implant-supported immediately loaded fixed full-arch rehabilitation via All-on-four treatment yields good long-term results for both the maxilla and the mandible....
The All-on-four concept for fixed full-arch rehabilitation of the edentulous maxilla and mandible: a longitudinal study in Japanese patients with 3-17-year follow-up and analysis of risk factors for survival rate.
PURPOSE
Implant-supported immediately loaded fixed full-arch rehabilitation via All-on-four treatment yields good long-term results for both the maxilla and the mandible. However, the risk factors affecting long-term implant survival are unknown, and the long-term prognosis of All-on-four concept procedures in Japanese individuals has not been elucidated. We aimed to determine the cumulative implant survival rate after 3-17-year follow-up and identify the associated risk factors.
METHODS
We analysed 561 cases (307 maxillae, 254 mandibles) with 2364 implants (1324 maxillae, 1040 mandibles) that received All-on-four treatment. We investigated the cumulative implant- and patient-level survival rates and various risk factors for implant failure. Statistical analysis was performed using the log-rank test for differences in Kaplan-Meier curves, univariate analysis using the Chi-square test, and multivariate analysis for risk factors affecting the survival rate.
RESULTS
The cumulative survival rate was 94.4% by patient level and 97.4% by implant level for the maxilla, and 96.7% by patient level and 98.9% by implant for the mandible, with up to 17 years of follow-up. The maxillary survival rate at the implant level was significantly lower (p < 0.05). Furthermore, the maxillary survival rate within 24 months was significantly lower at the implant level (p < 0.01). Multivariate analysis revealed that the maxilla was the most significant risk factor (p < 0.01).
CONCLUSIONS
All-on-four treatment yielded high long-term survival rates in Japanese patients. However, the maxilla showed a significantly lower cumulative survival rate than the mandible, while early failure was significantly higher. Furthermore, the maxilla was a significant risk factor influencing the survival rate.
Topics: Humans; Maxilla; Survival Rate; Longitudinal Studies; East Asian People; Follow-Up Studies; Mandible; Mouth, Edentulous; Risk Factors
PubMed: 37938479
DOI: 10.1186/s40729-023-00511-0 -
Folia Morphologica 2023The lingual surface of the mandible's body is commonly indicated as presenting the submandibular and sublingual fossae, which are separated by the mylohyoid line. The...
The lingual surface of the mandible's body is commonly indicated as presenting the submandibular and sublingual fossae, which are separated by the mylohyoid line. The mylohyoid line attaches to the mylohyoid muscle (MM). Less attention has been paid to the 'mylohyoid boutonnières', which allow the 'sublingual buttons' to pass through the mylohyoid muscle in the submandibular space. The cone-beam computed tomography files of patients were routinely examined for anatomical studies. Two cases were found with unexpected morphologies of the mandible's body - the mylohyoid lines were incomplete anteriorly, and herniated sublingual tissue determined an additional fossa inferior to that line in the premolar region. That fossa was termed the 'accessory submandibular fossa'. It determined on coronal slices a 'sand watch' contour of the mandible's body. With such a peculiar morphology, the mandible is more prone to fracture. Moreover, when inserting endosseous implants, the procedure should be carefully personalised in such rare cases.
Topics: Humans; Sand; Mandible; Cone-Beam Computed Tomography; Neck Muscles
PubMed: 35112336
DOI: 10.5603/FM.a2022.0012 -
Legal Medicine (Tokyo, Japan) Nov 2023The degree of sexual dimorphism expressed by human bones is of primary importance for the development of accurate methods for sex estimation. The objective of the...
The degree of sexual dimorphism expressed by human bones is of primary importance for the development of accurate methods for sex estimation. The objective of the present study was to investigate sex differences in shape and size of the mandible using geometric morphometric methods. The study also aimed to examine the impact of age on the sex classification ability of the size and shape of the mandible. Computed tomography images of 190 Bulgarians (98 males and 92 females) were used in the study. Polygonal surface models of the skulls were generated and used for digitizing 45 landmarks located on the mandible. The raw three-dimensional coordinates of the landmarks were processed via generalized Procrustes superimposition. The sex differences in mandibular size and shape were evaluated for statistical significance. Multivariate regression was applied for correction of the allometric effect. Principal component analysis, discriminant analysis, and canonical variate analysis were also used in the study. Mandibular size differed significantly between males and females and achieved a sex classification accuracy of 87%. The significance of the sex differences in mandibular shape depended on the type of shape variables used in the analysis. The shape variables provided different classification accuracy: 78% using the Procrustes coordinates and 53% using the regression residuals. The male and female mandibles differed significantly in size and shape, including the allometric component. Mandibular size is a more effective sex indicator than shape. Age has an ambiguous effect on the classification accuracy of the size and shape variables of the mandible.
Topics: Animals; Humans; Male; Female; Sex Characteristics; Mandible; Skull; Discriminant Analysis; Principal Component Analysis; Coleoptera
PubMed: 37722156
DOI: 10.1016/j.legalmed.2023.102322 -
PeerJ 2022The modern walrus is characterized by marked sexual dimorphism, related to its polygynous behavior and the aggressive competition between males during the breeding...
The modern walrus is characterized by marked sexual dimorphism, related to its polygynous behavior and the aggressive competition between males during the breeding season. Previous studies treated skeletal sexual dimorphism in walruses either qualitatively or with basic quantitative measurements. The present study combines a detailed qualitative comparison of male and female walrus mandibles with quantitative two-dimensional geometric morphometrics analysis (principal component analysis, Procrustes ANOVA and a linear discriminant analysis). In addition to identifying previously recognized sexually dimorphic features (e.g., convexity of the anterior margin of the mandible in adult males), our study finds new morphological differences between males and females, such as a relative dorsal expansion of the anterior part of the mandible and an accentuated concavity between the dorsal margin and the coronoid process in adult males. Both our qualitative comparisons and quantitative analyses demonstrate that sexual dimorphism as expressed in the mandible of extant walruses is statistically significant and that (variation in) mandibular morphology can be used as tool to attribute sex with a good degree of accuracy to isolated mandibles or skeletons lacking the cranium. Sexual dimorphism in walruses is directly related to their sexual behavior, characterized as aggressive in males and linked to a polygynous reproduction system. Indeed, the difference in size of the tusks between males and females but also the use of these during intraspecific fights, can reasonably account for this great mandibular morphological disparity between adult males and females, but also among different ontogenetic stages. Finally, the results obtained in the present study may serve as a starting point for assessing sexual dimorphism more in-depth and studying inter- and intraspecific variation in the mandibles of fossil walruses by identifying quantified size and shape mandibular features.
Topics: Animals; Male; Female; Walruses; Sex Characteristics; Mandible; Skull; Tooth
PubMed: 36157061
DOI: 10.7717/peerj.13940 -
Indian Journal of Dental Research :... 2005Of the many variants in the mandible, the retromolar foramen is the most important. The incidence of retromolar foramen was studied in a collection of 157 south Indian...
Of the many variants in the mandible, the retromolar foramen is the most important. The incidence of retromolar foramen was studied in a collection of 157 south Indian mandibles available at the department of Anatomy, St. John's Medical College, Bangalore. On each side of the mandible, the area behind the last molar tooth was inspected for the presence of retro molar foramen. Wherever present, their distance from the last molar tooth and their size if they were sufficiently large were measured with a sliding caliper to the nearest millimeter. Retromolar foramen were found to be bilateral in 8 mandibles (5.1%) and unilateral 20 [right: 9 (5.7%); left: 11 (7%)] mandibles. The diameter of the foramina was 2 mm on both sides.
Topics: Cephalometry; Dental Arch; Humans; Mandible; Molar, Third
PubMed: 16375231
DOI: No ID Found -
Anatomical Record (Hoboken, N.J. : 2007) Nov 2022Veterinary dentistry is one of the specialties with the greatest potential to contribute to animal welfare; however, it requires a deep anatomical knowledge of the...
Veterinary dentistry is one of the specialties with the greatest potential to contribute to animal welfare; however, it requires a deep anatomical knowledge of the region to be treated. Therefore, the aim was to describe the macroscopic, morphometric, and tomographic anatomy of the mandible of the collared peccary in order to provide support for a better understanding of local morpho-physiology and to improve clinical procedures and interpretation of imaging exams in live adult specimens. Four mandibles from wild adult Pecari tajacu were used. The mandibles were submitted to CT scanning, and comparative analyses were performed using multiplanar views. Afterward, mandibular morphometry was conducted following the literature. Each hemimandible is composed of body, angle, and ramus. The main bony landmarks are the mandibular foramen, three main lateral mental foramina, two medial mental foramina, condylar and coronoid processes, and mandibular and angular notches. The teeth are bunodont, and the dental formula is I3/C1/PM3/M3. All bony structures were observed both in the prepared mandible and in the tomographic images and their 3D reconstruction. No obvious differences were observed in the morphometric data between males and females, or between right and left hemimandibles. It can be concluded that the mandible of the collared peccary may be anatomically structured to favor its omnivorous feeding habit. CT scan proved to be an excellent tool for evaluating the teeth and mandible, and it also provides reliable 3D bone reconstructions that can be helpful in the structural identification and the planning of oral care in live adult animals.
Topics: Animals; Artiodactyla; Female; Male; Mandible; Tomography, X-Ray Computed
PubMed: 35143707
DOI: 10.1002/ar.24897 -
Journal of Anatomy Oct 1978Adult Polynesian mandibles are predominantly of the rocker form. Polynesian crania have an open cranial base angle, and a rather large upper facial height in the adult....
Adult Polynesian mandibles are predominantly of the rocker form. Polynesian crania have an open cranial base angle, and a rather large upper facial height in the adult. The mandibular growth rotations necessary for normal occlusion to be maintained in the presence of this cranial morphology lead to development of a particularly small gonial angle. There is an increased 'bowing' of the basal component of the bone. Such 'bowing' leads to a sufficiently posterior displacement of the basal component in the gonial region for the development of a distinct angular process (for muscle attachment) to be unnecessary.
Topics: Adult; Cephalometry; Child; Child, Preschool; Female; Humans; Male; Mandible; Maxillofacial Development; Polynesia
PubMed: 721687
DOI: No ID Found