Early correction of childhood malocclusion is timely managing morphological, structural, and functional abnormalities at different dentomaxillofacial developmental stages. The selection of appropriate imaging examination and comprehensive radiological diagnosis and analysis play an important role in early correction of childhood malocclusion. This expert consensus is a collaborative effort by multidisciplinary experts in dentistry across the nation based on the current clinical evidence, aiming to provide general guidance on appropriate imaging examination selection, comprehensive and accurate imaging assessment for early orthodontic treatment patients.
Humans ; Malocclusion/diagnostic imaging* ; Child ; Consensus

Objective: To investigate the indications and long-term outcomes of endoscopy-assisted removal of parotid gland calculi via a transoral approach. Methods: From August 2005 to December 2016, 158 consecutive patients with parotid gland calculi underwent endoscopy-assisted lithectomy transorally. They included 71 males and 87 females, with an age of 5-84 years. The immediate safety and effectiveness were evaluated. After surgery, the patients were followed up, and gland function was analyzed on the basis of clinical manifestations, sialography, scintigraphy and sialometry. Postoperative sialograms were categorized into 2 types: ①type Ⅰ, the main duct was normal or had ectasia and stenosis, but no persistent contrast was seen on the functional film; ②type Ⅱ, the main duct had ectasia or stenosis, with persistent contrast media on the functional film. Results: Under one endoscopic procedure, the stones (or foreign bodies) were completely removed in 134 cases and almost completely removed in 10 cases, with a success rate of 91.1% (144/158). Of the 144 successful cases, the treatment options included direct basket retrieval or forceps grasping in 77 cases, basket entrapment with direct ostium incision in 36, basket capture with perio-ostium incision in 23 and perio-ostium incision in 8 cases with impacted stones. In two of the initial 14 failure cases, the stones were discharged spontaneously 3 months after operation. During 3-120 months′ follow-up (mean 36 months) of the 146 patients, one had recurrent stone, two developed ductal obturation, 16 had mild symptoms, and the remaining 127 cases were asymptomatic. Of the postoperative sialograms in 34 stone-free patients 25 were type Ⅰ, 9 were type Ⅱ. Both scintigraphy and saliva flow rate indicated an improvement of the affected gland function in some degree (P<0.05). Conclusions Transoral endoscopy-assisted removal of parotid gland calculi is a safe and effective technique. It is mainly indicated for mobile stones in the main duct or impacted stones in the anterior third of the Stensen′s duct. Sialography, scintigraphy and sialometry show postoperative improvement of gland function in most of the cases.

With the rapid development of imaging technology, the application of dental imaging in diagnosis, treatment planning, intraoperative surgical navigation, monitoring of treatment or lesion development and assessment of treatment outcomes is playing an essential role in oral healthcare. The increased total number of dental X-ray examinations is accompanied by a relatively significant increase in collective dose to patients as well as to dental healthcare workers, which is harmful to human bodies to a certain degree. Some radiation protection standards and guidelines in dental radiology have been published in European countries, US, Canada and Australia, etc. Adherence to these standards and guidelines helps to achieve images with diagnostic quality and avoid unnecessary and repeated exposures. However, no radiation protection standard or guideline with regard to dental X-ray examinations has been put in force so far in mainland China. Therefore, a literature review on available radiation protection standards and guidelines was conducted to provide reference to the development of radiation protection standards or guidelines in mainland China.

Objective To investigate the clinical effects of endoscopy-assisted sialolithectomy for the calculus in the Stensen's duct.Methods From August 2005 to July 2013,67 consecutive patients with calculus (or foreign bodies) in the Stensen's duct underwent explorative and interventional endoscopy in our hospital.The stones (or foreign bodies) were removed by endoscopy-assisted technique.After operation,the patients were followed-up periodically,and treatment effects were analyzed.Results Among the 67 patients,the stones (or foreign bodies) were completely removed in 58 cases,and almost completely removed in 3 cases,with a success rate of 87％ (58/67).Among the 61 stone-removed cases,treatment options included direct removal with aid of basket or forceps(24 cases),basket entrapment and opening-up of the ostium (21 cases),basket entrapment and mucosal incision near the ostium (8 cases),open removal via buccal incision (2 cases) and open removal via pre-auricular flap (6 cases).During the 6-90 months' follow-up of the 61 cases,48 cases were asymptomatic,7 had mild symptoms,3 developed ductal obturation,1 had numbness in the parotid region,and the remaining 2 were missed.Conclusions Endoscopy-assisted sialolithectomy is a safe and effective gland-preservation technique for the patients with parotid gland calculus.

OBJECTIVETo investigate the effects in vitro of 17 beta-estradiol (E2) on the proliferation and metabolism of rabbit mandibular condylar cartilage cells.

METHODSChondrocytes were derived from neonatal rabbit mandibular condylar cartilage using a modified enzyme method. 17 beta-estradiol was added to the culture medium in a variety of concentrations. Cell growth and DNA, collagen, and proteoglycan synthesis were used as indicators of proliferation and differentiation of condylar chondrocytes. These were measured by cell number, 3H-proline and 35S-incorporation, respectively.

RESULTSE2 increased cell number and 3H-thymidine incorporation at 10(-8) to 10(-10) mol/L, and 10(-8) to 10(-11) mol/L in a dose-dependent manner, peaking at 10(-8) mol/L and 10(-9) mol/L, respectively. However, further increase in the concentration of estradiol caused inhibition of both cell number and 3H-thymidine incorporation, and this was significant at 10(-6) mol/L. The effect of E2 on proteoglycan synthesis was similar; the maximum stimulating effect was at 10(-8) mol/L, and inhibition was significant at 10(-6) mol/L. There was no obvious stimulatory effect of E2 on 3H-thymidine incorporation observed.

CONCLUSIONSEstradiol affects condylar chondrocyte cell growth, DNA, and proteoglycan synthesis in a biphasic manner depending on its concentration. This indicates that estrogen may be important in the proliferation and differentiation of mandibular condylar chondrocytes, and could be relevant to some aspects of certain temporomandibular joint diseases by modulating the function of the chondrocytes.

Animals ; Cartilage, Articular ; cytology ; metabolism ; Cell Differentiation ; Cell Division ; drug effects ; Cells, Cultured ; Estradiol ; pharmacology ; Mandibular Condyle ; cytology ; metabolism ; Rabbits