A restorative-orthodontic treatment approach in the older patient

This report presents a case requiring a combination of restorative dentistry and orthodontic treatment in a mature adult patient. Occlusal splint and periodontal therapies were used initially. Orthodontic treatment combined the use of the occlusal splint and fixed appliance in the maxillary arch. Sectional fixed appliances were used in the mandibular arch. The final restorations were fixed--movable bridges in the mandibular arch and a removable tooth and mucosally borne prosthesis in the maxilla. Retention of the orthodontic result was provided by the fixed prostheses in the lower arch and the continued wear of a full coverage maxillary occlusal splint at night served to prevent relapse of the upper teeth.     

The effects of Fr?nkel II treatment on arch width and arch perimeter

Changes in dental arch width and total arch perimeter in 24 Class II, Division 1 patients treated with the Fr?nkel II appliance were compared with changes in an untreated control group. Measurements were made on pretreatment and posttreatment plaster casts at three points on each of four maxillary and four mandibular teeth. Increases in width were computed at the occlusal point and compared for the two samples. A significant increase in occlusal arch width for all measures was suggestive of both a minor tipping movement of the maxillary teeth and a bodily movement of the mandibular teeth. Width development in the maxilla was greater than in the mandible. Occlusal arch width increased more in the molar and premolar regions in the maxilla and in the premolar region in the mandible. Wide arches were found to have as much increase as narrow arches. The total arch perimeter decreased significantly less in the treatment sample than in the control sample. The documented gains in arch width and arch perimeter would not be sufficient to relieve severe crowding, but could be useful in avoiding removal of teeth in borderline extraction cases.     

Fabrication of maxillary single complete denture in a patient with deranged mandibular occlusal plane: A case report

Construction of a single complete denture (SCD) is a challenging clinical situation especially when the opposing natural dentition is not in a normal plane of occlusion. Mal-aligned, tilted or supra-erupted teeth in the opposing arch are some of the problems that should be corrected to achieve a balanced occlusion in patients who require SCD. Achieving harmonious occlusal plane is a primary objective of any restorative procedure to facilitate natural mandibular movements and ease of mastication. Establishment of normal occlusal plane in opposite arch is pre-requisite to maintain the stability of the SCD. This clinical report describes restoration of mandibular teeth (with severe attrition and deranged occlusion) by establishing normal plane of occlusion with the help of custom made occlusal plane template (OPT) followed by construction of a complete denture in maxillary arch.     

Treatment of occlusal plane canting using miniscrew anchorage

Two patient therapies introduce the use of miniscrew anchorage in adult patients for the correction of mild to moderate occlusal plane canting without severe facial asymmetries. A miniscrew implanted in the infrazygomatic buttress was used as anchorage for intruding the overerupted maxillary quadrant. As unilateral intrusion of maxillary posterior teeth will develop a posterior unilateral open bite, box elastics were subsequently used to extrude the opposing teeth in the mandibular arch. These treatments show that miniscrew anchorage offers a simple, efficient method of correcting occlusal plane canting and mild facial asymmetries.     

下颌第三磨牙阻生情况与急性冠周炎发生的关系

目的:研究下颌第三磨牙位置特征与急性冠周炎发生的关系。方法:选择122名临床诊断为下颌第三磨牙急性冠周炎患者(年龄18～31岁),分别记录下颌第三磨牙的萌出角度、软组织覆盖率、有无上颌牙列的咬合创伤及其萌出高度,然后对以上数据分别进行统计学分析。结果:发生急性冠周炎的下颌第三磨牙以垂直阻生最多见(57%),近中阻生次之(34%),水平阻生(7%)和远中阻生最少(2%),各种阻生之间的差别具有统计学意义(P<0.05)。发生急性冠周炎的下颌第三磨牙部分软组织覆盖(以75%的覆盖率最多见)多于全部软组织覆盖,差别具有统计学意义(P<0.05)。有无上颌牙列的咬合创伤与急性冠周炎的发生没有明显的统计学意义(P>0.05)。发生急性冠周炎的下颌第三磨牙萌出高度多数与(?)平面平齐,萌出高度间的差别具有统计学意义(P<0.05)。结论:垂直阻生、软组织部分覆盖、萌出高度平齐于(?)平面的下颌第三磨牙容易发生急性冠周炎,具有这些特征的下颌第三磨牙要高度重视。     

Cephalometric and in vivo measurements of maxillomandibular anteroposterior discrepancies: a preliminary regression study

One of the aims of the present investigation was to assess three-dimensionally the anteroposterior discrepancy of dental bases using a noninvasive direct procedure. A second aim was to verify the relationship of three-dimensional soft-tissue measurement to the well-established two-dimensional cephalometric assessments of anteroposterior discrepancy. Dental and facial landmarks were directly digitized on 20 orthodontic and maxillofacial surgery patients aged 8 to 26 years using an electromagnetic three-dimensional computerized digitizer. The anteroposterior maxillomandibular discrepancy was measured by calculating the linear distances between the projections of subnasal and sublabial landmarks on the occlusal plane, subnasal and sublabial landmarks on Camper's plane, and insertion of maxillary and mandibular median labial frenula on the occlusal plane. From lateral cephalograms of the same patients, the following measurements were obtained: subspinale point-nasion-supramentale point (ANB) angle; corrected ANB angle that compensates for the position of the maxilla and rotation of the mandible relative to the cranial base; Wits appraisal; MM-Wits, linear distance between the projections of points A and B on the bisector of the palatal plane to mandibular plane angle; and soft-tissue Wits, linear distance between the projections of soft-tissue points A and B on the bisecting occlusal plane. The best two-dimensional vs three-dimensional linear regression (r = 0.91) was found between Wits appraisal and the linear distances between the projections of maxillary and mandibular median labial frenula on the occlusal plane (Wits = -1.05 x 3D measurement - 3.75). The three-dimensional evaluation of the sagittal discrepancy of the jaws directly performed in vivo may allow a more complete analysis of a patient's soft-tissue drape together with the underlying hard-tissue structure.     

“Occlusal Plane Orientor”: An Innovative and Efficient Device for Occlusal Plane Orientation

Correct occlusal plane orientation is a prerequisite in Prosthodontic reconstructive treatment therapy as it helps in achieving esthetics and phonetics anteriorly and forms a milling surface posteriorly where tongue and buccinator muscle position the food bolus during mastication. Activity of Muscles during clenching will be least, when the occlusal plane is made parallel to plane of lost natural teeth. Conventionally the ala-tragus line (Camper’s plane) is used as a guide for assessment of the occlusal plane and fox plane is used to check the parallelism between the two. Occlusal plane orientor is a new device developed to mark occlusal plane parallel to ala-tragus line on maxillary occlusion rim, thereby saving clinician’s time and increasing efficiency. Additionally, it is a useful tool for occlusal plane orientation in patients with facial deformity, absence of an eye or an ear.     

A clinical study on occlusal plane in relation with orofacial morphology and stomatognathic function

Occlusal plane is one of the important and fundamental factors that establish the mandibular position and the form of dental arch and prosthesis. The aim of this study is to investigate the morphological and functional importance of occlusal plane in relation with orofacial morphology and stomatognathic function. Cephalograms were taken and electromyograms of masseter, anterior and posterior temporal muscles were recorded during clenching, tapping and chewing movements in 30 normal young adult subjects. Mandibular movements were simultaneously recorded using Sirognathograph (Siemens, West Germany). A correlation analysis was performed to study the relationship between the occlusal plane and morphological and functional parameters. As a result, the occlusal plane angle showed; 1) close correlations with the mandibular plane angle, Camper's plane angle and palatal plane angle, 2) correlations with the duration of activity of anterior temporal muscles and the sagittal angle of chewing pathway. The results suggest that there is a close relationship between the occlusal plane and orofacial morphology. Furthermore, the morphological parameters closely related to the occlusal plane were found to affect stomatognathic function. It is concluded that the occlusal plane is the important factor which harmonizes morphology and function of the stomatognathic system.     

Critical assessment of a device to measure incisor crown inclination.

The aims of this study were to critically assess the use of a disposable device--the tooth inclination protractor (TIP)--to record incisor crown inclination and to compare its reliability and validity with that of traditional cephalometric radiographic analysis. The sample comprised 30 dental students with lateral cephalometric radiographs and dental casts. Four examiners were trained and calibrated to digitize radiographs and to use intraoral (on patients and dental casts) and extraoral (on dental casts) TIPs. The following angles were measured on the radiographs: maxillary incisor to maxillary plane, mandibular incisor to mandibular plane, maxillary incisor to occlusal plane, and mandibular incisor to occlusal plane. Measurements were also made with the TIP: maxillary incisor to occlusal plane and mandibular incisor to occlusal plane. All techniques were reliable between examiners. There were statistically significant systematic differences between the TIP and the radiographic assessments. The following differences were found. The TIP tended to record maxillary incisor crown inclination an average of 14 degrees less than maxillary incisor to maxillary plane. The TIP tended to record mandibular incisor crown inclination as similar to mandibular incisor to mandibular plane. The TIP recorded mandibular crown inclination 19 degrees less than mandibular incisor to occlusal plane. The disposable TIP was shown to be a simple, inexpensive, reliable, and valid method of assessing incisor inclination.     

正常(牙合)青年(牙合)平面与咀嚼运动轨迹的相关性分析

目的 分析个别正常(牙合)青年(牙合)平面与咀嚼运动轨迹特征的相关性,以期为临床定位(牙合)平面提供参考.方法 收集43名个别正常(牙合)青年志愿者,拍摄头颅侧位X线片,测量耠平面倾斜度(OP-CP);记录下颌中切牙切点的左右侧咀嚼运动轨迹,测量矢状面垂直向最大位移(V)、矢状面水平向前后最大位移之和(P+A)、冠状面水平向左右侧方位移之和(L+R)以及(牙合)平面与咀嚼运动轨迹的夹角,对(牙合)平面倾斜度(OP-CP)与V、(P+A)、(L+R)以及(牙合)平面与咀嚼运动轨迹的夹角进行Pearson线性相关分析.结果 OP-CP为(2.1±3.8)°.V为(20.22±4.28)mm,(P+A)为(11.42±2.45)mm,(L+R)为(8.62±1.52)mm.OP-CP与(L+R)呈负相关,相关系数r为-0.39(P<0.05).矢状面(牙合)平面与牙尖交错位及其附近的咀嚼运动开闭口轨迹近似垂直;OP-CP与咀嚼运动轨迹(牙合)期阶段2.0 mm、(牙合)外期上段的(牙合)平面-闭口轨迹角呈正相关(P<0.05);咀嚼轴角平均为(66.50±7.98)°,与OP-CP不相关(P>0.05).结论 矢状面(牙合)平面倾斜度与咀嚼运动轨迹有一定相关性.(牙合)平面对咀嚼运动(牙合)期闭合轨迹的影响较明显.     

Face-bow record without a third point of reference: theoretical considerations and an alternative technique.

Accurate mounting of dental casts is achieved by transferring the tridimensional spatial relationship of the maxillary arch to an articulator. A face-bow is used to transfer this relationship to the articulator, usually by relating the face-bow to a plane of reference. The most common reference plane is the Frankfort plane, which has been assumed to be horizontal when the patient is in the natural head position. The axis-orbitale plane has also been considered horizontal and used as reference. However, it has been shown that both planes are not horizontal, and mounting a maxillary cast according to these planes can result in an inaccurate mounting. This article describes an alternative procedure for face-bow transfer without a plane of reference, and uses the angular relationship between the occlusal plane and the condylar path to mount the maxillary cast on the articulator. The elimination of a reference plane, to which relate the functional determinants of occlusion, avoids an additional source of error during the mounting procedure.     

Use of linear occlusion with fixed restorations opposing a mandibular complete denture: a clinical report

Restoring an edentulous mandibular arch opposing maxillary natural dentition with conventional occlusal schemes historically has proven to be extremely difficult. Using a noninterceptive anterior and posterior occlusal concept with a myostatic peripheral border extent provides a means to enhance stability of the mandibular prosthesis.     

Retrospective evaluation of treatment outcome in Japanese children with complete unilateral cleft lip and palate. Part 1: Five-year-olds' index for dental arch relationships.

OBJECTIVE: To evaluate the dental arch relationships of Japanese children with complete unilateral cleft lip and palate (UCLP) and to examine the 5-year-olds' index for its validity. DESIGN: Retrospective study and comparison with previous reports. SUBJECTS: One hundred thirty-six children with complete UCLP who received primary cheiloplasty and palatoplasty in the Kyushu University Hospital from 1966 to 1999. MATERIALS: Dental models taken from children 53 to 67 months of age and their cephalograms. Methods: Study models were assessed using five scores; 1=excellent, 2=good, 3=fair, 4=poor, and 5=very poor, in accordance with the 5-year-olds' index and also evaluated using Huddart and Bodenham's numerical classification. Dental arch widths, three-dimensional maxillary dental arch form, and lateral cephalograms were traced and measured. The outcome by 5-year-olds' index was compared with Huddart and Bodenham's numerical classification, dental arch dimensions, and cephalometric measurements. RESULTS: Occlusal outcome evaluated by the 5-year-olds' index was rated 2.95, which was classified as fair. This index rating showed a significant relationship with numerical classification and dental arch length, but not with dental arch width. The index showed a relationship with mandibular form and position, but not with maxillary position. CONCLUSION: The occlusal outcome of the cases with UCLP was fair as evaluated using the 5-year-olds' index. The index evaluates the anteroposterior relationship of maxillary/mandibular dental arches but does not evaluate the collapse of maxillary segments.     

Rapid maxillary expansion with incisor intrusion: a study of vertical control.

This is a prospective study of 20 consecutively treated patients needing maxillary expansion and incisor intrusion. The patients were treated with a bonded maxillary expansion appliance, intrusion of the incisors with either a one-piece or three-piece base arch and anchorage augmented by the use of vertical-pull chincup therapy. Because rapid palatal expansion and intrusion of maxillary incisors both produce extrusion of posterior teeth, this study was undertaken to determine if a combination of controlled forces could prevent undesirable increases in vertical dimension. The maxillae were widened approximately 8 mm, the incisors were intruded 3 mm, the maxillary molars stayed the same or were intruded slightly, and the mandibular plane angle stayed essentially the same. In addition, A-point was retracted slightly and the occlusal plane was rotated in a counter-clockwise direction.     

正畸治疗中磨牙的拔除和保留（五十三）——利用骨钉矫治生长发育期上颌后缩下颌前突型反

目的：评价骨钉前方牵引治疗对生长发育期上颌后缩下颌前突型反[牙合]病例的矫治效果。方法：选择替牙晚期和恒牙早期骨性Ⅲ类错病例8例,男2例,女6例,年龄11～14岁,平均12.2岁。均为上颌发育不足并伴有下颌、下牙弓轻度前突的凹面型,在双侧上颌颧牙槽嵴区植入骨钉,骨钉与牵引面罩的牵引钩相连,与[牙合]平面成向前下30°夹角,力值维持在350g左右,每日戴用时间为10～12h。有3例恒牙早期病例因牙列拥挤或下牙弓前突,设计对称拔除了上、下颌第二或第三磨牙,植入下颌磨牙骨钉以牵引排齐内收下牙弓。结果：8例患者前方牵引5～10个月,平均7个月,均有效解除前牙反[牙合]。结论：应用骨钉做前方牵引,牵引力通过上颌骨阻力中心,不会致颌骨出现异常旋转。牵引力完全作用在颌骨上,避免了对牙齿产生副作用。骨钉还可用于牵引上下颌牙列远中移动,减少上前牙唇倾并增强前方牵引对下牙弓的矫治作用。     

Occlusal‐supporting ability of individual maxillary and mandibular teeth

This study aimed to analyse occlusal force, area and pressure for individual maxillary and mandibular teeth by assessing their occlusal‐supporting abilities. Ninety‐nine subjects (49 men and 50 women; average age, 24·7 ± 3·4 years; range, 20–37 years) performed maximal voluntary clenching twice for 3 s in both the intercuspal position and the intercuspal position with sliding movement from edge‐to‐edge occlusion, with a pressure‐sensitive sheet placed between the maxillary and mandibular dental arch. Occlusal force, area and pressure of individual teeth were calculated by colour development in the pressure‐sensitive sheet with special analytical equipment and software. Occlusal contact condition of individual teeth was confirmed using the intra‐occlusal record. All data were analysed using unpaired Student's t‐test, Kruskal–Wallis test and Scheffe's test for multiple comparisons with a significance level of P < 0·05. The occlusal pressure in the intercuspal position with sliding movement from edge‐to‐edge occlusion was adopted as the representative occlusal‐supporting ability for each individual tooth, although there were, in part, statistically significant differences in the effects of laterality, performance and gender. Overall, the occlusal pressure increased gradually from the central incisor, peaked at the canine or first premolar and decreased sharply–and significantly (P < 0·01)–towards the second molar. We conclude that the occlusal pressure of individual teeth can be used as an indicator of occlusal‐supporting ability. This is therefore proposed as a possible suitable parameter for epidemiologic research, specifically for verifying the relationship between occlusal‐supporting ability and status of residual periodontal ligament support.     

Spatial relationship between anatomic landmarks in edentulous patients: a radiographic study

In 67 edentulous patients the crests of the residual ridges, the incisive papillae, the maxillary tuberosities, and the mandibular retromolar pads were located and identified with metallic wires inside the acrylic resin denture bases. Occlusal cephalometric radiographs were used to record the spatial relationship between the described anatomic landmarks in the dentures with the mandible in centric relation.     

Using the Kinesiograph to measure mandibular movements during speech: a pilot study

This study was a pilot investigation to determine a method of measuring mandibular movement during speech using the Kinesiograph. Some observations and trends were evident. 1. The Kinesiograph is an excellent instrument for measuring mandibular movement in three dimensions. 2. Production of the /s/ sound can occur anywhere within a three-dimensional range rather than at one position. 3. The distance between the upper and lower incisors during speech was much less than 1 mm and was consistent throughout the range used by each subject. 4. The functional angle of mandibular movement during speech to the maxillary occlusal plane was essentially the same as the angle of rest position to centric occlusion and appeared to be related to the cephalometric occlusal plane angle. It seems likely that rest position is the key to functional mandibular movement. 5. Three-dimensional clinical studies of mandibular movement during speech using the Kinesiograph could lead to more precise answers to questions concerning mandibular function and occlusal dysfunction.     

Mandibular distraction osteogenesis and maxillary osteotomy in a class II division 1 patient with chronic juvenile arthritis

A patient with juvenile chronic arthritis presented with a malocclusion characterized by mandibular hypoplasia, symphysial deficiency, and an increased mandibular occlusal plane angle. Correction of the mandibular defect required both the horizontal advancement of the mandible and a counterclockwise rotation of the proximal segment to reduce the mandibular occlusal plane angle. This was achieved by a combination of distraction osteogenesis to horizontally advance the mandible (14 mm), followed by manipulation of the postdistraction regenerate to reduce the mandibular occlusal plane and increase the symphysial projection. The counterclockwise rotation of the mandibular body resulted in the creation of a posterior open bite. After a three-month period to allow consolidation of the mandibular distraction osteogenesis, secondary maxillary surgery at the Le Fort 1 level was performed to reestablish maxillary occlusal contact at the new mandibular occlusal plane. A genioplasty was also performed to improve chin projection.