Evaluation of dehiscence and fenestration in adolescent patients affected by unilateral cleft lip and palate: A retrospective cone beam computed tomography study

Objective:To evaluate the presence of dehiscence and fenestration defects around anterior teeth in the cleft region and to compare these findings with the noncleft side in the same patients using cone beam computed tomography (CBCT).Materials and Methods:CBCT scans of 44 patients (26 males, 18 females; mean age, 14.04 ± 3.81 years) with unilateral cleft lip and palate (UCLP) were assessed to define dehiscences and fenestrations of the anterior teeth in both cleft and noncleft sides of the UCLP patients and a control group of noncleft patients (51 patients; 21 males, 30 females; mean age, 14.52 ± 1.16 years). Data were analyzed using Pearson’s χ² and Student’s t-test.Results:The prevalence of dehiscences at the maxillary central incisors, lateral incisors, and canines teeth were 43.2%, 70.6%, and 34.1% on the cleft side and 22.7%, 53.1%, and 27.3% on the noncleft side of UCLP patients, and 13.7%, 7.8%, and 13.7% in controls, respectively (statistically no difference between the sides of cleft patients). The cleft patients had a statistically significantly higher prevalence of dehiscences than did the controls on both the cleft and noncleft sides (P < .05), except for the maxillary central incisors. Fenestrations for these teeth were significantly more common on the cleft side in UCLP patients compared with controls (P < .05), whereas the difference for maxillary lateral incisors was not statistically significant.Conclusions:Patients with UCLP showed a higher prevalence of dehiscence and fenestration defects around the maxillary anterior teeth.     

Evaluation of maxillary central incisors on the noncleft and cleft sides in patients with unilateral cleft lip and palate—Part 2: Relationship between root resorption,horizontal tooth movement,and quantity of grafted autogenous bone

Objective:To evaluate the relationship between external apical root resorption (EARR) of the maxillary central incisors (U1), horizontal orthodontic tooth movement, and quantity of grafted bone in subjects with unilateral cleft lip and palate (UCLP) over an average duration of 8 years.Materials and Methods:Thirty subjects with UCLP were evaluated for EARR of U1 after edgewise treatment (T2). The teeth were classified as having no EARR, moderate EARR (combined into “no/moderate” EARR), or severe EARR. Frontal cephalometric radiographs acquired at eruption of U1 (T0), less than 6 months before secondary alveolar bone grafting (T1), and T2 were evaluated to determine the horizontal inclination (U1-axis angle) and distance of the root apex from the median line (U1-root–VL distance). On the cleft side, the quantities of grafted bone at less than 12 months postsecondary bone grafting and at T2 were evaluated using the alveolar bone graft (ABG) scale.Results:Cleft-adjacent teeth exhibited more severe EARR than did teeth on the noncleft side. The cleft side exhibited greater changes in U1-axis angle and U1-root–VL distance between T0 and T2 than did the noncleft side. On the cleft side, the ABG score at T2 in the severe EARR group was significantly lower than that in the no/moderate EARR group. These measurements were correlated with EARR grade.Conclusions:Cleft-adjacent U1 exhibited more severe EARR than did the U1 on the noncleft side, which might be associated with orthodontic treatment-induced changes in horizontal inclination and root apex movement. On the cleft side, severity of EARR may be correlated with the success of ABG.     

Permanent maxillary central incisor and first molar rotations in the mixed dentition in repaired complete unilateral cleft lip and palate and their relationship with absence of teeth in their vicinity

Objectives:To describe qualitatively and quantitatively the directions and magnitudes of rotations of permanent maxillary central incisors and first molars in the mixed dentition in repaired complete unilateral cleft lip and palate (UCLP) and study their associations with absence of teeth in their vicinity.Materials and Methods:Dental casts and orthodontic records taken prior to orthodontic preparation for alveolar bone grafting of 74 children with repaired UCLP (53 male, 21 female; aged 8.9 ± 1.0 years) were studied. Directions and magnitudes of permanent maxillary central incisor and first molar rotations were recorded. Tooth absence was confirmed from longitudinal radiographic records. Incisor and molar rotations were analyzed in relation to the absence of teeth in their vicinity.Results:Distolabial rotation of the permanent maxillary central incisor was noted in 77.14% on the cleft side, while distopalatal rotation was noted in 82.19% on the noncleft side. Incisor rotation was greater when a permanent tooth was present distal to the cleft side central incisor, in the greater segment. The permanent maxillary first molar showed mesiopalatal rotation, which was greater on the cleft side and when there was absence of one or more teeth in the buccal segment.Conclusions:Presence and absence of teeth were associated with the severity of incisor and molar rotations in UCLP. Crowding of anterior teeth in the greater segment was associated with a greater magnitude of rotation of the cleft side permanent central incisor. Absence of one or more buccal segment teeth was associated with greater magnitude of rotation of the molar.     

Biomechanical evaluation of sagittal maxillary internal distraction osteogenesis in unilateral cleft lip and palate patient and noncleft patients: A three-dimensional finite element analysis

Objective:To compare the pattern and amount of stress and displacement during maxillary sagittal distraction osteogenesis (DO) between a patient with unilateral cleft lip and palate (UCLP) and a noncleft patient.Materials and Methods:Three-dimensional finite element models for both skulls were constructed. Displacements of the surface landmarks and stress distributions in the circummaxillary sutures were analyzed after an anterior displacement of 6 mm was loaded to the elements where the inferior plates of the distractor were assumed to be fixed and were below the Le Fort I osteotomy line.Results:In sagittal plane, more forward movement was found on the noncleft side in the UCLP model (−6.401 mm on cleft side and −6.651 mm on noncleft side for the central incisor region). However, similar amounts of forward movement were seen in the control model. In the vertical plane, a clockwise rotation occurred in the UCLP model, whereas a counterclockwise rotation was seen in the control model. The mathematical UCLP model also showed higher stress values on the sutura nasomaxillaris, frontonasalis, and zygomatiomaxillaris on the cleft side than on the normal side.Conclusions:Not only did the sagittal distraction forces produce advancement forces at the intermaxillary sutures, but more stress was also present on the sutura nasomaxillaris, sutura frontonasalis, and sutura zygomaticomaxillaris on the cleft side than on the noncleft side.     

Cone beam computed tomography evaluation of distance from cementoenamel junction to alveolar crest before and after nonextraction orthodontic treatment

Objective:To evaluate the distance between the cementoenamel junction and the alveolar bone crest before and after orthodontic treatment using cone beam computed tomography (CBCT).Materials and Methods:The sample comprised 30 patients with Angle Class I malocclusion and mild to moderate crowding. The study database comprised dental CBCT scans obtained before and after orthodontic treatment. The distance between the cementoenamel junction to the bone crest of the buccal (n  =  720) and lingual (n  =  720) surfaces was measured in 24 teeth for each patient using a specific software tool (Xoran version 3.1.62). The Wilcoxon test was used for statistical analysis, and the level of significance was set at P < .05.Results:The distance between the cementoenamel junction and the bone crest increased in 822 (57%) of the 1440 surfaces after orthodontic treatment. The buccal surface of the lower central incisors had the greatest frequency of increased distance (75%), and the lingual surface of lateral incisors had the lowest (40%). The distance between the cementoenamel junction and the alveolar bone crest was greater than 2 mm (alveolar bone dehiscence) in 162 (11%) of the 1440 surfaces before orthodontic treatment and in 279 (19%) after treatment.Conclusions:The distance from the cementoenamel junction to the bone crest changed after orthodontic treatment; the distance was greater than 2 mm in 11% of the surfaces before treatment and in 19% after treatment.     

Three-dimensional Evaluation of Mandibular Volume in Patients with Cleft Lip and Palate During the Deciduous Dentition Period

ObjectivesTo examine the relationship between mandibular volume and craniofacial morphology in patients with cleft lip and palate using cone beam computed tomography (CBCT) and to compare these findings with control (noncleft) patients undergoing CBCT for other purposes during the deciduous dentition period.Materials and MethodsEighty-four patients were categorized into the unilateral cleft lip and alveolus (UCLA) group (n = 25; mean age, 4.60 ± 0.40 years), unilateral cleft lip and palate (UCLP) group (n = 23; mean age, 4.52 ± 0.39 years), bilateral cleft lip and palate (BCLP) group (n = 22; mean age, 4.54 ± 0.37 years), and control group without cleft (n = 14; mean age, 5.19 ± 0.52 years). Mandibular volume and craniofacial cephalometric measurements were obtained using CBCT. All measurements were assessed by analysis of covariance (ANCOVA) using Bonferroni post hoc pairwise comparison tests.ResultsANCOVA revealed no statistically significant differences in mandibular volume among the groups. SNA° and ANB° were significantly larger in the UCLA and BCLP groups than in the control group. SN-MP° was smallest in the UCLA group. Co-A in the UCLP group was shorter than in the UCLA and BCLP groups. Go-Gn was shortest in the UCLP and BCLP groups compared with the control group.ConclusionsThree-dimensional evaluation of craniofacial morphology using CBCT can provide valuable information on malocclusion and other dentoskeletal problems among patients with CLP.     

改良唇挡单侧扩弓后牙槽骨高度与厚度变化的CBCT研究

目的 研究改良唇挡单侧扩弓后裂侧牙槽骨高度与厚度的变化.方法 对年龄在12～16岁应用改良唇挡完成单侧扩弓的18名单侧完全性唇腭裂患者扩弓前后的CBCT图像进行重建,测量扩弓后裂侧牙槽骨高度与厚度,对测量结果进行统计学分析.结果 裂侧尖牙、第一、第二前磨牙颊、腭侧牙槽骨的高度均降低,其中尖牙变化量最大(P<0.01),尖牙颊侧骨开裂的患者增多.第一、第二前磨牙颊侧牙槽骨在釉牙骨质界下4mm、6mm处厚度增加,尖牙颊侧在6mm处骨厚度增加(P<0.01),在4mm处骨厚度减少(P<0.05),尖牙、第一、第二前磨牙腭侧牙槽骨厚度减少.结论 唇挡扩弓后,裂侧牙齿颊侧牙槽骨的高度降低,厚度增加.对于裂侧尖牙正畸治疗前后的牙周状况应该引起重视.     

Anterior Maxillary Labial Bone Thickness on Cone Beam Computed Tomography

AimThe objective of this research was to measure the labial bone thickness (LBT) in relation to the 6 anterior maxillary teeth at different levels along the long axis and the distance between cementoenamel junction and bone crest (CEJ-BC) based on cone beam computed tomography (CBCT) scans retrieved from patients of Arab ethnicity and identify any association with patients’ characteristics.Materials and methodsA total of 100 CBCT scans were evaluated by one calibrated examiner. The thickness of the labial bone was measured perpendicular to the long axis of the tooth at 1, 3, and 5 mm from the alveolar crest (LBT-1, LBT-3, and LBT-5, respectively) and CEJ-BC using a medical imaging viewer.ResultsCBCT scans of 58 female patients and 42 male patients with a mean age of 39.7 ± 9.5 years were included. A high variation of CEJ-BC was observed (range, 0.55-3.90 mm). Statistically significant higher CEJ-BC values were associated with men and increased age (>50 years). The overall means of LBT-1 were 0.76 ± 0.26, 0.79 ± 0.26, and 0.83 ± 0.37 mm; LBT-3: 0.92 ± 0.36, 1.05 ± 0.46, and 1.03 ± 0.48 mm; LBT-5: 1.17 ± 0.52, 0.80 ± 0.45, and 0.81 ± 0.40 mm for central incisors, lateral incisors, and canines, respectively. The LBT was <1 mm in 74.2% of all maxillary anterior teeth, with central incisors showing the highest predilection (85% with LBT <1 mm). No significant association between LBT and patient characteristics was observed.ConclusionsThe CEJ-BC distance is greater in men and increases with age, particularly in those aged 50 years and older. The LBT in the 6 maxillary anterior teeth is predominantly thin (<1 mm) and has no correlation to age or sex. An increased LBT was observed at a 3-mm level when compared with LBT-1 and LBT-5. Such variability should be taken into consideration when planning for implant placement.     

单侧完全性唇腭裂患者前牙区牙槽骨开窗、骨开裂的锥形束CT研究

目的 利用锥形束CT（cone-beam CT,CBCT）研究单侧完全性唇腭裂（unilateral cleft lip and palate,UCLP）患者前牙区牙槽骨开窗、骨开裂的发生率。方法 选取2014年6月—2017年9月就诊于中南大学湘雅二医院的UCLP患者42例（男25例,女17例）。匹配性别和年龄,纳入42例骨性Ⅲ类非唇腭裂患者为对照组。利用CBCT评估UCLP组与对照组前牙区骨开窗和骨开裂的发生率,采用SPSS 22.0软件包对数据进行统计学分析。结果 裂隙侧、非裂隙侧及对照组前牙骨开裂发生率分别为50.88%、42.39%和28.77%。UCLP组裂隙侧上颌前牙同名牙骨开裂的发生率均显著高于对照组（P<0.05）,非裂隙侧上颌侧切牙骨开裂的发生率显著高于对照组（P<0.05）,裂隙侧上颌中切牙骨开裂发生率显著高于非裂隙侧（P<0.05）。裂隙侧、非裂隙侧与对照组前牙区骨开裂均好发于唇侧。骨开窗的发生率在裂隙侧、非裂隙侧及对照组间无显著差异（P>0.05）。结论 在UCLP患者中,牙槽骨开窗和骨开裂较常见,临床治疗中应引起重视。     

唇腭裂患者上颌前部牙槽骨厚度及骨开窗、骨开裂的三维评价研究

目的　利用锥形束CT（cone-beam CT,CBCT）评价不同类型唇腭裂患者上颌前部牙槽骨厚度和形态,以及上前牙骨开窗、骨开裂情况。方法　选择016年8月至019年10月间在南京医科大学附属口腔医院就诊拟行口腔正畸治疗的唇腭裂患者85例（男51例,女34例,平均年龄（14.65±4.95）岁）,其中单侧唇裂伴牙槽突裂（unilateral cleft lip and alveolus,UCLA）患者19例,单侧完全性唇腭裂（unilateral complete cleft lip and palate,UCLP）患者5例,双侧完全性唇腭裂（bilateral complete cleft lip and palate,BCLP）患者14例。在正畸治疗开始前均予以拍摄颌面部CBCT,应用Image J软件测量其上前牙唇腭侧牙槽骨厚度（alveolar bone thickness,ABT）,计算骨开窗、骨开裂发生率,并比较不同唇腭裂类型患者上颌前部ABT及上前牙骨开窗、骨开裂发生率的差异。结果　UCLP、UCLA患侧上前牙骨开裂发生率（34.9%、4.9%）显著高于其健侧（10.7%、11.1%）,但骨开窗发生率无统计学差异。UCLP健侧上中切牙（5.9%）、侧切牙（9.7%）骨开裂发生率低于UCLA。UCLA、UCLP、BCLP三组间患侧上前牙骨开裂及骨开窗发生率均无统计学差异。UCLP、UCLA患侧上前牙ABT在多部位小于其健侧。除UCLP/UCLA患侧侧切牙外,UCLA、UCLP、BCLP各类型上前牙唇侧平均ABT均小于腭侧。UCLA、UCLP、BCLP三组间患侧上前牙唇腭侧平均ABT无统计学差异。UCLP患侧上侧切牙、尖牙分别在唇侧和腭侧根颈处ABT大于UCLA。结论　单侧唇腭裂患者患侧上前牙骨开裂发生率高于健侧,ABT则在多部位小于其健侧;而三种类型患者上前牙唇侧ABT均小于其腭侧。单侧唇裂伴牙槽突裂与单侧完全性唇腭裂患者健侧上中切牙、侧切牙骨开裂发生率及患侧侧切牙、尖牙根颈处牙槽骨厚度存在差异;单侧与双侧完全性唇腭裂间上前牙骨开窗、骨开裂发生率及牙槽骨厚度则无差异。     

Can posterior teeth of patients be translated buccally,and does bone form on the buccal surface in response?

Objective:To produce buccal translation and determine whether buccal bone forms on the cortical surfaces.Materials and Methods:Eleven patients requiring maxillary first premolar extractions participated in this prospective, randomized, split-mouth study. Pre- and posttreatment records included models, photographs, and small field of view CBCT images. One randomly chosen maxillary first premolar was moved buccally with 50 g of force applied approximately at the tooth’s center of resistance. The other premolar served as the control. Forces were re-activated every 3 weeks for approximately 9 weeks, after which the teeth were held in place for 3 weeks. Pre- and posttreatment records were analyzed and superimposed to evaluate changes in the dental-alveolar complex.Results:There was significant (P < .05) movement of the experimental premolar with minimal buccal tipping (2.2°). Changes in maximum bone height were bimodal, with 6 patients showing 0.42 mm and 5 patients showing 8.3 mm of vertical bone loss. Buccal bone thickness 3 mm apical to the CEJ decreased 0.63 mm. Direct measurements and CBCT superimpositions showed that buccal bone over the roots grew 0.46 mm and 0.51 mm, respectively.Conclusions:It is possible to produce buccal bodily tooth movement with only limited amounts of tipping. Such movements are capable of producing buccal bone apposition, but there are potential limitations.     

基于CBCT的下颌前牙区颌骨形态学研究

[摘要]目的：利用锥形束CT（codebeamcomputedtomography,CBCT）图像研究测量下颌前牙区的颌骨形态和宽度,为临床种植手术提供治疗依据。方法：选取2011年--2013年间50名成年受试者的CBCT检查结果,利用CBCT图像对下颌前牙区颌骨外形、唇舌侧宽度、近远中距离等进行观察和测量。结果：1．下颌前牙区颌骨形态唇侧均为凹形,最凹点位于下颌骨上中份,舌侧外形多样化,凸形比例最高。2．下颌骨前牙区颌骨唇舌侧宽度在下颌骨中1／2和下颌骨下缘较宽,在牙槽嵴顶和根尖区较窄。3．左右尖牙、侧切牙、中切牙于牙槽嵴顶的近远中距离是4．46～6．94mm,尖牙最长,侧切牙次之,中切牙最小。结论：下颌前牙缺失后,尤其是下颌侧切牙或中切牙个别缺失,如行种植修复近远中距离可能不足,易损伤邻牙;植入种植体等手术时应当注意下前牙区颌骨外形,避免因倒凹导致唇舌侧穿通;CBCT可作为下颌前牙区种植手术术前的常规影像学检查手段。     

牙龈厚度与上前牙唇侧骨板厚度的相关性研究

目的：测量分析上前牙牙龈厚度与唇侧骨板厚度及牙槽嵴顶到釉牙骨质界距离的相关性。方法：对30位青年受试者用间接显影法进行 CBCT 扫描,测量并记录以下数据并进行统计分析：龈缘下2 mm 牙龈厚度,牙槽嵴顶下2、4、6 mm 骨板厚度,牙槽嵴顶到釉牙骨质界的距离。CBCT 测量的准确性用直接测量法进行检测。结果：牙龈厚度与牙槽嵴顶下2、4、6 mm 处骨板厚度相关系数（r）分别为0．493、0．383、0．342（P ＜0．001）,牙龈厚度与牙槽嵴顶至釉牙骨质界距离相关系数（r）为－0．213（P ＜0．01）。CBCT 扫描法测量与直接测量法之间差异无统计学意义（t ＝－0．521,P ＝0．603）结论：上前牙唇侧中央牙龈厚度与对应牙槽骨骨板厚度正相关,与牙槽嵴顶到釉牙骨质界的距离呈负相关。     

露龈笑患者上颌前牙区牙槽骨形态的研究

目的 通过锥形束CT(cone-beam computed tomography,CBCT)扫描测量露龈笑患者上颌前牙区牙槽骨,探讨露龈笑患者的牙槽骨解剖特征,为微种植钉的植入提供参考.方法 选取63例临床表现露龈笑的成年患者,CBCT扫描并三维重建.在距离牙槽嵴顶4 mm、6 mm、8 mm高度的3个层面上分别测量上颌前牙区相邻两牙根间的近远中向、唇腭向骨质厚度及唇侧皮质骨厚度.结果 在相邻两牙之间,近远中向牙根间的距离随测量高度的增加逐渐增加(P<0.05).中切牙与侧切牙间的牙根间距离最小(P<0.05).两中切牙间唇腭向根间骨厚度最薄(P<0.05).中切牙与侧切牙间、侧切牙与尖牙间的根间骨厚度差异无统计学意义(P>0.05).在相邻两牙之间,唇侧根间皮质骨厚度随测量高度增加而增加(P<0.05).两中切牙根间唇侧骨皮质最薄(P<0.05),侧切牙与尖牙间骨皮质厚度最厚(P<0.05).结论 牙根间近远中向骨厚度、唇腭向骨厚度和唇侧皮质骨厚度随高度增加而增加,且在侧切牙与尖牙间最厚.尖牙与侧切牙间的骨质区域可以考虑作为植入微种植钉的部位.     

Efficacy of injectable platelet-rich plasma in reducing alveolar bone resorption following rapid maxillary expansion: A cone-beam computed tomography assessment in a randomized split-mouth controlled trial

Objectives:To evaluate the effectiveness of platelet-rich plasma (PRP) with its growth factors in minimizing the side effects of rapid maxillary expansion (RME) on the periodontal tissue of anchoring teeth using cone-beam computed tomography (CBCT).Materials and Methods:A randomized, split-mouth clinical trial was conducted on 18 patients aged 12–16 years (14 ± 1.65) with a skeletal maxillary constriction who underwent RME using a Hyrax appliance. The sample was randomly divided into two groups: intervention and control sides. PRP was prepared and injected on the buccal aspect of supporting teeth in the intervention group. High-resolution CBCT imaging (H-CBCT) was carried out preoperatively (T0) and after 3 months of retention (T1) to study the buccal bone plate thickness (BBPT) and buccal bone crest level (BBCL) of anchoring teeth. Changes induced by expansion were evaluated using paired sample t-test (P < .05).Results:Results showed that there was no significant difference in BBPT and BBCL between the two groups after RME (P > .05). The prevalence of dehiscence and fenestrations was increased at (T1) in both groups and the percentage was higher in the PRP group.Conclusions:RME induced vertical and horizontal bone loss. PRP did not minimize alveolar defects after RME.     

Cone beam computed tomography evaluations of marginal alveolar bone before and after orthodontic treatment combined with premolar extractions

Using cone beam computed tomography (CBCT) we investigated the distance between the cemento-enamel junction (CEJ) and the marginal bone crest (MBC) at buccal, lingual, mesial, and distal surfaces of incisors to first molars in adolescents before (baseline) and after extractive orthodontic treatment (study end point). Patients with Class I malocclusion, crowding and an overjet of ≤ 5 mm were examined with a CBCT unit using a 60 × 60-mm field of view and a 0.125-mm voxel size. Large differences in marginal bone height were found at baseline, particularly between tooth surfaces. There was a slight correlation between age and CEJ-MBC distance. From baseline to the study end point, large bone-height changes among teeth and tooth surfaces could be seen. Lingual surfaces, followed by buccal surfaces, showed the largest changes. Eighty-four per cent of lingual surfaces of mandibular central incisors exhibited a bone-height decrease of > 2 mm. The bone-height decrease was larger at lingual surfaces in the mandible than in the maxilla, and larger in girls (mean=1.8 mm) than in boys (mean=1.5 mm). Fewer than 1% of proximal surfaces exhibited changes of > 2 mm. It is unknown whether the changes in marginal bone height are transitory. A high-quality CBCT technique may help to determine this by providing a deeper insight into the long-term side effects of orthodontic treatment.     

Reliability of an indirect bone-probing method for diagnosis of labial bone crest level of the mandibular anterior teeth

ObjectivesTo evaluate the null hypothesis that there would be no difference between the labial bone crest level of the mandibular anterior teeth evaluated with an indirect bone-probing method (IBP) and cone-beam computed tomography (CBCT).Materials and MethodsTwenty-nine adult patients with a mean age of 32.15 ± 8.75 years were enrolled. An IBP based on indirect tactile perception was used to determine the labial bone crest level of the mandibular anterior teeth clinically. Bone crest perception degree, gingival thickness, and patient discomfort during IBP were also recorded. CBCT scans were used to evaluate the level and thickness of the labial bone crest. IBP and CBCT methods were compared statistically. The significance level was set at 5%.ResultsThere was a significant difference between the labial bone crest level diagnosed by IBP and CBCT. However, the difference was not clinically significant. IBP and CBCT measurements were significantly and strongly correlated (R = 0.74). Thinner gingival tissue was associated with a higher perception of bone crest. Only two patients reported mild to moderate discomfort during IBP.ConclusionsIBP allowed the labial bone crest level to be determined with acceptable clinical accuracy, especially in patients with thinner gingival tissue.