Frenulum morphology tracks with dentition stage and midline spacing in children
A cross-sectional study of 381 children ages 2 to 13 found a clear association between maxillary labial frenulum morphology and two familiar pediatric dental features: dentition stage and the presence of a maxillary midline diastema. The most common frenulum types were papillary and gingival, and papilla penetrating attachments appeared disproportionately in children with midline spacing. In a clinic population drawn from two university dental centers in Izmir, the anatomy of this small soft-tissue band was not merely a descriptive finding. It aligned with tooth eruption stage and, in a more specific way, with the gap between the maxillary central incisors.
The study used the Mirko classification, dividing frenula into mucosal, gingival, papillary, and papilla penetrating types. That framework matters because the frenulum is not a static marker. As the upper dentition develops, the attachment can appear to shift in relation to the gingival margin and interincisal papilla, and this changing anatomy may reflect growth, eruption, and the evolving relationship between soft tissue and teeth. In practical terms, the mixed dentition phase was where these patterns clustered most often.
A single finding stood out. Papilla penetrating frenula were significantly more common among children with midline diastema.
Why the mixed dentition period showed the strongest signal
The sample included 51.4% girls and 48.6% boys, with a mean age of 7.58 years. Primary dentition was present in 29.9% of participants, mixed dentition in 63.8%, and permanent dentition in 6.3%. That age distribution is clinically important because the mixed dentition period is when the maxillary incisors erupt, separate, and then often drift toward a more stable alignment. A frenulum that inserts more incisally may plausibly exert traction across the midline during this transitional phase, especially when the central incisors are still erupting and the surrounding tissues are remodeling.
The frequency of frenulum types tracked that developmental window. Papillary frenula accounted for 37.2% of cases, gingival for 36.5%, mucosal for 17.2%, and papilla penetrating for 9.1%. Different frenulum types were most frequently observed during mixed dentition, and the overall association between frenulum morphology and dentition stage reached statistical significance. In a pediatric dental clinic, that pattern reinforces a basic point: the frenulum should be read in context, not in isolation from eruption status.
Midline diastema, not inflammation, drove the association
Midline diastema was present in 47.1% of the children, a high proportion that reflects the age range and the prevalence of transitional spacing in developing anterior teeth. Frenulum type showed a significant association with this spacing, while no significant relationship emerged between frenulum morphology and gingival health or maxillary anterior caries. The study also found no significant association between frenulum type and gender.
This separation is clinically useful. A frenulum that inserts low or penetrates the papilla may be part of the anatomical picture in a child with a visible midline gap, yet that same anatomy did not map onto gingival index scores in this cohort. The absence of an association with gingival inflammation suggests that frenulum morphology is not a proxy for generalized periodontal irritation in these children. In other words, the tissue attachment pattern appears linked to spacing and eruption stage, not to gingival status as measured here.
Caries followed gingival status, not frenulum anatomy
Caries in the maxillary anterior teeth was present in 28.1% of the children, but frenulum type did not show a significant association with caries prevalence. Gingival index scores were most commonly 1, at 58.3%, and higher gingival index scores were significantly associated with increased caries prevalence. That pattern fits everyday pediatric dentistry: plaque retention, oral hygiene quality, and local inflammatory burden often travel together. The frenulum itself did not explain anterior caries in this study, but inflamed gingiva tracked with a higher caries burden, likely reflecting a shared behavioral and biofilm-mediated pathway rather than a structural one.
This distinction has bedside relevance. A prominent frenulum may draw attention because of esthetics or spacing, but it should not automatically be treated as a caries risk marker. Caries prevention still depends on the factors that truly drive disease in young children: exposure patterns, plaque control, diet, fluoride, and recall discipline. The frenulum may be part of the orthodontic story. It was not the caries story in this sample.
What pediatric dentists can and cannot infer from these data
The study supports a measured clinical interpretation. Maxillary labial frenulum morphology appears associated with dentition stage and with the presence of a midline diastema in children aged 2 to 13 years. Papilla penetrating attachments were especially frequent among children with midline spacing. Those observations may help clinicians decide when to monitor, when to re-examine after eruption changes, and when a spacing concern belongs more to growth than to immediate intervention.
The study does not justify broader claims. It was cross-sectional, so it cannot determine whether a frenulum configuration causes diastema or simply accompanies a developmental phase in which spacing is more visible. It also cannot show whether an early anatomic pattern predicts persistence of the gap into later dentition. A longitudinal design would be needed to separate transient eruption-related spacing from a stable orthodontic problem.
Even so, the anatomy is not trivial. In pediatric dentistry, the frenulum is often one of the first soft-tissue features noticed during an anterior examination, and this dataset suggests that the attachment pattern deserves attention when the upper incisors are erupting. The practical question is not whether every papilla penetrating frenulum needs treatment. It is whether the child’s spacing, eruption stage, and soft tissue anatomy fit a developmental pattern that should be watched rather than rushed.
Limits of a single-clinic snapshot
The cohort came from pediatric dentistry clinics at two Turkish universities, and the study relied on a cross-sectional examination with categorical outcomes. Those features help define the sample, but they also limit how far the findings can be generalized. The association between frenulum morphology and midline diastema was statistically significant, yet the study did not provide a mechanistic trial of tissue tension, orthodontic response, or future space closure. The relationship between anatomy and function remains inferential.
The most defensible reading is also the most clinically grounded: in children, maxillary labial frenulum morphology belongs in the developmental exam, especially during mixed dentition. Its strongest association in this study was with midline diastema, not with gingival inflammation or anterior caries. Longitudinal follow-up will have to determine which children outgrow the spacing and which retain a frenulum pattern that merits intervention later in childhood.