Unilateral cleft lip repair treatment outcomes using triangular flap and rotation-advancement techniques: A systematic review

Introduction

Cleft lip and palate is a common congenital facial malformation that significantly impacts the developmental, physical, and psychological aspects of a patient, and its occurrence is estimated as 1 in 600 live births. Therefore, good outcomes of cleft lip and palate reconstruction are indispensable [1]. The goal of surgical treatment for children born with cleft lip and palate is to restore esthetical appearance of the lip and nose and continuation of the primary and secondary palate, and to improve speech, language, and hearing functions. Additional goal is to restore airway patency, occlusion and mastication function, and normal psycho-social development [1, 2].
In recent decades, the understanding of surgical cleft lip repair has evolved, allowing for an improved ability to restore anatomical shape and function [3]. The first documented cleft lip repair occurred in the fourth century AD in the Tang dynasty in China. The simple surgical technique involved incision and suturing of the cleft edges, and the child was instructed not to speak post-operatively for about three months [4, 5]. In the early 20th century, a Rose-Thompson method has developed as a straight-line technique, and was used by many surgeons. This technique was later found to have disadvantages in vertical scar formation that causes a notch in the upper lip [3-7]. This condition has led many surgeons to develop other unilateral cleft lip surgery techniques, such as quadrilateral flap, triangular flap, and rotation-advancement [4]. The rotation-advancement technique was introduced by Dr. Ralph Millard in 1955 and until now, it was the most widely used lip repair technique [8-12]. The triangular flap technique was introduced by Dr. Charles Tennison in 1952 and developed by Dr. Peter Randall in 1959, and it has also attracted interest of many surgeons [13-16]. The two primary techniques have undergone many modifications, including Mohler technique as an improvement of Millard rotation-advancement technique and Cronin technique for Tennison-Randall triangular flap technique. Each method has advantages, and addresses the importance of muscle repositioning into correct anatomical orientation to achieve both functional and aesthetic outcomes [15, 16].

Objectives

Since treatment guidelines have become an integral part of contemporary clinical practice, it is essential to measure treatment outcomes in cleft lip and palate surgery to evaluate the cleft treatment and improvement in the era of evidence-based medicine. Studies have been conducted to evaluate the outcomes of each surgical technique, including dento-facial growth and development, facial shape, speech function, breathing function, hearing ability, quality of life, and patient satisfaction. The aim of the current systematic review was to analyze and compare repair outcomes of the primary unilateral cleft lip using triangular flap compared with rotation-advancement techniques.

Material and methods

Search strategy

In selecting articles, preferred reporting items for systematic reviews and meta-analysis (PRISMA) guideline was employed in several databases, including PubMed, Medline, ScienceDirect, and Cochrane Library. Key words used for selecting articles were (Cleft lip surgery OR Cleft lip repair) AND (Triangular OR Cronin OR Tennison Randall) AND (Rotation-advancement OR Millard) AND (Outcome OR Result). Detailed selection procedure is shown in Figure 1.

Inclusion and exclusion criteria

Inclusion criteria were analyzed based on PICOS components, as shown in Table 1. Population (P) – subject with unilateral cleft lip with or without alveolar cleft or cleft palate. Intervention (I) – patient who has undergone primary cleft lip surgery or repair. Comparison (C) – surgical technique using rotation-advancement or triangular flap techniques. Outcome (O) – all surgical outcomes measured with manual, anthropometric, photographic, and scoring basis measurements. Study design (S) – retrospective/prospective/ambispective cross-sectional studies, cohort studies, and randomized clinical trials. Exclusion criteria were case reports, review papers, letters to editors, studies with inadequate follow-up time, and non-English written articles. The research question of this study was “How are treatment outcomes of unilateral primary cleft lip repair using triangular flap technique compared with rotation-advancement technique?”.

Study selection

Two reviewers independently reviewed title and abstract of each study identified through electronic searching. Studies that did not have adequate information in the abstract and did not meet inclusion criteria were not included in eligibility assessment. Adequate studies that were approved underwent eligibility assessment. If reviewers disagreed, an independent third reviewer was involved.

Data extraction

Data extracted from eligible articles were author (s), year of publication, number of subjects, diagnosis, surgical technique, variable assessed, measurement methods, and clinical outcomes.

Critical appraisal of studies

An independent risk of bias assessment was conducted by two reviewers using Newcastle-Ottawa scale [17]. This scale uses a star system with a maximum of 9 stars. Studies that obtain 9 stars reflect a low-risk of bias, a score of 7 or 8 indicates medium-risk, while a score below 7 indicates a high-risk of bias. Aspects evaluated included subject selection technique, comparability of study group, ascertainment of outcomes, and exposures of interest. Disagreements were resolved through discussions involving an independent third party.

Summary measures and synthesis of results

Data obtained in this study were analyzed based on descriptive statistics. Data on primary cleft lip repair clinical outcomes using triangular flap and rotation-advancement techniques were tabulated, including data of follow-up period. Publication bias in selected studies used funnel plots. In addition, regression analysis was also performed to identify a trend between each therapy and its recurrence rate.

Results

Results of literature searching

Studies selection process is shown in Figure 1. The initial database search obtained 339 articles. After screening for duplication, 40 articles were eliminated, leaving 299 articles to be screened for titles and abstracts. Eligibility screening was carried out through extensive reading of the abstract, where 266 articles did not meet the inclusion criteria. There were 33 articles for eligibility assessment; 24 were eliminated due to various factors regarding relevancy issues. Ultimately, eight studies were selected for review (Chowdri et al., 1990; Lazarus et al., 1998; Yamada et al., 2002; De Silva Amaratunga, 2004; Cheema et al., 2012; Iliopoulos et al., 2014; Gadre et al., 2016; Adetayo et al., 2018).

Description of included studies

Complete description of the selected articles is presented in Table 2. Most of the studies are retrospective (5 studies), prospective (2 studies), and cross-sectional (1 study). Four hundred ninety-one subjects’ data were analyzed with 1-10 years of follow-up.

Results of variable outcomes

This study analyzed treatment outcomes of primary cleft lip repair using triangular flap and rotation-advancement techniques in various measurements, including anthropometric, photographic, dental cast analysis, and manual measurement using a caliper. The variables also analyzed the shape of the nose, the shape and length of Cupid’s bow, philtral height, vermilion height, presence of a notch, white roll match, and satisfactory scar. From the results of the 8 systematic studies, 3 used photographic analysis, 2 used anthropometric studies, and 2 used manual measurement studies using a caliper. Recapitulation and comparison of clinical outcomes between the triangular flap and rotation-advancement techniques are shown in Table 3.
Table 3 shows that the rotation-advancement group presented better results in the shape of the nostril and the length of the Cupid’s bow, but with a higher finding of notching and nasal deformities. Meanwhile, the triangular flap group showed more desirable results in the Cupid’s bow shape, philtral height, white skin roll match, satisfactory scar, vermilion height, lip height, and nasal width. On the contrary, the triangular flap group had a more significant number of nasal defect formations compared with the rotation-advancement group.

Risk of bias within studies included

The risk of bias in each study was analyzed using Newcastle-Ottawa scale assessment form for cohort studies [17]. Each article was evaluated based on several critical aspects regarding case selection, comparability, and outcome. In this systematic review, scores greater than 7 showed a high-quality study. From the 8 studies, five articles obtained a score of 9. This result indicated that the article had a low-risk of bias. Meanwhile, three articles obtained a score of 8, showing that the article had a medium-risk of bias [17]. Details of critical appraisal are listed in Table 4.

Discussion

Cleft lip is the most common congenital anomaly, with as many as 76% classified as unilateral [18, 19]. Surgical cleft lip repair procedure has become a challenge for surgeons since surgical outcomes can affect the patient’s quality of life in the future [7]. There are various methods of cleft lip repair, but the most commonly used are rotation-advancement and triangular flap techniques. Both the techniques have their respective advantages and disadvantages. Nevertheless, post-operative deformities can be found in some cases, including asymmetry of the Cupid’s bow, flattened philtrum, elongated white lip, tilted columella, and flattened ala nasi [20].
Yamada et al. [20] conducted a study to evaluate facial morphology after primary cleft and lip repair through a triangular flap and rotation-advancement techniques in three-dimensional analysis. This study showed that nasal protrusion and nostril symmetry were better in the rotation-advancement group due to simple reconstruction of the orbicularis oris muscle. This technique also stabilizes the nasal base and makes the alar to rotate. On the contrary, a better Cupid’s bow shape was found in the triangular flap group. In some cases, the length of Cupid’s bow in the triangular group was more extended due to distribution of the large orbicularis oris muscle in the lower part of the lip. Moreover, the tubercle in the upper lip was pulled towards the cleft side [20].
The outcome of philtral and vermilion heights was discussed in a study by De Silva Amaratunga et al. [10] by calculating cleft lip component symmetry index score. In this study, the philtral height outcomes in the triangular flap group (Cronin technique) obtained a better score, so the results of vermilion height. The poor result of the philtral height symmetry in the rotation group (Millard technique) was caused by the inadequacy of rotation and contracture in the straight-line scar. Cronin technique is considered more able to overcome this problem through mathematical calculations and breaking the scar line by introducing the triangular flap [21].
Adetayo et al. [16] analyzed comparative surgical outcomes of the two techniques using quantitative anthropometric measurements. The results exhibited that the Millard group had a more significant increase in vertical lip height post-operatively and a greater reduction in the nasal width than the triangular flap group using Tennison-Randall technique. However, reasons for this finding were not clearly explained [16].
Cheema et al. [22] conducted a cross-sectional study analyzing the presence of a notch in the repaired vermilion area in Millard rotation-advancement and Noordhoff triangular flap techniques. This study revealed that a notch of more than 1 mm in Millard technique was evident in two cases (5%), whereas Noordhoff technique did not show any wide notch at the vermilion. Similarly, in the Millard group, two sub-groups of 0.5 mm and 0.5-1 mm notch presented a slightly higher number than the Noordhoff technique (3 cases in each sub-group). Therefore, it can be concluded that the triangular group was proven to reduce the possibility of notching. The better notching result of the triangular flap group was caused by the break of linear repair on the vermilion, in which the procedure to bring the vermilion from lateral to the medial segment helped to reconstruct a symmetrical vermilion [22].
Chowdri et al. [23] reported no significant difference in overall lip and nose post-operative appearance between the two types of repairs. However, in the rotation-advancement group, a larger hypertrophic scar was found [23]. The overall incidence of hypertrophic scar was 6.5%, smaller than reported in a study by Holtmann and Wray [24], which stated that there was a hypertrophic scar of 47.4% [23, 24]. Similar results were also reported by Gadre et al. [25], who revealed that scar quality was better in the Tennison-Randall triangular flap group than in the Millard rotation-advancement group [25].

Conclusions

Overall, the rotation-advancement group showed better results in the nostril shape and length of the Cupid’s bow, but with a higher finding of notching and nasal deformities. Meanwhile, the triangular flap group presented more desirable results in the Cupid’s bow shape, philtral height, vermilion height, white roll match, satisfactory scar quality, lip height, and nasal width, despite having a more significant number of nasal defect formation compared with the rotation-advancement group. Further systematic review studies should be conducted to analyze the treatment outcome of unilateral primary lip repair using other surgical techniques, with various measurement methods and larger number of subjects.

Conflict of interest

The authors declare no conflict of interest

References