Effects of mouth breathing on facial skeletal development and malocclusion in children: A systematic review and meta-analysis.

Abstract

BACKGROUND: Mouth breathing is closely related to the facial skeletal development and malocclusion. The purpose of this systematic review and meta-analysis was to assess the effect of mouth breathing on facial skeletal development and malocclusion in children. METHODS: An electronic search in PubMed, the Cochrane Library, Medline, Web of Science, EMBASE and Sigle through February 23rd, 2020, was conducted. Methodological quality assessments of the selected articles were performed using the Newcastle-Ottawa Scale. Review Manager 5.3, was used to synthesize various parameters associated with the impact of mouth breathing on facial skeletal development and malocclusion. RESULTS: Following full-text evaluations for eligibility, 7 studies (387 mouth-breathing subjects and 433 nasal-breathing controls) were included in the final quantitative synthesis; they were all high-quality. The included indicators were SNA (p>0.050), ANS-PNS (p>0.050), 1.NB (p>0.050), MP-H (p>0.050), FMA (p>0.050), SNB (MD: -1.99, P <0.0001), ANB (MD: 0.95, P = 0.0005), SN-OP (MD: 3.20, P < 0.0001), SNGoGn (MD: 4.34, P < 0.0001), 1-NA (MD: 0.72, P = 0.004), 1. NA (MD: 1.98, P = 0.020), 1-NB (MD: 1.06, P < 0.0001), SPAS (MD: -5.23, P < 0.0001), PAS (MD: -2.11, P < 0.0001), and C3-H (MD: -1.34, P < 0.0001). CONCLUSIONS: The results showed that mouth breathing can cause underdevelopment of the mandible. The mandible rotated backward and downward, and the occlusal plane was steep. However, there was little effect on the maxilla. In addition, mouth breathing presented a tendency of lip inclination of the upper and lower anterior teeth. Airway stenosis was common in mouth-breathing children. TRIAL REGISTRATION: crd-register@york.ac.uk; registration number CRD42019129198 KEYWORDS: Mouth breathing; Facial skeletal development; Children; Systematic review, Meta-analysis.

Prevalence of Malocclusion Patterns in Mouth Breathing Children Compared to Nasal Breathing Children – A Systematic Review

“…A total of seven studies were included. The results of this review revealed that mouth breathing can be associated with an underdevelopment of the mandible, where it rotates backward and downward, and a steep occlusal plane [16]. Notably, there was little effect on the maxilla and a tendency of lip inclination in mouth breathing children.…”

“…Notably, there was little effect on the maxilla and a tendency of lip inclination in mouth breathing children. This, to date, is the first systematic review and meta-analysis that assessed this relationship [16]. It is an interesting finding which can draw conclusions on the severity of the malocclusion, but it cannot give an indication of whether the prevalence of malocclusion is indeed increased due to the mouth breathing.…”

“…These assumptions are generally based on single studies that have been conducted more than a decade ago when research standards only just started to emerge, and reporting of the studies was most likely suboptimal. Only recently, Zhao et al (2020) has conducted a systematic review and meta-analysis to assess the effect of mouth breathing on facial skeletal development and malocclusion in children [16]. The study authors included all evidence published up to February 2020.…”

“…The authors of this review concluded that mouth breathing can cause underdevelopment of the mandible [16]. It is unclear how this statement has been arrived at when the author of this review did not assess studies where the aetiology of mouth breathing has been removed, and subsequent assessments have taken place to compare it with a control group.…”

“…A recent systematic review and meta-analysis on the effects of mouth breathing on facial development and malocclusion suggests that mouth breathing can cause underdevelopment of the mandible, with backwards and downward rotation of the mandible and steep occlusal plane. Additionally, a tendency of lip inclination of the anterior teeth, as well as airway stenosis, was found in mouth breathers [16].…”