Recent progress in the treatment of intractable sialolithiasis / 北京大学学报(医学版)

Sialolithiasis occurs in approximately 0.45% to 1.20% of the general population. The typical clinical symptom manifests as a painful swelling of the affected glands after a meal or upon salivary stimulation, which extremely affects the life quality of the patients. With the development of sialendoscopy and lithotripsy, most sialoliths can be successfully removed with preservation of the gland. However, sialoliths in the deep hilar-parenchymal submandibular ducts and impacted parotid stones located in the proximal ducts continue to pose great challenges. Our research center for salivary gland diseases (in Peking University School and Hospital of Stomatology) has used sialendoscopy for 17 years and treated >2 000 patients with salivary gland calculi. The success rate was approximately 92% for submandibular gland calculi and 95% for parotid calculi. A variety of minimally invasive surgical techniques have been applied and developed, which add substantial improvements in the treatment of refractory sialolithiasis. Further, the radiographic positioning criteria and treatment strategy are proposed for these intractable stones. Most of the hilar-parenchymal submandibular stones are successfully removed by a transoral approach, including transoral duct slitting and intraductal basket grasping, while a small portion of superficial stones can be removed by a mini-incision in submandibular area. Impacted stones located in the distal third of parotid gland ducts are removed via "peri-ostium incision", which is applied to avoid a cicatricial stenosis from a direct ostium incision. Impacted parotid stones located in the middle and proximal third of the Stensen's duct are removed via a direct mini-incision or a peri-auricular flap. A direct transcutaneous mini-incision is commonly performed under local anesthesia with an imperceptible scar, and is indicated for most of impacted stones located in the middle third, hilum and intraglandular ducts. By contrast, a peri-auricular flap is performed under general anesthesia with relatively larger operational injury of the gland parenchyma, and should be best reserved for deeper intraglandular stones. Laser lithotripsy has been applied in the treatment of sialolithiasis in the past decade, and holmium ∶YAG laser is reported to have the best therapeutic effects. During the past 3 years, our research group has performed laser lithotripsy for a few cases with intractable salivary stones. From our experiences, withdrawal of the endoscopic tip 0.5-1.0 cm away from the extremity of the laser fiber, consistent saline irrigation, and careful monitoring of gland swelling are of vital importance for avoidance of injuries of the ductal wall and the vulnerable endoscope lens during lithotripsy. Larger calculi require multiple treatment procedures. The risk of ductal stenosis can be alleviated by endoscopic dilation. In summary, appropriate use of various endoscopy-assisted lithotomy helps preserve the gland function in most of the patients with refractory sialolithiasis. Further studies are needed in the following aspects: Transcervical removal of intraglandular submandibular stones, intraductal laser lithotripsy of impacted parotid stones and deep submandibular stones, evaluation of long-term postoperative function of the affected gland, et al.

Studies on newly recognized chronic sialadenitis / 北京大学学报(医学版)

Some kinds of chronic sialadenitis were recognized during the recent years. They have specific pathogenesis, clinical and histopathologic appearances, and require specific treatment. IgG4-related sialadenitis (IgG4-RS) is one of the immune-mediated diseases, characterized by tumefactive lesions. The incidence of IgG4-RS obviously increased during the past 30 years. The study on the potential relationship between occupational exposure to chemical substances and the incidence of IgG4-RS showed that subjects with occupational exposure to agents known to cause IgG4-RD had an increased risk for IgG4-RS. Surgical excision of involved SMG could not control the disease progression, which is not recommended for treatment of IgG4-RS. The combination of glucocorticoid and steroid-sparing agents is effective for treating IgG4-RS, and restores salivary gland function. Radioiodine induced sialadenitis (RAIS) is one of the common complications of postoperative adjuvant treatment of differentiated thyroid cancer by 131I. The incidence of the disease is related to radiation dosage. Clinically, the patients suffered from swelling and tenderness in the buccal or submandibular regions, especially during the mealtime. Imaging appearances are similar to those of chronic obstructive sialadenitis. Conservative managements, such as gland massage, sialagogues, are the mainstream methods in the treatment of RAIS. Sialendoscopy is feasible for RAIS, but not as effective as conventional obstructive sialadenitis (COS). Therefore the prevention of RAIS is crucial. Eosinophilic sialodochitis (ES) is a new type of chronic inflammatory disease of the salivary gland related to allergy. It has characteristics of swelling of multiple major salivary glands, strip-like gelatinous plugs discharged from the duct orifice of the gland, elevated level of serum IgE and eosinophils in peripheral blood, infiltration of eosinophils and IgE positive plasma cells in the tissues, allergic history, increased expression of allergy-related cytokines, such as IL-4, IL-5, IL-13, and eotaxin, which suggest allergic reactions as a potential pathogenesis of the disease. The clinical, laboratory, histological, and immunohistochemical characteristics of ES are significantly different from conventional obstructive sialadenitis (COS). Therefore, it is suitable to separate ES from COS. Conservative managements, such as self-maintenance therapy and anti- allergic modality are the choices of treatment for ES. Based on the results of our comprehensive studies a new classification of chronic sialadenitis is suggested.

Three-dimentional radiographic features of 67 maxillary radicular cysts / 北京大学学报(医学版)

OBJECTIVE@#To analyze the three-dimensional radiographic characteristics of maxillary radi-cular cysts using cone-beam computed tomography (CBCT) and spiral CT.@*METHODS@#Clinical records, histopathological reports, and CBCT or non-enhanced spiral CT images of 67 consecutive patients with maxillary radicular cysts were retrospectively acquired, and radiographic features, including size, shape, expansion, internal structure and relationship with the surrounding tissues, were analyzed. The lesions were divided into three types according to the involved tooth number, as follows: type Ⅰ (single tooth), the epicenter of the cyst was located at the apex of a nonvital tooth, without involvement of the neighbo-ring tooth; type Ⅱ (adjacent tooth involvement), the cyst was located at the apex of a nonvital tooth with involvement of the mesial and/or distal tooth root; and type Ⅲ (multi-teeth), the cyst involved the apexes of ≥4 teeth. Besides, these cysts were classified as another three types on sagittal views, as follows: centripetal, the root apex was oriented centripetally to the center of the cyst; palatal, the cyst was located mainly at the palatal side of the apex; and labial/buccal, the cyst was located mainly at the labial/buccal side of the apex.@*RESULTS@#Totally, 67 patients with maxillary radicular cysts were acquired, including 38 males and 29 females, and their ages ranged from 13 to 77 years. Among them, 46 lesions (68.7%) were located in the anterior maxilla and 65 (97.0%) were round or oval. Labial/buccal cortex expansion was present in 43 cases (64.2%) and palatal cortex expansion in 37 cases (55.2%). The nasal floor was invaded in 27 cases (40.3%), the maxillary sinus was invaginated in 26 cases (38.8%), and root resorption was present in 9 cases (13.4%). The average diameter of lesions was (20.89±8.11) mm mesio-distally and (16.70±5.88) mm bucco-palatally. In spite of the 4 residual cysts, the remaining 63 lesions included 14 type Ⅰ, 26 type Ⅱ and 23 type Ⅲ cysts according to the involved tooth number. Besides, the 63 lesions included 46 centripetal, 15 palatal and 2 buccal cysts on sagittal views.@*CONCLUSION@#The maxillary radicular cysts were frequently well-circumscribed round or oval radiolucency, with significantly different sizes. According to the involved tooth number, it can be divided into single tooth, adjacent tooth involvement and multi-teeth types. On sagittal views, the root-cyst relationship was centripetal in most cases, while a minority of cysts expanded palatally or buccally.

Three-dimensional morphology analysis of the supraosseous gingival profile of periodontally healthy maxillary anterior teeth / 北京大学学报(医学版)

OBJECTIVE@#To measure the three-dimensional morphology of the labial supraosseous gingiva (SOG) and the thickness of related labial bone in maxillary anterior teeth of periodontally healthy Han nationality youth using soft tissue indirect imaging cone-beam computed tomography (CBCT).@*METHODS@#Twenty-five periodontally healthy subjects (11 males and 14 females) with 150 maxillary anterior teeth were involved in this study. A special impression with radiopaque material including the maxillary teeth was made, then a CBCT scan with the elastomeric matrix in position was taken for each subject. The imaging data were generated and transferred to a volumetric imaging software in which three-dimensional reconstruction was conducted and the image analyses were carried out. Measurements were made at the site of labial center of the maxillary anterior teeth. The height of the SOG, the distance between cemento-enamel junction (CEJ) and bone crest, the gingival thickness at the CEJ, and the thickness of bone 2 mm below the labial bone crest were measured and the correlation analysis between the parameters was made. All the data analyses were performed using SPSS 22.0. The data were analyzed with ANVOA and Pearson correlation tests with the significance level at α=0.05.@*RESULTS@#The mean SOG values were (3.49±0.70) mm, (3.48±0.81) mm, and (3.54±0.67) mm for central incisors, lateral incisors and canines, respectively. There were no statistically significant differences among the different sites (P > 0.05). The mean gingival thickness values were (1.45±0.23) mm, (1.13±0.24) mm, (1.14±0.22) mm for central incisors, lateral incisors and canines, respectively. The gingival thickness of the central incisors was the largest among the maxillary anterior teeth with statistically significant difference (P < 0.05). No correlation was found between the SOG and gingival thickness among the maxillary anterior teeth (P > 0.05).@*CONCLUSION@#The gingival thickness of central incisors was the largest and the supraosseous gingival height had no correlation with gingival thickness among the periodontally healthy maxillary anterior teeth.

Inflammation grading and sialoendoscopic treatment of 131I radioiodine-induced sialadenitis / 北京大学学报(医学版)

OBJECTIVE@#To investigate the inflammation grading of 131I radioiodine-induced sialadenitis based upon sialoendoscopic and sialographic appearances, and to evaluate the results of sialoendoscopic intervention.@*METHODS@#The patients diagnosed with 131I radioiodine-induced sialadenitis and underwent sialoendoscopic exploration and intervention procedures in Peking University Hospital of Stomatology from Nov. 2012 to Oct. 2018 were included in this study. The appearances of sialogaphy and sialoendoscopy were analyzed and classified. The treatment options included irrigation with saline and dexamethasone and mechanical dilatation by sialoendoscope. The patients were followed up after treatment.@*RESULTS@#Forty-two patients with 131I radioiodine-induced sialadenitis were included. There were 5 males and 37 females, with a male-to-female ratio of 1 ∶7.4. Symptoms included recurrent swelling and pain in the parotid glands, and dry mouth. Sialography showed stenosis in the main duct,and in some cases nonvisua-lization of the branches. Sialoendoscopy showed narrowing of the main duct, and the branch duct atresia was seen. The appearances of sialogaphy and sialoendoscopy were analyzed and classified into 3 groups: (1) Mild inflammation: stenosis and ectasia occurred in the main duct, whereas the 0.9 mm sialoendoscope could pass through easily. (2) Moderate inflammation: one point of severe stricture could be seen in the main duct where 0.9 mm sialoendoscope could not be passed through. (3) Severe inflammation: two points or more of severe strictures or diffused strictures occurred in the main duct. Thirty-three patients with 65 affected glands were examined by both sialography and sialoendoscopy. Eight glands were classified as mild inflammation, 23 glands moderate inflammation, and 34 glands severe inflammation. The duration of follow-up ranged from 3-72 months. The clinical results were evaluated as good in 22 glands, fair in 22 glands, and poor in 19 glands, with an overall effective rate of 69.8% (44/63).@*CONCLUSION@#The clinical, sialographic and sialoendoscopic appearances of 131I radioiodine-induced sialadenitis showed their characteristics. We proposed an inflammation grading standard for the 131I radioiodine-induced sialadenitis based on the appearances of sialography and sialoendoscopy. Sialoendoscopy can significantly alleviate the clinical symptoms, which is an effective therapy, and better for early lesions.

Endoscopy-assisted sialodochoplasty for the treatment of severe sialoduct stenosis / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effects of endoscopy-assisted sialodochoplasty for the treatment of severe sialoduct stenosis with concurrent megaducts.@*METHODS@#From Jul.2010 to Dec. 2016, 8 patients presenting with severe parotid duct stenosis and 3 patients with occlusion of the Wharton's duct underwent endoscopy-assisted sialodochoplasty.All these patients had concurrent severe ductal ectasiaand manifested a painful swelling of the involved salivary glands.The diameter of ectasia and length of stenosis of the sialoducts were measured preoperatively by sialography, computed tomography, or ultrasonography. The megaducts were opened transorally and sutured to the buccal or oral floor mucosa, therefore creating a neo-ostium. All the patients were followed up periodically after operation. The treatment effects were evaluated by clinical signs, sialogram and sialometry.@*RESULTS@#The length of the Stensen's duct stenosis was 5-12 mm, and the diameter of the concurrent ectasia was 8-16 mm. The length of the Wharton's duct stenosis was 10-20 mm, and the diameter of the concurrent ectasia was 6-8 mm.The neo-ostiums healed uneventfully 2 weeks after operation. The duration of the follow-up varied from 6 to 78 months (median: 24 months). Among the 8 patients with Stensen's duct stenosis, two experienced re-obliteration of the neo-ostium, but the buccal bulge and clinical symptoms disappeared; one reported recurrent clinical symptoms after initial alleviation, which could be controlled with self-massaging; the remaining 5 patients had satisfactory clinical results, i.e., disappearance of the obstruction symptoms and buccal bulge, patent ostium,clean saliva and improvement of the ductal ectasia on sialogram. Three patients with Wharton's duct occlusion were asymptomatic with clear saliva and patent ostium;two exhibited approximately normal appearance and one showed improvement of the sialogram.Sialometry was performed in 9 patients with patent neo-ostium of the involved glands,the resting saliva flow rate of the affected glands showed no differences compared with the normal side, and stimulated flow rate showed a significant increase, though less than the control side.The clinical results included good in 5 patients, fair in 4 patients, and poor in 2 patients, with a total effective rate of 82% (9/11).@*CONCLUSION@#Endoscopy-assisted sialodochoplasty appears to be effective and can be a viable option for patients presenting with severe sialoducts tenosis and concurrent ectasia.

Double Roots of Mandibular Premolar in Full-mouth Periapical Films / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the incidence of two-rooted mandibular premolar morphology using full-mouth periapical film series in a Chinese population, with particular emphasis on bilateral incidence, so as to provide a clinical anatomical basis for root canal treatment in mandibular premolars.</p><p><b>METHODS</b>A total of 2015 patients who underwent dental treatment and had full mouth periapical radiographs at the Peking University School of Stomatology from April 2011 to April 2012 were enrolled in this study. Three experienced dentists reviewed the patients' periapical films and classified the root morphology of mandibular premolars bilaterally. The incidence of unilateral and bilateral double roots were recorded and calculated, including confirmed and suspected bucco-lingual root types.</p><p><b>RESULTS</b>In terms of the morphology of two-rooted mandibular first premolars, of the 2015 cases with complete root formation, two-rooted first premolars were detected in 120 cases, with a total number of 159 teeth. According to the number of teeth, the overall incidence of double roots was 4.03% (159/3972). In terms of the morphology of two-rooted mandibular second premolars, of the 2015 cases with complete root formation, two-rooted second premolars were detected in 24 cases, with a total number of 33 teeth. According to the number of teeth, the overall incidence of double roots was 0.85% (33/3880).</p><p><b>CONCLUSIONS</b>The roots of mandibular premolars display specific morphological patterns. Based on a large sample, we observed and calculated not only the occurrence rate of bucco-lingual and mesio-distal double roots in first and second mandibular premolars, but also the incidence of unilateral or bilateral double roots within the same mandible. These findings could provide useful information on the anatomical structure of mandibular premolars for endodontic, prosthodontic and surgical procedures, and could improve the quality of treatment and reduce complications.</p>

Measurement of sagittal root position and the thickness of the facial and palatal alveolar bone of maxillary anterior teeth / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To classify the relationship of the sagittal root positions of the maxillary anterior teeth to their respective osseous housings, and to measure the thickness of facial and palatal alveolar bone by cone-beam computed tomography (CBCT).</p><p><b>METHODS</b>Twenty-three subjects [9 male, 14 female, mean age: (24.5 ± 1.6) years] who fulfilled the inclusion criteria were involved in this study. The CBCT images were evaluated and the relationship of the sagittal root position of the maxillary anterior teeth to its associated osseous housing was recorded as Kan's Class 1, 2, 3, 4. The facial and palatal alveolar bone thickness at three locations:2 mm apical to crest level, mid-root level and apical level, was measured respectively.</p><p><b>RESULTS</b>Ninety seven point one percent(134/138)of the anterior maxillary teeth were classified as Class 1. Only 2.9% (4/138) were Class 4.Occurrences of > 2 mm thickness of maxillary facial alveolar bone were found 2.2% (6/276 sites) at 2 mm apical to crest level and mid-root level in the sample of maxillary anterior teeth.</p><p><b>CONCLUSIONS</b>The majority of the anterior maxillary teeth roots were positioned close to the labial cortical plate. Most tooth sites in the anterior maxilla had a thin facial bone wall.</p>

Preliminary study on measuring interdental papilla height and thickness of the maxillary anterior teeth based on cone-beam computed tomography / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the features of the fill of interdental spaces by gingival papillae and the associated factors.</p><p><b>METHODS</b>Fifteen volunteers with healthy gingiva were involved in this study. The height and thickness on the alveolar crest level of 62 maxillary anterior papilla were measured radiographically with cone-beam computed tomography (CBCT) scans. A standardized periodontal probe with Williams markings was used for measurements of the papilla width on the alveolar crest level.</p><p><b>RESULTS</b>When the papilla was complete fill interdentally, the mean height of papillary tissue on the alveolar crest level (equal to contact point-bone crest) was (3.67 ± 0.51) mm. The mean thickness of papilla on the alveolar crest level was (8.38 ± 0.75) mm. The papilla height had a positive correlation with papilla thickness (r = 0.433, P < 0.001).</p><p><b>CONCLUSIONS</b>The cone-beam computed tomography can be used for clear visualization of the papilla profile and the measurements of papilla height and thickness. Thicker and wider tissue was associated with an increased likelihood of having a complete papilla fill.</p>

Sialoendoscopically-assisted sialolithectomy for the hilar stones of the Wharton's duct / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the clinical effects of sialoendoscopically-assisted sialolithectomy for the sialolithiasis in the hilum of the submandibular glands.</p><p><b>METHODS</b>Between December 2005 and March 2011, treated 80 cases of radiography-verified sialiolithiasis in the hilum of the submandibular glands, The patients included 42 males and 38 females aged from 13 to 68 years. All these patients underwent sialoendoscopic observation and sialoendoscopically-assisted sialolithectomy and were followed up periodically for 3 - 6 months after operation. The success rate of stone removal, postoperative complications and clinical effects were analysed.</p><p><b>RESULTS</b>The stones were completely removed in 71 cases, and almost completely removed in 5 cases, with a successful rate of 95% (76/80). Among 76 successful cases, 8 were treated by basket entrapment, 59 by intraoral open surgery and 9 by both of these two techniques. Within 3 - 6 months' follow-up, 1 case suffered temporary lingual nerve parenthesis and two suffered ranula formation.</p><p><b>CONCLUSIONS</b>Sialoendoscopically-assisted sialolithectomy is a safe and effective gland-preservation technique for the patients with the hilum of the submandibular glands.</p>

Preliminary study on gingival biotype by periodontal probing / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To establish a convenient, objective and applicable method to assess gingival biotype using periodontal probing.</p><p><b>METHODS</b>A total of 66 maxillary anterior teeth from 14 volunteers (6 males, 8 females) with healthy gingiva, aged from 20 to 30 years, were recruited in this study. The gingival biotypes were evaluated by whether or not the outline of the periodontal probe was clear inside the gingiva. Gingival thickness of the cemento-enamel junction (CEJ) in upper anterior teeth was measured by cone-beam CT (CBCT).</p><p><b>RESULTS</b>The method of periodontal probing-assessed gingival biotype had good consistency and repeatability. The result of probing-assessed gingival biotype was consistent with that obtained by CBCT. The mean thickness of gingiva in thin, compromised and thick gingival biotype was (1.02 ± 0.20), (1.28 ± 0.25) and (1.46 ± 0.25) mm. These differences were significant for all three comparisons (P = 0.001, respectively).</p><p><b>CONCLUSIONS</b>Periodontal probing-assessed gingival biotype is a simple, relatively objective and suitable method for clinical examination.</p>

Radiographic study on joint space changes of patients with anterior disc displacement of temporomandibular disorders / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To compare the temporomandibular joint space and condylar position on transcranial projections between the patients with anterior disc displacement (ADD) and the healthy controls. To investigate the diagnostic value of the condylar position for the ADD patients.</p><p><b>METHODS</b>120 joints of 120 ADD patients and 30 joints of healthy adults, who were taken transcranial projections, were included in this study. The transcranial projections were scanned with precise scanning apparatus and saved as joint photographic group image. The joint spaces were measured with the software of Auto CAD. Two different quantitative methods of joint space measurement, ZHANG Zhen-kang's method and Kamelchuk's method, were used based on the transcranial projections. The ln(P/A) values were calculated (P:width of the posterior joint space; A: width of the anterior joint space). Concentric position of the condyle was defined if ln(P/A) value was between -0.25 and +0.25. If ln(P/A) was larger than +0.25, the condylar position was defined as anteriorly eccentric. Posteriorly eccentric position was indicated when ln(P/A) value was lower than -0.25. The results were compared and software SPSS 12.0 was used for statistical analysis.</p><p><b>RESULTS</b>The results of the two linear measurement methods demonstrated that the superior and posterior joint spaces of the ADD patients were narrower than those of the healthy controls significantly (P < 0.05), while the anterior joint spaces of the ADD patients had no significant differences with those of the controls (P > 0.05). In addition, there were significant differences in ln(P/A) values of joint spaces between the patients with ADD patients and the controls (P < 0.05).</p><p><b>CONCLUSION</b>Posterior position of the condyle could be a sign of existence of ADD, but ADD could not be diagnosed only by the posterior condyle position showed on the transcranial projections because of the variation of the condylar position.</p>

Relationship between the impacted mandibular third molar and the mandibular canal on panoramic radiograph and cone beam computed tomography / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the actual relationship between the impacted mandibular third molars (IMTM) and the mandibular canals on panoramic radiographs and cone beam computed tomography (CBCT).</p><p><b>METHODS</b>A cross-sectional study design was used and panoramic radiographs of 390 patients (645 sides developed IMTM) were included in the present study. The relationship between the IMTM and the mandibular canal on panoramic radiographs was defined in three types: 'untouched', 'touching in point', and 'superimposition or line touching'. The IMTM superimposing and line touching with mandibular canals on panoramic radiographs were examined by CBCT.</p><p><b>RESULTS</b>The relationship types on panoramic radiographs were as follows: 'untouched' type 441 IMTM (68.4%), the type of 'touching in point' 149 IMTM (23.1%) and the type of 'superimposition and line touching' 55 IMTM (8.5%). CBCT showed that 25 (50%) of 50 IMTM of superimposition and line touching type impinged on the mandibular canals.</p><p><b>CONCLUSIONS</b>More than 90% of IMTM which do not have intimate relationship with the mandibular canals can be screened out by panoramic radiographs. The IMTM which belong to the line touching and superposition type on panoramic radiographs should be examined by CBCT.</p>

Endoscopic management of sialolithiasis (a practical experience in 52 cases) / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the value of endoscopy in the diagnosis and treatment of sialolithiasis.</p><p><b>METHODS</b>Diagnostic and interventional sialoendoscopic procedures were performed in 52 patients with sialolithiasis (43 submandibular glands and 9 parotid glands).</p><p><b>RESULTS</b>Of the 34 sialoliths in the anterior and/or posterior part of the Wharton's duct, 24 were removed with basket retrieval; 2 removed with open surgery and basket retrieval, and 8 removed with open surgery under the guidance of endoscopy. Eight sialoliths in the hilum of the Wharton's duct were treated with open surgery. Of the 9 stone cases in the Stensen's duct, 3 was removed with basket retrieval, 3 was removed after opening-up of the ostium, 1 was treated with basket capturing and open surgery. The obstructive symptoms were improved in these cases during 1-24 months' follow-up.</p><p><b>CONCLUSIONS</b>Sialoendoscopy is a minimal invasive and efficacious technique for the diagnosis and treatment of sialolithiasis.</p>

Cone beam computed tomography in the diagnosis of temporomandibular joint osteoarthrosis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical use of cone beam dental CT in the diagnosis of temporomandibular joint osteoarthrosis.</p><p><b>METHODS</b>Forty-eight cases diagnosed as temporomandibular joint osteoarthrosis (OA) and disk displacement with or without reduction accompanied by OA changes were included, and a total of 96 joints received both trans-pharyngeal radiography and cone beam CT (CBCT) examination. The detectable rate for OA radiographic changes was compared between the two examinations.</p><p><b>RESULTS</b>The radiographic appearances of osteoarthrotic condyle included six types: loss of the lamina dura density of condyle surface (type I), destructive and erosive bone changes (type II), flattening of the articular surface (type III), sclerosis (type IV), osteophytes (type V), and false cyst change (type VI). The detectable ratio of CBCT for all types of osteoarthrosis was 65.63%, 37.50%, 27.08%, 31.25%, 28.13%, 1.04%, respectively, and the detectable ratio of trans-pharyngeal radiographs was 52.08%, 19.79%, 32.29%, 23.96%, 12.50%, 2.08% respectively. Intraobserver and interobserver reproducibility for type I and type II was in good agreement with both the trans-pharyngeal radiographs and CBCT, Kappa > 0.60.</p><p><b>CONCLUSIONS</b>CBCT had higher detectable rates for pathological changes of osteoarthrosis, and could show the exact location, size, and the types of pathological changes. CBCT may be used as a measure in evaluating disease severity and progression, and in clinical trials of disease treatment.</p>

A study of trabecular bone structure in the mandibular condyle of healthy young people by cone beam computed tomography / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility of cone beam computed tomography (CBCT) for the evaluation of trabecular bone structure in mandibular condyle and to investigate the distribution of the trabecular bone structure within mandibular condyle.</p><p><b>METHODS</b>Eighty condyles from 40 healthy young volunteers (aged 20-32) were scanned by CBCT. A coronoid image was acquired of each condyle and divided into 8 regions where regions of interest were specified. After CBCT images were binarized, four morphological parameters including bone volume fraction, trabecular thickness, trabecular number and trabecular separation were computed.</p><p><b>RESULTS</b>All parameters were significantly different between the superior zone and middle/inferior zone of the condyle (P < 0.05). Superior zone showed the largest bone volume fraction (52.2%), the highest trabecular number (1.33 mm(-1)), the thinnest trabecular thickness (393.48 microm), and the smallest trabecular separation (361.59 microm). Inferior zone showed the smallest bone volume fraction (49.64%). These results were not significantly different between bilateral sides of the condyles (P > 0.05).</p><p><b>CONCLUSIONS</b>Trabecular bone structure was inhomogeneous within the condyle, but symmetrical between bilateral sides of the condyles. CBCT combined with image processing is a feasible tool in evaluating trabecular bone structure of human mandibular condyle.</p>

A preliminary study of angiographic classification and treatment of central arteriovenous malformations in jaws / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To elaborate on the angiographic classification of central arteriovenous malformations (AVMs) in jaws, and to evaluate the correlation between this classification and treatment options.</p><p><b>METHODS</b>X-ray films and angiograms of 25 cases with AVMs in the jaw were retrospectively reviewed to evaluate the appearance of radiolucency, feeding arteries, nidus of the malformations and draining veins. Based on the findings a classification of angioarchitecture was recommended. Furthermore, the treatment results of these cases were reviewed to assess the correlation between this classification and treatment options.</p><p><b>RESULTS</b>The angiographic pictures of 25 cases with central AVMs could be divided into five types: type I (n = 5) was with merely diffused micro-arteriovenous fistulas (AVFs); type II (n = 8) demonstrated a large venous pouch, all the feeding arteries drained into it; type III (n = 7) had a large venous pouch together with diffused micro-AVFs (I + II); type IV (n = 2) had multiple venous pouches; type V (n = 3) had multiple venous pouches and diffused micro-AVFs (I + IV). The angioarchitecture corresponded well to the radiographic appearance in all except one case. With respect to the treatment, type II, III, IV AVMs gained clinical cure in 100% of cases, whereas type I and type V AVMs obtained clinical cure only in 3 of 5 and 1 of 3 cases respectively.</p><p><b>CONCLUSIONS</b>Central AVMs in jaws exhibited variant patterns of angioarchitecture, which could be divided into five types. Elaboration of this classification was helpful for decision-making on choosing appropriate therapy.</p>