Defects were created in the mandible of a rabbit model whereby the right side was implanted with hydroxyapatite (HA) while the left side was left empty to act as control. Both the implant and control sites were evaluated clinically and histologically at 4,12,20,22 weeks. Decalcified sections were studied under confocal laser scanning microscope. No reactive cells were evident microscopically in all sections. There was bone ingrowth as early as 4 weeks when viewed by the topographic method. Enhancement of osteoconduction was evident by the presence of abundant capillaries, perivascular tissue and osteoprogenitor cells of the host. At 22 weeks, the implanted defect showed mature bone formation filling almost the whole field. This study demonstrated that the dense HA exhibits excellent biocompatibility as noted by the complete absence of reactive cells. It also promotes osteoconduction.
*Bone Substitutes ; *Hydroxyapatites ; Mandible/pathology ; Mandible/*surgery ; *Materials Testing ; Osseointegration/physiology

OBJECTIVEThe purpose of this study is to analyze the incidence and the type of the bifid mandibular canal (BMC) by using cone beam computed tomography (CBCT) images.

METHODSA total of 216 patients (104 female and 112 male) who underwent CBCT were included in this study. The CBCT images were evaluated for the incidence and the type of the BMC.

RESULTSBMC was observed in 39 (18.06%) of 216 patients and 50 (11.57%) of 432 sides, female 18 (17.31 %) and male 21 (18.75%). BMC were classified into four types: type I 17 sides (3.94%), type II 11 sides (2.55%), type III 20 sides (4.63%), and type IV 2 sides (0.46%).

CONCLUSIONBMC is detected at a high rate by using CBCT. When doctors perform surgical procedures in the mandible, they should pay attention to the anatomical variations of BMC of the mandibular canals.

Cone-Beam Computed Tomography ; Female ; Humans ; Incidence ; Male ; Mandible ; pathology

Bicuspid ; Dental Pulp Cavity ; pathology ; Humans ; Mandible ; Root Canal Therapy

Semi-fixed mandibular lingual arch expansion appliance is composed of a mandibular molar band, a keyway and arch expansion spring. The arch expansion spring are used to expand maxillary arch symmetrically or asymmetrically when bolts of the two ends are inset into keyways. Dental arch expansion appliance for 25 patients with mandibular arch stenosis showed that semi-fixed mandibular lingual arch expansion had good effect and could be used to expand mandibular arch.
Dental Arch ; Humans ; Mandible ; pathology ; Orthodontic Appliances ; Palatal Expansion Technique

The mandibular metastatic spread of carcinoma from the thyroid gland is exceedingly rare. Follicular thyroid carcinoma is the second most common type of thyroid carcinoma，accounting for approximately 10% to 15% of all thyroid cancers. The prognosis of FTC is relatively satisfactory. Due to its rich blood transport, it is easy to metastasize hematological, with the main sites of metastasis are bone and lung. However，mandibular metastasis of thyroid follicular carcinoma is rare. We report a case of thyroid follicular carcinoma that metastasized to the ascending ramus of the mandible 21 years after surgery.The operation was successfully completed, and there was no recurrence during postoperative follow-up. Due to the absence of obvious clinical symptoms in the patient, the diagnosis and treatment were challenging. We have provided detailed radiographic and pathological images to facilitate understanding and discussion of the disease.
Humans ; Adenocarcinoma, Follicular/pathology* ; Thyroid Neoplasms/surgery* ; Prognosis ; Mandible

OBJECTIVETo figure out the differences of the morphological characteristics of mandibular symphysis between Class II and Class III adult skeletal malocclusions with different abnormal vertical skeletal patterns.

METHODS109 Chinese female adults of skeletal Class II and Class III were chosen and divided into four groups according to vertical and sagittal skeletal pattern: Class II--vertical-growth-pattern group (n=30), Class III--vertical-growth-pattern group (n=25), Class II--horizontal-growth-pattern group (n=29), Class III--horizontal-growth-pattern (n=25). Lateral cephalograms were taken. The symphyseal widths and heights, along with lower incisor positions were evaluated. Observation and statistics analysis were done to clarify the morphological characteristics of the symphyseal region of different skeletal patterns.

RESULTSThere were morphological differences of symphyseal region between Class II and Class III skeletal malocclusions, but not significant in width and total height. With a vertical-growth-pattern, Class II malocclusions had higher alveolus than Class III, but smaller chin prominence and lower basal bone (P < 0.01). With a horizontal-growth-pattern, Class II malocclusions had higher alveolus (P < 0.05) and larger alveolar top width (P < 0.001). With a same sagittal skeletal pattern, vertical-growth-pattern group had thinner but higher symphyseal region and bigger chin prominence (P < 0.001 in Class II while P < 0.05 in Class III). Besides, a vertical-growth-pattern malocclusion was prone to have a cucurbit-morph chin, of which Id width was larger than basal width (P < 0.01).

CONCLUSIONThere are morphological differences in symphyseal region between Class II and Class III skeletal malocclusions with different abnormal vertical skeletal patterns. The influence of abnormal vertical skeletal pattern to symphyseal morphological characteristics is greater than that of abnormal sagittal skeletal pattern. There is a risk of orthodontic movement of low incisors in vertical-growth-pattern skeletal malocclusion.

Adult ; Female ; Humans ; Malocclusion, Angle Class II ; pathology ; Malocclusion, Angle Class III ; pathology ; Mandible ; pathology

Adult ; Endothelium, Vascular ; pathology ; Female ; Humans ; Hyperplasia ; Mandible ; blood supply ; pathology ; Mouth Mucosa ; blood supply ; pathology

Pus overflow from patent's fistula belew the left face near mandibular angle 2 years agowith a little pain. Symptoms relieved after oral antibiotics. This symptom frequently occurred in the past six months. Postoperative facial paralysis occurred after surgery, and recovered after treatment. It was diagnosed as the postoperative facial paralysis after first branchial fistula surgery.
Branchial Region ; pathology ; surgery ; Face ; Facial Paralysis ; etiology ; Fistula ; pathology ; surgery ; Humans ; Mandible ; Pain

OBJECTIVES: This study investigate the clinical and imaging features of Ewing sarcoma (ES) of the jaw. METHODS: Eight cases of pathologically diagnosed ES of the jaw from January 2010 to June 2022 were included in the study. Clinical and radiological features were retrospectively analyzed. RESULTS: Among the eight cases, the mean age at onset was 29.4 years, and the male to female ratio was 7∶1. The predilecting site was the posterior part of mandible, accounting for 75% of the cases. The lesions often exhibited early numbness of the lower lip and lymphadenopathy. The main radiographic manifestation of mandibular lesions was ill-defined radiolucency, mixed with fibrous or brush-like tumor matrix, and soft tissue mass. The maxillary ES lesions mainly presented as lytic bone destruction accompanied by adjacent soft tissue mass. Periosteal ossification was rarely seen. CONCLUSIONS The clinical and imaging characteristics of ES in the jaw are helpful for its diagnosis.
Male ; Humans ; Female ; Sarcoma, Ewing/pathology* ; Retrospective Studies ; Radiography ; Mandible/pathology* ; Lip ; Bone Neoplasms

INTRODUCTIONThe objective of this study was to investigate whether a reduction of obstructive sleep apnoea (OSA) severity is associated with significant airway and craniofacial changes with mandibular advancement device (MAD) in Chinese subjects.

MATERIALS AND METHODSA total of 14 Chinese subjects (8 males, 6 females) diagnosed with OSA by overnight polysomnography (PSG), were fitted with the MAD. The mean +/- standard deviation baseline apnoea-hypopnoea index (AHI) was 38.4 +/- 17.2 and minimum arterial oxygen saturation (SaO2) was 75.5 +/- 11.1%. The second lateral cephalogram was taken (wearing the MAD) after the second PSG. The second PSG was indicated when symptoms have improved as shown by the Epworth Sleepiness Score and sleep questionnaire after wearing the MAD for 1 month. Comparison of cephalometric variables was done to evaluate the effects of the MAD on the upper airway and anatomical variables. Pre-treatment versus post-treatment variables were compared using Wilcoxon signedrank test to determine the statistical significance at the 5% levels. The changes in airway variables were correlated with the changes in AHI using the Spearman correlation test.

RESULTSAt the second polysomnogram, AHI was significantly reduced to 10.9 +/- 14.7. Minimum SaO2 was significantly increased to 86 +/- 8.4%. Mean airway dimension was significantly increased at the nasopharyngeal area from 22.7 +/- 3.0 mm to 24.8 +/- 2.1 mm. The distance of the hyoid bone to the mandibular plane was significantly reduced with the MAD from a mean of 21.2 +/- 5.7 mm to 13.9 +/- 7.0 mm (P <0.05). This reduction of the distance of the hyoid bone to the mandibular plane was significantly correlated with the reduction in the AHI.

CONCLUSIONAn increase in the nasopharyngeal airway and reduction of the distance of the hyoid bone to the mandibular plane was observed for this sample of Chinese OSA subjects. This study forms the baseline for future studies on the effects of MAD on the airway and craniofacial structures in a larger sample.

Cephalometry ; China ; Facial Bones ; pathology ; Female ; Humans ; Hyoid Bone ; pathology ; Male ; Mandible ; pathology ; Mandibular Advancement ; instrumentation ; Occlusal Splints ; Palate, Soft ; pathology ; Sleep Apnea, Obstructive ; pathology ; therapy ; Tongue ; pathology