Eruption Of Maxillary Canines Research Articles

Editor's Summary and Q&A: Percentiles relative to maxillary permanent canine inclination by age: A radiologic study

<h3>Introduction</h3> Few studies have investigated developmental norms for maxillary permanent canine eruption. In this observational cross-sectional study, we aimed to provide an age-related description of the percentiles relative to canine inclination in a large sample of nonorthodontic patients. Associations between inclination and sector were also analyzed. <h3>Methods</h3> Canine inclination and sector location were measured on 1020 panoramic radiographs obtained from subjects of white ancestry aged between 8 and 11 years not seeking orthodontic treatment. The total sample comprised 2037 canines. <h3>Results</h3> Canine inclination increases between 8 and 9 years and decreases between 9 and 11 years. The greatest value for each percentile is at 9 years. A linear model should be hypothesized for differences in canine inclination between 2 successive ages in correspondence to each percentile. The proportion of sector 2 canines decreases and that of sector 1 increases with age. In the same age group, the inclination generally decreases as the sector decreases. <h3>Conclusions</h3> Percentiles by age show the average canine inclination in a certain population. Further studies are required to verify whether percentiles can be a diagnostic aid for determining normal canine inclination at a given age and for quantifying the risk of canine impaction or adjacent root resorption.

Alignment of Impacted Maxillary Canines: Critical Analysis of Eruption Path and Treatment Time

The aim of this study was to evaluate a possible correlation between treatment time and the distance covered by the canine tip during forced eruption of impacted maxillary canines. We also addressed the question whether it is possible to estimate the treatment time based on this data. Orthopantomograms of 57 juvenile patients below 18 years of age with at least one palatally impacted canine were examined. We determined the position of the canine in relation to the neighboring teeth, its axial inclination and distance to the occlusal plane. We also introduced a new linear measurement representing the distance covered by the canine's crown tip during the alignment of the impacted tooth. The length of overall treatment time and canine alignment, its axial inclination and the distance covered by the canine correlated significantly with the canine's position relative to its neighboring teeth. The newly-introduced linear measurement was the only measure that proved gender specific. With regression analysis we demonstrated that this measure is sufficient to predict the active treatment time for canine alignment (r(2) = 0.391). This indicates that 39.1% of the differences observed in active treatment time can be explained by variation in this new parameter. The new measure introduced in this study provides a practice-oriented parameter with which to predict the treatment time for aligning impacted canines. Current 2D imaging diagnostics most likely restrict the ability to predict the length of therapy at 40%. Individual bone density and metabolism seem to have a strong influence on treatment time and must be taken into account for a more exact prognosis.

Radiographic assessment of dental anomalies in patients with ectopic maxillary canines

The aetiology of palatally and labially located ectopic maxillary canines is multifactorial. Accordingly, early prediction of this eruptional disturbance is in most cases not possible. The purpose of this study was to analyse dental deviations in cases with either palatal or labial ectopic canines. Panoramic and intra-oral radiographs from 50 patients with palatally located (38 females and 12 males) and 19 patients with labially located ectopic canines (11 females and 8 males), aged 10 years, 2 months-18 years, 1 month, were analysed. Dental deviations registered were crown and root malformations, agenesis, and eruption deviations. Registrations were performed in the maxillary incisor field and in the dentition in general. The study documented that palatally as well as labially located ectopic canines can occur in dentitions without other dental deviations. Dental deviations occurred in approximately two-thirds of all cases, more often in females and in cases with palatally located canines. More than half of the females with palatally located canines had deviations in the maxillary incisors and in the dentition in general. Dental deviations may be considered a risk factor for maxillary canine ectopia. Early identification of patients at risk and appropriate interceptive treatment may reduce ectopic eruption of maxillary canines.

Management of Ectopic Maxillary Canines

To document and analyze factors involved in decision-making by orthodontists in managing disturbances of eruption of maxillary canines. The participants comprised orthodontic specialists and active members of the Swedish Orthodontic Society. Those selected for the study sample were under 65 years of age or younger and had been treating orthodontic patients for at least 1 year as a specialist. Three typical cases were presented for treatment proposals. The case notes, including radiographs and specific background data, were sent to the 182 selected orthodontists. The orthodontists were also requested to complete a questionnaire about practice profile, comprising eight questions. The response rate was 86.3%; yielding 157 participants (mean age 53.8 years, SD 8.12). Analysis disclosed no differences between responders and nonresponders regarding age, gender, and years of specialist practice. For treatment plans based on panoramic radiographs, intraoral radiographs, and status and anamnesis, there was general consensus. However, when supplementary information from computer tomography (CT) was provided, disclosing root resorption half-way to the pulp or more on the lateral incisor, the orthodontists' treatment proposals varied. Gender, age, and practice profile of the orthodontists had little association with the decision-making. Supplementary CT information led to variations in decision-making with respect to treatment of eruption disturbances of maxillary canines. This lack of consensus among specialist orthodontists can have negative implications for patients.

Eruption of the maxillary canines in relation to skeletal maturity

Our aim in this study was to assess the relationship between the eruption of the permanent maxillary canines and skeletal maturity in subjects with different skeletal relationships in the sagittal and vertical planes. A sample of 152 subjects (63 boys, 89 girls) with erupting permanent maxillary canines was analyzed. On the lateral cephalograms, the stage of cervical vertebral maturation was assessed. Then the subjects were divided into prepeak (before the pubertal growth spurt, cervical stage [CS]1 and CS2), peak (during the pubertal growth spurt, CS3 and CS4), and postpeak (after the pubertal growth spurt, CS5 and CS6) groups. Skeletal relationships in the sagittal and vertical planes were evaluated, and relationships to timing of canine eruption were tested statistically. The prepeak group comprised 86 subjects, the peak group 66 subjects, and the postpeak group 0 subjects. The differences in prevalence rates between either the prepeak or peak groups and the postpeak group were statistically significant (P < 0.001). The prevalence rate for hyperdivergent subjects showing eruption of the permanent maxillary canine in the prepeak group (37.2%) was significantly higher than in the reference orthodontic population (21%). The eruption of the permanent maxillary canine can occur at any stage in skeletal maturation before the end the pubertal growth spurt (CS1-CS4), with hyperdivergent subjects more frequently having prepubertal canine eruption.

Premaxillary Osteotomy and Guided Tissue Regeneration in Secondary Bone Grafting in Children with Bilateral Cleft Lip and Palate

To introduce a surgical technique for secondary alveolar bone grafting performed in conjunction with premaxillary osteotomy and guided tissue regeneration in children with bilateral clefts. This paper also looks at the outcomes of this surgery in a series of 15 consecutive patients. Secondary alveolar bone grafting (with a premaxillary osteotomy and guided tissue regeneration with a collagen membrane) is usually carried out in the mixed dentition stage. This retrospective study used patients' medical records, radiographs, and clinical examination to assess the outcome of the surgery. Patients were followed up for an average of 3 years. Bone grafting was successful in all cases. No premaxillae were lost and there was no long-term morbidity of the donor site. Radiographic assessment of the bone heights showed an average of 94% retention, 3 months postoperatively. Preliminary assessment of maxillary canine eruption is encouraging, with 79% being fully erupted in those patients who are at least 3 years post-bone grafting. Premaxillary osteotomy allows repositioning of the premaxilla to its optimal preplanned position and successful closure of all fistulae. We have found that use of a collagen membrane is a useful adjunct.

Ensuring Success in Alveolar Bone Grafting

Alveolar bone grafting is an integral part of correcting dental arch interruption in those with cleft lip and palate. Often included within a combination of treatment modalities, alveolar grafting must be conducted in a technically effective manner and at the appropriate stage of development in order to maximize outcome and avoid morbidity. Although much regarding this procedure remains unclear, continued research and experience has provided several key insights. Bone grafting appears optimal between maxillary growth completion and maxillary canine eruption (usually between 8 and 10 years of age). Coordination of efforts and planning between surgeon and orthodontist is imperative. Correction of the alveolar defect helps not only restores dental arch continuity, but also supports the nasal base, stabilizes the maxilla, and restores volume to the lip. Appreciation of the 3-dimensional nature of the defect helps to reliably correct the defect in an anatomically correct fashion. Optimization of soft tissue, bony, and, periodontal conditions adjacent to the cleft help maximize the likelihood of success. Staging of the procedure is often necessary to maximize outcome and avoid unnecessary procedures. Here, we review several variables of alveolar bone grating based on current literature as well as our own experience.

Factors associated with the duration of forced eruption of impacted maxillary canines: A retrospective study

More information is needed to better predict the duration, cost, success rate, and incidence of complications when treating impacted maxillary canines. The aim of this study was to identify factors that affect the number of visits required to complete the canine forced eruption phase. Data from diagnostic and treatment notes and radiographs of 87 consecutive adult and adolescent patients were analyzed by stepwise regression analysis. The results indicated a strong direct correlation of the number of visits with the patient's age (P < .0001), the distance between the canine cusp tip and the occlusal plane (P <.0001), and the zone (P = .0058); mesially located cusps required more visits. A weaker inverse correlation was found with the beta angle (P = .0289), that is, and the angle between the canine and lateral incisor axes. No significant correlation was found with other variables, including sex and several linear and angular measurements made on panoramic and sagittal radiographs. Age, distance from the canine cusp tip to the occlusal plane, zone, and beta angle appear to provide a rather accurate estimate (R2 = 0.42) of the number of visits needed to complete the forced eruption phase. This information allows for a prediction that might be sufficient to give the patient correct information and to estimate the final cost of the treatment.

Association between ectopic eruption of maxillary canines and first molars

The purpose of this study was to elucidate a possible association between ectopic first molar eruption causing root resorption on the distal root of the primary maxillary second molar, and ectopic canine eruption causing root resorption on the permanent maxillary incisors. The subjects consisted of 30 patients, 22 females and eight males in the age range 8.3-15.0 years in whom root resorption of the permanent maxillary lateral and/or central incisor caused by the erupting permanent canine was diagnosed, and clinical and/or radiographic information concerning maxillary first molar eruption existed. It was found that of the 30 patients, seven (23.3 per cent) also had pathological root resorption of the second primary molar caused by ectopic molar eruption. It is suggested that patients with ectopic maxillary first molar eruption leading to pathological root resorption of the maxillary second primary molar are followed closely during the period of premolar and canine eruption, as the ectopic first molar could be an early warning of an increased risk of ectopic canine eruption leading to root resorption of the maxillary permanent incisors.

Severe incisor resorption by impacted maxillary canines: case report and literature review

This paper reviews the literature relating to incisor resorption caused by impacted maxillary canines, and describes the presentation and management of a patient with unusually severe early resorption. This case highlights the need for careful monitoring of maxillary canine eruption for all paediatric patients.

Root resorption: The possible role of extracellular matrix proteins

During maxillary permanent canine eruption, the deciduous canine root is selectively resorbed while the adjacent permanent lateral incisor root is left intact. An understanding of this selective resorption could provide insights into the cause of moderate to severe iatrogenic root resorption during orthodontic tooth movement. This study investigated the possible role of extracellular matrix (ECM) proteins in the selective resorption process. The spatial expression patterns of 2 ECM proteins, osteopontin (OPN) and bone sialoprotein (BSP), were assessed within the periodontal ligament (PDL) surrounding root surface areas of deciduous and permanent teeth. Intact and resorbed root surface areas from 14 deciduous roots and intact root surface areas from 12 permanent tooth roots were examined. In the deciduous roots, BSP and OPN were locally expressed in the cell layer adjacent to the root surface and most intensely concentrated in areas surrounding and within odontoclasts proximal to the resorptive lacunae. In contrast, BSP and OPN were expressed in a generalized pattern throughout the PDL of permanent roots. These preliminary findings suggest a differential expression of ECM proteins on deciduous versus permanent tooth roots, which could act as a signal for selective odontoclast adhesion to, and subsequent resorption of, deciduous root surfaces.

Clinical conditions for eruption of maxillary canines and mandibular premolars associated with dentigerous cysts

The aim of this study was to investigate the eruption of teeth associated with dentigerous cysts in the mandibular premolar and maxillary canine regions in preadolescents. Fifty-eight cyst-associated teeth, including 47 mandibular premolars and 11 maxillary canines, were examined retrospectively by using normalized panoramic radiographs and histological materials. The subjects were divided into 2 groups: the erupted group, in which the teeth had erupted successfully after marsupialization, and the nonerupted group, in which the teeth had undergone orthodontic traction or cystectomy with removal of the cyst-associated tooth. Eighty-one percent of the mandibular premolars and 36% of the maxillary canines in the cysts erupted successfully about 100 days after marsupialization without traction. The eruption of a mandibular premolar was significantly related to a shallow position in the alveolar bone, shallow angulation of the tooth, and young age of the patient but not to cyst size and dental space for the eruption. The eruption of the maxillary canine was significantly related to the small size of the cyst and the patient's age. The cyst walls of the erupted group showed severe inflammatory cellular infiltration. These findings present a treatment guideline for dentigerous cysts associated with mandibular premolars and maxillary canines in preadolescents.

Early and unusual incisor resorption due to impacted maxillary canines

A very early and severe case of maxillary incisor resorption caused by impacted canines is reported. An estimated 50,000 cases of ectopic eruption and impaction of maxillary canines occur each year in the United States. Although incisor resorption due to ectopically positioned permanent maxillary canines can be swift, silent, and devastating, an effective protocol has been developed for early detection and management of this condition. Palpation and, if indicated, radiographic evaluation are combined with primary canine removal in selected cases. These strategies—particularly when used early—can prevent the vast majority of palatally impacted maxillary canines and the potentially devastating resorption of adjacent incisors.

Dental anomalies as a microsymptom of palatal canine displacement.

A retrospective study was performed to investigate whether palatal canine displacement is associated with other dental features permitting early clinical diagnosis of the eruption disturbance. The study was based on the complete records of 235/8556 patients at the Department of Orthodontics, School of Dental Medicine, University of Freiburg i.Br. (mean age = 14.11 years) with at least one palatally displaced permanent canine. These patients were examined for ten different morphologic parameters, e.g. impaction and congenital absence of further teeth, hypoplastic, peg-shaped, rotated and congenitally missing upper lateral incisors, supernumerary teeth, Angle classification, and cover-bite (= "Deckbiss"). The data were compared with those of a control sample of the same size with physiologic upper canine eruption (mean-age = 10.0 years). Furthermore, in a right/left comparison the local influence of anomalies of the upper lateral incisors on palatal canine displacement was evaluated by multiple linear regression analysis. The statistical analyses revealed that the risk of palatal canine displacement was significantly higher in patients with hypoplasia, peg shape or congenital aplasia of upper lateral incisors, further impacted and congenitally missing teeth and cover-bite. The intergroup differences in terms of gender, rotation of upper lateral incisors and Angle classification were not statistically significant. The right/left comparison revealed a significantly higher risk of palatal canine displacement in association with an adjacent hypoplastic or peg-shaped lateral incisor and with aplasia of the contralateral upper incisor. The clinical significance of the study is that the occurrence of palatally displaced canines is often closely linked with other dental anomalies. In this context, anomalies of upper lateral incisors, aplasia or impaction of further teeth, and the anomaly of cover-bite may serve as indicators of palatal canine displacement. A retarded development of the upper lateral incisor seems to be more disturbing for physiologic canine eruption than aplasia. In patients exhibiting the stated microsymptoms, close clinical follow-up of the maxillary permanent canine eruption during the late exfoliation period is strongly recommended.

Early intervention in the transverse dimension: Is it worth the effort?

Am J Orthod Dentofacial Orthop 2002;121:572-4

Does the canine dental follicle cause resorption of permanent incisor roots? A computed tomographic study of erupting maxillary canines.

We performed computed tomography (CT) on 107 children and adolescents aged 9-15 years with 176 unerupted maxillary canines (152 erupting ectopically and 24 erupting normally) to determine whether there is an association between widened dental follicles of the maxillary canines and resorption of the adjacent incisors during eruption. Contiguous axial (transverse) CT scans were obtained through the maxilla in the region of the canines. The width and shape of the dental follicles were recorded, as were any contacts between the follicles and the crowns of the maxillary canines and neighboring incisors. Fifty-eight lateral incisors (38%) and 14 central incisors (9%) had some type of root resorption. The position of the maxillary canine in relation to the root of the lateral incisor varied greatly, as did the width and shape of the canine dental follicle. Follicle width ranged from 0.5 mm to 7.0 mm. The mean +/- SD width of dental follicles was, on average, larger for the ectopically positioned canines (2.9 +/- 0.8 mm) than for the normally erupting canines (2.5 +/- 0.8 mm) (P < or = .01). We found that during eruption, the follicle of the erupting maxillary canine frequently resorbed the periodontal contours of adjacent permanent teeth but not the hard tissues of the roots. We concluded that the dental follicle did not cause root resorption of permanent teeth. Resorption of neighboring permanent teeth during maxillary canine eruption was most probably an effect of the physical contacts between the erupting canine and the adjacent tooth, active pressure during eruption, and cellular activities in the tissues at the contact points, all of which are part of the eruptive mechanism. The findings also confirm an association between root resorption of deciduous canines and the dental follicles of erupting permanent canines.

Resorption of incisors after ectopic eruption of maxillary canines: a CT study.

The purpose of the study was to analyze the extent and prevalence of resorption of maxillary incisors after ectopic eruption of the maxillary canines in a sample of subjects referred to an orthodontic specialist clinic for consultation. The subjects consisted of 107 children, 39 boys and 68 girls, between 9 and 15 years of age (mean 12.5 years), with 156 ectopically and 58 normally erupting maxillary canines. All children were subjected to a basic clinical and intraoral radiographic investigation. These radiographs were supplemented with computerized tomography (CT) of the upper alveolar bones in order to get more precise information on the positions and relationships between the maxillary canines and adjacent incisors and to evaluate resorptions on the roots of the incisors. The results showed that, relative to the roots of the adjacent incisors, the crowns of 21% the ectopically positioned canines were located to the buccal, 18% to the distobuccal, 27% to the lingual, 23% to the distolingual, 5% apically and 6% between the central and lateral incisors. Ninety-three percent of the ectopically positioned canines were in contact with the roots of the adjacent lateral incisor and 19% were in contact with the central incisor. The corresponding figures for the normally erupting canines were 49%. Resorptions on the roots of the incisors adjacent to the ectopically positioned canine occurred in 38% of the laterals and in 9% of the centrals. The resorptions were graded and tended to be extensive. Among the 58 resorbed lateral incisors, resorptions were slight in 31%, moderate in 9%, and severe with pulpal involvement in 60%. The corresponding figures for the 14 resorbed centrals were 36%, 21%, and 43%, respectively. About 60% of the resorptions involved the middle and apical thirds, the tip of the apex not included. On the sides with normally erupting canines, 3 lateral maxillary incisors were slightly or moderately resorbed distally. In all, 51 of the 107 subjects with ectopically erupting maxillary canines (48%) had resorbed maxillary incisors during the eruption of the maxillary canines. There were statistically significant correlations between ectopic eruption of the maxillary canine, contacts between the teeth and resorptions on the adjacent incisors. It was concluded that resorption on maxillary incisors after ectopic eruption of the maxillary canines is a more common phenomenon than previously reported and has to be considered in all cases with seriously diverging eruption of maxillary canines. It was also concluded that the resorptions of the roots of the incisors were caused by pressure during the eruption of the adjacent, aberrant canine. Finally, it was shown that CT scanning substantially increased the detection of root resorptions on incisors adjacent to ectopically erupting maxillary canines (about 50%). The sensitivity of intraoral films was low when diagnosing the resorptions, being calculated to 0.68.

A postretention study of patients presenting with a maxillary median diastema.

The purpose of this study was to assess postretention stability of maxillary midline diastema closure, to search for predictors of relapse, and to test for associations between relapse and other postretention changes. The sample consisted of 35 patients with pretreatment diastemas ranging from 0.9 mm to 3.0 mm (mean 1.4, SD = 0.5) following eruption of the maxillary canines. Data were gathered from treatment charts, study models, periapical radiographs, and cephalograms taken pretreatment, posttreatment, and 1 to 26 years postretention (mean 11.4, SD = 6.4). Measurable diastema relapse was observed in only 12 cases. The majority of the relapse was 0.6 mm or less, and maximum relapse was 3.0 mm. Abnormal frenums and/or intermaxillary osseous clefts did not appear to be risk factors for relapse, and no pretreatment predictors of relapse could be established. The only posttreatment change associated with diastema relapse was proclination of the maxillary incisors (p < 0.01).

Extrusion of the ectopic maxillary canine using a lower removable appliance

The ectopic eruption and impaction of maxillary canines is a frequently encountered problem. The prevalence is estimated to be between 0.92% to 2.2%. 1,2 It is found to be palatal to the dental arch in about 85% of cases and buccal only in about 15% of cases. 3-5 Ericson and Kurol 6 suggested that removal of the deciduous canine before the age of 11 years will normalize the position of the ectopically erupting permanent canine in 91% of cases if the canine crown is distal to the midline of the lateral incisor. We strongly endorsed this interceptive approach. Early recognition that a canine is erupting ectopically is extremely important. Ericson and Kurol 7 estimate that in 0.71% of children in the 10 to 13 year age group, permanent incisors have resorbed because of the ectopic eruption ,of maxillary canines. Resorption may be found as early as 10 years but occurs most frequently in the age groups 11 to 12 years. 8 In this article a simple, well-clasped lower removable appliance is shown to be an excellent base for using light elastics to move the impacted canine, first posteriorly away from the incisor roots and then vertically and buccally. A gold chain is bonded to the unerupted canine to provide a simple and flexible means of traction that ensures the canine erupts into a zone of attached mucosa with normal crown length. (A M J O RTHOD D ENTOFAC O RTHOP 1995;107:349-59.)

Ectopic eruption of maxillary first permanent molars and association with other tooth and developmental disturbances.

The associations between tooth and eruption disturbances in four groups of children selected primarily with only one diagnosed eruption or developmental disturbance in each group was analysed. Ninety-two children were primarily diagnosed with ectopic eruption of maxillary first permanent molars, 93 children with infra-occlusion and ankylosis of primary molars, 91 children with ectopic eruption of maxillary canines, and 97 children with aplasia of premolars. Of the children studied 69-79 per cent had only a single one of the four disturbances studied. In 18-28 per cent there was one additional disturbance and in 2-3 per cent two additional disturbances. From chi square contingency tests, it was found that infra-occlusion of primary molars and aplasia of premolars exhibited a higher prevalence in both directions compared to the expected population prevalence. Ectopic eruption of maxillary canines showed a significantly higher prevalence than expected in all the other three groups. Our interpretation is that these results support the hypothesis of a common, presumably hereditary, aetiology. Thus, the four conditions studied would be different manifestations of one syndrome, each manifestation having an incomplete penetrance. With closer follow-up of the maxillary canines during the eruption period in children with some of the other three disturbances, prophylactic, or early interceptive measures may be taken and complicated orthodontic treatment be reduced or avoided.