Bone-anchored maxillary protraction in patients with unilateral cleft lip and palate:: Is maxillary expansion mandatory?

ObjectivesTo assess the effectiveness of bone-anchored maxillary protraction (BAMP) in patients with unilateral cleft lip and palate (UCLP) and whether it was enhanced when preceded by maxillary expansion.Materials and MethodsThe sample consisted of 28 growing children (9–13 years old) with UCLP and Class III malocclusion. They were divided into two equal groups. In group I, patients were treated with BAMP not preceded by maxillary expansion. In group II, patients were treated with BAMP preceded by maxillary expansion. To assess treatment changes in three dimensions, Cone-beam computed tomography images were taken 1 week after surgical placement of the miniplates (T1) and after 9 months of treatment (T2).ResultsBAMP produced forward movement of the maxilla in both groups (3.17 mm) and (3.37 mm) respectively, without significant differences between the two groups except for clockwise rotation of the palatal plane in group I (1.6⁰).ConclusionsBAMP is an effective treatment modality for correcting midface deficiency in patients with UCLP whether or not maxillary expansion was carried out.     

Localizing ectopic maxillary canines--horizontal or vertical parallax?

This study compared the use of horizontal parallax (HP) and vertical parallax (VP) radiography for localizing ectopic maxillary canines (EMCs). The true positions of 43 EMCs were determined using the operative notes and subsequent study models following exposure and eruption. Thirty-four palatal and nine buccal EMCs were included in the study. Six experienced orthodontists examined the radiographs of the EMCs and were asked to localize each EMC using VP and HP on separate occasions. The examiners recorded a diagnosis of 'unsure' in 12 per cent of cases using VP and in 5 per cent of cases using HP. The level of agreement of the diagnoses with the true position of the EMCs was significantly greater for HP. Eighty-three per cent of EMCs were correctly located with HP while only 68 per cent were correctly located with VP (P < 0.05). The diagnostic sensitivity for palatally placed canines was significantly greater for HP (88 per cent) than for VP (69 per cent). Both techniques performed poorly when used to localize buccal EMCs, with HP and VP each having a sensitivity of only 63 per cent. It is concluded that HP is superior to VP in diagnostic accuracy, and that two peri-apical radiographs or one peri-apical and one anterior occlusal radiograph are the radiographs of choice for localizing EMCs.     

Does maxillary superior repositioning affect nasal airway function?

This study aimed to assess nasal airflow, nasal resistance, and the cross-sectional area of the nasal cavity in patients who have had maxillary superior repositioning (MSR). This is a cross-sectional study, and nasal airflow, nasal resistance, and the cross-sectional area of the nasal cavity were evaluated by rhinometry and acoustic rhinometry techniques in patients who had had MSR. Thirty-two patients were studied, and the mean (SD) MSR was 5.03 (1.61) (range 3-8) mm. There was a significant correlation between the mean MSR and the mean change in nasal airflow and nasal resistance (p = 0.001 and p = 0.005, respectively). There was also a correlation between MSR and the change in the cross-sectional area of the inferior concha (p = 0.001), but there was no correlation between the mean MSR and the change in cross-sectional area of the isthmus (p = 0.07). Nasal airflow increases when the mean MSR is less than 6.5 mm, and when maxillary impaction is 6.5 mm or more, nasal airflow decreases. It seems, therefore, that MSR of less than 6.5 mm was associated with an improvement in nasal airflow. When maxillary impaction was more than 6.5 mm, nasal airflow and the cross-sectional area of the nasal cavity decreased, and nasal resistance increased.     

Can maxillary incisor trauma be predicted from cephalometric measurements?

Dental injury is a traumatic event related to many factors, including dentofacial morphology. In a previous study in which we used a logistic regression model, 5 cephalometric variables were defined as being the best predictors of traumatic injury. The purposes of this study were to test the predictive value of the logistic regression analysis results for the occurrence of dental injury in a new patient sample and to compare these results with the outcome based on a visual evaluation of cephalograms. The study population consisted of 2 groups of orthodontic patients: patients with injured incisors (n = 64) and patients with non-injured incisors (n = 90). Cephalometric skeletal, dental, and soft tissue measurements were made. In addition, 6 professional judges visually evaluated all cephalograms. Classification tables were constructed for the results of the logistic regression model and for the assignment of patients according to the visual evaluation of the cephalograms. The percentage of correctly classified patients at the.7 probability level was 62%. Surprisingly, the professional panel rendered an equal predictive value. The relatively inferior performance of both the mathematical model and the "eyeballing" may demonstrate that dentofacial morphology is only partially responsible for susceptibility to trauma.     

Characterization of maxillary central incisor: novel crown–root relationships

Objectives

The periodontal biotype includes crown features of the maxillary central incisor (MCI), whereas root measures have been less studied. The aim of our study was to morphologically characterize MCI and search relationships between crown and root measures.

Material and methods

One hundred-fifty MCIs were used. On each tooth, several crown and root reference points were marked and the following measures were done: On crown: mesio-distal (MD?=?major, md?=?minor), axial (crown length, cervical convexity) and buccolingual diameters (Cbl); On root: mesio-distal (Rmd) and buccolingual diameters (Rbl); and tooth length. A ratio between md and MD was made in order to assess dental forms. Root diameter prediction was assessed by means of multiple and single linear regression analyses, with variable selection by backward method. Reliability of measurements was estimated by the Pearson correlation coefficient.

Results

Dental form groups were: Stout type 56.67 %, Intermediate type 22.67 %, and Strangled type 20.67 %. A significative association was found between Rbl and Cbl (p?=?0,000), Rmd with md (p?=?0.000), and Rmd with MD (p?=?0.000). The results allow predicting root diameters through crown measures.

Conclusions

There is a direct relationship between crown and root features, which allows the prediction of root diameters with a high accuracy (95 %), regardless of tooth form.

Clinical relevance

The morphometric data assess tooth diameters more accurately and could improve treatment planning, offering a more comprehensive approach to the periodontal biotype concept.     

Leukoplakia of the maxillary vestibule—an association with Viadent?

Objective. This report investigates a possible correlation between chronic use of Viadent products and the subsequent development of leukoplakia in the maxillary vestibule. Study Design. A retrospective review of 88 patients with leukoplakia of the maxillary vestibule is presented. Prevalence of Viadent use was determined in this group and in a group of 100 randomly selected adults who presented themselves for routine preadmission screening at a dental school. Results. Of the patients diagnosed with leukoplakia of the maxillary vestibule, 84.1% reported having used Viadent, whereas the prevalence of use was only 3% in the 100 randomly selected adults. Conclusions. Use of Viadent products appears to be associated with an increased prevalence of leukoplakia in the maxillary vestibule.(Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;87:61-6)     

Does absence of maxillary lateral incisor affect the status of maxillary canine before and after secondary alveolar bone grafting in patients with unilateral alveolar cleft?

ObjectivesTo investigate whether absence of maxillary lateral incisor (MXLI) would affect the status of maxillary canine (MXC) before and after secondary alveolar bone grafting (SABG) in patients with unilateral cleft lip and alveolus (UCLA) and unilateral cleft lip and palate (UCLP).Materials and Methods47 male patients with UCLA and UCLP, whose Bergland indices were type I or II after SABG, were divided into the MXLI-absence (n = 26) and MXLI-presence groups (n = 21). Using panoramic radiographs, the position, angulation, and development status of MXC on the cleft side, and the cleft width before SABG (T1) were evaluated. After full eruption of the permanent dentition (T2), the root length, root shape, and frequency of forced eruption of MXC on the cleft side were investigated. Then, statistical analysis was performed.ResultsCompared to the MXLI-presence group, the MXLI-absence group showed higher frequencies of mesial angulation of MXC at T1 (criteria: >25°; 46.2% vs 14.3%, P < .05) and dilaceration of MXC at T2 (26.9% vs 4.8%, P < .001). MXC on the cleft side showed positive correlations between horizontal position at T1 and forced eruption at T2, and between vertical position and mesial angulation at T1 and dilaceration at T2 (all P < .01).ConclusionsIn patients with UCLA and UCLP whose SABG outcome was successful, absence of MXLI on the cleft side increased only the frequencies of mesial angulation of MXC at T1 and dilaceration of MXC at T2, not frequency of forced eruption at T2.     

Use of self-setting α-tricalcium phosphate for maxillary sinus augmentation in rabbit

Purpose: The purpose of this study was to histologically and immuno‐histochemically evaluate tissue changes in the maxillary sinus after bone screw implantation and maxillary sinus augmentation using self‐setting α‐tricalcium phosphate (α‐TCP; BIOPEX^®‐R) in rabbit. Study design: Adult male Japanese white rabbits (n=15, 12–16 weeks, 2.5–3 kg) were used. The sinus lift was made from the nasal bone of a rabbit. Bone screws (Dual top auto‐screw^®) were implanted into the nasal bone, and after BIOPEX^®‐R was implanted into the left elevated space (operated side) an atelocollagen sponge (ACS: Teruplug^®) was implanted into the right elevated space (control side). The rabbits were sacrificed at 4, 12 and 24 weeks postoperatively, and formalin‐fixed specimens were embedded in acrylic resin. The specimens were stained with hematoxylin and eosin. For immune‐histochemical analysis, the specimens were treated with bone morphogenetic protein‐2 (BMP‐2) antibodies. Finally, these were evaluated microscopically. Results: Tight bonding without fibrous tissue continued between the bone screw and BIOPEX^®‐R, and the rigidity of the bone screw in the nasal bone was retained for 24 weeks in all cases. The area ofnew bone formation increased gradually on both sides; however, there was no significant difference between both sides at 4, 12 and 24 weeks. The number of BMP‐2‐stained cells on the experimental side was significantly larger than that on the control side after 4 weeks (P=0.0361). Conclusion: This study suggested the usefulness of self‐setting α‐TCP (BIOPEX^®‐R) to maintain the rigidity of implanted bone screws from an early period, and the result of BMP‐2 expression suggested that BIOPEX^®‐R could have bone‐conductive activity in the maxillary sinus augmentation. To cite this article:
Marukawa K, Ueki K, Okabe K, Nakagawa K, Yamamoto E. Use of self‐setting α‐tricalcium phosphate for maxillary sinus augmentation in rabbit
Clin. Oral Impl. Res. 22 , 2011; 606–612
doi: 10.1111/j.1600‐0501.2010.02023.x     

Does rapid maxillary expansion affect the eruption of upper third molars?

OBJECTIVE: To test the hypothesis that there is no difference in the movement of the upper third molars between rapid maxillary expansion (RME) and non-RME patients. MATERIALS AND METHODS: This study was performed on 30 patients divided into two groups. The study group included 20 patients who had maxillary narrowness and bilateral maxillary third molars and who had undergone RME application. The control group of 10 patients had a bilateral crossbite, had bilateral maxillary third molars, and did not receive orthodontic treatment. The records included lateral and frontal cephalometric films and maxillary plaster models. In the study group, records were taken before expansion (T1), after expansion (T2), and at the retention period (T3). T2 records were not taken in the control group because this period was too short to observe any changes. Friedman tests were used to observe within groups, and the Mann-Whitney U-test was used to see the differences between groups on films and casts. RESULTS: Frontal films showed that vertical eruption occurred after the retention period in the RME cases. Cephalometric films revealed that the angular eruption occurred immediately after expansion. However, the results were not significant with respect to the control group. CONCLUSION: The hypothesis was rejected. Rapid maxillary expansion affects maxillary third molar movement during and after the RME procedure. RME may indicate upper third molar eruption, but the final position of third molar was not different compared to the normal growth pattern.     

Tooth wear in maxillary anterior teeth from 14 to 23 years of age

Using a planimetric method, the size of horizontal wear facets on maxillary anterior teeth was studied longitudinally in the permanent dentition of 35 subjects at ages 14, 18, and 23?years. The study subjects had not previously undergone any orthodontic treatment and had Class I occlusion. We studied the association between the amount of wear and reported parafunctions and maximal bite force. Total wear areas in age groups 14, 18, and 23?years were 29.5?mm² (SD 11.4), 39.1?mm² (SD 12.7), and 45.0?mm² (SD 13.0), respectively. The total wear area increased significantly both from 14 to 18?years of age and from 18 to 23?years of age (p<0.0001). Between 18 and 23?years of age, the maxillary canines showed strongest wear, although the central incisors had largest wear facets. It can be concluded that wear of permanent anterior teeth is a continuous phenomenon in adolescence and young adulthood.     

Radicular dens invaginatus associated with radicular cyst in maxillary third molar – Rare case report

Dens invaginatus is a developmental tooth anomaly showing broad spectrum of morphological variations. Most extreme form of the invagination results in a bulbous expansion of the affected crown and/or root has been termed as dilated odontome. Radicular dens invaginatus is a rare dental anomaly formed by infolding of Hertwig's epithelial root sheath and in few forms invagination is lined by enamel. Various techniques of treatment including conservative treatment, nonsurgical root canal treatment, and endodontic surgery usually are unsuccessful because of their complex morphology and are associated with periapical lesions. We report a case of radicular dens in dente with dilated root and was associated with radicular cyst in the right maxillary third molar in a patient aged 38 years. Histological examination showed a dilated bulbous root with enamel formation within root invagination and the associated radicular cyst was lined by pseudostratified ciliated columnar epithelium.     

Periodontal surgery in furcation-involved maxillary molars revisited—an introduction of guidelines for comprehensive treatment

Maxillary molars with interradicular loss of periodontal tissue have an increased risk of additional attachment loss with an impaired long-term prognosis. Since accurate clinical analysis of furcation involvement is not feasible due to limited access, morphological variations and measurement errors, additional diagnostics, e.g., with cone-beam computed tomography, may be required. Surgical treatment options have graduated from a less invasive approach, i.e., keeping as much periodontal attachment as possible, to a more invasive approach: (1) open flap debridement with/without gingivectomy or apically repositioned flap and/or tunnelling; (2) root separation; (3) amputation/trisection of a root (with/without root separation or tunnel preparation); (4) amputation/trisection of two roots; and (5) extraction of the entire tooth. Tunnelling is indicated when the degree of root separation allows for opening of the interradicular region. Alternatively, root separation is performed particularly in root-canal treated teeth with reduced coronal tooth substance requiring crown restorations. As soon as the attachment of one or two roots in maxillary molars is severely reduced, root removal is indicated and performed either as amputation or trisection including the corresponding part of the clinical crown. While the indication for regenerative measures in maxillary molars with furcation involvement is very limited, extraction and replacement with implants is restricted, particularly in sites requiring complex alveolar ridge augmentation and sinus elevation. A systematic approach for decision making in furcation-involved maxillary molars is described in this overview, including what constitutes accurate diagnosis and what indications there are for the different surgical periodontal treatment options.     

Clinical study of distalization of maxillary molars with miniscrew implants anchorage in Class Ⅱ malocclusion

目的 研究临床上微螺钉种植体作为强支抗在推磨牙向远中的治疗效果.方法 选取10例AngleⅡ类重度拥挤的患者作为研究对象,采用双侧颊侧植入微螺钉种植体作为强支抗远移上颌磨牙,施力为2.45~2.94N.在治疗前后拍摄头颅侧位片,测量上颌第一磨牙在矢状向的位置变化.取研究模型,通过三维扫描仪及测量软件测量上颌磨牙的三维方向的变化,进行统计学分析.结果 所有病例都达到了预期的矫治效果,磨牙中性关系、面型得到了较好的改善.上颌第一磨牙平均向远中移动3.58±0.87mm;上颌磨牙的压低、颊倾、远中倾斜治疗前后均无显著性差异.结论 微螺钉种植体作为强支抗,能成功远移上颌磨牙,没有出现支抗丧失,是非常有效的非依从性远移磨牙的方法.     

Rapid maxillary expansion. Is it better in the mixed or in the permanent dentition?

The aim of this study was to compare the dentoskeletal effects of a modified acrylic-bonded rapid maxillary expansion (RME) device when it is used in the mixed and permanent dentitions. The study group consisted of 51 patients in the mixed and permanent dentition (26 girls and 25 boys) who underwent RME treatment. Group 1 was composed of 34 subjects in the mixed dentition (19 girls and 15 boys; mean age, 9.2 +/- 1.3 years). Group 2 consisted of 17 subjects in the permanent dentition (seven girls and 10 boys; mean age 12.7 +/- 1.2 years). Lateral and frontal cephalograms and upper dental casts were collected before treatment (T1), after treatment (T2), and after retention (T3). Intragroup and intergroup changes were evaluated by paired t-test and Student's t-test, respectively. In both groups after RME, the maxilla moved forward; mandible rotated posteriorly; facial height increased; nasal, maxillary, and maxillary intercanine and first molar widths increased; and the upper molars tipped buccally. Almost all these significant changes were stable at follow-up (T3). When overall (T1 - T3) differences were considered, upper molars tipped more, and the ANB angle increased less in the mixed dentition group compared with the permanent dentition group (P < .01). Within the limits of this study, the results suggest that the orthopedic effects of RME are not as great as expected at early ages, and it might be a better alternative to delay RME to early permanent dentition.