Figure 2 : Orthopantomogram at 27 months.
Treatment:
The management of this labial hypoplasia can be discussed, but the less invasive technique remains lipofilling with autologous fat graft or hyaluronic acid. In the meantime, follow-up is required to monitor speech development and eruption of the teeth.
Discussion:
The presence of a gingival notch, a mucosal bridle, and difficulty erupting teeth led us to believe that this may be an incomplete Tessier cleft 28-29. There are only five articles in the literature reporting a paramedian cleft of the lower lip 3–7 from localised lower lip hypoplasia associated with bilateral upper lip and palate clefts (Oka et al. 1983), to complete lower lip clefts without mandibular clefts (Hassanpour et al. 2018, Chauvel-Picard et al. 2018, Ghorpade et al. 2023), to incomplete lower lip cleft with mandibular defect (Morritt et al. 2007). In all these cases, the lip defect is localised on a thin part of the lower lip without extension to the commissure. Regarding the anatomical differences between a lower cleft lip defect and this total external third lower lip hypoplasia, we believe that this may be the first congenital partial lower lip hypoplasia reported in the literature.
For Chisholm et al 8, atrophic skin conditions are caused by abnormalities in the dermis and/or subcutaneous tissue. Although the epidermis may be thin and atrophic, there must be a loss of substance in the subepidermal tissue for the skin to look and feel atrophic. In this case, we can assume that both the orbicularis oris and the depressor labii inferioris are hypotrophic but remain functional