Comparison of cephalometric variables between adult Spanish and Japanese women with Class I malocclusion

OBJECTIVE: To our knowledge, no study has compared the facial and dental morphology of adult Latin and Japanese populations. The purpose of this study was to assess differences in the facial and dental morphology between adult Spanish and Japanese women with Class I malocclusion using lateral cephalograms. MATERIALS AND METHODS: The lateral cephalograms of 33 adult Spanish and 33 adult Japanese women were traced and digitized by a single investigator. All patients satisfied the following criteria: female sex; age 18–35 years; skeletal Class I malocclusion (ANB angle, 2°–5°; angle Class I malocclusion; arch length discrepancy, −10 to + 10 mm; overjet, 1–5 mm; overbite, 1–5 mm); absence of congenital anomalies, significant facial asymmetry, or congenitally missing teeth, with the exception of the third molars; significant temporomandibular joint problems; severe crowding; and no history of orthodontic treatment. RESULTS: Eleven and six angular measurements for the skeletal and dental hard tissues, respectively, were computed in accordance with previous studies. The results showed that Japanese women had significant maxillary and mandibular protrusion, clockwise mandibular rotation, greater labial tipping of incisors, and a smaller interincisal angle compared with Spanish women. CONCLUSION: At the time of orthodontic treatment planning, it is important to consider the facial and dental morphological characteristics of individual ethnic groups to achieve satisfactory outcomes and retention. The findings of this study provide valuable information that will aid in orthodontic treatment planning for adult Spanish and Japanese women.