Agenesis of maxillary lateral incisors: A global

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Agenesis of maxillary lateral incisors: A global overview of the clinical problem Article in Orthodontics : the art and practice of dentofacial enhancement · December 2011 Source: PubMed

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Agenesis of maxillary lateral incisors: A global overview of the clinical problem Smaragda Kavadia, DDS, MSD1 Sofia Papadiochou, DDS2 Ioannis Papadiochos, DDS2,3 Lazaros Zafiriadis, DDS, MSD2,4

The agenesis of maxillary lateral incisors is a common developmental anomaly and represents a clinical problem impairing dental esthetics and function from a very young age. Several dental specialties deal with the management of this clinical problem because a multidisciplinary approach can cover the complete dental needs of patients with dental agenesis. There is controversy, however, about whether missing lateral incisor spaces should be orthodontically opened or closed using permanent canines to replace the missing teeth. The article presents a review of the existing literature about the prevalence, etiology, diagnostic evaluation, and treatment strategy of maxillary lateral incisor agenesis. Also, this article aims to present the key determinants leading to selection of space opening or closure and to report professional judgments and layperson perception concerning the available treatment alternatives. The English-language literature associated with this topic was searched via PubMed. The articles retrieved were then reviewed with an attempt to fulfill the aims of this review. Maxillary lateral incisors are one of the most common congenitally missing teeth, and to date, the origin of their agenesis has not been completely identified. Prompt diagnosis and careful evaluation of treatment determinants through a multidisciplinary approach are essential for the proper management of clinical problems. Each of the available means of rehabilitation has its own advantages, disadvantages, indications, and limitations. The configuration of the treatment plan should be devoid of clinician biases, whereas patients’ realistic expectations should be taken into account. Orthodontics (Chic) 2011;12:296–317.

1Associate

Professor, Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece. 2Private Practice of General Dentistry, Thessaloniki, Greece. 3Trainee in Oral and Maxillofacial Surgery, Greece. 4Master of Science in Operative Dentistry, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece. CORRESPONDENCE Dr Smaragda Kavadia 19 Proxenou Koromila Thessaloniki 54623 Greece Email: smaragda@ dent.auth.gr, sofiapapadiochou@ gmail.com

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Key words: agenesis, aplasia, congenitally missing, developmental absence, maxillary lateral incisors

D

ental agenesis—the congenital absence of one or more teeth in the primary and/or permanent dentition—constitutes a developmental anomaly of normal tooth number that can be associated with systemic syndromes and other oral anomalies.1,2 As a general principle, esthetic and functional problems do arise in the dentofacial complex of those individuals congenitally missing one or more teeth, owing to the unfavorable positions of teeth that are present within the dental arches. According to epidemiologic studies,3–7 the maxillary lateral incisor is the most common congenitally missing permanent tooth in the maxillary anterior region (esthetic zone). This

The Art and Practice of Dentofacial Enhancement

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© 2011 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.

region directly affects the smile appearance, so when maxillary lateral incisors are missing, there is a visible and negative effect on dentofacial esthetics.3 Individuals with a congenital absence of maxillary lateral incisors are confronted with functional problems and poor smile esthetics at a young age, which may impair self-confidence and psychology3,8–10 at a sensitive period of life (adolescence).11 Dental agenesis comprises various aspects of rehabilitation rarely addressed by an isolated specialty. Establishing optimal esthetics, function, and periodontal health in patients with maxillary lateral incisor agenesis is a complex and challenging process, so the appropriate management implies interaction among several dental specialties. Each specialty involved has to contribute at a different stage of the overall management. After reviewing the literature, it is clear that the involved clinicians have to choose between two treatment approaches: (1) opening of the space created by the congenital absence followed by the placement of some type of prosthesis12 or autotransplantation13 of the developing maxillary premolar(s) or (2) space closure via canine(s) substitution in conjunction with a set of corrective procedures that will make the repositioned teeth closely resemble the missing ones.12 The selection of the suitable approach is the crux of the treatment and requires evaluation of certain determinants. The aim of this literature review was to summarize the contemporary data related to prevalence, etiology, diagnostic procedures, and treatment planning of patients with agenesis of maxillary lateral incisors. Especially in terms of treatment planning, this paper deals with the advantages, disadvantages, indications, contraindications, as well as the crucial factors for each of the available options of rehabilitation. It is also among the objectives of this review to include the reported professional judgments and layperson perceptions concerning the existing treatment alternatives.

Prevalence The prevalence of dental agenesis in the permanent dentition (excluding the third molars) has been cited in several studies to range from 2.7% to 11.3% with various patterns of absence within the dental arches.4–7,14–25 The prevalence of maxillary lateral incisor agenesis in the majority of studies ranges between 1% and 3%.26–29 In Caucasian populations, maxillary lateral incisors account for approximately 20% of all missing teeth.3 Among different ethnic groups, maxillary lateral agenesis has been reported to occur with the greatest,4–7,17,18,22,23 Volume 12, Number 4, 2011 © 2011 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.

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second greatest,4–7,16,21 and the third greatest frequency.19,20,24,25 With regard to the primary dentition of Caucasian populations, maxillary lateral incisor agenesis accounts for 50% of all affected teeth.30–32 Moreover, it has been found that when there is agenesis of one or two teeth, the most frequently absent teeth are the maxillary lateral incisors.33 Concerning sex differences, the prevalence of the anomaly seems to be slightly greater in females than males.28,34–37 Moreover, it has been reported that bilateral agenesis of the maxillary lateral incisor is more frequent than the unilateral one.7,38 Finally, with regard to clinical cases associated with cleft lips and palates, it is cited that the maxillary lateral incisor is the most frequently affected tooth in the cleft area in both primary39 and permanent dentitions.39–43

Etiology Dental agenesis has been attributed to genetic and environmental factors.39 The genetic background is involved in the majority of cases. In fact, the expression of more than 200 genes is responsible for tooth development,39,44 so a mutation in any of these can arrest this process.45 Familiar dental agenesis may be inherited in an autosomal (dominant or recessive) or X-linked (dominant or recessive) pattern.46 Moreover, both the genotype and phenotype of dental agenesis, in general, present heterogeneity.39 To date, only the cases of severe dental agenesis with dominant inheritance and syndromic dental agenesis with recessive inheritance are well known as the result of specific genetic defects.39 The most common types of dental agenesis—maxillary lateral incisors and premolars—are merely identified.39 There is little evidence indicating an association between genotype and phenotype in cases of nonsyndromic dental agenesis, such as maxillary lateral incisors.39 From the available data, mutations in three different genes—PAX9, MSX1, and AXIN2—cause nonsyndromic dental agenesis in humans.47 The PAX9 gene participates in the sequential and reciprocal signaling cascades between epithelial and mesenchymal cell layers,45 and its mutation results in permanent molar agenesis in conjunction with agenesis of the maxillary lateral incisors and premolars in some cases.39 The MSX1 gene has a crucial role, repressing transcription and interacting with other molecules such as DLX-family and TATA-binding proteins during the signaling paths of odontinogenesis.45 The most affected teeth in MSX1 defects are the third molars, the second premolars, the maxillary first premolars, and the incisors.45,48 With regard to the third gene, AXIN2, it has been discovered that its role is crucial during the processes of tooth replacement and development of permanent molars.48 Mutations in AXIN2 also predispose patients not only to tooth agenesis but also to colorectal cancer.48 Ectodermal dysplasia (genetic defects), orofacial-digital syndromes, and syndromes with orofacial clefting such as Pierre Robin and Van der Woude syndrome belong to the type of syndromic dental agenesis.39 The susceptibility of maxillary lateral incisors to dental agenesis has been associated with their anatomical position in the areas of fusion of facial processes.49,50 Moreover, because they are the last to develop in their respective tooth classes, they are the most common congenitally missing tooth. This fact could be derived from limitations of the adjacent developing teeth or a tendency of those teeth to be under a threshold of development.39 Among the environmental factors causing dental agenesis are infection51 (eg, rubella), different types of trauma in the apical area of the dentoalveolar processes52 (eg, fractures, extraction of primary tooth), chemical substances or drugs53 (eg, thalidomide, chemotherapy), exposure to dioxin,54–56 radiation therapy,57,58 and disturbances in jaw innervations.59,60 298


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Diagnosis Accurate diagnosis should be based on the systematic collection of information arising from medical and dental history, clinical examination, and radiographic evaluation. The clinical examination especially reveals a variety of esthetic problems such as unpleasant space between the permanent central incisor and canine,12 deviation of the midline to the affected site12 (in unilateral cases), median diastema,12 multiple interdental gaps,12 reduced perimeter of the maxillary arch,61 as well as drift and rotation of the central incisors and canines.12 Agenesis of the maxillary lateral incisors can bring about mesial migration of the canines.62 Also, if selective early extraction of the maxillary primary teeth precedes, a considerable mesial drift of the posterior maxillary teeth will follow. Since there is a proven connection between dental agenesis and microdontia (which suggests a possible genetic linkage),36,63 a diminutive contralateral maxillary lateral incisor frequently coexists in unilateral absence cases.2 In spite of what was previously mentioned, the clinician should also inspect for further clinical findings that arise suspicion for the agenesis of maxillary lateral incisors. Overretention of the primary maxillary lateral incisor and canine, absence of developmental canine eminence, asymmetric loss of primary teeth, dental asymmetries, as well as ectopically erupted (mostly migrated in the mesial position) or impacted permanent canine(s) are elements that should receive considerable attention, especially when a family history of dental anomalies also exists.64 A permanent maxillary lateral incisor that has failed to erupt by the age of 9 or within 9 months of the contralateral is very likely to suggest congenital absence,65 which therefore requires radiographic verification. Radiographic evaluation is a reliable and valuable means of investigating for congenitally missing maxillary lateral incisors. Panoramic radiography remains the major diagnostic tool, but to obtain a broader view with supplementary examination, the clinician can use additional types of radiographs—eg, a complete periapical mouth survey or a lateral cephalometric radiograph. In addition, radiographic control provides information to assess the position of adjacent teeth. An association between canine impaction and maxillary lateral incisor agenesis has been cited.66–68 Also, the root of the maxillary lateral incisor is thought to guide maxillary canine eruption, and consequently, an absent or diminutive maxillary lateral incisor root may lead to canine impaction.2 Additionaly, in a recent study, Garib et al69 mentioned an association between maxillary lateral incisor agenesis and permanent tooth agenesis (third molars and second premolars), maxillary lateral incisor microdontia, palatally displaced canines, and distoangulation of mandibular second premolars. Finally, a correlation between maxillary lateral incisor agenesis and maxillary canine–first premolar transposition has been reported.68,70,71 Peck et al,68,70 in particular, cited a prevalence of maxillary lateral incisor agenesis of 26%—13 times higher than average—in cases of maxillary canine–first premolar transposition.

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Accurate diagnosis should be based on the systematic collection of information arising from medical and dental history, clinical examination, and radiographic evaluation.

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MANAGEMENT-TREATMENT APPROACHES Space opening and subsequent restorative alternatives

The rationale of this approach intends to provide the appropriate space for the replacement of missing maxillary lateral incisors and eventually maintain or establish the “normal” buccal Angle Class I occlusion.72 While applying orthodontic space opening, the orthodontist attempts to redistribute the total available space produced by the gaps between the anterior teeth, which, in turn, result from maxillary lateral incisor agenesis and ectopic eruption of canine(s).72 Space opening can be achieved by closing the midline diastema and by distally retracting and uprighting the ectopic maxillary canine(s).72 In cases of orthodontic space opening, the determination of the amount of space needed to accommodate the maxillary lateral incisor substitute is critical. Although this space has been reported to range from 5 to 7 mm,73 its exact amount can be determined via one of the following methods: • The first method involves the application of the golden proportion among the anterior teeth.74,75 The rule of golden proportion indicates that optimal esthetics can be established as long as the perceived mesiodistal dimension of an anterior tooth (as viewed from a direct frontal aspect) fulfils a ratio of 1:0.618 with the tooth next to it.73 Thus, the width of the lateral incisor should be equal to 61.8% of the width of the central incisor. However, due to the fact that the measurements are performed only from a direct frontal view, the true dimensions of teeth are not reproduced.73 Besides, this method considers esthetics just a specific width of the maxillary lateral incisor and not a range of widths as the research demonstrates.76,77 • The second method can be applied only in cases of unilateral agenesis of the lateral incisor because it simply concerns the measurement of the contralateral lateral incisor size.62 Nevertheless, it is evident that the particular method cannot be advantageous when the contralateral tooth is peg-shaped or severely worn.73 • The third method to determine the exact amount of required space suggests the performance of Bolton analysis78: the ratio that amounts to the sum of the mesiodistal width of the six mandibular anterior teeth divided by the mesiodistal width of the six maxillary anterior teeth. To achieve ideal occlusal relationships, this ratio should be approximately 0.78.79 Therefore, the width of the missing maxillary lateral incisors can be mathematically calculated by the solution of an equation. • The construction of a diagnostic wax-up is regarded as the most predictable (fourth) means to assess the optimal required space.73 Esthetics and appropriate occlusal relationships are those key factors conducting this procedure. Specifically, meticulous attention should be directed toward teeth positioning to establish the coincidence of midlines, normal canine relationships (Angle Class I), appropriate teeth inclination, and ideal overbite and overjet for central incisors.80 All of these not only indicate the remaining space for replacing maxillary lateral incisors, but also contribute to proper anterior disclusion in conjunction with a pleasing esthetic appearance.62,81

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In cases of orthodontic space opening, the determination of the amount of space needed to accommodate the maxillary lateral incisor substitute is critical.

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Appropriate candidates for orthodontic space opening are patients with upright maxillary incisors that need to be protruded,72 to be inclined labially, to provide additional lip support, and to improve correct anterior crossbites. Orthodontic space opening is contraindicated in patients with accentuated alveolar protrusions and soft tissue conxevity.81 The choice of orthodontic space opening facilitates the maintenance of the canine(s) in its/their natural position within the dental arch having the ideal intercuspation through first premolars,81,82 provision of canine-protected occlusion,72 and preservation of morphologic features of the canine(s) and first premolar(s) because there is no need of reshaping sound teeth.72 However, in as much as the prosthesis concerns the anterior oral region where several crucial factors such as tooth size, shape, shade, gingival contour, and margins should be properly addressed,83 the treatment is so complicated that any of prosthetic substitutes of maxillary lateral incisors cannot guarantee an optimal outcome. Whatever prosthodontic option is selected after orthodontic space opening, this commits patients to bear a restoration that needs special maintenance and does not last as long as healthy natural teeth. Consequently, patients may expect, at some point, the prosthesis to be replaced by another that, in turn, creates additional expense and potential risks of complications.


Restorative alternatives

Fixed tooth-supported restorations. The following options are available: • Full-coverage fixed partial dentures (FPDs). Full-coverage FPDs, besides being the conventional and least conservative of all fixed tooth-supported restorations, are indicated when73: (1) an existing fixed partial denture must be replaced, (2) the adjacent teeth require restoration because of severe structure lesions (fracture, caries, attrition), (3) the morphology of the adjacent teeth need to be altered to improve the dentofacial esthetics, and (4) the exerted occlusal forces need to be controlled. Orthodontists should establish appropriate inclination and angulation (alignment) of the central incisor and canine to prevent overpreparation of these teeth and to allow the proper “line of draw” for a restoration.73 Faciolingual position of the abutment teeth also plays an important role in palatal tooth preparation and joint size, especially in cases of all-ceramic FPD placement.73 Thus, orthodontists should leave an anterior horizontal overjet of approximately 0.5 to 0.75 mm to provide an adequate joint size and a more conservative palatal preparation.73 The mean survival rate of conventional FPDs is clearly greater than the mean survival rate of adhesive FPDs.84 Sharma85 also reported 10-year, full-coverage FPD survival and success rates of 92% and 81.1%, respectively. • Resin-bonded fixed partial dentures (RBFPDs). RBFPDs represent the most conservative alternative among the tooth-supported restorations, seeing that the least sacrifice of sound tooth structure is required for their preparation.73 One can meet alterations in their retentive design associated with the use of pins or grooves, but the most common type of this category is based exclusively on adhesion to secure retention.73 When RBFPDs are the selected treatment solution to maxillary lateral incisor agenesis, all of the following are ideal73: (1) shallow anterior overbite, (2) absence of parafunction, and (3) abutment teeth that are nonproclined, nonmobile, moderately thick, and translucent in the incisal one-third. Ketabi et al86 reported an RBFPD mean survival rate better than 69% (without including the rebonded restorations) after a 13-year observation period; and Aggstaller et al87 also demonstrated a survival rate of 77% after a 10-year follow-up period (without including the rebonded or repaired restorations). Volume 12, Number 4, 2011 © 2011 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.

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• Cantilever FPDs. Cantilever FPDs are the second most conservative toothsupported restoration in cases of congenitally missing maxillary lateral incisors.73 This type of prosthesis includes either partial or full-coverage preparation of the canine, which is a unique abutment for the cantilevered lateral pontic, because of its long root and increased crown dimensions.73 Full-coverage preparation of the canine is selected when the facial esthetics of the canine has to be altered.73 When the use of a cantilevered partial denture is decided upon, interferences in excursive movements should be removed from the cantilever.73 The latter allows for long-term success of the restoration.73 A recent study88 demonstrated that the cantilever FPDs have lower success rates than end-abutted FPDs after a 10-year follow-up. According to this study, after a 10-year observation period, the survival and success rates of cantilever FPDs were 81.2% and 63%, respectively. • Fiber-reinforced composite fixed partial dentures (FRC FPDs). This type of prosthesis utilizes fiber-reinforced composite resin (FRC) as an alternative material to metal-ceramic for the construction of resin-bonded prostheses. FRCs are characterized by significant stiffness and strength.89 Glass fibers, which make up these restorations, are either impregnated in a resin matrix or nonimpregnated using either a substructure of a polyethylene weave or a glass weave.90 The FRC FPD fabrication can be either direct in a patient’s mouth or indirect in a laboratory. The advantages of FRC FPDs are (1) optimal esthetics,90 (2) reduced wear of opposing teeth,90 (3) moderately conservative tooth preparation,90 (4) low cost in comparison with conventional FPDs,89 (5) lack of metal allergies,89 and (6) natural feeling.89 However, the use of FRC FPDs is contraindicated under conditions that impede the adhesive bonding procedure, such as presence of traumatic occlusal forces and inappropriate abutment teeth.91 van Heumen et al92 reported a three-unit anterior FRC FPD survival rate of 64% after 5 years. Removable dentures. Conventional removable dentures (complete or partial) and overdentures are applied when there are extended edentulous spaces within the maxillary arch, in addition to the congenitally missing lateral incisors.93 This type of prosthetic restoration is beneficial to patients with continuing craniofacial (skeletal) growth because it is easily subjected to modification.93 Removable dentures are mainly utilized as provisional prostheses in patients with maxillary lateral incisor agenesis since many of them cannot tolerate wearing a removable device due to its movement during function and speech, its bulkiness, and psychosocial reasons.93 Implant-supported restorations. Replacing the maxillary lateral incisors with dental implant–supported restoration(s) is indisputably regarded as the most conservative among the prosthodontic options since there is no need to harm sound parts of the natural dentition.94–96 Furthermore, such a restoration provides the following advantages: (1) alveolar bone maintenance,94,97 (2) enhancement of the occlusal function,94,97 (3) esthetic short-term appearance,94,97 (4) long-term survival,98 and (5) short and relatively simple orthodontic treatment.98 Despite the fact that single dental implants present high survival rates, longterm biologic implications often occur with a negative impact on smile esthetics.99–111 Among these complications are (1) increasing rates of infraocclusion even after the end of growth,100–104 (2) no uprighting of an implant crown as opposed to natural teeth,105,106 (3) blue coloring of the labial gingiva,107 (4) exposure of a metal or porcelain abutment over time,102 (5) recession particularly of the distal papilla,107,108 (6) demanding procedures for making porcelain implant crowns look natural,98 and (7) lack of long-term observations (>10 to 15 years).98

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Once osseointegrated dental implants have been incorporated in the treatment plan, both the quantity and quality of the available bone in the edentulous site should be evaluated.112 In cases of a standard-diameter implant (3.75 mm), it is recommended that:


• The minimal mesiodistal space required for a single-tooth replacement should be approximately 7 mm.113 This is necessary to provide at least 1.5 mm between the implant platform and the adjacent teeth114 for the development and preservation of papilla.113 If mesiodistal space is less than 7 mm, a smaller-diameter implant can be used.113 • The minimum incisogingival and facial-lingual bone should be 10 and 6.0 mm, respectively.62 • A minimum of 1 mm of bone should exist between the implant and adjacent roots.115 To provide adequate space for implant placement because of the potential risk of tooth movement during the retention period, Olsen and Kokich116 suggest a minimum of 6.3 and 5.7 mm between the crowns and roots of the canine and central incisor, respectively. The latter is associated with a minimum of 1 mm of bone on either side of the implant. Moreover, during the retention period, a bonded wire or a resin-bonded FPD helps restrict potential root approximation.116 Bone augmentation techniques should be considered if the amount of alveolar bone is not adequate for implant placement.112 However, such surgical techniques may be avoided. Keeping overretained primary lateral incisors or canines as long as possible is a useful method to preserve supporting bone for future implant placement.62 Both the shape and size of these teeth could be altered with composite resin additions so as to resemble the definitive restoration.62 This serves to maintain space, bone, and esthetics until implant insertion.62 Furthermore, the orthodontist can apply “orthodontic implant site development.”115 According to this process, if canine eruption occurs into the maxillary lateral incisor position, the buccolingual dimension of the alveolar ridge will be increased due to the large buccolingual width of the tooth.117 While the canine is being retracted distally to open the space, the root movement stretches the periodontal ligament and eventually results in a sufficient buccolingual dimension of the alveolar ridge.115 Novácˇková et al118 reported that the bone created by maxillary canine distalization was stable for 5 years after treatment, both in the horizontal and vertical directions. One study demonstrated that orthodontic space opening should be initiated after the age of 13 to prevent the risk of relapse and higher degree of bone resorption.119 Excessive incisor proclination also brings about extra-axial stress on the implant, so the anchorage of the maxillary incisors needs maintenance.119 Implant placement must be avoided before the growth of the maxilla, mandible, and alveolus ends.62 If placed earlier, discrepancies between the gingival contours of the implant and natural teeth, as well as occlusal and restorative complications, may occur.62,120 While the surrounding bone presents vertical growth and adjacent teeth keep on erupting, the implant reacting as an ankylosed tooth119 will seem to have been submerged. The most suitable method to ascertain the cessation of facial growth is the superimposition of sequential cephalometric radiographs taken 6 months to 1 year apart.117 Absence of changes in facial height, represented by nasion to menton distance, indicates that facial growth has been completed.62,101,121–123

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Implant placement must be avoided before the growth of the maxilla, mandible, and alveolus ends.

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Autotransplantation of developing maxillary premolar(s)

Slagsvold and Bjercke124 first applied the treatment concept of transplanting teeth with incompletely formed roots in circumstances of missing maxillary anterior teeth. In fact, autotransplanted teeth can achieve functional adaptation because their roots continue developing after autotransplantation.125 Determinant factors for the success of the autotransplantation are125: • Appropriate timing: The recommended time to perform autotransplantation of premolars to the maxillary lateral incisor positions is as soon as their roots have developed at two-thirds to three-fourths of their definitive length.125 Kristerson126 reported that the prognosis for complete periodontal healing at this stage exceeds 90%. • Surgeon’s ability and experience: When a surgeon performs autotransplantion of premolars, he should avoid any damage in the periodontal ligament— otherwise, ankylosis of the tooth may be caused.125 • Sufficiency of space on the mesial and distal sides of the graft.125 • Limitation of premature contacts/interferences between the transplant and the opposing teeth during the first 2 months.125 • Presence of physiologic mobility of the graft during the fixing period.125 Although autotransplanted teeth can be orthodontically moved like other normally erupted teeth within the dental arch, it is advisable that an observation period of 3 to 4 months intervene after the autotransplantation before initiating orthodontic treatment.125 Once an autotransplanted premolar occupies the maxillary lateral incisor position, its crown should be properly modified to resemble and function as the maxillary lateral inicisor.125 Therefore, direct composite resin buildups will be initially performed. Then, porcelain laminate veneers should replace the buildups.125 According to Czochrowska et al,127 after a mean follow-up of 26.4 years, the survival and success rates of 33 transplanted premolars were 90% and 79%, respectively. Jonsson and Sigurdsson128 also reported a 92.7% success rate of 40 transplanted premolars in premolar sites during a mean observation period of 10 years and 4 months, while Mensink et al,129 after a mean 1.76-year follow-up period, observed a 100% survival rate of 44 transplanted premolars. Finally, in a study by Kvint et al,130 after a mean 4.8-year follow-up period, the success rate of the autotranplanted premolars in the maxillary lateral incisor region was 100%.

Orthodontic space closure

Orthodontically moving canine(s) into contact with the central incisors rather than maintaining or opening the maxillary lateral incisor edentulous space— namely, orthodontic space closure via canine substitution—the need for prosthetic replacement of the maxillary lateral incisor is eliminated. Afterward, when orthodontic space closure has been completed, canine(s) and first premolar(s) should be carefully altered to resemble and function as lateral incior(s) and canine(s), respectively. Contrary to the aforementioned treatment approach, the occlusal scheme created by orthodontic space closure implies an anterior group function during lateral excursions instead of canine-protected occlusion.83,131,132 Orthodontic space closure is indicated for patients presenting (1) an Angle Class II occlusion with no crowding in the mandibular arch,133 (2) an Angle Class I occlusion with severe crowding or protrusion to dictate mandibular extractions,133 (3) a balanced, relatively straight, or even mild convex profile, in conjunction with normally inclined anterior teeth and minimal or no space available in the maxillary arch,133 and (4) anterior maxillary teeth severely protruded or tipped labially,72 since orthodontic space opening will worsen such a situation. 304


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Unacceptable candidates for orthodontic space closure are patients presenting (1) a moderately convex profile,133 (2) a retrusive mandible,133 or (3) a deficient chin prominence.133 When considering orthodontic space closure for patients with congenitally missing lateral incisor(s), canine substitution puts forward as a major advantage the permanence of the initial treatment outcome in comparison with the other types of rehabilitation.83 Also, normal gingival and alveolar architecture can be established through mesial movement of the canine in the position of the maxillary lateral incisor.134 In this way, the need for removable retainers until implant placement can be avoided.134 Natural dentition presents a better chance of preserving the amount of alveolar bone in the region of the maxillary lateral incisor than all the other prosthetic options. This allows the clinician to attain a favorable esthetic result concerning the management of marginal gingival contours. Moreover, by moving the maxillary canines into the maxillary lateral incisor positions, the possibility of third molar impaction decreases.81,83 The main disadvantage of orthodontic space closure is the tendency to recreate interdental spaces (space reopening) among the anterior teeth of young patients after the end of treatment.135 However, this complication can be avoided, provided that the orthodontist performs long-term fixed retention with a lingually bonded flexible spiral wire retainer from the first premolar to the first premolar in the maxilla.136 It is evident that the success of orthodontic space closure is contingent upon the clinician’s ability to transform the repositioned canine(s) and first premolar(s) into lateral incisor(s) and canine(s), correspondingly. Considerable efforts must be made to provide the optimal tooth labial aspect, shade, contour, marginal gingival contours, and crown torque and rotation. For these reasons, after the teeth have been orthodontically moved to their terminal position, the need for special corrective procedures arises so as to achieve normal occlusion and an optimal esthetic appearance. The set of available corrective procedures should serve the following treatment goals:


• Esthetic reshaping of canine: Remorphologization. Enameloplasty, composite buildups, porcelain laminate veneers, or combinations of the above are means of esthetic canine reshaping.136 Kokich and Kinzer133 suggested that the ideal anatomy of the maxillary lateral incisor substitute entails a canine that: (1) is narrow at the cementoenamel junction buccolingually and mesiodistally for creating a more esthetic emergence profile, (2) presents a relatively even labial surface, and (3) has a narrow midcrown width buccolingually. Careful reduction of canine enamel by grinding with diamond instruments (enameloplasty) is necessary to obtain incisoform contours.133 When enameloplasty is decided upon, the wider mesiodistal dimension of the canine (on average, 1.2 mm wider than the lateral incisor)79,83 requires reduction of its distal surface, which is too convex for an incisor substitute.132 Proximal reduction of the canine should be limited and carried out when access to the proximal surfaces is more attainable.137 In addition, for the purposes of eliminating premature contacts with mandibular incisors, the reduction of the canine palatal aspect and incisal edges should be considerable.72 Regarding the grinding of the labial surface of the canine, this should be accomplished with respect to dental tissue and at the end of orthodontic treatment to achieve high bond strength of the orthodontic bracket.138 Finally, undesirable reactions of pulp, such as sensitivity to cold and heat, can be prevented with abundant water cooling, air spray, preparation of smooth/self-cleansing surfaces, and topical fluoride applications.137,139 • The use of ultra-thin porcelain laminate veneers is recommended in young patients after the end of orthodontic treatment to avoid the risks of the Volume 12, Number 4, 2011 © 2011 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.

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Fig 1 (a to c) Examples of space closure and canines in the position of missing maxillary lateral incisors. (d to f) Posttreatment photographs. The alterations of maxillary lateral incisor shape include composite buildups. Soft tissue architecture provides an attractive appearance. On the right side, the gingival margins of the central incisor and “new canine” are not at the same level. However, “new lateral incisor” gingival margins are more incisal than central incisor. The shape and size of relocated canines after composite builds up are consistent with the normal maxillary lateral incisor morphology.

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(1) perforation of large pulp cavity during full-crown preparation and (2) exposure of gingival crown margins during canine eruption.140,141 Correction of color disparity between canine and central incisor. Color harmony among the anterior teeth is another need that should be properly fulfilled in cases of canine substitution. Because maxillary canines are usually one or two shades darker than the central incisors,133 the color disparity between central incisors and new lateral incisors with no doubt compromises smile esthetics and therefore needs to be eliminated. Ideally, the color of the repositioned canine should approximately that of the central incisor.133 This can be achieved by either in-office or at-home bleaching procedures.136 Recontouring of gingival architecture. The ideal gingival architecture of the anterior maxillary segment dictates that central incisors and canines should have their gingival contours at the same level.142 In addition, those of the maxillary lateral incisors should be approximately 1 mm incisal from this level142 (Fig 1). Whenever a high smile line exists, canine substitution may cause esthetic problems in the anterior gingival architecture.143 To avoid unfavorable esthetic results, clinicians should carry out orthodontic extrusion of the canine and orthodontic intrusion of the first premolar.136 Provision of optimal torque. Crown torque of the relocated canine should be similar with the favorable crown torque of the maxillary lateral incisor.136 Not only canines but also the medially positioned first and second premolars should obtain the optimal crown torques.136 Functional occlusion. According to some authors,2,132 there is no substantial difference in the efficiency of functional occlusion between groups treated with space closure or with space opening treatment approaches. Therefore, when space closure with canine substitution is decided, the functional occlusal scheme involves the provision of an anterior group function during the lateral excursive movements.83,131,132 To avoid occlusal overloading as a result of mesial movement of maxillary canines, occlusal equilibration has been suggested.143 Moreover, both grinding of the canine incisal edges to avoid premature contacts136 with mandibular incisors as well as flattening of first premolars to limit cross-tooth balance interferences81 are considered essential.


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PROFESSIONAL AND LAYPErson PREFERENCES In reviewing the literature about maxillary lateral incisor agenesis, one can find studies reporting professional and layperson preferences with regard to possible treatment options. A recent study144 was conducted to determine and compare the laypeople’s and dental professionals’ views concerning the outcomes of maxillary lateral incisor agenesis treatment, including space closure with canine substitution or space opening with prosthetic replacement. The study aimed to specify among the respondents the factors that cause satisfaction or dissatisfaction. The panel of respondents consisted of 30 patients with no maxillary lateral incisor agenesis who had received orthodontic treatment for other types of malocclusion, 20 patients with maxillary lateral incisor agenesis, 20 parents of patients with maxillary lateral incisor agenesis, and 20 general dentists. Panel members were asked to determine the overal treatment outcome, the disturbing situations, and the treatment needs and goals of 16 cases with maxillary lateral incisor agenesis. The treatment included space closure, resin-retained restorations, porcelain-bonded-to-gold restorations, and implant restorations. Among panel members, 38% of general dentists estimated the overall treatment result as good, whereas only 18% of laypeople shared the shame opinion. With regard to the most disturbing factors of treatment results, general dentists ranked from most to least significant the following: color of the teeth (40%), shape of the teeth (26%), and asymmetry/midline shift (13%). Laypeople rated also the color of the teeth as the most disturbing situation followed, however, by spacing (19%) and shape of the teeth (16%). Furthermore, 51% of general dentists considered that there was no need for treatment, opposed to 19% of laypeople who held the same opinion. Tooth color and shape were thought as the main treatment goals by 23% and 19% of general dentists, respectively. Laypeople considered color (41%), space condition (15%), and the shape of the teeth (13%) to be the most significant treatment goals. Generally speaking, in all three aspects analyzed, there was a significant difference between general dentists’ and laypeople’s views. The most statistically significant difference between them concerned the treatment goal. In addition, the study concluded that the color of the teeth was considered to be the most disturbing as well as the most reported treatment goal by all four groups. Laypeople also expressed a more critical attitude than general dentists toward the four aspects of treatment. No midline shift, finally, was of great importance in cases treated with unilateral space closure. A second study3 included a sample of 50 patients who had maxillary lateral incisor agenesis. Thirty patients were treated by orthodontic space closure with canine substitution. The other 20 patients accepted prosthetic replacement of maxillary lateral incisors with porcelain-bonded-to-gold and resin-bonded FPDs. The patients of both groups were examined for the functional status, dental contact patterns, periodontal condition, and quality of the prosthetic replacement. In addition, they were asked to express their opinion about the esthetic result (regarding tooth shape, tooth color, space conditions, and symmetry of the maxillary anterior teeth) according to a modified version of the Eastman Esthetic Index questionnaire. The study concluded that patients with prosthetic replacements presented a greater tendency to accumulate plaque and develop gingivitis, whereas significant differences in the prevalence of signs and symptoms of temporomandibular dysfunction were not observed between the two groups. Patients treated with orthodontic space closure generally seemed to be more satisfied with their dental appearance than those in the prosthetic replacement group. However, it is remarkable that 55% of patients in the orthodontic space closure group expressed dissatisfaction because there


Volume 12, Number 4, 2011 © 2011 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.

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was color imbalance between canines replacing the maxillary lateral incisors and the adjacent teeth. The drawback of this study was that single implant– supported restorations were not included. In another study, Armbruster et al145 attempted to identify in what way general dentists, combined specialists, orthodontists, and laypeople valued the relative attractiveness of a series of photographs that depicted the treatment outcomes in cases of maxillary lateral incisor agenesis. The cases were treated with FPDs, dental implants, and orthodontic space closure with canine substitution. The study included cases of normal dentition with no missing teeth as controls. The results revealed that the respondent group of laypersons evaluated the category of photographs depicting the canines as lateral incisors as the most attractive, followed, in order, by the groups of no missing teeth, FPDs, and implant restoration. “No missing teeth” was considered to be the most appealing treatment option to all the other groups. There was a statistically significant difference among the four ratings in the group of orthodontists who weighed from best to worst the following treatments options: no missing teeth, canines as lateral incisors, FPDs, and implants. With regard to general dentists, they rated no missing teeth and canine substitution as the best esthetic treatment choices, with no statistically substantial difference between them, followed by FPDs. According to them, treatment with implants was the least important rating. Finally, for the combined dental specialists, “no missing teeth’’ and “canines as laterals incisors” were assessed almost equally as the best treatments, followed by FPDs and implant therapy. In the second part of the retrospective study of Armbruster et al,146 general dentists, combined specialists/orthodontists were asked to select their preferable treatment in cases with maxillary lateral incisor agenesis, namely prosthetic restorations or space closure with canine substitution. A substantially greater percentage of general dentists and dental specialists would choose the prosthetic restoration of the maxillary lateral incisors to achieve better esthetic results. According to the group of orthodontists, prosthetic replacement of maxillary lateral incisors and canine substitution mattered almost as equally as treatment options. With regard to the question of whether the primary reason for restoration of missing lateral incisors was the provision of function or esthetics, the higher percentage of all groups responded the esthetic factor. Finally, it is worthy of mentioning that 81% responded that the treatment approach of canine substitution could provide proper esthetics, while only 47% of general dentists and 50% of specialists held the same opinion. A study of Louw et al147 aimed to investigate which orthodontic approach would be chosen by orthodontists of the British Orthodontic Society in cases of maxillary lateral incisor agenesis. Two groups of orthodontists were included in this study—group 1 consisted of orthodontists who worked solely in an orthodontic practice environment, while group 2 consisted of orthodontists who worked full- or part-time in an environment with access to advice from restorative dentists. The study demonstrated that a significantly greater number of orthodontists of group 1 would select space closure as treatment in cases of maxillary lateral incisor agenesis. Conversely, more orthodontists in group 2 were likely to select resin-retained FPDs or dentures, as well as getting informed by restorative dentists before the beginning of orthodontic treatment. Moreover, regarding the question of how they treated cases with maxillary lateral incisor agenesis, a higher percentage of orthodontists from group 1 responded space closure, whereas a greater number of orthodontists from group 2 responded the resin-retained FPDs. This study concluded that factors such as the practice environment, experience, and availability of restorative dental advice affected the treatment approach of maxillary lateral incisor agenesis that involved either space closure or resin-retained FPDs. However, these factors had no impact when the treatment plan included dental implants.


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A study of Brough et al148 was conducted to determine whether the variances in canine morphology, shape, and shade would affect the orthodontists’, dentists’, and laypeople’s perceptions of the esthetic smile in cases of maxillary lateral incisior agenesis treated with space closure and canine substitution. The study consisted of three groups (orthodontists, dentists, and laypeople) of 40 judges. A photo of a case with bilateral maxillary lateral incisor agenesis treated with space closure and canine substitution was digitally modified regarding canine shape, width, crown tip, and shade, creating four groups of images. The judges were asked to rank the most and least attractive photograph in each of the four groups, as well as the most and least attractive smile of all images. Generally, orthodontists selected narrow rather than wide teeth, natural shades, gingival margins just 1 mm below the level of the central incisor, and rounded tips. Dentists preferred a less narrow or averagesized tooth, as well as a tooth shade darker than the orthodontists did. There was a variability of opinions among laypeople, but in general, preferred narrower (3.0-mm narrower) and slightly brighter canines than the orthodontists and the dentists did. Also, both the laypeople and dentists selected a canine gingival height 0.5 mm below central incisor level. In general, increasing pointed canine tips and widths as well as dark canines were found highly unattractive by all groups. The most commonly appealing photograph overall concernednarrow canine crowns, whereas the photograph with canines 20 times darker than the original was considered to be the least attractive. Both orthodontists and dentists disliked a greater than 1.0-mm increase in canine tip while laypeople also liked a 1.0-mm (but not greater than 1.5-mm) increase in canine tip height. A clinical study of Bukhary et al77 aimed at determining the impact of varied maxillary lateral incisor dimensions on perception of smile esthetics. A photograph of a female smile displaying only her lips and teeth was digitally modified to create six maxillary lateral incisor widths at 52%, 57%, 62% (the golden proportion), 67%, 72%, and 77%. In a second group of photos, the length of the lateral incisor was altered at 0.5-mm increments. Five images with the lateral incisor 0.5, 1.0, 1.5, 2.0, and 2.5 mm shorter than the adjacent central incisor were produced. The photos were judged for their attractiveness by 41 hypodontia patients, 46 nonhypodontia control patients, and 30 dentists. The study concluded that the golden proportion (62%) is not a single value but rather a range taking into account that the 67% lateral-to-central width proportion was most preferred by all groups. Also, the general trend among respondents concerned a wider maxillary lateral incisor. Although hypodontia patients preferred longer maxillary lateral incisors compared with the other groups, the general perception of the maxillary lateral incisor length is 1.0 to 1.5 mm shorter than the central incisor. The very short and very long maxillary lateral incisors were consistently assessed as the least attractive.


DISCUSSION Dental agenesis of maxillary lateral incisors is a developmental anomaly that creates esthetic and functional problems. In the majority of cases, genetic defects are responsible for the arrest of tooth development in humans. However, so far, the specific genetic origin that causes maxillary lateral incisor agenesis has scarcely been identified.149 In cases in which the treatment of congenitally absent maxillary lateral incisors has been delayed, patients present problems, including drifting of teeth. For this reason, prompt diagnosis provides adequate time for clinicians to evaluate the available treatment alternatives and commence the proper one in a timely manner and with enhanced perspectives. Volume 12, Number 4, 2011 © 2011 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.

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Convex Class I (with mandibular crowding) Class II (without mandibular crowding) Bilateral No Crowding High Easily modified

Approach determinants Facial profile Underlying class

Concave Class III malocclusion

Type of absence Multiple teeth absent Arch alignment Smile line Canine shape/color

Unilateral/bilateral Yes Spacing Low Hardly modified

Space closure

Space opening

Orthodontic treatment

Orthodontic treatment

+

+

Orthodontic retention

Orthodontic retention

Canine Substitution Evaluation/correction of: • Shape → General dentist, prosthodontist, orthodontist • Color → General dentist, prosthodontist • Gingival contour → Periodontist, general dentist, orthodontist • Occlusion → General dentist, prosthodontist, orthodontist

Treatment modalities • Fixed tooth-supported restorations → General dentist, prosthodontist • Implant-supported restorations → Oral surgeon, periodontist, prosthodontist, general dentist • Autotransplantation of premolars → Oral surgeon, periodontist, general dentist • Removable dentures → General dentist, prosthodontist

Fig 2 Chart to help clinicians quantify all determinants and not consider each of them individually.

Dental agenesis is perceived as a multidimensional clinical problem. Its management has gained the attention not only of several dental specialties (pediatric dentistry, orthodontics, implant dentistry, periodontics, oral surgery, and prosthodontics), but also of pediatrics (in case of coexisting dental anomalies with systemic syndromes) and genetics for the identification of gene defects. Similarly, in cases of congenitally missing maxillary lateral incisors, the appropriate management presupposes teamwork and a multidisciplinary treatment approach. Among the specialists involved, orthodontists have a crucial role in developing the treatment plan because they have to solve the dilemma concerning which approach should be followed. In fact, their decision needs to derive from meticulous evaluation of certain determinants having a powerful effect on the treatment outcome rather than rising from an arbitrary judgment based on personal or empirical opinions. Determinants such as the patient’s skeletal pattern, facial profile, smile line, absence or not of multiple teeth, and canine color and shape should be always assessed since they are basic elements of thethe treatment algorithm (Fig 2). When space opening is determined, the trend among clinicians concerns the replacement of maxillary lateral incisors with dental implant restorations. Although the survival rates of single-tooth implants exceed 90% in the majority of studies,150–153 there is a lack of evidence about the long-term biologic complications of implant restorations.98 It is noteworthy that during a 10-year follow-up of dental implant restorations, Thilander et al101 reported infraocclusion as a complication of implants in the anterior region of maxilla even after the end of growth, as well as a substantial loss of marginal alveolar bone in tooth surfaces adjacent to dental implants. To avoid the possible esthetic complications of implant restorations (Fig 3), Rosa and Zachrisson136 considered that the presence of gummy smiles indicates that the space closure approach should be 310


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a

a

c

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Fig 3 (a) Panoramic radiograph showing agenesis of multiple teeth. Maxillary lateral incisors are among the missing teeth. Canines have significantly drifted mesially next to central incisors. (b) Mesial drifting of canines next to central incisors. (c) A fixed orthodontic appliance and provisional acrylic teeth in the maxillary lateral incisor positions to maintain space. (d) Definitive restorative treatment of missing maxillary lateral incisors with implant restorations. Despite the establishment of an Angle Class I occlusion, the implant restorations did not result in optimal esthetics because of blue coloring in the labial gingiva of the maxillary left lateral incisor region.

preferred. Otherwise, if the treatment plan necessarily dictates space reopening, this should be alternatively applied in the region of the premolars.110 The presence of undesirable buccal corridors may be a drawback for smile esthetics when canines are orthodontically moved in the position of the maxillary lateral incisors. Buccal corridors occur as a result of the reduction in the arch circumference.61 Zachrisson,153,154 however, in extraction cases, suggested adding labial torque of the lingually inclined permanent canines and premolars, which diminishes this esthetic drawback. The prominence of the canine root eminence132 is another esthetic concern of the space closure approach in patients with high smile lines. Henns,155 however, considered that the aforementioned element has been overstated as an esthetic implication. In a space-opening approach followed by implant restorations, Park et al61 underlined the importance of permanent canine eruption in the placement of maxillary lateral incisors. Afterward, by distally repositioning the teeth, an adequate amount of bone will be developed in the position in which an implant will be inserted, which may create better perspectives for optimal esthetics.61 With regard to Class I malocclusions with no mandibular crowding and dentoalveolar protrusions, space opening is preferable.61 In contrast, Class II malocclusions with canines that have already erupted in the position of missing lateral incisors are treated easily through space closure with canine substitution.61 The distalization of molars, premolars, and eventually canines seems to be mechanically difficult because of the concavity between canine and first premolar roots.61 Patients with congenitally missing maxillary lateral incisors and skeletal Class III appearance should be treated with space opening followed by prosthetic rehabilitation, which will support the upper lip. The existing skeletal disharmony can be camouflaged.143 Volume 12, Number 4, 2011 © 2011 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.

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Fig 4 Bilateral maxillary lateral incisor agenesis treated with space closure followed by canine substitution. The finished outcome is inferior in terms of optimal esthetics. After space closure, the modification procedures were only restricted in tooth grinding. Optimal gingival architecture was not achieved because the gingival margins of the central incisors and “new canines” are not at the same level. Also, the “new lateral-relocated canines” are pointed and wide and, therefore, differ from normal maxillary lateral incisor shape. This figure underscores the importance of alteration procedures to achieve optimal esthetics.

Taking into account patients’ frontal view, it may be more efficient to select space closure as a treatment option in oval faces rather than in square ones. Patients with Class II, division 1 occlusions present usually convex profiles, as well as oval/mesocephalic to dolichocephalic faces.156 Common intraoral findings in these patients are the narrow, V-shaped maxillary arches156 that make the orthodontic recovery of the appropriate space for the maxillary lateral incisor rehabilitation more difficult. On the contrary, in patients with Class II, division 2 occlusion and brachicephalic frontal view, broad, U-shaped maxillary arches often exist.156 Therefore, in these patients, the space-opening treatment option may be more feasible, especially when multiple interdental gaps exist. Some inferences can be drawn when comparing the available two approaches. Space closure seems to be a more conservative, biocompatible, and simplified approach, while space opening implies surgical procedures and advanced restorative techniques. In addition, when space opening is followed by dental implant restorations, overall treatment time and cost increase. The outcome of both treatment approaches is not enough to restore only function but must lend an acceptable appearance. Space closure with canine substitution may compromise optimal esthetics if the shape, color, and gingival contours of the canines are not in harmony with adjacent teeth (Fig 4). Likewise, each prosthesis means requires precision and skillfulness during the construction and restoration procedures to achieve long-term stability of the optimal esthetic result. The longevity of rehabilitation is also a matter of concern for both alternative approaches. Space closure offers the advantage of rehabilitation with a natural substitute, which creates better perspectives for long-term maintenance. On the other hand, each of the prosthesis means following space opening presents a decrease in survival rates over time and increase in occurrence of complications. When space opening is indicated, autotransplantation should always be considered by clinicians instead of prosthetic restorations. Although it involves demanding surgical procedures, this method represents a valuable option that provides biocompability since the maxillary lateral incisor substitute is natural (premolar) and not artificial, such as a dental implant. The high long-term success rates of autotransplantated teeth indicate predictability and highlight their capability for functional adaptation. The reported divergence—either mild or significant—between laypeople’s and clinicians’ preferences in the perception of ideal esthetics dictates that clinicians should take into account patients’ realistic expectations and realize that treatment plans need to be individualized. Different preferences in recommending approaches among dental professionals indicate that the multidisciplinary approach may be useful to eliminate biases and provide better treatment plans covering all the patients’ dental needs. It is evident that randomized controlled studies are needed in the future to compare survival rates and esthetic outcomes of the available means of rehabilitation and report patient satisfaction ratings regarding the finished result.

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CONCLUSION Maxillary lateral incisors represent one of the most common congenitally missing teeth, and the etiology of its agenesis has not been completely identified. Early investigation of maxillary lateral incisor agenesis, as well as careful evaluation of treatment determinants through a multidisciplinary approach, are essential for the proper management of clinical problems. The current literature review illustrated that each of the available means of rehabilitation has its own advantages, disadvantages, indications, and limitations. The configuration of the treatment plan, as it was also pointed out in this review, should be devoid of the existing clinician’s biases and satisfy the patient’s realistic expectations.


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