Editorial Type:
Article Category: Research Article
 | 
Online Publication Date: 13 May 2022

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

,
,
,
,
,
, and
Page Range: 683 – 690
DOI: 10.2319/102221-788.1
Save
Download PDF

ABSTRACT

Objectives

To investigate whether absence of maxillary lateral incisor (MXLI) would affect the status of maxillary canine (MXC) before and after secondary alveolar bone grafting (SABG) in patients with unilateral cleft lip and alveolus (UCLA) and unilateral cleft lip and palate (UCLP).

Materials and Methods

47 male patients with UCLA and UCLP, whose Bergland indices were type I or II after SABG, were divided into the MXLI-absence (n = 26) and MXLI-presence groups (n = 21). Using panoramic radiographs, the position, angulation, and development status of MXC on the cleft side, and the cleft width before SABG (T1) were evaluated. After full eruption of the permanent dentition (T2), the root length, root shape, and frequency of forced eruption of MXC on the cleft side were investigated. Then, statistical analysis was performed.

Results

Compared to the MXLI-presence group, the MXLI-absence group showed higher frequencies of mesial angulation of MXC at T1 (criteria: >25°; 46.2% vs 14.3%, P < .05) and dilaceration of MXC at T2 (26.9% vs 4.8%, P < .001). MXC on the cleft side showed positive correlations between horizontal position at T1 and forced eruption at T2, and between vertical position and mesial angulation at T1 and dilaceration at T2 (all P < .01).

Conclusions

In patients with UCLA and UCLP whose SABG outcome was successful, absence of MXLI on the cleft side increased only the frequencies of mesial angulation of MXC at T1 and dilaceration of MXC at T2, not frequency of forced eruption at T2.

Keywords: Maxillary lateral incisor; Maxillary canine; Secondary alveolar bone grafting

INTRODUCTION

The main purposes of secondary alveolar bone grafting (SABG) for patients with alveolar cleft are to eliminate the bony defect and to allow eruption of the maxillary canine (MXC) into the graft site.1–3 The preferred timing of SABG is the mixed dentition period with half-completion of the root development of MXC, which is between 9 and 11 years of age.4

Despite SABG on the cleft side, the prevalence of MXC impaction is reported between 12% and 35%, which might be 10 times higher compared to that of a noncleft, normal population.3,5–8 The reasons for eruption disturbance of MXC in cleft patients might be related to genetic background, scar tissue formation after SABG, insufficient bone volume in the SABG site, and dental problems including congenitally missing or abnormal shape and size of the maxillary lateral incisor (MXLI), presence of a supernumerary tooth, and severe mesial angulation of MXC.5,8–11

In a systematic review, Lacerda-Santos et al.12 reported that, although a majority of previous studies reported an association between increased frequency of MXC impaction and agenesis of MXLI, the certainty of evidence was very low. Therefore, considerations for study design and methodology on eruption disturbance of MXC in relation to absence and presence of MXLI in cleft patients might be: (1) Limit subjects to a specific cleft type (ie, unilateral alveolar cleft) and sex (ie, boys) for increasing sample purity; (2) All patients should have undergone cheiloplasty, palatoplasty, and SABG with the same protocol in method and timing to minimize the confounding factors; (3) Follow-up until full eruption of the permanent dentition is needed for definitive diagnosis of eruption disturbance of MXC; and (4) Include subjects whose outcome of SABG was identical.

No previous study compared the position and angulation of MXC and cleft width before SABG (T1) and the root length, root shape, and frequency of forced eruption of MXC after full eruption of the permanent dentition (T2) according to the presence and absence of MXLI in preadolescent patients with unilateral cleft lip and alveolus (UCLA) and unilateral cleft lip and palate (UCLP). Therefore, the purpose of this retrospective study was to investigate whether absence of MXLI affected the status of MXC before and after SABG in patients with UCLA and UCLP. The null hypothesis was that there was no difference in the status of MXC before and after SABG in patients with UCLA and UCLP between those with presence and absence of MXLI.

MATERIALS AND METHODS

The initial samples consisted of Korean patients with UCLA and UCLP, who were treated at the Departments of Orthodontics and Oral and Maxillofacial Surgery, Seoul National University Dental Hospital (SNUDH), and the Department of Pediatric Plastic and Reconstructive Surgery, Seoul National University Children Hospital (SNUCH), Seoul Republic of Korea between January 2006 and December 2019. This retrospective study was reviewed and approved by the Institutional Review Board of SNUDH (ERI21032).

The inclusion criteria were (1) patients with UCLA and UCLP to be able to use MXC on the noncleft side as control; (2) male patients to avoid influence of sex; (3) patients with history of primary cheiloplasty (Millard rotation and advancement flap) at the age of 3–5 months and palatoplasty (Furlow double-opposing Z-plasty or V–Y pushback method for one-stage palatal repair) at the age of 12–18 months; (4) patients who underwent SABG with particulate cancellous bone and marrow from the iliac crest at age of 8–12 years; (5) patients who had a successful outcome 1 year after SABG (Bergland index type I (<25% bone resorption) and II (<50% bone resorption)2; (6) patients whose chart, photographs, radiographs, and three-dimensional computed tomography (3D-CT) were available; and (7) patients who were treated by a single orthodontist (SHB). When evaluation of the status of MXLI and MXC was difficult, 3D-CT was used for reference. The exclusion criteria were (1) patients who did not have MXC on the noncleft side; (2) patients with syndromic clefts or craniofacial anomalies; and (3) patients with endocrine diseases such as hyperparathyroidism that could affect tooth development and eruption.

As a result, the final sample consisted of 47 male patients with UCLA (n = 16) and UCLP (n = 31), who had undergone SABG. They were retrospectively divided into the MXLI-absence group (n = 26; 6 UCLA and 20 UCLP; missing MXLI on a single side [n = 23] and missing of MXLI on both sides [n = 3]) and the MXLI-presence group (n = 21; 10 UCLA and 11 UCLP; peg lateral incisor on one side [n = 18] and peg lateral incisors on both sides [n = 3]) (Table 1).

Table 1. Demographic Data of Subjectsa–e
Table 1.

The definitions of parameters used are presented in Figure 1 and Table 2. The horizontal and vertical positions and angulation of MXC on the cleft side and cleft width at T1, and the root length, root shape, and frequency of forced eruption of MXC on the cleft side at T2 were investigated by a single operator (HHS).

Figure 1.Figure 1.Figure 1.
Figure 1. The parameters used in this study. MXC indicates maxillary canine; MXCI, maxillary central incisor; MXLI, maxillary lateral incisor; MXP1, maxillary first premolar.

Citation: The Angle Orthodontist 92, 5; 10.2319/102221-788.1

Table 2. Parameters Used in This Studya
Table 2.

The Sample Size Determination Program Ver. 2.0.1 (SNUDH, Registration number 2007-01-122-004453) suggested 21 as the minimum sample size.

To assess intraexaminer reliability, 10 subjects were randomly selected using Random Number Generator (https://www.calculator.net/). The parameters were evaluated again one month later by the same investigator (HHS). The Cohen kappa agreement ranged from 0.615 to 1.000 and showed “substantial and almost perfect” agreement for the horizontal and vertical positions (MXC on the noncleft side; MXCI or MXLI and MXP1 on the cleft side), angulation, root shape, and forced eruption of MXC. Therefore, the first evaluation was used for further statistical analysis.

Independent t-test, chi-square test, the Fisher exact test, and the Spearman rho test were performed using SPSS (version 23.0; IBM, Armonk, NY, USA). A P value of less than .05 was considered statistically significant.

RESULTS

Demographic Data (Table 1)

The composition of cleft type, mean ages at T1 and SABG, and distribution of the Nolla stage,13 frequency of expansion therapy, and Bergland index type did not differ between the two groups (all P > .05), indicating that the subjects in the two groups were well matched.

Status of MXC and Cleft Gap Width at T1 (Tables 3 and 4)

Approximately 90% of patients showed normal horizontal position of MXC in the MXLI-absence and MXLI-presence groups. They did not differ in the distribution of normal and abnormal horizontal positions of MXC on the cleft side [(88.5% and 11.5%) vs (90.5% and 9.5%), P > .05].

Table 3. Comparison of the Position and Angulation of MXC on the Cleft Side at the T1 Stagea–e,*
Table 3.
Table 4. Comparison of the Cleft Width at the T1 Stagea
Table 4.

Compared to MXC on the noncleft side, MXCI or MXLI on the cleft side, and MXP1 on the cleft side, the two groups did not show a difference in the distribution of vertical position of MXC on the cleft side (all P > .05).

The MXLI-absence group showed a marginally higher mean angulation value (22.9° vs 15.4°, P = .051) and a higher percentage of mesial angulation compared to the MXLI-presence group (mesial and normal angulation: (46.2%, 53.8%) vs (14.3%, 85.7%), P < .05).

The two groups did not differ in the cleft width at the nasal 1/4 and middle 1/2 vertical levels (all P > .05).

Status of MXC at T2 (Table 5)

The two groups did not show a difference in the root length of MXC between the cleft and noncleft sides (normal length: all 100%; all P > .05). However, the MXLI-absence group showed a higher frequency of dilaceration of MXC compared to the MXLI-presence group (dilaceration and normal shape: [26.9%, 73.1%] vs [4.8%, 95.2%] P < .001]).

Table 5. Comparison of the Root Length, Root Shape, and Frequency of Forced Eruption of MXC on the Cleft Side at the T2 Stagea
Table 5.

Frequency of forced eruption of MXC on the cleft side of the two groups was very low, without a significant difference between the MXLI-absence and MXLI-presence groups ([7.7%, 92.3%] vs [9.5%, 90.5%]; P > .05).

Correlations Between the Status of MXC at the T1 and T2 Stages (Table 6)

MXC on the cleft side showed positive correlations between horizontal position at T1 and forced eruption at T2; and between vertical position and mesial angulation at T1 and dilaceration at T2 (all P < .01).

Table 6. Correlations Between Status of MXC at the T1 and T2 Stagesa
Table 6.

DISCUSSION

Parameters at T1

Horizontal and Vertical Positions and Angulation of MXC (Table 3).

Approximately 10% of patients showed horizontal overlapping between MXC and MXLI or between MXC and MXP1 on the cleft side regardless of absence and presence of MXLI at T1 (11.5% and 9.5%). However, successful SABG might have provided space for self-correction of horizontal overlapping between MXC and MXLI or between MXC and MXP1 on the cleft side. Therefore, all subjects in both groups exhibited normal horizontal position of MXC on the cleft side at T2. However, Russell and McLeod5 reported a difference in the pattern of the change in abnormal horizontal position of MXC after ABG: an increase from 22% to 32% in the MXLI-absence group and a decrease from 26% to 18% in the MXLI-presence group. The reasons for this difference might have been a difference in the cleft type (UCLA and UCLP vs UCLP and BCLP) and timing of ABG (late SABG vs early and late SABG) between the two studies.

The MXLI-absence group showed a relatively higher prevalence of the gingival position of MXC than the MXLI-presence group (compared to MXC on the noncleft side: gingival, 50% vs 38.1%; compared to MXCI or MXLI and MXP1 on the cleft side: sum of root cervical 1/4, root middle 1/2, and root apical 1/4: 64% vs 23.8%; 24% vs 4.8%). Hereman et al.9 reported that there was a great risk for MXC impaction on the cleft side in UCLP patients when the MXC position was more apical than one-third of the root of the adjacent MXLI. Similarly, Simões Holz et al.10 also reported that early risk indicators for MXC impaction in UCLP patients were a higher position of MXC and agenesis of MXLI on the cleft side.

However, in the present study, most patients in both groups showed normal eruption regardless of absence and presence of MXLI (92.3% and 90.5%). Russell and McLeod5 reported a decrease in the abnormal vertical position of MXC after ABG from 72% to 36% in the MXLI-absence group and from 43% to 36% in the MXLI-presence group. In addition, Oberoi et al.7 reported that the presence or absence of MXLI did not affect vertical eruption of MXC. Therefore, successful SABG might provide a space for normal eruption of MXC on the cleft side.

Hereman et al.9 and Westerlund et al.8 reported that there would be a great risk for MXC impaction on the cleft side when the angle between MXC and a vertical reference line is larger than 23.8° and 30°, respectively. Therefore, the criteria for deciding the mesial angulation was set as 25° in the present study. Although the MXLI-absence group showed a higher percentage of mesial angulation compared to the MXLI-presence group (46.2% vs 14.3%, P < .05), the frequency of forced eruption of MXC in the two groups was very low (7.7% and 9.5%). These findings suggested that successful SABG might provide a space for self-correction of mesial angulation of MXC on the cleft side. In other words, successful SABG might be more important than angulation of MXC for normal eruption of MXC on the cleft side.

Cleft Width (Table 4).

In the present study, successful SABG outcomes were achieved even in the moderate and wide cleft gaps at the middle 1/2 level in the MXLI-absence and MXLI-presence groups (19.3% and 19.0%). This was in agreement with Kim et al.,14 which reported that initial cleft width in patients with UCLA and UCLP did not affect the change in height, labiolingual bone thickness, and volume of the grafted bone. Therefore, successful SABG might provide a space for normal eruption of MXC regardless of the degree of cleft width.

Parameters at T2 (Table 5)

All subjects in both groups showed normal root length of MXC on the cleft side compared to the noncleft side. This was similar to the study by Park et al.15 that reported that, although the UCLP group showed delayed development of MXC on the cleft side compared to the noncleft side one month before SABG, the MXC on the cleft side developed faster than that on the noncleft side after SABG, eventually resulting in no difference in the Nolla stage.

The root development stage at the time of MXC bonding was mostly around 2/3 of root development. Since patients who obtained successful outcomes 1 year after SABG (Bergland index type I and II) were included as subjects in the present study, MXC might successfully move into the bone grafted site. These two factors can contribute to the normal shape of the MXC root, not root dilaceration. More root dilaceration of MXC was found in the MXLI-absence group than in the MXLI-presence group (26.9% and 4.8%, P < .001), which indicated that an abrupt change in the eruption direction of MXC could produce root dilaceration, especially in the case of rapid alignment of MXC by fixed orthodontic treatment after SABG.

In the present study, the frequency of forced eruption of MXC in both groups was less than 10%. This finding was similar to the study Hogan et al.,16 which reported that 8% of MXC required surgical exposure and forced eruption, and Antunes et al.,17 which reported that there was spontaneous eruption of impacted MXC after SABG in cleft patients.

Correlations Between the Status of MXC at T1 and T2 (Table 6)

A positive correlation between forced eruption of MXC at the T2 stage and horizontal position of MXC at the T1 stage on the cleft side (P < .01) suggested that abnormal horizontal position of MXC on the cleft side (ie, overlapping with MXP1), not absence of MXLI, might lead to an eruption disturbance, requiring forced eruption. A strong correlation between dilaceration of MXC at T2 and vertical position and mesial angulation of MXC at T1 on the cleft side (all P < .01) could be attributed to an abrupt change in the eruption path of MXC when MXC had a mesial angulation and was located at the gingival level compared to MXP1.

Clinical Implications

In the present study, only four patients (8.5%, 3 UCLP and 1 UCLA) underwent forced eruption of MXC. All of these patients showed more gingival position of MXC compared to MXC on the noncleft side and normal angulation of MXC. Half of these patients showed horizontal overlapping with the adjacent tooth and a wide cleft gap. Therefore, when MXC on the cleft side is located more gingivally compared to that of the noncleft side before SABG, clinicians should be prepared for the possibility of the need for forced eruption of MXC and inform patients and their parents. In addition, a normal angulation and horizontal position of MXC and a narrow cleft gap might not guarantee normal eruption of MXC.

A flowchart of considerations for possible impaction and need for forced eruption of MXC after SABG in patients with UCLA and UCLP is presented in Figure 2.

Figure 2.Figure 2.Figure 2.
Figure 2. A flowchart of considerations for possible risk of impaction and need for forced eruption of MXC after secondary alveolar bone grafting (SABG) in patients with unilateral cleft lip and alveolus (UCLA) and unilateral cleft lip and palate (UCLP). A dotted line indicates a possible course; a solid line indicates a natural course.

Citation: The Angle Orthodontist 92, 5; 10.2319/102221-788.1

There were some limitations of the current study: (1) Since a peg lateral incisor could be a “forme fruste” of hypodontia, it would be necessary to investigate the difference in the status of MXC among normal size and shape, abnormal size and shape, and absence of MXLI in patients with UCLA and UCLP; and (2) Since the degrees of accuracy and reliability of 3D-CT or 3D-CBCT are better than those of panoramic radiographs, it would be necessary to investigate the difference in the status of MXC in patients with UCLA and UCLP using serial 3D-CTs or 3D-CBCTs.

CONCLUSIONS

  • In patients with UCLA and UCLP whose outcome of SABG was successful, absence of MXLI on the cleft side increased only the frequency of mesial angulation of MXC at T1 and dilaceration of MXC at T2, not the frequency of abnormal vertical and horizontal position at T1 and need for forced eruption at T2.

REFERENCES

  • 1. 
    Enemark H, Krantz-Simonsen E, Schramm JE. Secondary bone grafting in unilateral cleft lip palate patients: indications and treatment procedure. Int J Oral Surg. 1985;14: 2–10.
  • 2. 
    Bergland O, Semb G, Abyholm FE. Elimination of the residual alveolar cleft by secondary bone grafting and subsequent orthodontic treatment. Cleft Palate J. 1986;23: 175–205.
  • 3. 
    Matsui K, Echigo S, Kimizuka S, Takahashi M, Chiba M. Clinical study on eruption of permanent canines after secondary alveolar bone grafting. Cleft Palate Craniofac J. 2005;42: 309–313.
  • 4. 
    El Deeb M, Messer LB, Lehnert MW, Hebda TW, Waite DE. Canine eruption into grafted bone in maxillary alveolar cleft defects. Cleft Palate J. 1982;19: 9–16.
  • 5. 
    Russell KA, McLeod CE. Canine eruption in patients with complete cleft lip and palate. Cleft Palate Craniofac J. 2008;45: 73–80.
  • 6. 
    Tortora C, Meazzini MC, Garattini G, Brusati R. Prevalence of abnormalities in dental structure, position, and eruption pattern in a population of unilateral and bilateral cleft lip and palate patients. Cleft Palate Craniofac J. 2008;45: 154–162.
  • 7. 
    Oberoi S, Gill P, Chigurupati R, Hoffman WY, Hatcher DC, Vargervik K. Three-dimensional assessment of the eruption path of the canine in individuals with bone-grafted alveolar clefts using cone beam computed tomography. Cleft Palate Craniofac J. 2010;47: 507–512.
  • 8. 
    Westerlund A, Sjöström M, Björnström L, Ransjö M. What factors are associated with impacted canines in cleft patients? J Oral Maxillofac Surg . 2014;72: 2109–2114.
  • 9. 
    Hereman V, Cadenas De Llano-Pérula M, Willems G, Coucke W, Wyatt J, Verdonck A. Associated parameters of canine impaction in patients with unilateral cleft lip and palate after secondary alveolar bone grafting: a retrospective study. Eur J Orthod. 2018;40: 575–582.
  • 10. 
    Simões Holz I, Martinelli Carvalho R, Lauris JR, Lindauer SJ, Gamba Garib D. Permanent canine eruption into the alveolar cleft region after secondary alveolar bone grafting: are there prediction factors for impaction? Am J Orthod Dentofacial Orthop . 2018;154: 657–663.
  • 11. 
    Desai SK, Adirajaiah S, Desai AK, Kumar N. Observing the eruption of canine after secondary alveolar bone grafting. J Oral Maxillofac Surg. 2021;79: 2562–2573.
  • 12. 
    Lacerda-Santos R, Batista RG, Neves SS, et al. Effectiveness of secondary alveolar bone graft on canine eruption: systematic review. Eur J Dent. 2021;15: 579–587.
  • 13. 
    Nolla C. The development of the permanent teeth. J Dent Child. 1960;27: 254–266.
  • 14. 
    Kim KR, Kim S, Baek SH. Change in grafted secondary alveolar bone in patients with UCLP and UCLA. A three-dimensional computed tomography study. Angle Orthod. 2008;78: 631–640.
  • 15. 
    Park HM, Han DH, Baek SH. Comparison of tooth development stage of the maxillary anterior teeth before and after secondary alveolar bone graft: unilateral cleft lip and alveolus vs unilateral cleft lip and palate. Angle Orthod. 2014;84: 989–994.
  • 16. 
    Hogan L, Shand JM, Heggie AA, Kilpatrick N. Canine eruption into grafted alveolar clefts: a retrospective study. Aust Dent J. 2003;48: 119–124.
  • 17. 
    Antunes CL, Aranha AM, Bandeca MC, de Musis CR, Borges ÁH, Vieira EM. Eruption of impacted teeth after alveolar bone graft in cleft lip and palate region. J Contemp Dent Pract. 2018;19: 933–936.
Copyright: © 2022 by The EH Angle Education and Research Foundation, Inc.
Figure 1.
Figure 1.

The parameters used in this study. MXC indicates maxillary canine; MXCI, maxillary central incisor; MXLI, maxillary lateral incisor; MXP1, maxillary first premolar.

Figure 2.
Figure 2.

A flowchart of considerations for possible risk of impaction and need for forced eruption of MXC after secondary alveolar bone grafting (SABG) in patients with unilateral cleft lip and alveolus (UCLA) and unilateral cleft lip and palate (UCLP). A dotted line indicates a possible course; a solid line indicates a natural course.

Contributor Notes

a  PhD Student, Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
b  Assistant Professor, Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
c  Professor, Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
d  Clinical Assistant Professor, Department of Plastic and Reconstructive Surgery, Seoul National University Children Hospital, Seoul, Republic of Korea.
e  Professor Emeritus, Department of Plastic and Reconstructive Surgery, College of Medicine, Seoul National University, Seoul, Republic of Korea.
f  Professor, Department of Orthodontics, School of Dentistry, Dental Research Institute, Seoul National University, Seoul, Republic of Korea.
Corresponding author: Dr. Seung-Hak Baek, Department of Orthodontics, School of Dentistry, Dental Research Institute, Seoul National University, Daehak-ro #101, Jongro-gu, Seoul 03080, Republic of Korea (e-mail: drwhite@snu.ac.kr)
Received: 01 Oct 2021
Accepted: 01 Mar 2022
  • Download PDF